Compatability question (Page 1/1)
Turbowedge FEB 11, 12:06 AM
So I have a 88 with the 2.5 iron duke and 5 speed. The oil pump gear cast in the crank stripped out therefore no oil pressure. Do not want to try a rebuild this one, question is that is there another plain gm 2.5 that is a bolt in replacement for the duke. Just need this back on the road as a daily for now. Thanks in advance.

[This message has been edited by Turbowedge (edited 02-11-2025).]

82-T/A [At Work] FEB 11, 07:46 AM
I would say yes, however, you're going to be limited by the engines you can put in there as a direct swap because it's an 88. The only motors that will drop right in will be an 87-88. The 87 didn't have the balance shaft, or the oil filter in the bottom. Your best bet is to get a rebuilt or replacement 88 motor.

I've never owned an 88, but are you sure the oil pump gear is on the crank?

My daughter just rebuilt her 1985 Iron Duke, and the oil pump gear is on the camshaft.


Also, you live in Ocala. There's a person with a Fiero yard and a lot of 88s with left over motors that you might try. His name is Villain: https://www.fiero.nl/cgi-bi...bio&UserName=Villain


He doesn't have any of his contact information here, but I know some people have his personal information (I don't keep a contact list so I lost it), but you can PM him, or maybe someone on here can share his info.

There's also Larry Hubert in St. Petersberg that has a lot of 88 stuff too.


But to answer your question, I'd say that you have the best Iron Duke there was, so going to any other year below that would have to be a downgrade, but also... you'd have to swap out other things, like going from DIS ignition to a distributor, etc... so your best bet is to get an 87+ Iron Duke... you can probably get one from a GrandAm or something as well.
Vintage-Nut FEB 11, 10:07 AM

quote
82-T/A:
Also, you live in Ocala. There's a person with a Fiero yard and a lot of 88s with left over motors that you might try. His name is Villain / He doesn't have any of his contact information here



Villain's Phone Number

quote
Villain:
shoot me a line on here or text or call me at 4zero7473935



My shop in florida! by Villain
https://www.fiero.nl/forum/Forum1/HTML/100101.html

Another engine source to check is 'TheMall'

member olejoedad has three good 2.8's for sale; perhaps a 2.4L too...

Contact Brian at 517-554-0452 for information.

[This message has been edited by Vintage-Nut (edited 02-11-2025).]

Raydar FEB 11, 11:52 AM
If you want to stick with a Fiero Duke engine, I would look for an 87.
It has the DIS system, but it uses a regular oil pump and filter. The 88 and later Dukes have the "unobtainium" force balancer and oil pump assembly, which is driven by the trigger wheel on the crank.
(Possibly useful - or useless? - trivia. They both use a crank with the trigger wheel for the DIS. The 87 crank just doesn't drive a balancer/pump assembly. IIRC, I believe that Rockauto sells the same crank for both years.)

89 and later Dukes will likely work decently, but be aware that sometime around 91, they dropped the composite timing gear and went to sprockets and a chain.
The big thing is to make sure all of your accessories will bolt to the block, and that it will fit in the car. Grand Ams and similar platform cars had a different block, that may not be a direct fit. (Try to find a "VIN R" engine.)
82-T/A [At Work] FEB 11, 02:13 PM

quote
Originally posted by Vintage-Nut:


My shop in florida! by Villain
https://www.fiero.nl/forum/Forum1/HTML/100101.html

Another engine source to check is 'TheMall'

member olejoedad has three good 2.8's for sale; perhaps a 2.4L too...

Contact Brian at 517-554-0452 for information.





Correcting Villain's phone number: 4zero7-473-9350

(was missing the last zero)