early f head on a 2f

[bsmith123]

Welcome to ROCKCRAWLER.COM (Land Cruiser Q&A Feb.18, 1998)


"With the earlier head, you will have to arrange to supply the oil to the rocker arms, as these heads do not have the oiling galley that the 2F does. An oil line similar to the one employed in the F engine can be fabricated, and the F engine rocker assembly used."

I found this post---- has anyone done this? How did you fab the oil line he refers to

 

[Cruiserdrew]

Why would you want to do this? Just get the correct head run in stock configuration.

 

[IDave]

The reason to do is the higher compression ratio. Domed pistons and a head meant for flat tops.


I would think it would be of limited benefit to go through this, especially given the need to rebore the water passages in the head as they mention in the response. Maybe if you own the machine shop, and have several heads to play with.

 

[Cruiserdrew]

The reason to do is the higher compression ratio. Domed pistons and a head meant for flat tops.


I would think it would be of limited benefit to go through this, especially given the need to rebore the water passages in the head as they mention in the response. Maybe if you own the machine shop, and have several heads to play with.

I understand that, but you can just mill a stock head that actually works without mods. Mark W posted the max amount some time back. Something huge like 0.1 was possible, which seemed like a lot. Lots of extra meat in these old trucks!

 

[FJ40Jim]

How high can the CR go and still run on cheap gas?

 

[Pighead]

How high can the CR go and still run on cheap gas?

What is cheap gas?

 

[FJ40Jim]

87 octane or less.

 

[bsmith123]

work

I see the point on milling the head I also wondered why you would do this instead but if a line for the oil can be refashioned from the F-head parts or a quick trip to the Auto parts?

He said " There is a small bit of work to do at the rear of the head to match the 2F style water passages, but this is very minor."

From that I am assuming he is meaning a dremel job not a mach shop


I'll have to search for some head pics and see what the 2f vs 1f is like--I have the early 1f


If this is doable then you could raise the compression and save the price of the head if you only had a short block or if something was wrong with your 2f heads and you had a 1F head around.

So based on that I'm asking if anyone has done it already and can post up on it to educate me--could come in handy as I have a 1F with a 2F OTW

 

[Mark W]

I no longer feel thee is any need to rework the cooling passages.

you do not put a head for lat tops on a domed piton short block
won't fit

interference problems

the lat model F head worsk on the ealry model 2F... 73/73 F with domes. th '69-'72 F head will work on the later 2F.

these heads can be milled also if you choose

you have to provide for oiling of the early F head rocker arm assembly... the 2F oiled via a drilled out bore in the block and heads which the F had does not have.

Simplest way is to use the F engine rocker arm assembly and put a t in at the il pressure sending port on the oil filter mount... run an external lip up to th head and drill a hole in the lip under th valve cover to run the line in. Other ways to do it too... use th 2F rockers an tap into th pedestal...


Mark...

I have taken these to a (nominal) 9:1 compression and a bit over and run 87 octane with a longer duration cam...

 

[Godwin]

Had an '74 F head on an '85 2F block rebuilt with flat top pistons. Compression was up from stock, in the 190-195 psi range. It ran best on 93 octane. Great low end torque and could easily run 80+ without feeling strained. Mileage was in the 14-16 mpg range.

 

[bsmith123]

74

was it a bolt on mod?---supposedly the later ones were

 

[bsmith123]

from 1F to 2F

While we are at it. IF you bought a 2F shortblock how much of the F motor parts could swap over

water pump, carb, intake, exhaust, flywheel, starter, etc

Would everything swap over? Or would it be necessary to have the 1F heads to use everything?

 

[Mark W]

the 74 and th 73 head is a bolt on for the early 2f... it has an open chamber for use with domed pistons. it will also bolt onto the later flat top piston 2Fs... but the compression gain is less.

make sure that the oiling passages are drilled. some of the earlir '73s had the boss... but it was not drilled.


Mark...

 

[bsmith123]

drilling

Can you drill out the boss yourself or at a machine shop and be good then?

 

[IDave]

How high can the CR go and still run on cheap gas?

Ha! Is this a trick question, Jim?

(Just kidding).

I took the point about the domed pistons with flat top head directly from the guy on Rockcrawler's answer:

"I have two different 2F engine running in this configuration myself. Using the earlier 2F shortblock configuration (domed pistons), and the smallest F engine combustion chambers ('68-'72 with flat top pistons) you will see about 9.0:1-9.3:1 on a stock displacement engine."

Guess that's not right.

 

[Cruiser_Nerd]

I did this for an entirely different reason, but the idea is the same at the head.

I drilled and tapped the head for 1/8" NPT, the fitting is 1/8" NPT x 1/8" compression that I thru drilled so that I could feed the tubing through it to the rocker assembly, the ferrule seals it. Beats the hell out of RTV.

 

[bsmith123]

pic

A pic is worth a thousand words--thanks cruisernerd!

Nice model on your avatar ---got one on my desk at work till I get my engine issues sorted and start rolling around in the real thing!

 

[SouthBostonFJ40]

I have an F head with a 2F block. I'll take some pictures. I have the F intake and exhaust manifolds as well as an F air cleaner secured by two head bolts, but I have a 2F block and engine number.

 

[bsmith123]

SBFJ

Thanks

I'd appreciate that and since yours is a 71 also----perfect!

did it make a noticeable perf diff?

I think this might be a good route if I go with a short block otherwise milling the head would probably make sense.

why did you decide to use the F head?

 

[SouthBostonFJ40]

Thanks

I'd appreciate that and since yours is a 71 also----perfect!

did it make a noticeable perf diff?

I think this might be a good route if I go with a short block otherwise milling the head would probably make sense.

why did you decide to use the F head?

I won't be of much help because I bought it that way. It does run extremely well and it will do 75 mph with ease.