I'm getting my reading from a sensor on the back of my intake manifold. I've also shot a couple places on the block with an IR thermometer.
SBC Running Hot
- Thread starter toyotaspeed90
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I'm getting my reading from a sensor on the back of my intake manifold. I've also shot a couple places on the block with an IR thermometer.
Pulled a fan off a 79 rwd caddy a couple years back and installed it along with a hd fan clutch in my 40. had to move the radiator forward a little for better clearance. Had an electric pusher fan in front I removed because of the moving of the radiator but I don't need it now. that fan and clutch moves a lot of air. I found the info for that mod searching mud.
That's good info there.
I'm running a 5.3 Vortec in one of the 40's and upgrading the radiator and fan set-up really helped hold the temp down. I also shrouded it, but I'm going to look and see the position of the fan in relations to the shroud.
Thanks Downey.
Downey
SILVER Star
Toyotaspeed, I think you are going to spend far more time and money experimenting with mods that don't solve your over heating problem (i.e. radiators, fans, shrouds, water pump/pulley stuff) than you'd spend fixing engine location (i.e. new motor mounts, transfer-case linkage mod, drive shaft mod, and re-doing exhaust connections at the engine)- - - either way, you can't just leave it the way it is now.
- Thread starter
- #25
Yes, I am stubborn. I've also done a lot of things to a lot of cars that others say "that can't be done" or "that won't work" and it does... so it's sort of my nature.
If I wasn't already where I am (and yes it's probably my fault for not researching this prior to putting it all back together and "fixing" the issue earlier) then I would put the engine in the more desirable location.
Given that it isn't crammed into the firewall and that there is sufficient airflow around the engine, along with reading that some of the biggest contributors in Chevota's is a shroud, a bigger fan, and t-stat selection (and that I'm within 10% of desired temps anyways), I'm not 100% sold that it can't be resolved within my vehicle.
The friend's 68 came from CA and was pretty damn well built for offroad (SOA, flipped front springs, high steer, TBI 350, dual batteries, NV4500, transfercase converted to stick, yadda yadda yadda) - and I've seen the engine location, I'm pretty sure it's within range of the recommended engine placement. For years he has been having cooling issues as well (varying t-stat options, having his radiator recored, mechanical and electronic fan variations, adding airflow to the engine bay, etc) and his issues are significantly worse than mine.
Since it's also suggested to have things like a higher flowing water pump (mine might be suspect) and a shroud, these aren't additional cost items/modifications in excess of what it would cost to move the engine a couple inches back. These are already things people say to do or should be done in addition-to....
I was hoping this thread wasn't going to be purely about my issues - but about what people are doing that works with their setup because info is scattered and usually the suggested changes vary for each persons situation.
What it seems to be is that it boils down to:
Don't cram the engine into the firewall
Make sure the engine is tuned well
Move as much air as possible through a properly functioning radiator
Have an appropriate thermostat
Yes - there may be formulas when starting from scratch that make it easier to attain, but 1+1 = 2 but 1x2 also = 2.... Meaning that sometimes different variables will yield the same result. The end result with my vehicle may be that I have to move the engine back (begrudgingly) and someone could say 'I told you so'.
If I wasn't already where I am (and yes it's probably my fault for not researching this prior to putting it all back together and "fixing" the issue earlier) then I would put the engine in the more desirable location.
Given that it isn't crammed into the firewall and that there is sufficient airflow around the engine, along with reading that some of the biggest contributors in Chevota's is a shroud, a bigger fan, and t-stat selection (and that I'm within 10% of desired temps anyways), I'm not 100% sold that it can't be resolved within my vehicle.
The friend's 68 came from CA and was pretty damn well built for offroad (SOA, flipped front springs, high steer, TBI 350, dual batteries, NV4500, transfercase converted to stick, yadda yadda yadda) - and I've seen the engine location, I'm pretty sure it's within range of the recommended engine placement. For years he has been having cooling issues as well (varying t-stat options, having his radiator recored, mechanical and electronic fan variations, adding airflow to the engine bay, etc) and his issues are significantly worse than mine.
Since it's also suggested to have things like a higher flowing water pump (mine might be suspect) and a shroud, these aren't additional cost items/modifications in excess of what it would cost to move the engine a couple inches back. These are already things people say to do or should be done in addition-to....
I was hoping this thread wasn't going to be purely about my issues - but about what people are doing that works with their setup because info is scattered and usually the suggested changes vary for each persons situation.
What it seems to be is that it boils down to:
Don't cram the engine into the firewall
Make sure the engine is tuned well
Move as much air as possible through a properly functioning radiator
Have an appropriate thermostat
Yes - there may be formulas when starting from scratch that make it easier to attain, but 1+1 = 2 but 1x2 also = 2.... Meaning that sometimes different variables will yield the same result. The end result with my vehicle may be that I have to move the engine back (begrudgingly) and someone could say 'I told you so'.
The 2 row radiator may be your biggest draw back right now. I just had my stock radiator rebuilt as it blew a hole in one of the columns. The radiator guy told me it was a 3 row HD core. This was the factory radiator and it had worked fine even with the 350 SBC. Your 2 row may not have the capacity to pull enough heat out of your system. I was told that if I wanted to add AC a 4 row would be better suited but since that wasn't in my immediate plans a 3 row HD core was put back in. The 4 row would have been thicker, can't remember the numbers right now, but I was also concerned with not having enough clearance so that too played into my decision.
Unless the engine is set back some to where you can get a 3 or 4 row radiator in there I think you need to be prepared for a hot engine.
Unless the engine is set back some to where you can get a 3 or 4 row radiator in there I think you need to be prepared for a hot engine.
- Thread starter
- #27
http://www.championradiators.com/Toyota-Land-cruiser-radiator
These are the champion radiators.
The 2 core is 2.75" thick and the 3 core is 3" thick. The 3 core is the stock width. I originally went with the 2.75" so that I had added clearance for the trans and PS coolers to fit between the radiator and the grill. In my current setup I *might* be able to flip the trans/ps coolers and fit a 3 row, but that's less of a concern.
Update on my vehicle: ordered a Flowkooler water pump (in some reading it significantly increases water flow volume at lower rpm's). I ordered a 16" wide blade flex fan - with the blade projected width of 2.25" - although it "fits" that isn't exactly something I trust (there literally 1-2mm at rest between the fan blade back edge and the crank pulley & alt pulley - a thicker spacer cannot be used). I might have another 1/2" of clearance at the lower portion of the radiator to try a 17" nylon blade as they have a 2" projected blade width. Planning to call Summit Racing to determine if the flange to blade depth varies. I've swapped the t-stat to a 180 just as an inexpensive test.
Driving the vehicle a little around my "neighborhood" I reached temps of 220 but it never increased. As I climbed the (pretty steep) hills back to my house I actually saw the temp drop a small amount (few degrees).
Looking into oil filter sandwich adapters so that I can utilize that lower tank cooler in the radiator for the oil.
These are the champion radiators.
The 2 core is 2.75" thick and the 3 core is 3" thick. The 3 core is the stock width. I originally went with the 2.75" so that I had added clearance for the trans and PS coolers to fit between the radiator and the grill. In my current setup I *might* be able to flip the trans/ps coolers and fit a 3 row, but that's less of a concern.
Update on my vehicle: ordered a Flowkooler water pump (in some reading it significantly increases water flow volume at lower rpm's). I ordered a 16" wide blade flex fan - with the blade projected width of 2.25" - although it "fits" that isn't exactly something I trust (there literally 1-2mm at rest between the fan blade back edge and the crank pulley & alt pulley - a thicker spacer cannot be used). I might have another 1/2" of clearance at the lower portion of the radiator to try a 17" nylon blade as they have a 2" projected blade width. Planning to call Summit Racing to determine if the flange to blade depth varies. I've swapped the t-stat to a 180 just as an inexpensive test.
Driving the vehicle a little around my "neighborhood" I reached temps of 220 but it never increased. As I climbed the (pretty steep) hills back to my house I actually saw the temp drop a small amount (few degrees).
Looking into oil filter sandwich adapters so that I can utilize that lower tank cooler in the radiator for the oil.
- Thread starter
- #28
Update.... (granted the ambient temps here have dropped about 5-10*, still tested in the 70s though)
I called Summit Racing, their tech line - and the guy didn't know his ass from his mouth. When I asked (and verified twice) about the flange to back blade distance on a couple fans he continually gave me the spec-sheet for the blade width, not depth (and I even measured the 16" blade I have to verify the information he provided was not what I was asking for, even though he specifically stated it was). Either way, I didn't order another mechanical fan to try.
I have been reading a lot - and there are a lot of varying thoughts between mechanical and electrical fans. Mechanical fans typically have the ability to move more air, but have to be placed *just right* with the appropriate shroud or may be ineffective. Electric fans typically have less draw on the engine (though some on the alt may occur, causing power robbing issues) and can be controlled a little better... along with have less chance of "jumping" into the radiator in certain instances (as in, more extreme off road situations).
I have the oil cooler adapter parts (and associated fittings, that was a pain) and have yet to install, just needed to test a few other things first.
Next attempt was to block off air - to force air through the radiator (and also when the fan is running, force air to be pulled more through the radiator instead of around). This was my solution:
Simple angle iron on the sides, cut to fit the cooler tubes, cut to fit metal up top, welded them together, and screwed it to the radiator support. The black rubber surround was from an old AW11 (first gen MR2) trunk lid seal that I cut to fit, and actually works quite well.
I saw a drop in temps - not a lot, but a little.
I thought about electric fan options.... Reading a SPAL article and it suggests that the fan should cover at least 70% of the core...
Champion FJ40 core is 17.13x19.5 = 334 sq/in
16" fan covers about 201 sq/in....
201/334 = 60%
So unfortunately a single 16" fan isn't ideal.... the problem then becomes - the core of the Champion radiator is an odd size since a 16" fan is the largest available.
I then marked out the core of the radiator in cardboard to determine - just what fans could fit, if trying to use 2 or 4.... and the only thing that I came up with was trying to use 4 8" fans.
1 fan = 50 sq/in.... x4 fans = 200 sq/in.... so the overall core coverage doesn't increase, even though if you found 1000 cfm 8" fans (totalling 4000 CFM), the recommended radiator coverage still isn't there.
I threw caution to the wind and ordered a cheap 16" fan that claims high CFM. Even though it's a thin mount, it doesn't fit between the radiator and the water pump. Converted it to pusher, moved the coolers out of the way - and the fan really doesn't fit in the front, but mild modification and it will.
Took it for a drive with the fan on and saw the temp stick almost exactly between 190 and 220 on the gauge (maybe a little more towards 190).... stopped and let it idle for a few minutes and it still didn't budge.
I am by no means saying the issue is resolved, but am saying that at this time this setup is providing better cooling. I may play with the t-stat (180 vs 195, and even toss a 160 in to see what it does) as well....
I called Summit Racing, their tech line - and the guy didn't know his ass from his mouth. When I asked (and verified twice) about the flange to back blade distance on a couple fans he continually gave me the spec-sheet for the blade width, not depth (and I even measured the 16" blade I have to verify the information he provided was not what I was asking for, even though he specifically stated it was). Either way, I didn't order another mechanical fan to try.
I have been reading a lot - and there are a lot of varying thoughts between mechanical and electrical fans. Mechanical fans typically have the ability to move more air, but have to be placed *just right* with the appropriate shroud or may be ineffective. Electric fans typically have less draw on the engine (though some on the alt may occur, causing power robbing issues) and can be controlled a little better... along with have less chance of "jumping" into the radiator in certain instances (as in, more extreme off road situations).
I have the oil cooler adapter parts (and associated fittings, that was a pain) and have yet to install, just needed to test a few other things first.
Next attempt was to block off air - to force air through the radiator (and also when the fan is running, force air to be pulled more through the radiator instead of around). This was my solution:
Simple angle iron on the sides, cut to fit the cooler tubes, cut to fit metal up top, welded them together, and screwed it to the radiator support. The black rubber surround was from an old AW11 (first gen MR2) trunk lid seal that I cut to fit, and actually works quite well.
I saw a drop in temps - not a lot, but a little.
I thought about electric fan options.... Reading a SPAL article and it suggests that the fan should cover at least 70% of the core...
Champion FJ40 core is 17.13x19.5 = 334 sq/in
16" fan covers about 201 sq/in....
201/334 = 60%
So unfortunately a single 16" fan isn't ideal.... the problem then becomes - the core of the Champion radiator is an odd size since a 16" fan is the largest available.
I then marked out the core of the radiator in cardboard to determine - just what fans could fit, if trying to use 2 or 4.... and the only thing that I came up with was trying to use 4 8" fans.
1 fan = 50 sq/in.... x4 fans = 200 sq/in.... so the overall core coverage doesn't increase, even though if you found 1000 cfm 8" fans (totalling 4000 CFM), the recommended radiator coverage still isn't there.
I threw caution to the wind and ordered a cheap 16" fan that claims high CFM. Even though it's a thin mount, it doesn't fit between the radiator and the water pump. Converted it to pusher, moved the coolers out of the way - and the fan really doesn't fit in the front, but mild modification and it will.
Took it for a drive with the fan on and saw the temp stick almost exactly between 190 and 220 on the gauge (maybe a little more towards 190).... stopped and let it idle for a few minutes and it still didn't budge.
I am by no means saying the issue is resolved, but am saying that at this time this setup is providing better cooling. I may play with the t-stat (180 vs 195, and even toss a 160 in to see what it does) as well....
You might want to consider leaving the 195 and because that will force the water to stay in the radiator longer. Which is the key to cooling.
^^^^
This is what Georg has told me to try. I'm not running all that hot, but I haven't had my rig in extreme conditions either. May try a synthetic oil to see if that helps a little.
This is what Georg has told me to try. I'm not running all that hot, but I haven't had my rig in extreme conditions either. May try a synthetic oil to see if that helps a little.
- Thread starter
- #31
Um, well.... that may all depend....
I touched on this in another thread, but I personally am not convinced that using a 195 t-stat will help all that much (and I did have one before). If the system is flowing well and at a standstill you're already struggling to keep cool with the system being at 210, the t-stat would never actually close. I am considering throwing it in there just to see what happens, but I'm not expecting much.
OE was 195... but not for cooling purposes as many claim.
In the 60's Chevy actually ran lower temps (mostly being 180). The corvette's even had a stepped 160 - where they would start to open at 160 and fully open at a higher temp.
As emissions became more important - Chevy's response to running cleaner was to burn more fuel by upping the overall temp of the system and to pull timing back. If you wanted - you could run a lower t-stat, add more timing, and make more power. So the notion that 195 is OE so that coolant could stay in the radiator longer may not be the complete story.
I touched on this in another thread, but I personally am not convinced that using a 195 t-stat will help all that much (and I did have one before). If the system is flowing well and at a standstill you're already struggling to keep cool with the system being at 210, the t-stat would never actually close. I am considering throwing it in there just to see what happens, but I'm not expecting much.
OE was 195... but not for cooling purposes as many claim.
In the 60's Chevy actually ran lower temps (mostly being 180). The corvette's even had a stepped 160 - where they would start to open at 160 and fully open at a higher temp.
As emissions became more important - Chevy's response to running cleaner was to burn more fuel by upping the overall temp of the system and to pull timing back. If you wanted - you could run a lower t-stat, add more timing, and make more power. So the notion that 195 is OE so that coolant could stay in the radiator longer may not be the complete story.
If the coolant stays in the radiator longer, it also stays longer in the engine block. http://www.flowkoolerwaterpumps.com/cooling_faq.html Check out the info on cooling at this site. My personal cooling set up is 4 core radiator, mechanical fan with 7 steep pitched blades, truck rated fan clutch, shroud, high flow water pump, 180 degree thermostat. I run this setup on a 55 and a 40. Both have SBC.
- Thread starter
- #33
(I do have a flowkooler now)
I have to say this, as it seems mildly hilarious to me:
"
Cooling FAQ
1. Doesn't coolant have to have more time in the radiator to cool?
No. But a lot of people still think so. We have come up with some explanations for the Doubting Thomas."
guess what my first name is....
Doubting?
- Thread starter
- #35
So... in August I got a 3x locked 80 and the 40 sat on the back burner... especially due to the cooling issues. I even threw it up on Craigslist at an unreasonable cost to see if anyone would bite.
Yesterday I finally decided to clean up around and in the 40 to take a look. I figured that since the electric fan seemed to hell significantly but I wasn't sold I would determine what's needed to move the motor back. Money is an option as I have bills and an 80 now, haha.
So with regards to my rig, the physical moving of the engine would be easy.... pull the components, cut the mounts, re weld where I want. Easy enough.
Until I realize that I would have to replace the brand new power steering pressure line ($50 or so). Ok, not too terrible. Hmm, well looks like the header would hit the steering shaft.... so either modify the steering, or go with a different header on that side. I figure the PS would be better.... as it turns out the header would actually not even remotely fit as the entire fender and tub would be in the way. Ok, so some hugger headers (around $100) and an all new exhaust (probably another $100). Well, that would resolve the steering and passenger fender issue and it's up to $250-300.... not including the mech fan and shroud costs.... but that an in frame exhaust won't fit on the passenger side because of the transfercase linkage.... which means I would then need to swap the linkage to a stick (granted I do want to do later but isn't a necessity at this time), in order to fit the exhaust that had to be rerouted because the current wont work.
I did a little thinking.... then spent 10 minutes making some modifications to the back side of the bib, and now it clears the pusher fan easily, and if I wanted to throw a 3 row in there later, would also fit. Now I just need to modify the grill and mounting of the coolers, then install the oil cooler and all is good to go/done. I won't be able to post results until temps outside increase as right now I could probably drive it around without a fan since we're in the freezing temps.
Yesterday I finally decided to clean up around and in the 40 to take a look. I figured that since the electric fan seemed to hell significantly but I wasn't sold I would determine what's needed to move the motor back. Money is an option as I have bills and an 80 now, haha.
So with regards to my rig, the physical moving of the engine would be easy.... pull the components, cut the mounts, re weld where I want. Easy enough.
Until I realize that I would have to replace the brand new power steering pressure line ($50 or so). Ok, not too terrible. Hmm, well looks like the header would hit the steering shaft.... so either modify the steering, or go with a different header on that side. I figure the PS would be better.... as it turns out the header would actually not even remotely fit as the entire fender and tub would be in the way. Ok, so some hugger headers (around $100) and an all new exhaust (probably another $100). Well, that would resolve the steering and passenger fender issue and it's up to $250-300.... not including the mech fan and shroud costs.... but that an in frame exhaust won't fit on the passenger side because of the transfercase linkage.... which means I would then need to swap the linkage to a stick (granted I do want to do later but isn't a necessity at this time), in order to fit the exhaust that had to be rerouted because the current wont work.
I did a little thinking.... then spent 10 minutes making some modifications to the back side of the bib, and now it clears the pusher fan easily, and if I wanted to throw a 3 row in there later, would also fit. Now I just need to modify the grill and mounting of the coolers, then install the oil cooler and all is good to go/done. I won't be able to post results until temps outside increase as right now I could probably drive it around without a fan since we're in the freezing temps.
I think what you've done so far is quite good. Most people don't think about the air going into the radiator thus do great shrouds around the fan but nothing in front.... and still over heat.
since it's been a bit - have you verified that the thermostat is working? and by that I mean, remove it, put it in a pan of water and heat it until the water opens it?
also about thermostats. the thermostat creates a restriction in the system to slow the water down - it seems every few years I get someone who tells me that reducing the volume of water flow doesn't make any difference. It does. Jet boats get water pressure from the top of the pump - if you don't run a restrictor (at minimum) or a thermostat you will have overheating issues. Not if, not "well, my brother's brother didn't have any problems (he's a liar)" you will have problems. That said, opening temps of the thermostat don't make much, if any, difference when you're overheating.
Your fan seems not to have a lot of pitch on the blades....
and finally
be careful with flex fans - they, without remorse, pull themselves into the radiator and destroy it if placed too close
since it's been a bit - have you verified that the thermostat is working? and by that I mean, remove it, put it in a pan of water and heat it until the water opens it?
also about thermostats. the thermostat creates a restriction in the system to slow the water down - it seems every few years I get someone who tells me that reducing the volume of water flow doesn't make any difference. It does. Jet boats get water pressure from the top of the pump - if you don't run a restrictor (at minimum) or a thermostat you will have overheating issues. Not if, not "well, my brother's brother didn't have any problems (he's a liar)" you will have problems. That said, opening temps of the thermostat don't make much, if any, difference when you're overheating.
Your fan seems not to have a lot of pitch on the blades....
and finally
be careful with flex fans - they, without remorse, pull themselves into the radiator and destroy it if placed too close
I had a overheating 383 in a 40 that was to close to the firewall. I tried a flexalite black magic (the biggest baddest electric fan I could find) and it didn't help. Then - with some searching on MUD - went with a mechanical fan from a 72 Cadillac 500 and a heavy duty truck clutch - BINGO problem solved. Never got hot again even in 100 degree weather in traffic. It did sound like a Cessna taxiing when it was cooling but small price to pay. I will be using the same set up on my current build cause I know it works.
- Thread starter
- #38
I don't currently have room for any bigger mechanical fans, at all.
I had a thread wanting to see what people were doing for aftermarket grills, and it turned to overheating (not that I wanted it to)... but got some good insight.... and I'll be installing a larger surface area universal/chevy fitment radiator. I figure at the very least, even if I do move the engine back, it will help to have a larger radiator regardless. Should be here tomorrow and next week I plan to squeeze it in.
I had a thread wanting to see what people were doing for aftermarket grills, and it turned to overheating (not that I wanted it to)... but got some good insight.... and I'll be installing a larger surface area universal/chevy fitment radiator. I figure at the very least, even if I do move the engine back, it will help to have a larger radiator regardless. Should be here tomorrow and next week I plan to squeeze it in.
- Thread starter
- #39
Mock fitting to ensure it will actually clear the hood:
Brackets were built..... Didn't want to weld anything more to the body/frame, so found stock bolt-hole/hole locations that I could use/repurpose.
Decided to not hard mount it (did some research and got some interesting thoughts/ideas). The bottom basically has 2 square'ish pieces that fit between the protruding fins of the core at the bottom - bought some 1/2" neoprene that it will sit on to "isolate" the bracket and the radiator:
Square tubing in the center was just used as a buffer/spacer to keep the other 2 pieces even
Has since been trimmed to cut off the extra lengths:
Used some simple angle iron at the top to start, welded them together at the ends to create the C channel brackets.... then used 1/4" neoprene as a spacer/isolator:
Unfortunately I didn't have my phone during any other fabrication..... but these are them drying (using an undercoating paint):
The upper mount (bottom in the photo) bolts to the fenders at the top... the driver-side was built a little different to clear the upper radiator hose.
As for fans.... there is no longer room at the front for the electric fan. I can switch it to the back of the radiator and there's about 1/2" clearance or so.... I'm undecided. I may be able to go to a mechanical fan at this point as well, but again, undecided. The lower radiator hose should be.... interesting.... The upper will be easy/simple to find.
Brackets were built..... Didn't want to weld anything more to the body/frame, so found stock bolt-hole/hole locations that I could use/repurpose.
Decided to not hard mount it (did some research and got some interesting thoughts/ideas). The bottom basically has 2 square'ish pieces that fit between the protruding fins of the core at the bottom - bought some 1/2" neoprene that it will sit on to "isolate" the bracket and the radiator:
Square tubing in the center was just used as a buffer/spacer to keep the other 2 pieces even
Has since been trimmed to cut off the extra lengths:
Used some simple angle iron at the top to start, welded them together at the ends to create the C channel brackets.... then used 1/4" neoprene as a spacer/isolator:
Unfortunately I didn't have my phone during any other fabrication..... but these are them drying (using an undercoating paint):
The upper mount (bottom in the photo) bolts to the fenders at the top... the driver-side was built a little different to clear the upper radiator hose.
As for fans.... there is no longer room at the front for the electric fan. I can switch it to the back of the radiator and there's about 1/2" clearance or so.... I'm undecided. I may be able to go to a mechanical fan at this point as well, but again, undecided. The lower radiator hose should be.... interesting.... The upper will be easy/simple to find.
- Thread starter
- #40
Forgot to mention, I will probably use the angled upper bracket arms to mount the trans and PS coolers.... just to keep heatsoak of the radiator to a minimum, and will use some otherwise wasted space.... I very quickly did a test fit of the trans cooler (which is larger of the 2) and it fits pretty darn perfectly without even cutting hoses, and out of the way of the radiator (possible fans) and of the alternator.
