Building a Carbureted 3F Using 3FE Long Block and 2F Accessories? (1 Viewer)

[4Cruisers]

I've got a 3FE short block from a late FJ62 or FJ80, and am looking at buying a complete cylinder head with valve train from a '91 FJ80. I've got a large stash of 2F engine accessories, including carburetor, air conditioning compressor, power steering pump, water pump, smog pump, alternator, emissions, radiator, etc. I've also got 2 complete FJ60 wiring harnesses. I thought it might be fairly straightforward to build a 3F and get my '84 FJ60 parts vehicle back on the road. I know it's feasible, but is it worth the effort? Any disadvantages to a 3F versus a 2F, all else being equal? My other option is to find another complete donor FJ62 and build a 3FE, but I'm still in the middle of my '86 FJ60 3FE project.

 

[RockDoc]

Here's a thread you should take a peak at:

3FE vs 2/3F carb cyl. head

I have a feeling the carbed intake manifold and injector pockets in the head will not play nice together.

 

[4Cruisers]

Thanks - I took a look at the thread (I had to read through the posts a couple of times to try to understand it all). The thread seems to be mostly about putting 3FE fuel injection on a late 2F/3F head. I'll have to read up more on the injector pockets in the 3FE head. Oh well, at the least, I'll have a good start on my second 3FE .

 

[cruisermatt]

I've pondered the same thing as this many a time... I have the 3FE I pulled out but it's just a long block. I am very worried for the future of long-term 3FE owners when it comes to some of the EFI-specific parts, AFM, ISCV, etc. When that day day comes it will be a three-way fork in the road:
1. Engine swap
2. Convert to carb
3. Buckle down and work towards convert some of the components to more readily available counterparts via adapter plates and remaps of the ECU, etc.

 

[Cruzerman]

No expert here, but it seems like you are going the wrong way. 3F is a smaller displacement than a 2F. Seems like a carburated 3F would be even more anemic than the 2F. And if you put it behind an automatic, I'm thinking very slow.

I want to go the other way and make a 2FE and put it behind my 5 speed.

 

[LAMBCRUSHER]

I think these guys are trying to figure out how to make lemonade from the left overs of a 2fe swap...Cruzerman is right, but he didn't include a turbo in his keyboard build...

 

[LAMBCRUSHER]

seems that the 3F head we all know and love here has much larger combustion chambers than a true ROW carb 3F head. picture a 7.2ish:1 compression ratio from a 3FE bottom and a USA 3F head(as found on later 2Fs)...maybe 7.5ish

 

[FJ40Jim]

Don't buy the 3FE head to put a carb on the engine.
Use the USA 85-newer 61040 head. If there are no other changes, it will drop CR to 7.5. Install flatface SBC valves and mill .030" and CR will be back above the stock 8.3.

 

[4Cruisers]

Thanks, Jim. I'll look into going that route.

 

[LAMBCRUSHER]

@FJ40Jim is full of PRICELESS information...and has just given me another recipe to cook with

 

[60 toy ota]

I would think that people would want to go from carb to efi in terms of parts being nla, that's one of the many reasons I 2fe'd. Putting my 2f head on the 3f block it seemed there was some interference between the water pump and t Stat housing, but again, it's been a while and the head was pre 85

 

[LAMBCRUSHER]

Don't buy the 3FE head to put a carb on the engine.
Use the USA 85-newer 61040 head. If there are no other changes, it will drop CR to 7.5. Install flatface SBC valves and mill .030" and CR will be back above the stock 8.3.

how can I "like" this post again???

 

[LAMBCRUSHER]

@FJ40Jim , do you know the CCs of the 74 F.5 head
/ I was told when I got it, it was smaller chambers than a 2F open chamber head, but I haven't CCed it, or found the spec for it posted... would using the small open chamber head be a total waste of time to doll up to use with a 3F block compared to the 2/3F closed chamber head with a valve and mill job?

Also, do you know if a 3F carb bowl will bolt to a 2F carb throttle body?

 

[RockDoc]

would using the small open chamber head be a total waste of time to doll up to use with a 3F block compared to the 2/3F closed chamber head with a valve and mill job?

I think you'd end up with low compression. The F and 3F have very similar displacement, but you'd get flat top pistons and open chambers intended for domed pistons (i'm pretty sure the "1.5F" has domes....). Maybe it would suit a turbo? (if only I knew a guy with a few spare 3FEs and a possibly locked up 1.5F in a FJ55 that might become a farm use "side-by-side"..... )

 

[LAMBCRUSHER]

you been in my garage?

 

[RockDoc]

I hereby trademark the "3.5FT"

 

[RockDoc]

you been in my garage?

You must have the same Lego pieces I have in my shed and yard.

 

[LAMBCRUSHER]

I hereby trademark the "3.5FT"

don't challenge me with a good time...

 

[FJ40Jim]

@FJ40Jim , do you know the CCs of the 74 F.5 head
/ I was told when I got it, it was smaller chambers than a 2F open chamber head, but I haven't CCed it, or found the spec for it posted.

Dunno the number, but the F open chamber is visibly smaller than 2F open chamber.

would using the small open chamber head be a total waste of time to doll up to use with a 3F block compared to the 2/3F closed chamber head with a valve and mill job?

Dunno about a waste of time, but it would make more sense to do the machine work to a close chamber F head for a 3F block.

Also, do you know if a 3F carb bowl will bolt to a 2F carb throttle body?

Haven't actually tried it, but the main body looks identical between the 2 types of carb. The T-body is different on the manifold bolt pattern, but everything above that looks unchanged.

 

[LAMBCRUSHER]

...

Dunno about a waste of time, but it would make more sense to do the machine work to a close chamber F head for a 3F block.


...

Thank you for your input!

in the above quote from your reply, did you mean closed chamber 2F head, or do you mean to drill the oil galley into an earlier closed chamber F head?