Isuzu 4FB1 overhaul/resto-mod for CJ5 conversion

[DieselJeep]

how did you make the cool CAT logo badge?

It is a real "Caterpillar" aluminum badge from a Cat 3406. Cut down to read "Cat". I ground off "isuzu" and epoxied it to the valve cover before I painted it.

[bthood]

nice!

[FiatSpider2]

This is one of the few forums that does not allow image uploading so without an image hosting account I am unable to even post an old picture since I do not support cloud or other image/file sharing schemes especially if a fee is required.

We are strictly against the use of image hosting accounts on here because pictures disappear. Scroll down to attachments and you can attach photos. Message me if you need further assistance

Yes, exactly what Halden said.

Jack

Sorry about that I may have confused this board with another since the image button does not bring up the file browser window.

Nice that it supports drag and drop.

Here's a pic of the little car.

[bthood]

By chance did you make a temp plate for the turbo manifold did you?

[DieselJeep]

Make a thread about your car. It's neat. And judging by what my turbo'd 4fb1 does in a 4x4 barn door on 31" tires with 3.73 axles, I can imaging that uber light thing is darn zippy.

I bought an "Apex" chinese complete gasket kit available at RockAuto. Had a local machine shop scan the exhaust gasket, and water jet it out of 3/8 cold rolled plate. Then used 1.5" OD t304 mandrels for the primaries, with a 3/8" cold rolled plate with a 40MM/1.5" hole for the turbo flange.

I could make more, as I had the shop make me two, and they have the pattern.

But I highly doubt any 4FB1 owner would pay me what I would need for my fabrication time. It took a LOT.

If there were interest I could sell the exhaust flanges, but I would have to ask at least $50 apiece.

[DieselJeep]

A pic I took a few days ago. Still much work and refinement to be done, but the "big money" projects are all done.
Sorry still no vids.

[FiatSpider2]

The Spider has a 4.10 rear axle with 13 inch tires so it pulls more like a tractor and you could almost start off in second or third gear. It has a front load diff so changing out to a better ratio is fairly easy however the only other choice I've found so far is a 3.90. The cars the 4FB1 came in I believe had a 3.36 diff and also rode on 13 inch tires.

The 3.90 is available in limited slip and like this its all shimmed and ready to go.

[DieselJeep]

I didnt take pics, so you'll have to trust me.
Over the last few weeks, I completely went through and re-engineered the cj5's hydraulic clutch system. It did EXTREMELY WELL for 6-7 years of service. Especially for being relatively "thrown together". However, the organic stock type friction material in such a small stock chevette friction area would slip horribly, and I couldn't get above 4psi boost.
So, I sent off my friction plate to Kentucky Clutch, and for the same price as some wanted to reline with organic, I got a Kelvar/ceramic hybrid friction plate. HIGHLY RECOMMEND them!
Of course, a complete degrease, inspection, and repaint in Genuine Cat yellow for bellhousing, T5 5 spd transmission, and D300 transfer case.
I engineered a 3/16" line, buying new 12mm and 7/16" tube nuts. These both being odd sizes for the 1996 Isuzu Rodeo slave cylinder, and 1982 Jeep master cyl. This eliminated the 1/4" line I originally used, with what tube nuts corner parts stores could get me. It worked, but was stiff, and very semi truck feeling, with little pedal feathering.
I also plumbed in a new factory Rodeo clutch slave hose.
The original throw out bearing I had used was a cheaper '82 or so Jeep bearing. The contact surface was very flat. So, I found a better brand with a rounded outer edge. This required using a different length slave pushrod, to improve slave stoke "centering" of the piston during travel.
However, after a few head scratching moments, pondering, experimentation, and pulling the trans out a few times, I have a clutch that "tightens up" at 2" pedal depression, completely releases at about 5", and bottoms out at 7". And is so easy to use, my petite wife can release the clutch with her hand. Which was the goal of the extra time completely redesigning and engineering!
And, it holds 12psi boost perfectly!
Think Ill experiment with a smaller turbo. Its absurd, and scares the wife.

[DieselJeep]

Was a chilly ride to work last week.
New set of axles, bunch of parts.
Pics of all that shortly.
4fb1 in service 10? years, and tens of thousands of miles.

[puttputtinpup]

Love it!

[DieselJeep]

After 4 years of off road bumps my original turbo manifold cracked.

So, a no holds barred no expense spared, sch40 and 3/8" bar stock solid stainless turbo manifold. Ceramic coating and header wrap before installation. Should never crack.

[DieselJeep]

No expense spared.
Ten years later and I'm still developing the 4FB1.

[ArtieM]

After 4 years of off road bumps my original turbo manifold cracked.

So, a no holds barred no expense spared, sch40 and 3/8" bar stock solid stainless turbo manifold. Ceramic coating and header wrap before installation. Should never crack.
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Looks great! What size pipe did you use for the runners? I like that you added a support bracked from the get go on this revision

[DieselJeep]

Thank you.
I used 1.5". It is bigger ID than what I used before. But it spools nicely. Even though I didn't bother with wrap this time.

[DieselJeep]

Thank you.
I used 1.5". It is bigger ID than what I used before. But it spools nicely. Even though I didn't bother with wrap this time.
I also added a stainless vertical stack and rain cap.
Here's the wife and I on the shakedown after a month of work