HELP! 2.8 or 3.1 block

[jt350]

I'd drop in the whole good 3400, much better to start off with than the short block you have now. The 3400 has the correct CPS hole.


Depending on the year of your Beretta you may need a different front mount, daveycav90 on v6z24.com sells them. There are also some other random things you'll need but it's not a hard swap at all.

Yea i do still have one of them mounts and other parts to do swap that i was going to do before i had the turbo.I was hoping if i could get the cps problem straight i could use my turbo set up off my 91 3.1. I would jump on the 3400 swap if i had exhaust to work for the turbo flange though with the short block i would prolly have to lower compression some.?maybe cam choice?

[Superdave]

I'd drop in the whole good 3400, much better to start off with than the short block you have now. The 3400 has the correct CPS hole.


Depending on the year of your Beretta you may need a different front mount, daveycav90 on v6z24.com sells them. There are also some other random things you'll need but it's not a hard swap at all.

[jt350]

3400 won't need the external trigger, it's set up just like your 3.1 and even has the exact same crank.

Are you talking full 3400 swap wont need ext. trigger? I have 2 full 3400 eng.'s 1 is out of a 2000 venture(known to be in good shape)and other i was told was out of a 2000 lumina (?) it is in my 95 beretta now but has head problem.Remember my 3.1 short block with the (what looks like) 2.8 pistons does not have the hole drilled for crank sensor or has the notches on crank for sensor pickup. Also i have a fresh set of 3.1 heads that i orig. going to use.

[Superdave]

3400 won't need the external trigger, it's set up just like your 3.1 and even has the exact same crank.

[trotterlg]

Think they are iron head pistons, here is a picture of my block (3.1 with iron head pistons) Larry

[jt350]

I did check crank #'s and they are the same. 881 or 981.3.1 Below is a better pic. of pistons. Also would it be easier to do 3400 swap with the external crank sensor or get machine shop to drill hole for cp sensor. I have a spare 3400 eng. but needs heads gone over.I did kinda want it stock looking.Also fuel economy is not a worry but power is.

[23TrackroadsterV6]

A couple of years ago, I bought what was supposed to be a rebuilt S-10 2.8 engine off of Craigslist, but upon closer inspection, it turned out to be a 3.1 from an Isuzu. If I had been going to use it in an S-10 or Camaro, I would have been upset as the starter location and engine mount location would have made it almost impossible to use for that application. But since I intended to put it in a street rod, and the price was "right", it just made it a little more difficult to fab engine mounts.

[trotterlg]

Isuzu 3.1 also has the starter in same location as FWD applications and it is RWD. It also has FWD motor mount pads.

Yes, an it also has the iron head pistons in it, so that may be what you have. I think the Jeep is the same thing. You could just put some aluminum heads on it with a large overlap low LSA cam to make use of the compression and have a really nice little engine. Larry

[23TrackroadsterV6]

Isuzu 3.1 also has the starter in same location as FWD applications and it is RWD. It also has FWD motor mount pads.

[trotterlg]

Fiero uses a FWD starter location. (to the left of the flywheel when looking at the engine from the flywheel end) Larry

[Superdave]

With the stock cam they'll clear but you are going to have some really high compression.

2.8 Iron heads used 0cc flat tops, 3.1's had a 12cc dish. yours look like the 12cc..

If that's the case then;
.040" head gaskets (Stock thickness for a Gen 1), 11.88:1
.060" head gaskets (Stock thickness for a Gen 2), 11.14:1


You can run that high with good tuning and a stock cam, however i'd go with something a little bigger like a 260 grind from Delta or maybe WOT-Tech can get you a decent custom grind.

It'll have more torque than your current engine and if you can get the tune really dialed in you may get some better gas mileage out of it.



That engine would be ideal for a stock swap into any 86 or older FWD GM as a replacement with iron heads, and it should work as well on a Fiero. The only thing i can't remember is if the Fiero's starter was in the RWD or FWD position. They do run iron heads stock though. There is also some early 90's Lumina Vans that had a FWD Iron head 3.1, that's probably what yours is made for.




If it's fresh and a good quality build, it could be a good candidate for a hybrid using a 3400 top end and a healthy cam. That's a little more work but if you want to go that direction it'll make tons of power.

[jt350]

Thanks for pointing out about the dish in the pistons. i unwrapped short block again today and piston are not dished as deep as my 3.1 pistons. so yea i am believing this is a early fwd iron head eng. Do you know what pistons they used in the early fwd. eng. Will the aluminum head valves hit the shallow dished pistons?I will have to check the crank #'s. Would this short block work for a fiero?THANKS SUPER D. AND TURBO G.( Hey that sounds cool).I guess i got an expensive boat anchor.Anybody got a boat?

What side of the block is drilled/tapped for a starter?





~86 and earlier FWD blocks probably didn't have the CPS hole drilled, 87-94 would. If it's a RWD block then 82-92 would all basically be the same and not have the hole drilled. If it's a RWD block it won't work in you application. The mounting bosses are quite different. There isn't much dish to those pistons either, they look like they're for an iron head application.

Here are some more gen 2 FWD block pictures to help..
Thanks for pointing out about the dish in the pistons. i unwrapped short block again today and piston are not dished as deep as my 3.1 pistons. so yea i am believing this is a early fwd iron head eng. Do you know what pistons they used in the early fwd. eng. Will the aluminum head valves hit the shallow dished pistons?I will have to check the crank #'s. Would this short block work for a fiero?THANKS SUPER D. AND TURBO G.( Hey that sounds cool).I guess i got an expensive boat anchor.Anybody got a boat?

http://www.sdsgarage.com/60degree/Gen2/atkdca4-1.jpg

http://www.sdsgarage.com/60degree/Gen2/atkdca4-2.jpg

http://www.sdsgarage.com/60degree/Gen2/atkdca4-3.jpg

http://www.sdsgarage.com/60degree/Gen2/atkdca4-4.jpg

[Superdave]

Ok, so you have an early FWD block then. The only way you'll know if it's a 2.8 or 3.1 is to measure the stroke or pull the pan and check the casting numbers on the crank.

[TurboGTU]

Superdave is refering to the motor mount bosses. Seems like they mixed parts up on that engine. If those are aluminum head pistons then they are using a iron head engine block and assymbly. Crank trigger will work for obd1

[jt350]

Thanks for the replys! I wanted to make sure of the obvious things before measuring crank. (didn't want to take apart yet)Like block does not have fuel pump hole and starter mount is on front side like a fwd.(Thank you for the pics.) The dish in the pistons look the same as my 3.1 out of my car.Also what do you mean the mounting bosses different? For what? Would the external crank sensor work with obd1? THANK YOU GUYS AGAIN! Guess that's why the company i got it from is out of buisness.