74 f engine head on a 2f

[slickrock]

So has it been confirmed . . . an F block can be mated to a F.5 (74.5) head without any issues or milling as long as the F split rocker arm is used and the old brass oil pick-up tube is transfered over?

 

[rsbcruiser]

So has it been confirmed . . . an F block can be mated to a F.5 (74.5) head without any issues or milling as long as the F split rocker arm is used and the old brass oil pick-up tube is transfered over?

I believe you are right. Using that combination will lower your compression though. The 74 head has a larger combustion chamber, the 74 had domed pistons. Earlier f engines had flat pistons. Two choices, shave the head or go with domed pistons.

 

[slickrock]

Dang! It might be easier to just rebuild my F head and leave the f.5. I was goign to give the old head to an old-timer in need. Maybe he can just take the whole engine . . .

 

[Godwin]

Very interesting Godwin, wondering though, do you think the cracked head was caused by the higher compression? I suppose there is no way to really tell, but was the head cracked through the combustion chamber? I'm thinking that if it was then the higher compression can't be ruled out as a cause.

I suppose I can't discount the higher compression leading to the cracking. IIRC the crack was between a couple of chambers. I had also been dealing with a slow coolant loss for about a year which may have been a contributing factor. As far as I know the coolant was not being lost into the head, but again I'm not certain that there had not been a minute crack long-term. When the head became evidently cracked it was quite noticeable. I was warming the engine on a cool morning and the tail pipe evaporative, instead of decreasing, became a huge steam plume.

 

[Texican]

I think there is no way the increase in compression had anything to do with the cracked head.
Usual cause of cracked heads is overheating.
Butch

 

[rsbcruiser]

Proper head gasket?

SO, if one were to put a 74 and a 1/2 head on an early 2f, what head gasket should the guy use? The f head gasket or the 2f head gasket? The World wonders, this and the meaning of life of course.

 

[Degnol]

SO, if one were to put a 74 and a 1/2 head on an early 2f, what head gasket should the guy use? The f head gasket or the 2f head gasket? The World wonders, this and the meaning of life of course.

The 2F gasket. The bore is the only thing that changed.


Ed

 

[hammered]

Sounds like all of you know what your talking about in this thread.

Here is my ?

I am running 110 octane LPG.
Runs great as is.
Somewhere in this form I read about shaving the head and porting to account for the Higher octane.
Just thinking I have this in the shop and could mill it for nothing.
If it will boost the LPG performance why not.
Cheap HP boost and maybe get better mileage out of the LPG.

Now the ?s
Have a head off the 1965 F motor in the shop. less than 70k miles
Forgot I had it till a couple weeks back.
Looks great and ran good till a couple rings cracked.
Just change out the motor at that time.

Wondering if this could be cleaned up shaved and ported.

Thing is, I am now running an 84 2f motor.

Would this Work? Also how much should I shave off it if it will work?

As always thanks for any feedback

 

[Toyo FJ40]

It needs to be a 74 F head to fit the F2 block and I'm not sure but I think the 84 F2 is back to the flat top pistons so if you have a 74 head It still wouldn't work.


Kevin

Edit: The older F heads will fit but won't raise your compression like the 74.5 head.

 

[LT]

You will need a '69 - '72 F head, since the early F motors had Siamese ports. I had my 73 F head milled .06 off the surface on my 79 2f, and it runs great.

 

[hammered]

Thanks for tip.

Guess I will drop it off with Paul Pilgrams shop here for his collection.
No point in having it rot in the shop.
I am sure he will put it to use in one of his restorations.

Was an idea.
Will have to keep my eye open in the future or will just pull mine if it the head gasket packet it in and rework it then.

Good thread and thanks for the tips.

 

[Degnol]

It needs to be a 74 F head to fit the F2 block and I'm not sure but I think the 84 F2 is back to the flat top pistons so if you have a 74 head It still wouldn't work.


Kevin

'74 F to oil the head properly.....I also think an '84 2F had flat tops, but it would work, albeit with lower compression.

You will need a '69 - '72 F head, since the early F motors had Siamese ports. I had my 73 F head milled .06 off the surface on my 79 2f, and it runs great.

How did you oil the head/valve train?


Ed

 

[Fuzzy Logic]

This thread is a incomplete train wreck

 

[bsmith123]

Somebody said this a few posts back, but I am curious if you noted the graphitizing of eutectoid cementite?

Conclusions It was found that during operation of cylinder heads complex physicochemical processes of internal oxidation occur in the thermally stressed section of the lower wall due to the influence of the exhaust gases. The service life of the cylinder head is determined by the changes in the properties resulting from these processes.Structural changes due to graphitizing of eutectoid cementite were not observed due to the submicroscopic character of such changes and the substantial heterogeneity of the metallic cast iron in the cylinder heads examined.

SpringerLink - Journal Article

originally posted by Mark W


Pre '68 F engines used siamesed exhaust ports and a deep "bathtub" style combustion chamber. They're pretty much on their own so far as interchanginf anything.

From then until '72 the F engine used a flattop piston and a closed combustion chamber.
'73 and '74 F engines used an open combustion chamber and a very small dome on the piston.

'75-'80 US variant 2Fs used an open chamber and a domed piston.

'81 and later 2Fs used a closed chamber and a flat top piston.


A '73-'74 F head will be a bolt on swap to any of the 2F, producing more compression on the '75-'80 blocks.

A pre '73 F head will swap to the later 2F engines once the rocker arm oiling is addressed. There will be piston/head interference on the early 2Fs

You can install an early 2F head on a late 2F engine. You will loose compression.

You can install any 2F head on the pre-'73 F engines. Again, you will loose compression, especially if you install an early 2F head with the open chamber.

CHECK OUT THESE LINKS
https://forum.ih8mud.com/40-55-series-tech/105385-2f-head.html
https://forum.ih8mud.com/40-55-series-tech/143065-head-comparisons-faq.html

 

[Rocky_LC]

My Late '74 (Oct '74) Head uses the 2F Oiling. I did not have any of the copper oil plumbing tubing (up top, or down below).

Rocky

 

[fj40er]

I am running a F head on a 2F block, I have board my motor to 30-over, and have a compression of - 9.5 to 1 - I love this set up. The motor runs great and pulls like all get out. A ton of torque. If you have any questions about this set up please just send me a PM. Its a great motor and very easy to put together.

pics:

 

[LT]

How did you oil the head/valve train?


Ed

Ancient chinese secret

Actually I need to write the article but I have successfully swapped a non 74.5 F head over to a 2f and still retain the factory oiling from the 2f. Stay tuned...