F.5 head on 2F engine (1 Viewer)

[SergP]

I have two heads: 60051 (1974) and 61031 (1977)
I have read many threads here, but not many really had comparisons between F.5 and F2 heads. Especially with the pictures.
I try my best to summarize some information here. All my measurements are not 100% accurate, but give some idea of the size.
Just may be useful for anyone who thinking to replace the head from 2f to f.5 to increase compression.

Head: f.5 (1974) model year (60051)
Block: 2f with the dome top pistons.
Head gasket: 2F

 

[SergP]

some measurements:

 

[SergP]

distance from valve to the head surface:

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[SergP]

how it will fit on the 2F engine block..

 

[SergP]

For f.5 head 2f gasket fit very well.

Edit: correct # in image 60051

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[SergP]

I have finally done a compression test (cold engine)
from approximately 125psi ...it jumps to 165-170psi across the head (60051)

 

[JKIII FJ40]

are you running it now, have you noticed anything different? thanks for the info, should my F.5 ever die its good to know there are more options.

 

[Dave54000]

How did the that head work out on a 2f block

 

[SergP]

How did the that head work out on a 2f block

So far good... start well at cold.. vacuum 16-17in .. heating is normal..
but I have not run too far yet.

 

[Pighead]

How did the that head work out on a 2f block

As an aside, I've got sorta the same thing. '74 1.5F head on an early 2F block. Had some pinging issues at first, corrected with timing and octane adjustments.
I put this engine together 20 years ago, plenty of miles on it. Been promising it a valve job for about 10 years now, getting around to it now so I'm disassembling for taking it to the machine shop.

 

[Godwin]

Ran this combination in the FJ40. Fresh rebuilt '85 2F block with domed pistons, and '74 F head. Compression was 195 psi and I had to run premium, but it was a strong pulling 2F.

 

[Dave54000]

I am putting a 75 2f in my fj and just found out it has flat top pistons and has a 61030 open chamber head so I need to find a closed chamber head or mill down the 61030 or the 1974.5 head I have around 300 to 400 bucks