'88 FJ-62 Threw a Rod, Rebuild 3FE or 2FE? (1 Viewer)

[60Works]

Hi, All.

Another puppy followed me home. This one is a reasonably clean, royal blue '88 FJ-62. Saw it on the side of the road with an oil slick leading to it. Threw a rod through the pan and shattered the block. Commiserated with the distraught owner for a while and made sure he had a tow coming. A couple of months later he decided it wasn't worth fixing and would I be interested. Well, of course. I keep buying more of these beautiful trucks (even the ugly ones are beautiful) thinking I will fix them and sell them but somehow I never sell. They just keep accumulating and I love them all for different reasons. (Admitting you have a problem is the first step... )

So, this 62 needs an engine. It's not going to be a V8 or a diesel swap. I'll either build up a 3FE or a 2FE. I have both short blocks. Both will need to be rebuilt. I expect overhaul costs to be fairly close. The head was recently overhauled and replaced on the tired short block. (This seldom works for long but is often done to try and save money.) 250k miles on the ODO. Because of the catastrophic and near instantaneous failure I expect the top end was neither starved for oil nor poluted with debris and is still intact. I'll check it but figure the odds are good.

The 2FE craze of 2015 seems to be past us and now there are now lots of 'kits' in the classified from mudders who started down this path and later opted out. We do seem to stampede towards the 'next big mod' that (we think/hope) will make our old trucks perform like newer models. Often we return to OEM roots once we've tried an improvement only to discover that Mr. T was way ahead of us. Over the years I've discovered that there are very few mods that are pure gains. My most reliable Cruiser is the one that I haven't altered anything except the radio.

For the 2FE:

Is there any real power/torque benefit that would make it worth the hassle of an experimental engine? Yes, torque would improve with the longer stroke but the 12% loss in horsepower from the lower RPM would offset the torque gain. This will probably be more of a DD than a trail rig. The H440F will remain. It was rebuilt 60k miles ago. Would anyone want a 2FE, or will it decrease resale. Since it's a 62 there aren't any wiring mods. The accessory mods, belts, radiator fan shroud, and exhaust would have to be resolved.

Thoughts from anyone who's actually built or driven a 2FE?

Thank you!

 

[gt7058a]

1UZ?

 

[cruisermatt]

If you have a 3FE short block on hand you can easily have it swapped in, with the rebuilt head that’s on the truck, in a weekend. Enough said.

 

[gt7058a]

I’m just saying that if you have multiple 62s and already one with a 3FE, it might be a good opportunity to have something more interesting like a 1UZ.

 

[RockDoc]

The 3FE would be easier.. that said, I built one 2FE in 2009/2010 for a 62, and put a second together for a 55 last year despite the fact I had 2 solid 3FEs on hand. Does that mean it's the right call for you?

I'm not sure where the idea of a HP loss with the 2FE comes from, but it doesn't match my experience.

 

[60Works]

If you have a 3FE short block on hand you can easily have it swapped in, with the rebuilt head that’s on the truck, in a weekend. Enough said.

I have both 2F and 3FE blocks which will need to be tore down and rebuilt. I'm trying to decide which short block to deliver to my machinist. The easiest path is the 3FE. I'm asking opinions about whether the 2FE is enough better to be worth the considerable effort of modifying the truck.

There isn't a wrong answer.

 

[RockDoc]

Not a stock bolt up, but I saw 20% improvement in 0-100km/hr and just under 40% improvement in 80-120 going from a solid 3FE to a built 2FE.

Help me plan for a 2FE

18-19 at sea level. I pull 14 at 5200ft.

forum.ih8mud.com

I've had that balanced engine to 5000 rpm without any fuss.

 

[60Works]

Thanks, Doc. Was that with a manual trans? I've read your thread but it's been years ago. I'll go through it again. IIRC you put a lot of TLC into porting and balancing. Even made silicone molds of the intake tubes.

This wouldn't be so fancy. Balancing the rotating mass probably but the rest left stock. I'm not nearly as fast as Matt.

 

[RockDoc]

In the 62 it went in front of a A440f with the extreme valve body. In the 55 in front of a SM420 4-speed. The one in the 55 saw milder porting/air flow work with no coatings or balancing, but still makes me smile when I lay into it in 2nd gear.

I hope more folks who have done a 2FE will post their thoughts, but I know I've been happy.

 

[captain75]

If time is not a concern, I highly recommend the 2FE. Real world example: pulling mountain passes in 5th gear.

 

[hjdca]

One question - if you can build a 2FE to have more hp and torque, why not build a 3FE to also have more power. What is the issue ? Also, note, in some states, like California, a post 1975 car requires permission to swap in a different model motor for registration. In general, this permission is only given for new model motors that have better stock smog grades. So, if the car needs to be smogged in one of these states, a knowledgeable tech. guy may nail you. Based on this, I believe your LC will be more valuable with the original model motor, and if it is been rebuilt and makes more power with the stock EFI, all the better.

 

[OSS]

I agree with @hjdca . If you plan on seliing it one day, that custom Frankenstein 2FE won't be doing you any favors. And agree with the "illegal" engine swap if the new owner needs to smog it - it won't pass no matter how clean the exhaust is.

 

[FJ60Cam]

The reason the 2FE works so well is that you are adding some displacement, but also drastically increasing the compression (due to the much smaller 3FE combustion chamber). If you bore the 2F block out all the way, you'll gain almost 500cc of displacement, and be somewhere in the range of a 9.5:1 compression ratio. This will net a huge improvement.

 

[60Works]

Thank you all for your thoughts.

This 62 (which I'm calling Isabel) will get a simple replacement 3FE. She's a clean enough truck that she will likely be around a while, so no experiments. Plus, this one I'm actually likely to sell and I heartily agree with your posts that the 2FE would probably detract from her appeal to most buyers.

I'm still very intrigued with the 2FE concept but it needs to go into a more 'experimental Cruiser. Maui is my most likely candidate. Along with a H42 and a Toybox if I can find one. He's almost back on the road BTW. I need to update his thread.

Thanks again,

 

[SteveH]

We need pix. How do you find a fairly clean FJ62 in NH? Did it spend most of its life elsewhere?

 

[LAMBCRUSHER]

If I had a good 2f bottom, I’d consider the striker... that said, if I had a choice, I’d rebuild the square block... the short stroke revs higher....

 

[LAMBCRUSHER]

3fe

 

[RockDoc]

If you ran equally balanced/built 2F (or 2FE) and 3FE engines side by side, I would put money on the bottom end of the 3FE failing at a lower engine speed.

Some details as to why from when I was working on my 2FE:

Stolen from Matt's thread, a comparison of piston/rod geometries between the 2F and 3F:
View attachment 324926
View attachment 324926

The strong points of a 2F are in the bottom end. Longer stroke, longer rods, taller, more stable pistons, IIRC a stronger crank. The bottom end of a 3FE is somewhat weaker. To shorten the deck the geometries were changed. On top of the shorter stroke it also has a much short rod and a shorter piston. The shorter rod means greater a greater maximum angle with respect to the centerline of the bore, and the shorter piston is less stable. Additionally, on a 3FE at bottom dead center the entire piston skirt has dropped out of the bore, IIRC, the piston stays completely within the bore at BDC on the 2F (I'll be able to check that in a couple days). *edit* A portion of the skirt also drops below the bore on the 2F, but it is slightly less in absolute amount, and significantly less in terms of proportional length than with the 3FE, since the 2F piston is much taller.

The strength of the 3FE is in the top end. The head has a tighter combustion chamber, the exhaust ports are bigger, the intake manifold and exhaust manifolds are both a more smooth flowing design than on the 2F, and of course you have a multiport fuel injection system, with all the engine management and fuel mixture benefits that come with it.

Compared to a 2F, you get better fuel management, and I would think an engine more suited to higher revs with the improved intake and exhaust. Compared to a 3FE, you get more low end grunt because of the extra stroke length (my 3FE doesn't really come alive till ~2500, but is strong in the 3000-4000 range) and you get a bottom end that while heavier, is supposedly stronger and better able to handle revs in the 4000-5000 range.

The 60 series trucks are well suited to fit a 2FE, since the 60 came with a 2F and was designed to accomodate the extra 2" of engine height. In a 60 or 62 with a 2FE, apparently the top of the intake manifold just rubs on the hood liner. With the 80 series trucks, I understand that underhood clearance is an obstacle for fitting a 2FE, you would either need a body lift, or a modified hood to get the clearance.

HTH

Showing the extent to which the piston skirts drop out of the bore at BDC on the 2F bottom end.

.... and on the 3FE. You can see that the pistons drop out greater portion of the shorter piston height. Sorry for the crappy pic, it was taken with the camera upside down underneath the block with little space...... best I could get.

 

[Haggis]

Great /informative thread. Anybody use the outfit Mosley Motors for a rebuild? I hear they can give the 2F a bit more kick. I'm getting near the rebuild point and refuse to put anything GM in my rig and don't want to spend 25K for a 2.8 Cummins transplant.

 

[NeverGiveUpYota]

Agreed w/ above, VERY informative esp from @RockDoc. Did you build a 2FE.... ignore me, I clicked on your name in the post and found your build. Will check it out.