3F-E or 2F advice (1 Viewer)

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Alex Waddell

SILVER Star
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Jan 11, 2020
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Location
tucson,az
I have a 3F-E that I was planning on putting into my 68' FJ40.
I only bought it because I couldn't find a 2F with good compression and the 3F-E was at a good price and the compression ran around 140-150 psi.
And I have put some work into it
- found a bell housing, rear motor mounts, flywheel
- throw out bearing, clutch slave, clutch & pressure plates
- new rear main seal, lifter cover seal, distributer o-ring, oil pan & intake gaskets
- Bought an ECU, AFM, Engine & Cowl harnesses and I have gone through & identified & tagged most of the connectors.
- New EFI fuel pump & filter
- New exhaust down pipes
- New speedometer pulse generator for the 3F-E
- New water pump & thermostat

However I have an opportunity to pick up a complete 2F motor that may be in good condition, However I have not done a compression test on it yet.
I bought the 3F-E and associated parts at good prices so I can likely sell it all for what I have in them.
The 3F-E conversion has advantages with higher HP, smoother running, & higher RPM.
However on the negative side, the 3F-e is more of a science project and will take more time to sort it all out.

However the 2F could cut out a lot of time out of my project.
And I could pick up the 2F for what I could likely sell the 3E-E for or less.

I am down the road pretty far with the 3F-E but do you think it would be a good idea to change course at this late date?
What are your thoughts about performance, fuel economy & project value between the 3F-E and the 2F?
 
Others may answer, but the 3F-E is better balanced and the factory EFI works nicely. The 2F might have more low-end grunt, but both would serve you well. I would stick with the 3F-E and get it all dialed in. I have an FJ62 with that engine and while underpowered, it's smooth and rock solid at 260K miles. It would move an FJ40 a bit better. I love 2Fs, too, but they would benefit from EFI (of some sort) to avoid carburation issues on hot days. That would be less work, but maybe less interesting than a 3F-E powered FJ40. It sounds like you have most of what you need, so I'd stay on the current path.
 
Steve’s advice is always rock solid. But if the 2f is a good one and you would like your 68 to appear close to stock it would be a fine option. I retrofitted an 86 2f in my 12/68 Fj40. I did what was called dumbing it down by using the f intake and a 73 Aisin carb and an f breather. It looks close to original but is a lot better. I kept the oil cooler and used the fj60 distributor. It drives really nice. My son jdc1 put a sniper on our 72 with an 86 2f if you really want fuel injection
 
As for fuel economy, we are driving a heavy brick no engine save for a Fred Flinstone runner motor is gonna not eat fuel. For performance, my 40 on 31 inch tires cruises comfortably at 60 to 65. I am going to go to 370 gears to drop the rpm and make it a really smooth 65. I will lose a bit of bottom end on the trails but I drive mostly on the roads.
 
Thanks for your good advice SteveH & dizadle.

Since I had not checked the compression on the 3F-E since I bought it, I re-checked it today and I did leak down tests too.
I must not have remembered it right when I said the compression was between 140 psi & 150 psi

Here are the numbers.
Compression - cold & dry (1 thru 6) 150, 150,155, 150, 150, 165
Compression - cold & with oil 160,156,158, 158, 150, 170
Leak down test - cold - 38%, 25%, 22%, 25%, 30%, 15% (note this was the second test after cranking the engine for the compression test)
The first leak down test was much worse before I did the compression tests.
The 38% may improve when the engine is warm. But 38% is still rated low on my gauge.

I am feeling a bit more confident about the 3F-E so I am leaning toward keeping it.
However I will likely test the other engine jut to see what kind of shape it is in.
Maybe I will buy it as a spare.

Thanks again!
 
IMO, that's a very solid 3F-E, compression-wise. I joke that a leakdown test is preferred by mechanics because it makes every engine look bad ;). You might check the oil pressure on the 3F-E as well. I suspect it will be fine.

Having a backup 2F in your garage is never a bad thing, if you can swing owning both.
 
I was told that this engine was only pulled for a V8 retrofit and that it ran fine. I bought it from the shop that pulled it. The 2F was supposedly only pulled for an LS retrofit so it may be in good shape too.
 
Another option is to put together a 2FE, you have the parts, 3FE head on the 2F block. There are posts on it if you want to read up on it.
That's an idea but it would add the cost of two engines. I have read the write-ups on the 2F-E and used it to get the parts I need for the 3F-E. Do you have any experience with a 2F-E?
 
That's an idea but it would add the cost of two engines. I have read the write-ups on the 2F-E and used it to get the parts I need for the 3F-E. Do you have any experience with a 2F-E?

You're correct it would add to the cost because once you've dismantled the engines to swap heads you'll have to replace gaskets at the minimum.

I do not have any experience with a 2FE but I have 2 FJ60s, one with a 2F and the second in which I did a 3FE swap. Low end torque of the 2F over the 3FE is noticeable while the 3FE has the smoothness of the fuel injection. 2FE you'd gain the longer stroke and larger displacement of the 2F.

Fuel mileage is about the same for both engines.
 
Another option is to put together a 2FE, you have the parts, 3FE head on the 2F block. There are posts on it if you want to read up on it.

The 3F(E) is a de-stroked 2F, which they did to get more top-end RPM out of it, at the cost of shifting the usable power band a bit higher in the rpm range also. So the appeal of the 2FE is that you are building a stroker 3FE and getting the best of both worlds - the low-end torque of the longer-stroke 2F combined with the factory EFI of the 3FE. But yeah, quite a bit more work to put it all together and make it work right.
 
I am new to the FJ40 world and with my 85' 22RE SR5 truck, I used gears to get the low end torque. On it, I have a 99:1 crawl ratio but can do 75 on the freeway. I don't know how important the low end engine torque is on an FJ40. I am not building a rock crawler and I wouldn't want to treat it like one. I am planning on building mine up to have all the style and looks and with moderate offroad capability. I have gone to 3.73 diffs so I may be out of the serious 4x4 range anyway.
 
I am new to the FJ40 world and with my 85' 22RE SR5 truck, I used gears to get the low end torque. On it, I have a 99:1 crawl ratio but can do 75 on the freeway. I don't know how important the low end engine torque is on an FJ40. I am not building a rock crawler and I wouldn't want to treat it like one. I am planning on building mine up to have all the style and looks and with moderate offroad capability. I have gone to 3.73 diffs so I may be out of the serious 4x4 range anyway.

I'm running 3.70 diffs, an H41 transmission, an Orion transfer case, and 33" tires. That nets me an almost 80:1 crawl ratio in low-range, 1st gear, and I can still go 75 on the freeway when needed.

But I understand if your build doesn't lean that way - everyone gets to do what they want with their own truck; more power to you.
 
I'm running 3.70 diffs, an H41 transmission, an Orion transfer case, and 33" tires. That nets me an almost 80:1 crawl ratio in low-range, 1st gear, and I can still go 75 on the freeway when needed.

But I understand if your build doesn't lean that way - everyone gets to do what they want with their own truck; more power to you.
My 85' truck is my trail vehicle and has the Arizona pin stripes & a few dents. I can't imagine putting a nice paint job on a 40 and treat it like my truck.
I get 99:1 fron an R151F 5-speed (4.31 1st gear), 4.7:1 Marlin crawler gears in the t-case, & 4:88's in the diffs (fully locked) and 33" tires.
 
Having a backup 2F in your garage is never a bad thing, if you can swing owning both.

This is a slippery slope to go down. Made even harder before the old Land Cruisers became so popular. I picked up a 3FE with accessories along with engine wiring and ECU for $200 down in Tucson years ago. Was pulled for a V8 conversion. Still has the A440F adapter plate, torque convertor and starter attached. Have a spare A440F/transfer case with 30K miles been sitting on since the nineties. My FJ62 has less than 125K miles and still runs fine. I closing in on the part needed for a H55F which may or may not happen. Have tubs full of spare FJ62 parts. Two tubs I bought for $75. Those were loaded with expensive parts. That's just my tiny collection compared to 40 series parts which is my real passion.
 
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This is a slippery to go down. Made even harder before the old Land Cruisers became so popular. I picked up a 3FE with accessories along with engine wiring and ECU for $200 down in Tucson years ago. Was pulled for a V8 conversion. Still has the A440F adapter plate, torque convertor and starter attached. Have a spare A440F/transfer case with 30K miles been sitting on since the nineties. My FJ62 has less than 125K miles and still runs fine. I closing in on the part needed for a H55F which may or may not happen. Have tubs full of spare FJ62 parts. Two tubs I bought for $75. Those were loaded with expensive parts. That's just my tiny collection compared to 40 series parts which is my real passion.
You got a great deal on the engine and the wiring. My engine set me back $800 and had to buy the wiring separately. I will certainly keep you in mind for 3F-E parts when I need them!
 
It's a good idea to stock some spare parts like TPS, AFM, IACV, distributor, coil, igniter, COR, EFI relay, start injector, and the various temperature switches/sensors for the efi. That way you can buy at a good price, not when you need it. The wiring for the 3fe is not bad. The EFI is reliable until it isn't then troubleshooting can be difficult.
 
It's a good idea to stock some spare parts like TPS, AFM, IACV, distributor, coil, igniter, COR, EFI relay, start injector, and the various temperature switches/sensors for the efi. That way you can buy at a good price, not when you need it. The wiring for the 3fe is not bad. The EFI is reliable until it isn't then troubleshooting can be difficult.
Thanks and I will keep that in mind.
I have a spare igniter, AFM and a few other parts.
I have done a lot of debugging on my 22RE using the engine codes that the ECU throws.
Have the codes been useful debugging the 3F-E for you?
 
The difference in power between the 3fe and 2f is just compression, but the 3fe looses some torque down low. The 3fe head also flows a tad better afaik but I don't know it it's enough to brag about. I would lean toward just shaving the head on the 2f to bump compression, install a nice reground performance camshaft. That should put you ahead of a 2fe power wise.. Eventually install a sniper maybe, the sniper is far more advanced than the old 3fe efi.
 

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