Hole in piston/scorched cylinders - 72 FJ40 (1 Viewer)

Joined
May 4, 2009
Messages
87
Location
Dallas/Austin, TX
Hi All,
I bought an FJ40 on here a few years ago from a local in NM (I'm searching for the thread) and have had some issues lately with it starting. It ran fine up until this winter (2020) and with COVID etc., my maintenance went under. I took it down to a local shop in Austin and we found water in the line. Replaced some lines, wiring and fuel tank. Still wouldn't turn over. Zero compression on 2 of the cylinders. Pulled the valve cover off and all the valves are moving correctly, so we think it is likely a bottom end area. Took a borescope to it and found out a likely hole in one of the pistons with sever scarring on the piston walls.

Couple of questions here. The FJ is sound otherwise. Body looks good etc. Been in the SW the entire life. No major rust areas, etc.

I'm wondering if I should pull the engine, bore it out and put it back in as a 1F, find a 2F, find a turbo diesel or go LS swap?

I'd be worried about the resell value if I don't keep the original engine, etc., and with any updates to the engine, I'd likely need to replace some brakes, steering?

Thanks
Chris
 
Joined
May 4, 2009
Messages
87
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Dallas/Austin, TX
Hi Tim,
Yup. That was the one from you a few years back. I remember you saying that one or two of the cylinders had low compression back in the day?
 
Joined
Oct 10, 2016
Messages
716
Location
Las Cruces, NM
Hi Tim,
Yup. That was the one from you a few years back. I remember you saying that one or two of the cylinders had low compression back in the day?

Yeah I looked at the original ad a bit ago to make sure I had listed that. With low compression on those two it was still fun to drive. Sucks that it fully went out. As far as swaps, I’d say do what you want that makes you happy with it. The value of these things just keeps getting crazier from what I’ve seen. I’ll keep an eye out for a good motor in NM for you. They come up time to time.
 

flee

SILVER Star
Joined
May 27, 2020
Messages
192
Location
Chatsworth
Hi All,
I bought an FJ40 on here a few years ago from a local in NM (I'm searching for the thread) and have had some issues lately with it starting. It ran fine up until this winter (2020) and with COVID etc., my maintenance went under. I took it down to a local shop in Austin and we found water in the line. Replaced some lines, wiring and fuel tank. Still wouldn't turn over. Zero compression on 2 of the cylinders. Pulled the valve cover off and all the valves are moving correctly, so we think it is likely a bottom end area. Took a borescope to it and found out a likely hole in one of the pistons with sever scarring on the piston walls.

Couple of questions here. The FJ is sound otherwise. Body looks good etc. Been in the SW the entire life. No major rust areas, etc.

I'm wondering if I should pull the engine, bore it out and put it back in as a 1F, find a 2F, find a turbo diesel or go LS swap?

I'd be worried about the resell value if I don't keep the original engine, etc., and with any updates to the engine, I'd likely need to replace some brakes, steering?

Thanks
Chris
You could be describing the engine in my '64! I'm most of the way through with a total rebuild.
The parts to rebuild your engine are readily available so I would vote to fix what you have.
Keeping it original is a no-brainer if you want to maximize the resale value, too.
 
Joined
Jan 17, 2005
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5,721
Location
Southern Colorado
I would find a good running 2F and drop that in. Done with care, it won't greatly affect value, and it will be smoother and more powerful than the F engine that was in it. You'll get electronic ignition, a better alternator, etc.

If you can find a shop you trust, there should be no reason you can't rebuild it, unless you have trouble sourcing pistons.
 

pjohnson

SILVER Star
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Jan 15, 2003
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2,500
Location
Idaho
If it's a really nice survivor, I would rebuild the F.

Otherwise, find a good 2F and upgrade to a 4sp as well.
 
Joined
Jun 10, 2017
Messages
268
Location
Washington
I would keep the original and rebuild....my parts and machine work (overbore, cam regrind, lifters ground, valves and seals, polish the crank shaft, magnflux and tank everything, new main/rod bearings, cam bearings, 6 new pistons and gaskets/rings) came to about $1500. I assembled the motor myself...that saved a good amount.

This is what I found when I had a similar issue.

These engines just aren’t that hard to assemble.

D8EE0E80-DB4A-4E9E-81B5-A29D1552BF56.jpeg


16DD89B9-97DB-49AE-8863-448A3E98ED53.jpeg
 

Dizzy

GOLD Star
Joined
Feb 5, 2018
Messages
2,094
Location
Santa Fe, New Mexico
I would keep the original and rebuild....my parts and machine work (overbore, cam regrind, lifters ground, valves and seals, polish the crank shaft, magnflux and tank everything, new main/rod bearings, cam bearings, 6 new pistons and gaskets/rings) came to about $1500. I assembled the motor myself...that saved a good amount.

This is what I found when I had a similar issue.

These engines just aren’t that hard to assemble.

View attachment 2457154

View attachment 2457156
Is that a 2F?
 
Joined
Jun 10, 2017
Messages
268
Location
Washington
Is that a 2F?
It’s an F, casting date 12/27/67, had some where north a gagillian miles on her before she blew. This was also a NM rig....originally from Hobbs. Piston came apart a block from the house. Sounded like it sucked a valve. To my awe and astonishment, broke clean at the top oil ring.

I have a second F, casting date 11/12/67 in the machine shop now. I’ll assemble a short block and the kids will have a spare when daddy’s gone...(lol)

C1727250-0CC3-4D76-9F9E-1785E54A2515.jpeg


FE941CDD-A707-4ADA-9469-BEB64655D30D.jpeg


Ain’t she per-dy.....(lol)....me and my wife finished a 100 mile drive in her this last weekend....I love the sound of that 6....all 55 and 60 mph....we were deaf for several hours afterward!

The proud daddy!

16F0F63B-DAC0-4767-9831-5116E9FDDB0D.jpeg
 
Joined
May 4, 2009
Messages
87
Location
Dallas/Austin, TX
Yeah I looked at the original ad a bit ago to make sure I had listed that. With low compression on those two it was still fun to drive. Sucks that it fully went out. As far as swaps, I’d say do what you want that makes you happy with it. The value of these things just keeps getting crazier from what I’ve seen. I’ll keep an eye out for a good motor in NM for you. They come up time to time.

Thanks Tim. Any help is appreciated. I'm going to talk to a friend today about pulling the F and boring it over. If it doesn't make sense, I'll pull it out and replace it with a 2F.
 
Joined
May 4, 2009
Messages
87
Location
Dallas/Austin, TX
You could be describing the engine in my '64! I'm most of the way through with a total rebuild.
The parts to rebuild your engine are readily available so I would vote to fix what you have.
Keeping it original is a no-brainer if you want to maximize the resale value, too.

That's the tough thing. I do like the originality of it and would love to keep it original (if not for the re-sell value but for nostalgia). Perhaps a donor and an LS swap is in order for FJ #2?
 
Joined
May 4, 2009
Messages
87
Location
Dallas/Austin, TX
I would find a good running 2F and drop that in. Done with care, it won't greatly affect value, and it will be smoother and more powerful than the F engine that was in it. You'll get electronic ignition, a better alternator, etc.

If you can find a shop you trust, there should be no reason you can't rebuild it, unless you have trouble sourcing pistons.
If it's a really nice survivor, I would rebuild the F.

Otherwise, find a good 2F and upgrade to a 4sp as well.
Is that a 2F?
I see the oiler to the rockers

Thanks guys. I guess the concern is that if I pull the 2F, I'll need to swap the tranny as well? May not be a bad thing just additional costs. What about brakes, steering etc?
 
Joined
May 4, 2009
Messages
87
Location
Dallas/Austin, TX
I would keep the original and rebuild....my parts and machine work (overbore, cam regrind, lifters ground, valves and seals, polish the crank shaft, magnflux and tank everything, new main/rod bearings, cam bearings, 6 new pistons and gaskets/rings) came to about $1500. I assembled the motor myself...that saved a good amount.

This is what I found when I had a similar issue.

These engines just aren’t that hard to assemble.

View attachment 2457154

View attachment 2457156

That's what I'm worried mine will look like when I get it out. I guess we will see what the local shop says. I'd love to work on it, but I don't have the space here at the house.
 
Joined
May 4, 2009
Messages
87
Location
Dallas/Austin, TX
It’s an F, casting date 12/27/67, had some where north a gagillian miles on her before she blew. This was also a NM rig....originally from Hobbs. Piston came apart a block from the house. Sounded like it sucked a valve. To my awe and astonishment, broke clean at the top oil ring.

I have a second F, casting date 11/12/67 in the machine shop now. I’ll assemble a short block and the kids will have a spare when daddy’s gone...(lol)

View attachment 2457196

View attachment 2457201

Ain’t she per-dy.....(lol)....me and my wife finished a 100 mile drive in her this last weekend....I love the sound of that 6....all 55 and 60 mph....we were deaf for several hours afterward!

The proud daddy!

View attachment 2457219
That looks great. What a clean engine bay. I'm impressed. Wanna make a trip to Austin? :)
 

Dizzy

GOLD Star
Joined
Feb 5, 2018
Messages
2,094
Location
Santa Fe, New Mexico
2F can go with a 4-speed, if that is what you are asking. But, many folks prefer the 2F platform, from a parts standpoint. However, Mark Jennings made the original F work.

Just fix what is broken. If you need a 2F with original cross-hatching on the cylinder walls, there is one waiting on my driveway.
 
Joined
May 4, 2009
Messages
87
Location
Dallas/Austin, TX
2F can go with a 4-speed, if that is what you are asking. But, many folks prefer the 2F platform, from a parts standpoint. However, Mark Jennings made the original F work.

Just fix what is broken. If you need a 2F with original cross-hatching on the cylinder walls, there is one waiting on my driveway.

Thanks Dizzy. Send me a PM with your price on that 2F if you don't mind?
 

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