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Anyone with experience using a 4ze1 flywheel on 4fb1?

Posted: Thu Jan 21, 2021 5:50 am
by BigAl51
At the risk of dropping a turd in a punch bowl, has anyone tried using a 2.6l flywheel on a 1.8l diesel to get a larger clutch surface?

I am trying get my project back in action, but I am having bolt pattern issues with the flywheel I have. I have an 8-bolt flywheel, but I need a 6-bolt flywheel. While checking out the bolt centers last night (they are the same by the way), I saw an old 2.6l flywheel I had from an 1989 Amigo. I placed it on the crank just to see how it would fit, and it went on just like the 1.8l. The bolt centers appear to be the same. I was able to start two bolts that were opposite each other by hand. I measured the ring gear stand-off from the back of the engine with a tape measure, and they were pretty close if not the same (did not have my glasses with me at the time).

So here is the main question - Since I will have to get the bolt pattern changed on the 1.8l, why not just use the 2.6l flywheel instead of cutting up a perfectly good, rare 1.8l flywheel? If it works, it would give me access to parts that are more readily available as well as a larger clutch surface.

Any insights are welcome,

Al

Re: Anyone with experience using a 4ze1 flywheel on 4fb1?

Posted: Fri Jan 22, 2021 4:37 am
by puttputtinpup
This would be a great question for Jerry Lemond. You can contact him at jlemond@bellsouth.net
Or call at
678-910-1023

Re: Anyone with experience using a 4ze1 flywheel on 4fb1?

Posted: Sat Jan 23, 2021 9:11 am
by BigAl51
Thank you for the reply. You are the first person to give any input, and it is much appreciated. I will definitely try to get in touch with Jerry.

Thanks again,

Al

Re: Anyone with experience using a 4ze1 flywheel on 4fb1?

Posted: Sun Jan 24, 2021 5:20 am
by gruff54
It probably doesn't relate to your application, but Jerry told me that someone had used a 4ZE1 flywheel on a 2.8L 4JB1T diesel. Much quicker spin up. Not sure how similar the 4FB1 is to the 4JB1T, but I'm curious.

Mike

Re: Anyone with experience using a 4ze1 flywheel on 4fb1?

Posted: Wed Jan 27, 2021 4:42 pm
by BigAl51
Sorry Mike,

Just getting back to this. I emailed Jerry, and he said it should work. I have an old 2.6 flywheel, but it has some serious heat cracks from the PO. I just picked up a new flywheel today, and I am going to an automotive machine shop to see what they would charge. Local shop in my town said like $275. I got the feeling he told me that so I would go away - it worked.

This is gonna take some time on my part, but I will try to update this as I go along.

Re: Anyone with experience using a 4ze1 flywheel on 4fb1?

Posted: Mon Feb 01, 2021 1:45 am
by diesel07
Hello, Put the 1.8 and the 2.6 flywheel back to back to see if the ring gear teeth match, diameter and tooth spacing, If it does bolt and go if not here's what I did- I had to turn the teeth off my 2.6 flywheel making a bushing for a c223 ring gear spot weld in 6 places around the inside. Also get a measurement from the backing plate on your engine to your flywheel ring gear so you can properly position the diesel gear on the 2.6 flywheel. I used a c223 ring gear because the c223 starter is more common the c223 may not work in your case you may have to use the 4FB1 diesel ring gear. It works perfectly on my 3.1 4JG2 (88) spacecab 4x4

Hope this help
Matt

Re: Anyone with experience using a 4ze1 flywheel on 4fb1?

Posted: Mon Feb 01, 2021 1:53 am
by diesel07
Hello, Put the 1.8 and the 2.6 flywheel back to back to see if the ring gear teeth match, diameter and tooth spacing, If it does bolt and go if not here's what I did- I had to turn the teeth off my 2.6 flywheel making a bushing for a c223 ring gear spot weld in 6 places around the inside. Also get a measurement from the backing plate on your engine to your flywheel ring gear so you can properly position the diesel gear on the 2.6 flywheel. I used a c223 ring gear because the c223 starter is more common the c223 may not work in your case you may have to use the 4FB1 diesel ring gear. It works perfectly on my 3.1 4JG2 (88) spacecab 4x4. One more thing, make sure your flywheel bolts are the correct length and don't bottom out in the crank.

Hope this helps
Matt

Re: Anyone with experience using a 4ze1 flywheel on 4fb1?

Posted: Mon Feb 01, 2021 5:49 am
by BigAl51
Thanks for the input diesel07. It is greatly appreciated. At least I know I am on the right track.

The stand-off from the backing plate to the ring gear was pretty close to the 1.8l flywheel (tape measure and no glasses - but should be within a 1/32"). If O'Reilly's website is correct, the 1.8l ring gear has like 142 teeth (if I remember correctly) and the 2.6l has 115. The 4fb1 and 4ze1 both have 9 teeth on the starter (according to O'Reilly again). the main difference is the gear reduction for the diesel and power rating (2kw for the diesel and 1kw for the 2.6). I am going to try putting it together and see if it will crank with my 4fb1 starter (with how this is going, I am not betting on it).

I was finally able to find a machine shop to to the re-drill the way I wanted it done, and I dropped the flywheel off Friday of last week. I have to go to another machine shop in another town to get it re-balanced when I get it back (if they can do it). I hope that in a couple of weeks I can give an update on if it works and what was done. All I know is every time I walk into a machine shop around here, my wallet starts to whimper.

Thanks again and fingers crossed,

Al

Re: Anyone with experience using a 4ze1 flywheel on 4fb1?

Posted: Mon Feb 08, 2021 7:28 am
by BigAl51
Alright... here is an update for anyone interested. I was able to get the bolt pattern modified (6 on 60 degrees instead of 8 on 45). They share the same bolt center spacing and center hole diameter, so that is a plus. I did a quick bolt on to see how it fit (which it did thank the lord). After the test fit, I got anxious to see if it would actually turn with the 1.8l starter, so I bolted the tranny on and mounted the starter. Long story short, it works fine. the teeth line up and it turns easily.

If I can figure out how to attach a video, I will try to upload it later today. Sorry for the rotated view.

Re: Anyone with experience using a 4ze1 flywheel on 4fb1?

Posted: Mon Feb 08, 2021 9:37 am
by JoeIsuzu
That's great news, thanks.

Unfortunately, video attachments don't go here. If you can post it on youtube and get the "short" link (click the "share" icon), please post that here.

Jack

Re: Anyone with experience using a 4ze1 flywheel on 4fb1?

Posted: Mon Feb 08, 2021 12:14 pm
by BigAl51
Thanks for the heads up Jack, and I will give it a shot as soon as I get a chance.

Al

Re: Anyone with experience using a 4ze1 flywheel on 4fb1?

Posted: Mon Feb 08, 2021 12:17 pm
by BigAl51
On a side note - if you have the 8-hole crank, you shouldn't need any flywheel modifications to make it work. Should just bolt and go.

Al

Re: Anyone with experience using a 4ze1 flywheel on 4fb1?

Posted: Tue Feb 09, 2021 11:24 am
by BigAl51
Here is a quick vid of the 4fb1 cranking with the 4ze1 flywheel. You may notice that there is a pair of vise grips helping to hold the starter on the bellhousing. At some point, I must have stripped the threads so there is another work-around that I have to do.

The vid is only 5 seconds, so be ready for it.

https://youtu.be/6UNGhiEe0l0

Al

Re: Anyone with experience using a 4ze1 flywheel on 4fb1?

Posted: Fri Feb 19, 2021 10:02 am
by DieselJeep
This is one respectable experiment.

My offhanded thought:

I have been casually pondering both the unobtainium 4FB1 manual flywheel for a few years. And a custom machined flywheel would run several hundred dollars as a guess. Even at my very inexpensive Mennonite owned machine shop.

Also a larger friction area. Clutch slippage at very low 4-5psi is preventing me from bigger tuning gains, and parts upgrades.

That 4FB1 is going to have amazing acceleration on the street. Like you added forced induction. Without the extra metal "bell" for inertia storage mass, and probably 10-15 lbs , 30%-50% off the flywheel that thing will zing like a hot gas 4 cyl, if timing and fuel are well tuned, and the motor isn't hurt or excessively tired. Rotational mass reduction is the biggest gain for acceleration.

Why I snicker at these kids with huge 80lbs each rims. Worse on a neglected, ill maintained pile, and a tired high mileage 4 cyl... I cringe inside lol

This comes with a few negativities though.
The very fat "thumps" of the ignition event in a 4 cyl diesel, and the inherent strong pulses of the "swing" of a 4 cyl diesel single plane crank are gunna be...whew. She might be a jumper and doing the tango, with as light as a motor they are. I'd have a motor hoist attached to her so she don't tango right off the blocks and flop over.

Might explore mecedes benz liquid filled engine mount isolators. Pricey but are supposed to massively help with diesel idle smoothness.

Hope to stonk that flywheel is zero balance? Probably IS though. Might want to be certain, as few ounces off in the worst place can fry a motor.

And without the mass of the ring storing inertia, off idle "torque", ie the ability to trundle at idle will be VERY reduced. Maybe a non issue in street car, possibly might in a truck application, depending on use. Definitely unwanted in a cj5.

SO expect some loss of economy. as more throttle will be required to stay at cruise, with loss of stored inertia and drag being more of a factor to fight vehicle momentum. The 4FB1 is crazy thrifty, but I estimate noticeable loss. But if you dont have a reference you wont notice. They are crazy thrifty.

A bunch of money balancing Isuzu diesel cranks and rotating assembly ALWAYS makes for very improved idle, acceleration and outright power.

Very best of luck with the project. Look forward to watching the progress!

Re: Anyone with experience using a 4ze1 flywheel on 4fb1?

Posted: Mon Feb 22, 2021 6:51 am
by BigAl51
I was worried about the change in weight at first, but I did have it running before I went too far into this. I wanted to make sure the engine would run before putting a lot of money and effort to get installed just to have to pull it out and start over. Since I had to change the timing belt, I prelube the engine by using an impact and socket to turn the oil pump until I saw oil at the top.

I used the flex plate from the automatic that it was mounted to to get it running. At some higher revs, it did vibrate some, but nowhere near what I thought it would. I think it will be fine with what I want to do with it. The 4ze1 flywheel is way more substantial than that combo. Here is a shot of the flex plate and counter weight that was on there originally (apologies for the rotated image):
flexplate.jpg


I have had this engine for quite a while (just sitting). Here is a vid of the engine running on the flex plate after sitting for like 8 years:
https://youtu.be/bCNBjhmahIo