Head gasket?

[FJ40Jim]

Yep, that HG is blown, just a bit.
The HG is the craptastic cheapo aftermarket one. Note that where it blew the fire rings are not contiguous.

Here's the Post showing difference between best & worst HG.

Measure the bores just for fun. The pistons are not OE. Maybe when the pistons were replaced, it was punched 1mm OS. Then you'd have a 4.3L 2F.

Edit: Are those pistons flattops? That would explain the 120# of compression.

 

[pigpen4x4]

That was a good post, thanks. Great pic showing the differences in HGs!

I will measure the bores when I get it all cleaned up. I do know that when it was rebuilt, it was bored over. You say that "Maybe when the pistons were replaced, it was punched 1mm OS." What does OS stand for? Over size?

Yes, the pistons are flat top. How does that explain my 120# compression? Is 120 above norm?

Yesterday, I was talking to someone that mentioned it is fairly common for the pistons to crack and since I have the head off I should check them. Can I drop the oil pan, unbolt the conn rod caps, and push the pistons up through the top? The only thing I have done so far is remove the head. Cam and crank are still in the engine, and it is still mounted in the cruiser.

Yep, that HG is blown, just a bit.
The HG is the ****tastic cheapo aftermarket one. Note that where it blew the fire rings are not contiguous.

Here's the Post showing difference between best & worst HG.

Measure the bores just for fun. The pistons are not OE. Maybe when the pistons were replaced, it was punched 1mm OS. Then you'd have a 4.3L 2F.

Edit: Are those pistons flattops? That would explain the 120# of compression.

 

[ruger280]

I wouldn't worry about the pistons. I try not to dig where there's not a problem. A fresh gasket should get you back on the road. With the rear main, if you can get a split rear seal, you only need to drop the pan, pull the rear main and replace it. But I don't know if they make a split rear seal for the 2F. Done it on older Fords.

 

[cruiserbrett]

yes, the lack of domed pistons is a problem for a pre 1980 2F. with the large combustion chamber head and flat top pistons(not domed) you are well below the already dismal 7.8 stock compression ratio. It will run, but not as well as it could.

120 psi is nearing rebuild time on a 2F, if its got the correct piston/head combo.

I'd hunt for a later head.

 

[malcb]

Can I drop the oil pan, unbolt the conn rod caps, and push the pistons up through the top? The only thing I have done so far is remove the head. Cam and crank are still in the engine, and it is still mounted in the cruiser.

If you do this watch out for a "ring" at the top of the bores, usally it will be carboned up there and sometimes on a high milage engine a step forms in the bore were the wear changes. It's possiable to crack a ring pulling the piston which is a PITA if your just having a quick look, but then it doesn't sound as if the engine has done much mileage since a rebuild, not with that head gasket.

That said even a naff gasket should hold up for a while on the 2F which is a fairly forgiving application. Is it possiable you had detonation occuring at some point - if you think so I would check the pistons for certain.

 

[pigpen4x4]

Well, I dropped the head off at the machine shop earlier this week to get a head job. I also had a friend come over and look the cylinders/block and he said all looked very nice and he didn't see a need to take the pistons out. Today, the machine shop called to let me know that they found three cracks in the head. NOT GOOD!!! I asked him if it could be fixed and his recommendation was to find a new head since he couldn't guarantee that once it was fixed that it would even hold. That really sucks and definitely pisses me off!!! Anyone have a spare head lying around that they need to get out of their garage?? The engine is a '77 2F, and I'm not sure what year heads are compatible. Any recommendations?

 

[FJ40Jim]

Remember that if the block has the flattop pistons, a 81-newer head is required. The casting number will be 61040 or higher.

 

[pigpen4x4]

I had no idea about this! Thanks for the info. What is the difference between a head for the years 76-80 and an 81-newer head? My 2F is a '77, or so I thought. Maybe just the block is a '77? I was also told it was bored over, if that makes a difference.

Remember that if the block has the flattop pistons, a 81-newer head is required. The casting number will be 60040 or higher.

 

[malcb]

I had no idea about this! Thanks for the info. What is the difference between a head for the years 76-80 and an 81-newer head? My 2F is a '77, or so I thought. Maybe just the block is a '77? I was also told it was bored over, if that makes a difference.

Post #21 FJ40JIM said the pistons in the photo were not OE (original equipment) so when it got bored over some flat top non Toyota pistons went in?

 

[pigpen4x4]

Ok, so I came home and looked at my cracked head and its casting number is 61031. So, according to you that is an 81 or newer head on there already, correct? Any way to tell what year it is? I'm still curious as to the why though. What is the difference and if the block is a '77 what causes the need for a later head? I'm definately glad you said something! I was about to get a new head this weekend.

Remember that if the block has the flattop pistons, a 81-newer head is required. The casting number will be 60040 or higher.

 

[FJ40Jim]

Doh! My typo.

The 61031 is a 77-80 open chamber head. It is to be used w/ domed pistons.

The 61040 head is to be used w/ flattop pistons.

The block is irrelevant.

What counts is: head & pistons must match, head & head gasket must match.

The flattop pistons and closed chamber head is a more efficient package, due to higher compression and much more squish area.

 

[pigpen4x4]

Do you have a pic of the chambers on the head to be used with flat top pistons???

Doh! My typo.

The 61031 is a 77-80 open chamber head. It is to be used w/ domed pistons.

The 61040 head is to be used w/ flattop pistons.

The block is irrelevant.

What counts is: head & pistons must match, head & head gasket must match.

The flattop pistons and closed chamber head is a more efficient package, due to higher compression and much more squish area.

 

[malcb]

Do you have a pic of the chambers on the head to be used with flat top pistons???

matt.mcinnes had some good photos of a 3FE head, he thought the head was the same as an 1980 2F, well that's what he thought at the beginning - long build with lots of information, doubt even matt can remember everything he found out on the way.

Y64 w533 have seen his engine thread, this is a link to an external site with everything tidied up. Head pictures about 1/2 way down.

FJ40-2F-ETI-LOCKED-N-LOADED - BUILD UP - BUILDING THE 2F ETI PART 1

 

[pigpen4x4]

Ok, I looked at the build mentioned in the previous post and I see the difference in the heads. So now I just need an '81 or later 2F head and matching year head gasket. What about the valve cover? Will my valve cover ('77 I assume) still fit on an '81 or later head? How about the valves, springs and rocker assembly? Is that all interchangable from my '77 to an '81 or later head? Sorry for all the questions, but I am seeing that there is a lot that I don't know, and its stuff that I need to know.

What about a 3FE head? What is the 3FE engine? Will that work, or will I also have to do other things to the head/engine? I saw one for sale in the classifieds and it is locoted close to me.

Doh! My typo.

The 61031 is a 77-80 open chamber head. It is to be used w/ domed pistons.

The 61040 head is to be used w/ flattop pistons.

The block is irrelevant.

What counts is: head & pistons must match, head & head gasket must match.

The flattop pistons and closed chamber head is a more efficient package, due to higher compression and much more squish area.

 

[matt.mcinnes]

Ok, I looked at the build mentioned in the previous post and I see the difference in the heads. So now I just need an '81 or later 2F head and matching year head gasket. What about the valve cover? Will my valve cover ('77 I assume) still fit on an '81 or later head? How about the valves, springs and rocker assembly? Is that all interchangable from my '77 to an '81 or later head? Sorry for all the questions, but I am seeing that there is a lot that I don't know, and its stuff that I need to know.

What about a 3FE head? What is the 3FE engine? Will that work, or will I also have to do other things to the head/engine? I saw one for sale in the classifieds and it is locoted close to me.

Toyota built the 1F then the 1.5 transition F, then the 4280cc 2F they then took a step backwards and built the 4000cc 3F but the USA never got this carbi engine you got the 3F-E with injection and five miles of vacuum hose due to you smog laws We only got the 3F-E in the very early 80 series and it was a dog of an engine in them.

The best of all world is a 2F block with flat pistons and a 3FE head along with its de smogged injection system. Better still is one of these a 2F-ETI

 

[pigpen4x4]

Matt, I've been following your thread. Very impressive! I can't wait to see it in action. Thanks for explaining the difference between the three engines, but what about all the other associated items? Will my valve cover ('77 I assume) still fit on an '81 or later head? What about the valves, springs and rocker assembly? Is that all interchangeable from my '77 to an '81 or later head? I saw your post in the classifieds about the 3FE head. Thanks!

Toyota built the 1F then the 1.5 transition F, then the 4280cc 2F they then took a step backwards and built the 4000cc 3F but the USA never got this carbi engine you got the 3F-E with injection and five miles of vacuum hose due to you smog laws We only got the 3F-E in the very early 80 series and it was a dog of an engine in them.

The best of all world is a 2F block with flat pistons and a 3FE head along with its de smogged injection system. Better still is one of these a 2F-ETI