A few questions about 3100 topend swap...

[dbtk2]

I had a 3100 out of a '97 Cutlass Supreme donated to me. I am going to start a topend swap on my car within the next couple days. I have a few questions before hand though.

1) Can I use '95 heads with the '97 Intakes? Not planning on it as I have both '95 & '97 heads, just wondering.
2) Where can I get an adaptor plate for my EGR?
3) Will I have a problem using the 3100 rocker arms?
4) Assuming I can use the rockers, do I still use my stock pushrods with the 3100 heads and 3100 rockers?
5) What would a 3100 power steering pump cost?
6) Where can I get the 3100 alternator bracket? Do I have to change alternators?

I'm sure I'll have more questions soon as well. Thanks for the help so far!

Shawn

[sharkey]

1)yes
2)i know www.jbodyperformance.com has one, but there is likely a cheaper alternative
3)no
4)i cant remember, i think you use gen 2 pushrods but not 100%
5)no clue, call your local parts store
6)call your local auto wreckers, and yes.

check out www.domesticcrew.com/660, all this info is on there, and if its not on the page, check out the forum.

[TheDirtyBen]

why not just do a complete engine swap? seems a bit easier to figure out, plus you will be getting the roller cam!

[geoffinbc]

You DO NOT have to change alternators. Just use the one you have in the car now along with the bracket.

You do however need a 3X00 PS pump. Just get it from a wrecker.

I too would do the 3X00 engine swap.

[dbtk2]

Swapping the engine seems to me like it would be more difficult, especially since i want to maintain my ECM. I am pretty sure the bottom end in the 3X00 is weaker than the bottom end in the turbo 3.1's as well. (I have a different crank & pistons than the regular 3.1) Also, the 3100 would have higher compression (bad idea in a turbo engine) and the roller cam is a bad thing IMO because I can't swap it out for a more turbo oriented cam (at least not at this point in time), and thats gonna gain me more than having a roller cam. I already have a different cam for my engine sitting in my garage, and I am tearing the engine down to replace a head gasket anyways, so I figure I might as well put the free 3100 topend on it while I'm at it. The only extra work over just changing the head gasket is anything that needs to be changed thats different between the intakes and the cam I am putting in. Also, it would cost me a lot of money because the 3100 that I had donated had a rod knock. Its a bad engine, thus why it was donated to me...but the topend is perfect in it. So I would basically have to buy another 3X00.

Thanks for the help.

Shawn

[geoffinbc]

Ok well if the 3100 is crap then I agree just do the top end swap.

A turbo 3.1L is no different in the bottom end than a regular 3.1L.

[sharkey]

there are a couple differances that people will argue. mostly it has a hardened (not forged) crank and hardened rods.

[geoffinbc]

Well according to an old post on this site... A guy actually had a discussion with a designer/engineer of the motor and it used the exact same bottom end. I believe that was the case. I cannot find the old post but I think thats what it said. In any case I'm just relaying what I read.

[sharkey]

i know it was the same crank (same part number anyways) it was hardened before it went into the motor. this is just what i have read on a few different sites.

[TheDirtyBen]

i remember the post "betterthanyou" is referring to and from what i remember, the bottom end was supposedly straight off of the assembly line. no modifications had to be made because it was already strong enough for the little bit of boost they were going to throw at it. hell, i think it had said that they'd even used the stock cam! it was already low compression and the ECM controls timing (which would be different for turbo), which is a just a diff. code burn.

i'm trying to remember where i saw it.........but i remember a guy had dropped a 3400 into his TGP with little modification, and was using the stock turbo setup

[dbtk2]

It has the exact same bottom end, yet GM lists the pistons as a different part number and it has lower compression? (not much lower, but it is lower) I'm think it has different rods as well. IIRC the crank is also a different part number, I thought I saw it listed different before, could be wrong though. But anyways, like I said, it would be a lot more work to put the 3100 in, the cam isn't very good for a turbo application, and there aren't any cams available for it. I can put a variety of different cams in my 3.1, and I already have the one I want so why switch to a different engine. I am already tearing the engine down that far, so i'll just install different parts when I put it back together, it isn't much more work than putting the 3.1 parts back on it. And like I said, I would have to buy a 3100 to do that anyways. I don't have gobs of money lying around that I can just buy an engine with. Maybe if someone donated it to me I would install it, but probably not even then. There is nothing wrong with the bottom end in my engine so why change it, especially to an engine that is basically exactly the same as mine except it has roller cam (which isn't going to be good for power because I can't get one with the right profile as of yet), and it has higher compression (which isn't going to be good for power because I have a turbocharger). The 9.5:1 compression would probably be good if I were only going to run like 8psi or something, but I'm going to be running 12psi so I can't see that being a good idea on pump gas.

Shawn

[geoffinbc]

No I agree. Keep your 3.1L. If the 3100 is toast like you say there is noo need to invest in a motor if you have top end parts for free.