Thinking of rebuilding the '85 2.5 engine. What bearing/piston sizes to choose? (Page 1/4)
cebix MAY 12, 06:12 PM
I'm thinking of rebuilding my 2.5 engine and want to order a rebuild kit but they all require main bearing, piston and rod bearing sizes. How do I tell which ones I need?

Anyway my car is an '85 but just to be sure how can I verify exactly what engine do I have?

Gall757 MAY 12, 06:18 PM
In the States, you take apart the engine, measure things, and then get the rebuild kit.
cebix MAY 13, 06:46 AM

Originally posted by Gall757:

In the States, you take apart the engine, measure things, and then get the rebuild kit.

That's what I thought, thanks.
Lou6t4gto MAY 15, 07:21 PM
until you "Open it up" there's no telling if the cylinders will remain standard, if the Crankshaft Needs to be turned .010/.010. you don't even know for sure if someone else has previously "done it".
cebix DEC 01, 10:32 AM
Thanks for the replies. So I'll have to open up the engine soon and I'm wondering - are there any rebuild kits available anymore? The only company that made these I think was Enginetech but they are all out of stock. Do you guys know where can I get a rebuild kit?
Spadesluck DEC 01, 10:53 AM
These guys have already covered it but I figured I would share my dumb move when I rebuilt my 2.8l. I like you wanted to get a head start and just bought standard rings/bearings but when I took the motor apart it had already been rebuilt at some point. Lesson of the story open it up and then figure out what you need. Less chance to waste money.
Dennis LaGrua DEC 01, 08:25 PM
You will need to buy or borrow a micrometer to measure the crankshaft journals and an inside micrometer to measure the cylinder bores. Compare these to the specs in the service manual. Sometimes everything measures up and a simple hone of the cylinders, a new set of standard size bearings, rings, seals and cam bearings can be used but not always. Be sure to measure the cylinders for taper, out of round and inspect the crankshaft for scores on the journals. The process is more involved than this but it should give you an idea.

" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H

[This message has been edited by Dennis LaGrua (edited 12-01-2018).]

Lou6t4gto DEC 03, 09:37 PM
If you are going to rebuild it, (Being a 1985 engine) make sure it has a roller cam. (1985 was a split year)( you Can install the stock roller cam into the flat tappet block) use a metal gear drive instead of "fiber"
cebix DEC 08, 01:21 PM
Thanks, I will look into that. I'm not even sure the engine is an 1985. It has the pre 87 TBI for sure though.

Anyway back to my latest question - where can I get a rebuild kit? It seems there are only some left on eBay but I'm not sure eBay is a legit place to buy these things.
Gall757 DEC 08, 08:26 PM
e bay would be OK if the rebuild kit has a brand name like Federal Mogul or one of the other brand names in the business like Sealed Power.

[This message has been edited by Gall757 (edited 12-08-2018).]