So you want to stretch your FJ40...

[dna9ster]

It's been a while since I posted. This time, I feel like this post won't be welcome in the 40-tech column. I'm going to stretch the frame because I want to swap in a 6BT. There is a perfect storm of poor judgements, good intentions, a disrespect for gravity, and a love for that legendary engine that has lead me to this point. So this is going to be the primary thread from now on. I humbly ask for you to look in occasionally to make sure that I'm not going to injure anybody.

Starting at the end of 2024, I reinforced the front frame section and boxed in the rear. In the process, I remounted the hangers for the front leafs because I didn't like shackle angle that it previously drove at. (20 years ago I did a 2.5" Manafre shackle reversal to allow for better handling). I also remounted the rear leaf hangers by reorienting the eye protruding beyond the rear cross member by ~1/2". (This will cause some major modifications to be made to the tub) Not having long enough rear springs anymore, I crafted a temporary set of shackles to allow for a rolling chassis.

The next task was to fit the motor. I wanted to go with hydraulic engine mounts rather than the OEM to minimize vibrations to the frame. I through something together in solidworks and out came an overbuilt set of brackets made from T1. After welding them together, I sent them out to have their bolting surfaces ground flat. And now I was ready for engine/transmission mock up.

I have a bunch of pictures during this process and I can provide more, but these sum up the fitting and mount fabrication. I wish I had more pictures to go off of when I was doing it. Ultimately I'll be giving up the mechanical fan for an electric....which really bothers me but it seems to be an absolute must without lengthening the cowl.

 

[Mike Shull]

It’s awesome to see another stretch project. Good luck and I will be watching.

@Ditcherman stretched his Cruiser and I believe that he installed the same engine.

 

[dna9ster]

So the fixed cross member that goes through the frame will need to be moved. I could delete it and weld in another close to the wheel arch. I estimate the wheelbase to be 99.5" with the axle still sitting on a flipped FJ60 spring. Ill be getting custom springs and I can lengthen the WB further at the tradeoff of having less quarter panel. But I'm going to stretch the frame and pretend for a little while that I don't need to modify the cross member. I also like the benefit of a shallower driveshaft angle which means less vibrations and better longevity. My previous rear driveshaft is ~25" which was set up for a SBC/4speed positioned on a ~6.3 degree incline. It performed pretty well, so I would want a driveshaft of at least that length.

There seems to be 3 different camps regarding how much to stretch your frame by. At the moment I'm leaning toward 14 inches but I haven't fully decided. If anyone has experience on 10" or 18" FJ40 frame stretching for 6BT swaps, I'd love to know what you consider the pros/cons and recommendations.

Lately, I've been prepping for the stretch and rebuilding the engine/NV4500. I also measured the frame for twist and squareness. The frame isn't perfect but it does have a difference of 3/16" between the left side and right side body mounts at the rear leaf springs perch. The spring perches are as square as I could measure. The entire frames squareness was only off by 1/8" with I believe is OEM tolerance. Regardless, I'll recheck the twist and squareness after the stretch and have it professionally sorted if need be.

And that leads me to the present day. Where and how do I make the incision?

From what I read, the standard is interlocking z-cut or 45 degree. But people do verticals all the time quite successfully too. The vertical is what I'm currently leaning toward, and will brace it with an external liner extending ~11.5 on both sides of the weld. Vertical cuts seem to greatly reduce the difficulty in crafting a liner.What is your experience with vertical welds?

 

[Mike Shull]

I would not personally do a vertical cut. You may be fine but an angle or z-cut will be much stronger with minimal bracing. I did an angle cut and lengthened mine 14”. I have a different drivetrain so I can’t speak to your setup in regards to driveline angles, though I wish that I had gone 18” longer with the same wheelbase, which is 109”. The extra room behind the axle would have been beneficial for my setup but I was still able to stuff a 22 gallon tank back there. I would definitely recommend going longer than 99”. I think that you will like the extra length for fitment and it should drive better on and off-road.

It also depends on your driving style. How are you planning to use this Cruiser?

 

[GLTHFJ60]

"a disrespect for gravity" lol. Following.

 

[DangerNoodle]

So the fixed cross member that goes through the frame will need to be moved. I could delete it and weld in another close to the wheel arch. I estimate the wheelbase to be 99.5" with the axle still sitting on a flipped FJ60 spring. Ill be getting custom springs and I can lengthen the WB further at the tradeoff of having less quarter panel. But I'm going to stretch the frame and pretend for a little while that I don't need to modify the cross member. I also like the benefit of a shallower driveshaft angle which means less vibrations and better longevity. My previous rear driveshaft is ~25" which was set up for a SBC/4speed positioned on a ~6.3 degree incline. It performed pretty well, so I would want a driveshaft of at least that length.

There seems to be 3 different camps regarding how much to stretch your frame by. At the moment I'm leaning toward 14 inches but I haven't fully decided. If anyone has experience on 10" or 18" FJ40 frame stretching for 6BT swaps, I'd love to know what you consider the pros/cons and recommendations.

Lately, I've been prepping for the stretch and rebuilding the engine/NV4500. I also measured the frame for twist and squareness. The frame isn't perfect but it does have a difference of 3/16" between the left side and right side body mounts at the rear leaf springs perch. The spring perches are as square as I could measure. The entire frames squareness was only off by 1/8" with I believe is OEM tolerance. Regardless, I'll recheck the twist and squareness after the stretch and have it professionally sorted if need be.

And that leads me to the present day. Where and how do I make the incision?
View attachment 4165164View attachment 4165165

From what I read, the standard is interlocking z-cut or 45 degree. But people do verticals all the time quite successfully too. The vertical is what I'm currently leaning toward, and will brace it with an external liner extending ~11.5 on both sides of the weld. Vertical cuts seem to greatly reduce the difficulty in crafting a liner.What is your experience with vertical welds?

I like a straight part of the frame, usually on a body mount or the likes that can easly be spliced and hidden. I've gotten away with a lot of weird cuts, usually around the radius arm mounts of 80 frames and a fishplate on the inside.

 

[Ditcherman]

So the fixed cross member that goes through the frame will need to be moved. I could delete it and weld in another close to the wheel arch. I estimate the wheelbase to be 99.5" with the axle still sitting on a flipped FJ60 spring. Ill be getting custom springs and I can lengthen the WB further at the tradeoff of having less quarter panel. But I'm going to stretch the frame and pretend for a little while that I don't need to modify the cross member. I also like the benefit of a shallower driveshaft angle which means less vibrations and better longevity. My previous rear driveshaft is ~25" which was set up for a SBC/4speed positioned on a ~6.3 degree incline. It performed pretty well, so I would want a driveshaft of at least that length.

There seems to be 3 different camps regarding how much to stretch your frame by. At the moment I'm leaning toward 14 inches but I haven't fully decided. If anyone has experience on 10" or 18" FJ40 frame stretching for 6BT swaps, I'd love to know what you consider the pros/cons and recommendations.

Lately, I've been prepping for the stretch and rebuilding the engine/NV4500. I also measured the frame for twist and squareness. The frame isn't perfect but it does have a difference of 3/16" between the left side and right side body mounts at the rear leaf springs perch. The spring perches are as square as I could measure. The entire frames squareness was only off by 1/8" with I believe is OEM tolerance. Regardless, I'll recheck the twist and squareness after the stretch and have it professionally sorted if need be.

And that leads me to the present day. Where and how do I make the incision?
View attachment 4165164View attachment 4165165

From what I read, the standard is interlocking z-cut or 45 degree. But people do verticals all the time quite successfully too. The vertical is what I'm currently leaning toward, and will brace it with an external liner extending ~11.5 on both sides of the weld. Vertical cuts seem to greatly reduce the difficulty in crafting a liner.What is your experience with vertical welds?

I’m 131” wheelbase, 4 door, so most of my frame/length stuff is irrelevant, but I did do straight frame cuts, then angles on the plates outer and inner, for the most part. Some boxing. But even more irrelevantly, I had to shorten my ‘89 super duty frame 36”. It’s a heavy thick frame.

I’ll try to be relevant now; what part of stretching the frame has anything to do with fitting a 6bt in? If your not going to lengthen the cowl as you stated, the firewall dictates where the back of the engine sits, (go ahead and plan on ‘massaging’ it, or just adding the body of a wheelbarrow as seen in here) the front axle needs to be where it needs to be, and that dictates the oil pan orientation, clearances both below and at the front. So nothing gets lengthened here, right?

I think stretching a 40 makes them much more drivable. Not too many originals cruise 75 or 80. So I get that part, just not where it’s “just” for the 12v.

I built a link suspension and think you might consider doing that.

I also have cooling advice if you want it, when you get there. As well as braking, insulation, whatever else I can help with.

I have concerns about you moving too far forward with “pretending” the cross member is ok for now, just make sure everything clears. My project got stalled for years because I was trying to work with a different frame and the crossmember was the whole issue.

What t case behind the nv4500? Something with a short tailstock?

Sorry if some of this sounds too direct, I don’t mean it to be, just don’t know how to ask without it sounding like that.

The other day my wife went for a ride and said “this would have been such a nice vehicle if it wasn’t so noisy”. I love it but it’s a disappointment at the same time.

 

[DangerNoodle]

I’m 131” wheelbase, 4 door, so most of my frame/length stuff is irrelevant, but I did do straight frame cuts, then angles on the plates outer and inner, for the most part. Some boxing. But even more irrelevantly, I had to shorten my ‘89 super duty frame 36”. It’s a heavy thick frame.

I’ll try to be relevant now; what part of stretching the frame has anything to do with fitting a 6bt in? If your not going to lengthen the cowl as you stated, the firewall dictates where the back of the engine sits, (go ahead and plan on ‘massaging’ it, or just adding the body of a wheelbarrow as seen in here) the front axle needs to be where it needs to be, and that dictates the oil pan orientation, clearances both below and at the front. So nothing gets lengthened here, right?

I think stretching a 40 makes them much more drivable. Not too many originals cruise 75 or 80. So I get that part, just not where it’s “just” for the 12v.

I built a link suspension and think you might consider doing that.

I also have cooling advice if you want it, when you get there. As well as braking, insulation, whatever else I can help with.

I have concerns about you moving too far forward with “pretending” the cross member is ok for now, just make sure everything clears. My project got stalled for years because I was trying to work with a different frame and the crossmember was the whole issue.

What t case behind the nv4500? Something with a short tailstock?

Sorry if some of this sounds too direct, I don’t mean it to be, just don’t know how to ask without it sounding like that.

The other day my wife went for a ride and said “this would have been such a nice vehicle if it wasn’t so noisy”. I love it but it’s a disappointment at the same time.

It doesn't take much of a wheelbase stretch to make them way more driveable, I'd say steering geometry does a lot as well.

Imo, ditch the stock firewall and a lot more, make the engine and trans fit properly without sacrificing cooling package space. If I ever do it again, I'd delete the stock firewall and floor pan. Way wasier.

If drivetrain length is an issue, I'd slam a short tailstock atlas in and never look back.

Every 4 / 6bt i've swapped has been loud and rattley, not much you can do there for a mechanically injected engine.

 

[dna9ster]

Thank you for all the feedback. Apologies for the bad grammar as well. I was a bit distracted while crafting the OP.

I would not personally do a vertical cut. You may be fine but an angle or z-cut will be much stronger with minimal bracing. I did an angle cut and lengthened mine 14”. I have a different drivetrain so I can’t speak to your setup in regards to driveline angles, though I wish that I had gone 18” longer with the same wheelbase, which is 109”. The extra room behind the axle would have been beneficial for my setup but I was still able to stuff a 22 gallon tank back there. I would definitely recommend going longer than 99”. I think that you will like the extra length for fitment and it should drive better on and off-road.

It also depends on your driving style. How are you planning to use this Cruiser?

I'll be using it for a combination of recreational travel, trails, and some agricultural use. I've been dreaming up a big expedition through the West coast all the way up to Alaska. I also have a good friend who owns a truggy and likes to do challenging trails in the Southwest. It would be great if my project was good enough to do the gatekeepers and bypasses.

I like a straight part of the frame, usually on a body mount or the likes that can easly be spliced and hidden.

Coincidentally, I think I arrived at the same conclusion. The mount happens to be a decent distance from rivets on the frame's upper and lower flanges. It was meant to be.

what part of stretching the frame has anything to do with fitting a 6bt in? If your not going to lengthen the cowl as you stated, the firewall dictates where the back of the engine sits, (go ahead and plan on ‘massaging’ it, or just adding the body of a wheelbarrow as seen in here) the front axle needs to be where it needs to be, and that dictates the oil pan orientation, clearances both below and at the front. So nothing gets lengthened here, right?

I think stretching a 40 makes them much more drivable. Not too many originals cruise 75 or 80. So I get that part, just not where it’s “just” for the 12v.

I didn't explain that very well, and you probably have some other valid criticisms that you're not mentioning. This is all a bit crazy and it has caused a small amount of ostracization at the household...

It has more to do with the transfer case selection. After the fire, my original plan was to swap in the 6BT/nv4500 and rebuild the car without stretching. After my latest mods, I estimate the wheelbase at 99.5" with scooped out quarter panels on custom springs, ~97" if I want to preserve the quarter panels somewhat (I remembered this wrong in my first post). On paper, my additional 7-9.5" inches of wheelbase should make up for the 7" additional length of the atlas/nv4500 combo. But it's a bit short for a NP205+adapter (7.5" additional length) unless I do scoop the quarter panels. The engine is tall, so I fit the motor at 5 degrees to tuck in the oil pan and hopefully prevent the transfer case from protruding excessively below the frame. So there is still a chance that I may be running with a steep driveshaft angle despite it all. I guess 15 degrees is a general case cut off for a double-cardon. Maybe that can work? However, if I want a doubler (for the amazing control going down some of the steep hills/drops on trails out here), I'll need an additional 7" on top of what I've gained. And I haven't made up my mind, but I'm leaning toward the doubler+np205. Or at least I want to have the option available in the future.

I've never seen the wheelbarrow method. I'll be certain to have a look. It would be great to have some additional space to service the head or run a coolant bypass valve back there. Otherwise, I don't intend to move the front axle. Lengthening the cowl might allow for the mechanical fan. I guess that I always assumed this would be really difficult technically and hard to pull off with subtlety. How was your experience doing it?

I built a link suspension and think you might consider doing that.

I also have cooling advice if you want it, when you get there. As well as braking, insulation, whatever else I can help with.

I have concerns about you moving too far forward with “pretending” the cross member is ok for now, just make sure everything clears. My project got stalled for years because I was trying to work with a different frame and the crossmember was the whole issue.

I'll look at your suspension build. Keeping a leaf spring suspension was mainly to limit the technical difficulty of everything. I already committed to rebuilding the engine w/ swap and the body restoration which is stretching me as is...and now I'm adding THE stretch (I'm not a professional mechanic...just youtube which makes me an unexperienced expert). I read that body sway becomes a much bigger issue in links compared to leafs....but I guess torsion bars tame it somewhat. I also wasn't sure about heim joint durability for daily abuse.

I'll definitely need the cooling advice, whenever you think I should start attending to it. I currently have an Aluminum Ron Davis radiator that worked outstanding with my 98' pre-LS sbc. Ron happens to live here in the valley and quoted me for an upgraded version that can take advantage of the 1 inch body lift that I'll use. But I think I try the old one first for a while. They are a bit pricey. The intercooler is going to be a hurdle as well. Some guy in Australia runs a rectangular cooler external to the bib, just below the grill and it didn't look half bad. I see others running air:water interfaces with a secondary radiator.

And sure thing about the cross member. I'm just going through the 5 phases of grief with it. I'll get there eventually.

would have been such a nice vehicle if it wasn’t so noisy”.

Did she mean the vibrations, the wind blowing by, the engine noise, or the gear box? Or all the above? lol

I'm willing to put up with a lot...vibrations not as much. I'm hoping that the anti-vibration mounts help. Supposedly, they reduce 60% of vibration transmitted from the engine to the frame. Lordes may go even higher but I had a hard time getting my hands on some.

Imo, ditch the stock firewall and a lot more, make the engine and trans fit properly without sacrificing cooling package space. If I ever do it again, I'd delete the stock firewall and floor pan. Way wasier.

Looks like that's the thing to do. Not looking forward to redoing the motor mounts, but the mechanical fan is worth it to me. I'll try to find one of these wheelbarrow builds to experiment with, if that's what you mean. Or were you thinking of something more extensive?

 

[Mike Shull]

Maybe we should team up on the drive to Alaska. I would love to drive mine there as well.

DJ is right that moderate lengthening will greatly improve drivability of a 40. An FJ43 drives pretty well, but they are still quite a bit twitchy down the road. My Friends HJ47 was a lot better for stability and comfort, though it was also heavier. I ran 97” wheelbase for 25 years before going to 109”. I also have 1-ton axles with the longer wheelbase that seem to plant the Cruiser on the ground nicely. Come out to CO if you want to go for a ride. Then go for a ride in a few others.

 

[DangerNoodle]

Thank you for all the feedback. Apologies for the bad grammar as well. I was a bit distracted while crafting the OP.


I'll be using it for a combination of recreational travel, trails, and some agricultural use. I've been dreaming up a big expedition through the West coast all the way up to Alaska. I also have a good friend who owns a truggy and likes to do challenging trails in the Southwest. It would be great if my project was good enough to do the gatekeepers and bypasses.


Coincidentally, I think I arrived at the same conclusion. The mount happens to be a decent distance from rivets on the frame's upper and lower flanges. It was meant to be.


I didn't explain that very well, and you probably have some other valid criticisms that you're not mentioning. This is all a bit crazy and it has caused a small amount of ostracization at the household...

It has more to do with the transfer case selection. After the fire, my original plan was to swap in the 6BT/nv4500 and rebuild the car without stretching. After my latest mods, I estimate the wheelbase at 99.5" with scooped out quarter panels on custom springs, ~97" if I want to preserve the quarter panels somewhat (I remembered this wrong in my first post). On paper, my additional 7-9.5" inches of wheelbase should make up for the 7" additional length of the atlas/nv4500 combo. But it's a bit short for a NP205+adapter (7.5" additional length) unless I do scoop the quarter panels. The engine is tall, so I fit the motor at 5 degrees to tuck in the oil pan and hopefully prevent the transfer case from protruding excessively below the frame. So there is still a chance that I may be running with a steep driveshaft angle despite it all. I guess 15 degrees is a general case cut off for a double-cardon. Maybe that can work? However, if I want a doubler (for the amazing control going down some of the steep hills/drops on trails out here), I'll need an additional 7" on top of what I've gained. And I haven't made up my mind, but I'm leaning toward the doubler+np205. Or at least I want to have the option available in the future.

I've never seen the wheelbarrow method. I'll be certain to have a look. It would be great to have some additional space to service the head or run a coolant bypass valve back there. Otherwise, I don't intend to move the front axle. Lengthening the cowl might allow for the mechanical fan. I guess that I always assumed this would be really difficult technically and hard to pull off with subtlety. How was your experience doing it?


I'll look at your suspension build. Keeping a leaf spring suspension was mainly to limit the technical difficulty of everything. I already committed to rebuilding the engine w/ swap and the body restoration which is stretching me as is...and now I'm adding THE stretch (I'm not a professional mechanic...just youtube which makes me an unexperienced expert). I read that body sway becomes a much bigger issue in links compared to leafs....but I guess torsion bars tame it somewhat. I also wasn't sure about heim joint durability for daily abuse.

I'll definitely need the cooling advice, whenever you think I should start attending to it. I currently have an Aluminum Ron Davis radiator that worked outstanding with my 98' pre-LS sbc. Ron happens to live here in the valley and quoted me for an upgraded version that can take advantage of the 1 inch body lift that I'll use. But I think I try the old one first for a while. They are a bit pricey. The intercooler is going to be a hurdle as well. Some guy in Australia runs a rectangular cooler external to the bib, just below the grill and it didn't look half bad. I see others running air:water interfaces with a secondary radiator.

And sure thing about the cross member. I'm just going through the 5 phases of grief with it. I'll get there eventually.



Did she mean the vibrations, the wind blowing by, the engine noise, or the gear box? Or all the above? lol

I'm willing to put up with a lot...vibrations not as much. I'm hoping that the anti-vibration mounts help. Supposedly, they reduce 60% of vibration transmitted from the engine to the frame. Lordes may go even higher but I had a hard time getting my hands on some.


Looks like that's the thing to do. Not looking forward to redoing the motor mounts, but the mechanical fan is worth it to me. I'll try to find one of these wheelbarrow builds to experiment with, if that's what you mean. Or were you thinking of something more extensive?

More extensive, I have yet to see someone go as far as I think it needs to. I plan to with my next one, but that may be a minute before I really get to it. If anything take a look at what the prerunner guys do with basically a shell. Even on a stock frame, you can probably gain about 7 inches of leg room forward and down, and then push the engine back another 5-6 without the factory firewall. That's enough space for a mechanical fan and an intercooler. I've packed a 4bt into a 40 a few times, and it is a stupidly big engine.

 

[Ditcherman]

More extensive, I have yet to see someone go as far as I think it needs to. I plan to with my next one, but that may be a minute before I really get to it. If anything take a look at what the prerunner guys do with basically a shell. Even on a stock frame, you can probably gain about 7 inches of leg room forward and down, and then push the engine back another 5-6 without the factory firewall. That's enough space for a mechanical fan and an intercooler. I've packed a 4bt into a 40 a few times, and it is a stupidly big engine.

4bt, thems rookie numbers! :;

 

[Ditcherman]

Maybe we should team up on the drive to Alaska. I would love to drive mine there as well.

DJ is right that moderate lengthening will greatly improve drivability of a 40. An FJ43 drives pretty well, but they are still quite a bit twitchy down the road. My Friends HJ47 was a lot better for stability and comfort, though it was also heavier. I ran 97” wheelbase for 25 years before going to 109”. I also have 1-ton axles with the longer wheelbase that seem to plant the Cruiser on the ground nicely. Come out to CO if you want to go for a ride. Then go for a ride in a few others.

Hey Mike.
He wanted to know about body sway.
Didn’t know if you wanted to add anything…


OP, Mike helped me down Black Bear and up Poughkeepsie. So thankful for him. Then he got in it and we drove to a hiking trailhead, and iirc he was crying like a little girl because of the sway going up highway 550.
I didn’t put sway bars in it to begin with, better now. @devo was there too, I think he was curled up in a fetal position.
Correct me if I’m wrong.

I’m weighing in at 7340 lbs, most of that frame, lower links, and Dana 60 axles. So I was well rooted but it was freaky for everyone who rode in it, even more so for those who actually know off roading and these trucks.

 

[Ditcherman]

Thank you for all the feedback. Apologies for the bad grammar as well. I was a bit distracted while crafting the OP.


I'll be using it for a combination of recreational travel, trails, and some agricultural use. I've been dreaming up a big expedition through the West coast all the way up to Alaska. I also have a good friend who owns a truggy and likes to do challenging trails in the Southwest. It would be great if my project was good enough to do the gatekeepers and bypasses.


Coincidentally, I think I arrived at the same conclusion. The mount happens to be a decent distance from rivets on the frame's upper and lower flanges. It was meant to be.


I didn't explain that very well, and you probably have some other valid criticisms that you're not mentioning. This is all a bit crazy and it has caused a small amount of ostracization at the household...

It has more to do with the transfer case selection. After the fire, my original plan was to swap in the 6BT/nv4500 and rebuild the car without stretching. After my latest mods, I estimate the wheelbase at 99.5" with scooped out quarter panels on custom springs, ~97" if I want to preserve the quarter panels somewhat (I remembered this wrong in my first post). On paper, my additional 7-9.5" inches of wheelbase should make up for the 7" additional length of the atlas/nv4500 combo. But it's a bit short for a NP205+adapter (7.5" additional length) unless I do scoop the quarter panels. The engine is tall, so I fit the motor at 5 degrees to tuck in the oil pan and hopefully prevent the transfer case from protruding excessively below the frame. So there is still a chance that I may be running with a steep driveshaft angle despite it all. I guess 15 degrees is a general case cut off for a double-cardon. Maybe that can work? However, if I want a doubler (for the amazing control going down some of the steep hills/drops on trails out here), I'll need an additional 7" on top of what I've gained. And I haven't made up my mind, but I'm leaning toward the doubler+np205. Or at least I want to have the option available in the future.

I've never seen the wheelbarrow method. I'll be certain to have a look. It would be great to have some additional space to service the head or run a coolant bypass valve back there. Otherwise, I don't intend to move the front axle. Lengthening the cowl might allow for the mechanical fan. I guess that I always assumed this would be really difficult technically and hard to pull off with subtlety. How was your experience doing it?


I'll look at your suspension build. Keeping a leaf spring suspension was mainly to limit the technical difficulty of everything. I already committed to rebuilding the engine w/ swap and the body restoration which is stretching me as is...and now I'm adding THE stretch (I'm not a professional mechanic...just youtube which makes me an unexperienced expert). I read that body sway becomes a much bigger issue in links compared to leafs....but I guess torsion bars tame it somewhat. I also wasn't sure about heim joint durability for daily abuse.

I'll definitely need the cooling advice, whenever you think I should start attending to it. I currently have an Aluminum Ron Davis radiator that worked outstanding with my 98' pre-LS sbc. Ron happens to live here in the valley and quoted me for an upgraded version that can take advantage of the 1 inch body lift that I'll use. But I think I try the old one first for a while. They are a bit pricey. The intercooler is going to be a hurdle as well. Some guy in Australia runs a rectangular cooler external to the bib, just below the grill and it didn't look half bad. I see others running air:water interfaces with a secondary radiator.

And sure thing about the cross member. I'm just going through the 5 phases of grief with it. I'll get there eventually.



Did she mean the vibrations, the wind blowing by, the engine noise, or the gear box? Or all the above? lol

I'm willing to put up with a lot...vibrations not as much. I'm hoping that the anti-vibration mounts help. Supposedly, they reduce 60% of vibration transmitted from the engine to the frame. Lordes may go even higher but I had a hard time getting my hands on some.


Looks like that's the thing to do. Not looking forward to redoing the motor mounts, but the mechanical fan is worth it to me. I'll try to find one of these wheelbarrow builds to experiment with, if that's what you mean. Or were you thinking of something more extensive?

You’re asking all the right questions I think. I want to go through and break this down more thoroughly when I have more time, but you’re on a good path if you’re set on the mechanical injection.

I’m thinking that wheelbarrow solution was maybe someone named afraptor, or possibly a10driver, pretty sure it was here in the hardcore corner.

 

[Mike Shull]

Hey Mike.
He wanted to know about body sway.
Didn’t know if you wanted to add anything…


OP, Mike helped me down Black Bear and up Poughkeepsie. So thankful for him. Then he got in it and we drove to a hiking trailhead, and iirc he was crying like a little girl because of the sway going up highway 550.
I didn’t put sway bars in it to begin with, better now. @devo was there too, I think he was curled up in a fetal position.
Correct me if I’m wrong.

I’m weighing in at 7340 lbs, most of that frame, lower links, and Dana 60 axles. So I was well rooted but it was freaky for everyone who rode in it, even more so for those who actually know off roading and these trucks.

No comment.

 

[Mike Shull]

Hey Mike.
He wanted to know about body sway.
Didn’t know if you wanted to add anything…


OP, Mike helped me down Black Bear and up Poughkeepsie. So thankful for him. Then he got in it and we drove to a hiking trailhead, and iirc he was crying like a little girl because of the sway going up highway 550.
I didn’t put sway bars in it to begin with, better now. @devo was there too, I think he was curled up in a fetal position.
Correct me if I’m wrong.

I’m weighing in at 7340 lbs, most of that frame, lower links, and Dana 60 axles. So I was well rooted but it was freaky for everyone who rode in it, even more so for those who actually know off roading and these trucks.

I was really concerned about your wellbeing. Ha! I am excited to see how it feels with a seat bar. I can always bring my ear plugs.

 

[Ditcherman]

Thank you for all the feedback. Apologies for the bad grammar as well. I was a bit distracted while crafting the OP.


I'll be using it for a combination of recreational travel, trails, and some agricultural use. I've been dreaming up a big expedition through the West coast all the way up to Alaska. I also have a good friend who owns a truggy and likes to do challenging trails in the Southwest. It would be great if my project was good enough to do the gatekeepers and bypasses.

Curious about the ag use, and what you do?

Coincidentally, I think I arrived at the same conclusion. The mount happens to be a decent distance from rivets on the frame's upper and lower flanges. It was meant to be.


I didn't explain that very well, and you probably have some other valid criticisms that you're not mentioning. This is all a bit crazy and it has caused a small amount of ostracization at the household...

My regular late night attendance in the barn is now fully expected.

It has more to do with the transfer case selection. After the fire, my original plan was to swap in the 6BT/nv4500 and rebuild the car without stretching. After my latest mods, I estimate the wheelbase at 99.5" with scooped out quarter panels on custom springs, ~97" if I want to preserve the quarter panels somewhat (I remembered this wrong in my first post). On paper, my additional 7-9.5" inches of wheelbase should make up for the 7" additional length of the atlas/nv4500 combo. But it's a bit short for a NP205+adapter (7.5" additional length) unless I do scoop the quarter panels. The engine is tall, so I fit the motor at 5 degrees to tuck in the oil pan and hopefully prevent the transfer case from protruding excessively below the frame. So there is still a chance that I may be running with a steep driveshaft angle despite it all. I guess 15 degrees is a general case cut off for a double-cardon. Maybe that can work? However, if I want a doubler (for the amazing control going down some of the steep hills/drops on trails out here), I'll need an additional 7" on top of what I've gained. And I haven't made up my mind, but I'm leaning toward the doubler+np205. Or at least I want to have the option available in the future.

I love my ORD Magnum box, it was a fantastic, albeit expensive way to mate the 205 to the NV4500. It's right up there at the top of my favorite things about the build when it comes to wheeling. I will say I'm pretty new to the wheeling scene, still a novice. Also the Magnum box might be a little shorter than a true doubler.

I've never seen the wheelbarrow method. I'll be certain to have a look. It would be great to have some additional space to service the head or run a coolant bypass valve back there. Otherwise, I don't intend to move the front axle. Lengthening the cowl might allow for the mechanical fan. I guess that I always assumed this would be really difficult technically and hard to pull off with subtlety. How was your experience doing it?

We eliminated pursuit of the mechanical fan very early on, just assuming we'd go electric from the beginning. right or wrong I don't know. I have a small AC condenser, then widened the stock 40 radiator bracket to hold a radiator that just fit in between the City Racer lights - they're a bit smaller at the rear than stock. Then a pair of Spal fans. There's 3/4" between the back of my fan and the pulleys on the motor. I definitely did not move the firewall enough, or early enough. It was too much of an afterthought.

So I assume you're familiar with the "coolant bypass kits" for a ridiculous $300 +? They plug in a port on the back of the head, and they're a relatively small line that just goes back to the water pump, IIRC. I didn't have room to get to that by the time I realized I needed it, and I knew that turning the heater on full blast gave me more time when my engine overheated. Turns out the threads where the heater hose plug in are 1", so I tee'd off that running 1" hose back to another radiator and the regular heater stuff reduced off that tee. The 1" hose has a 1" ball valve in it back at the 1" i/o radiator, closed to force water through the heater circuit in the winter. Constant flow, it's tee'd in the suction side of the water pump, with a switch at the radiator to turn the fan on at 180* water temp. It works so good that the front fans don't even come on until really hot weather. I only know this because I tested the fans up front and found they weren't working because my help had put a 205* temp switch in and the engine never got that hot in mild weather, say up to 70*.
The little rear radiator is maybe 12 by 16", 4 row and mounted just in front of the rear axle under the floor.

I'll look at your suspension build. Keeping a leaf spring suspension was mainly to limit the technical difficulty of everything. I already committed to rebuilding the engine w/ swap and the body restoration which is stretching me as is...and now I'm adding THE stretch (I'm not a professional mechanic...just youtube which makes me an unexperienced expert). I read that body sway becomes a much bigger issue in links compared to leafs....but I guess torsion bars tame it somewhat. I also wasn't sure about heim joint durability for daily abuse.

I'll definitely need the cooling advice, whenever you think I should start attending to it. I currently have an Aluminum Ron Davis radiator that worked outstanding with my 98' pre-LS sbc. Ron happens to live here in the valley and quoted me for an upgraded version that can take advantage of the 1 inch body lift that I'll use. But I think I try the old one first for a while. They are a bit pricey. The intercooler is going to be a hurdle as well. Some guy in Australia runs a rectangular cooler external to the bib, just below the grill and it didn't look half bad. I see others running air:water interfaces with a secondary radiator.

I have air to water, with the second radiator/fan mounted just in front of the second cooling radiator mentioned above.
I'm not sure how well they should work, I question how effective mine is and plan on adding an air scoop to direct air into the radiator better before I head back to Colorado.
I am monitoring temp between the turbo and the cooler, then again in the intake. Driving hard the intake might be 10-25* cooler, but the intercooler very quickly heat soaks in the engine compartment when you slow down.

And sure thing about the cross member. I'm just going through the 5 phases of grief with it. I'll get there eventually.



Did she mean the vibrations, the wind blowing by, the engine noise, or the gear box? Or all the above? lol

Mostly the engine/fuel pump noise, although she may not realize how much wind noise there actually is in the old truck.
I don't really have any vibration to speak of that I would notice. I've been told that's a real thing with 4bt's and can believe it. I just used the dodge motor mounts.

I'm willing to put up with a lot...vibrations not as much. I'm hoping that the anti-vibration mounts help. Supposedly, they reduce 60% of vibration transmitted from the engine to the frame. Lordes may go even higher but I had a hard time getting my hands on some.


Looks like that's the thing to do. Not looking forward to redoing the motor mounts, but the mechanical fan is worth it to me. I'll try to find one of these wheelbarrow builds to experiment with, if that's what you mean. Or were you thinking of something more extensive?

 

[dna9ster]

Apologies for the delayed responses. I appreciate the help!

Maybe we should team up on the drive to Alaska. I would love to drive mine there as well.

Absolutely, assuming you haven't already left. This is taking me a lot more time than I thought!

take a look at what the prerunner guys do with basically a shell. Even on a stock frame, you can probably gain about 7 inches of leg room forward and down, and then push the engine back another 5-6 without the factory firewall.

Very interested in leg room! Im hoping that the chassis extension allows me to move the seat back another 2-3 inches. I'll have to see though. The pillar might be too much in the way. I took a look at some of the Tacoma builds but didn't find anything that approaches what you described yet. Just Scooping out the front wheel wells to fit oversized tires.

I’m thinking that wheelbarrow solution was maybe someone named afraptor, or possibly a10driver, pretty sure it was here in the hardcore corner.

Found it in A10Driver's epic build. When it comes time to remount the engine, I think I'm going to do it.

Curious about the ag use, and what you do?

My father and I share a honey business. Sometimes I transport bees, honey barrels, and jars of honey over farm roads and city roads. I currently use a 2WD truck for this, but I think the land cruiser will offer me more sanity for bad weather days. (Although my primary motivation in doing the swap/extension is just that I want the project). I don't do anything else agriculturally.

So I assume you're familiar with the "coolant bypass kits" for a ridiculous $300 +? They plug in a port on the back of the head, and they're a relatively small line that just goes back to the water pump, IIRC. I didn't have room to get to that by the time I realized I needed it, and I knew that turning the heater on full blast gave me more time when my engine overheated. Turns out the threads where the heater hose plug in are 1", so I tee'd off that running 1" hose back to another radiator and the regular heater stuff reduced off that tee. The 1" hose has a 1" ball valve in it back at the 1" i/o radiator, closed to force water through the heater circuit in the winter. Constant flow, it's tee'd in the suction side of the water pump, with a switch at the radiator to turn the fan on at 180* water temp. It works so good that the front fans don't even come on until really hot weather. I only know this because I tested the fans up front and found they weren't working because my help had put a 205* temp switch in and the engine never got that hot in mild weather, say up to 70*.
The little rear radiator is maybe 12 by 16", 4 row and mounted just in front of the rear axle under the floor.

Yah, $500 for the fleece. The dual radiator set up sounds really nice. Do you run a stock pump/pulley with it? I guess the 1" circuit wouldn't be too much to handle, if it's draining into the bottom radiator hose. Do you run the tubing in the frame on the passenger side?

I have air to water, with the second radiator/fan mounted just in front of the second cooling radiator mentioned above.

So the arrangement has vertically stacked radiators with a pulling fan? Or do you have them separated with two different fans? I'm really hoping I can get away with a front grill radiator/intercooler set up. And AC too....that's the dream but we will see. I read that the mechanical fan offers 8-10k cfm when it's motivated.

 

[dna9ster]

Over the last week, I've been researching chassis modification methods. I don't have any pictures to post other than some prep work with the laser.

It's all very new to me, so I'm moving pretty slowly.

I found a couple of interesting videos from Professor Youtube on frame cuts:



They are posted by a mechanical engineer who compares an angled cut to the vertical and he also discusses failure through metal fatigue. He uses some good examples involving a defender 110. I'm a hobbyist welder at best, so I learned a lot.

For anyone else thinking about doing the same thing, I've also summarized some of the frame stretch projects found here in our forum. (In some cases the methods were a little unclear and I'm sorry if I got it wrong.)

Mike Shull	Build - Stretched 1-Ton FJ40 | IH8MUD.com Forum | Toyota, Lexus & Off-Road Community Discussions	Diagonal	Transecting 2nd body mount	Donor Frame, Outer C full weld, sidewall boxed inner C, fish plated outer C
Afraptror22​	Extended cab 45 SWB from a 40 | IH8MUD.com Forum | Toyota, Lexus & Off-Road Community Discussions	Near vertical	Between tubular crossmember and perch of rear leafspring	5 inch (?) Rectangle tube insert, outer wall fish plates
Matzell/Taz72	Build - matzell's stretched FJ40 build Now Taz72's | IH8MUD.com Forum | Toyota, Lexus & Off-Road Community Discussions	vertical	Between tubular crossmember and perch of rear leafspring	Donor frame, outer C full weld with interior fish plate?
fflood	Fj40 Stretch | IH8MUD.com Forum | Toyota, Lexus & Off-Road Community Discussions	vertical	Between 1st and 2nd body mounts	Donor frame, outer C full weld, boxed inner
Aandy767	5.3l, nv4500, np205, centered rea mini hybid driveline length questions | IH8MUD.com Forum | Toyota, Lexus & Off-Road Community Discussions	vertical	2nd body mount	Donor outer C?, partial welded raw inner C?, fish plated inner C and cover plates on flanges
Franken45	Build - Another FJ40 to FJ45ish Thread | IH8MUD.com Forum | Toyota, Lexus & Off-Road Community Discussions​	vertical	Between tubular crossmember and perch of rear leafspring	Unseparated donor frame, outer fish plate
DirtSniffer	Frame stretch - split frame channels? Ideas? | IH8MUD.com Forum | Toyota, Lexus & Off-Road Community Discussions	Vertical	Between tubular crossmember and perch of rear leafspring	Raw inner C (inner C flanges exposed by extended outer C cut), raw outer C
TCinVa	Build - 1972 FJ40 stretch and refresh | IH8MUD.com Forum | Toyota, Lexus & Off-Road Community Discussions	Vertical	Crossmember delete with preserved lower flange of outer C	A500 5” rectangle tube overlapping lower flange, inner wall and outer wall fish plating
Turnmeover	stretching the 40 | IH8MUD.com Forum | Toyota, Lexus & Off-Road Community Discussions	Step	Between 2nd body mount and crossmember	Donor?, outer fish plate

I think I'm going to go back to the idea of a vertical cut but move it toward the rear a couple of inches from where I drew the line in the OP. Having the splice close to the leafspring offers less bending stress, but I prefer the geometry of several inches of flat frame on both sides for a 3/16" external liner.

I liked Dirtsniffer's and TCinVa's techniques of tackling the inner C first to allow full access to the welds on the flanges. I think that I would be giving up the interior plating on the outer C though. So I'm going back and forth considering the inner C first approach versus the outer first.

 

[DangerNoodle]

Here's how I have always spliced frames, inner and outer c's bent up, then full plating on the inside of the inner c, then fully burn in the outer c.

Ignore my coworker digging for something, but you can see the ground and blended frame in there.