86v6CP

I have a 2.8 powered 1986 Camaro. I use this car exclusively for autocross competition. The class I run in requires the stock intake and TB so a full top end swap is out. Would a later aluminim heads off of say a 3.1/3.4 work with my intake and what compression would I end up with if I don't change pistons?

Remember this is a race only car.

bl85c

iTrader: (2)

Nope, wouldn't work. The 3x00 intake and the iron head intake are completely different. Besides, heads would probably qualify as part of the 'intake' assembly. Doesn't mean you couldn't change them out, you'd just need to disguise them real well.

You do have one other option, the prototype aluminum 'porsche-eater' heads. They're basically the old iron heads cast in aluminum. GM ran a short line of them and an early aluminum block that they planned to use in fiero's so they could spank on porsches in the road courses. But it's very unlikely that you'd be able to find a pair of them. If you do manage to track some down just make sure noone's running around checking with a magnet!

86v6CP

I'm allowed to change the heads to any material I want but I can't change the intake grrrrrrrrrrr. I was thinking perhaps the heads off an early 90s 3.1 like I had in my Pontiac 6000se would work I beleive they were aluminum.

chevyracingrox

put that engine on my dream list of parts! why didn't they put that engine into the production fiero?

86v6CP

so these heads are not compatible with the 2.8 tpi intake?
http://cgi.ebay.com/ebaymotors/2-8-3...spagenameZWDVW

bl85c

iTrader: (2)

Those won't work. like I said the aluminum (fwd) intake assembly is completely different. The later gen II aluminum heads are a better choice anyway.

The main reason gm didn't put aluminum components into production is obviously cost. The second was the reported engine fires the fieros were notorious for. GM decided to drop the fiero to avoid legal issues. The prototype aluminum blocks aren't a very good design. They use the early small main bearing design and 2 oil galleries, instead of 3 like the newer gm racing block. The aluminum racing block is a much better design, although expensive. Wish I could afford the racing block, but it's about $4K. Although they are available through summit now, maybe that'll bring prices down a bit.

grimmcs

iTrader: (1)

FirstFirebird has done alot of work in this area. In this pic from him you can see the obvious differences in the designs of the iron and aluminum heads/intake...

86v6CP

AWWWW NUTS!!!!!
well I guess I'm stuck with what I've got.

I wonder how much I can shave the Iron heads before the intake won't fit.

drdave88

iTrader: (3)

from what i remember, i believe its not more than about .020" but im not positive on that. but if youre looking for more power, you can find lots of other areas to find it. you can have your intake extrude honed after you port the upper and lower plenums (i did this, quite a good gain showed on the flow bench, do a search on my testing). you can also have your heads ported.

zs&tas

im guna p&p my heads and was looking at how much i can shave, i went through hundreds of old posts last night and there was one from MR 12 sec himself saying you can take off .05 quite easily as its not an interference engine - obviously depends on your valve lift thought. just need to shave the intake to make perfect..........

bl85c

iTrader: (2)

Milling the heads will bump up your c/r some, but if you really want to extract as much out of the iron heads as you can and you don't have any block restrictions you should swap to a 3.4 block. You'll have ~9.3 cr and much more torque. Extrude honing's a great idea if you have the money for it. And of course a cam that'll move the torque up in the powerband would help out tremendously.

firstfirebird

iTrader: (3)

The iron heads are non-interference and can be shaved quite a bit without valve clearance issues, but the LIM will need to match. In fact I believe the valves won't hit the pistons even in the event of a timing set failure.

Your best bet is to use a 3.4 block with the flatter dish pistons. It will bolt right in place of your 2.8. This will give you a few more ponies and raise compression (3.4 pistons are 8cc dish, 3.1 are 12cc).

If you want to stay with the 2.8 displacemaent, IIRC there are some flat tops on the Fiero store.

I've heard of the Potter heads that were made for racing, but have yet to see any (the FWD stuff is so common and are almost race-quality in stock form).


GrimmCS, nice pic - wonder where that came from ...

Dale

iTrader: (12)

depending on what class he is running in (csp?). Will depend on what he can change. Block, cam, porting, etc. I forget what is allowed in what classes. Mine was modded so much I was to be put in the "anything goes" section but begged and got put in ESP.

He can do some of this and "hide" it. But if he really starts spanking people all day long, there going to call "foul" on him and they rightfully can take his car apart and inspect it. At his expense too.

Post up what you can/cant change for the class you want to be in and we can help you more.

found a list.. http://sff.net/people/dburkhead/prepcompare.htm

zs&tas

what pistons do we have standard?? and how much do you reakon the CR will change by shaving the heads????

bl85c

iTrader: (2)

Stock 2.8's are flat-tops, 3.1's are dished. Not sure how many cc's/in you'll remove with milling, but you'll generally gain ~.14 cr point per cc.

Crux

Sorry to revive this thread but it has me asking a question:

If I can't use the 3.4 heads with the 2.8 intake plenum then I HAVE to use the 2.8l heads on the 3.4block.

And..putting the 2.8l heads on the 3.4l block will fit right?


By the way..please trust me when I say I've been doing alot of research and reading posts..it's just that it's often that it seems not all of the information matches up and that's when I ask questions.

On a side note: The 2.8-3.4 is back on since I now have a job and no insurance to pay
Working at a sushi & liquor bar as a dishwasher/busboy and I'm pretty sure it'll pay pretty well compared to my grocery store job.

grimmcs

iTrader: (1)

All the iron heads from late 85 (<-- I think) 2.8s, 3.1s, and the 3.4s were all the same.

awesome

has anyone on here tried to shave the heads? I was really thinkin about it but I want to know that someone else has done it, and by how much and if it was a success

Crux

But..that's not what the picture posted above is showing..


right?

grimmcs

iTrader: (1)

The setup on the left is the 2.8/3.1 Camaro setup...the 3.4 Camaro uses the same heads/LIM but a different UIM.
The setup on the right is from the 3100/3400...and it is from the FWD cars.

I think that is what you meant to say. And you are correct...the 3x00 heads cannot be used with the 2.8 intake manifolds.

Yes, the 3.4 has the same head bolt pattern.

bl85c

iTrader: (2)

If a moderator is paying attention we need a sticky defining the different head abbreviations since there seems to be so much confusion on what's what.

2.8, 3.1 and 3.4 reffers to iron heads. There's also the pre-'85 small valve iron heads.

3100, 3400, 3500 and 3x00 reffers to fwd aluminum heads. Also defined as the early (gen I) 2.8/3100 fwd aluminum heads and the later 3100 & 3400 (gen II/III) fwd aluminum heads.

grimmcs

iTrader: (1)

I would agree...but what does it matter? No one searches first or reads the damn things anyways

redlinex

im confused here now lol im under the impression that my heads on my 92 3.1 mpfi was aluminum heads.... thats what my manual stated.

Dale

iTrader: (12)

Then your manual is wrong. Go find out for yourself with a magnet.

Six_Shooter

iTrader: (2)

There are also generation II "2.8" and "3.1" that are aluminum heads.

NO RWD (660 equipped) vehicle was every equipped with aluminum heads from the factory.

redlinex

well i took a magnet to my heads this morning, and sure enough the heads on my 3.1(out of a 92 rs) are aluminum.

2.8RS

iTrader: (5)

Your heads can't be aluminum. All F-bodies had iron heads.

Six_Shooter

iTrader: (2)

Cast is also non magnetic, sometimes.

Like I said before NO RWD GM VEHICLES EQUIPPED WITH A 60DEGREEV6 CAME ALUMINIUM HEADS!!!!

redlinex

well if i do happen to have some kind of non-magnetic cast heads and the only way to equip on some aluminum heads is to use the intake off a 3x00 intake, then the aluminum heads from http://www.engine-parts.com/GMV6/gmv6heads.html or http://www.mantapart.com/ (in the 2.8, 3.1, 3100, 3.4 section) wouldnt fit? using my 3.1 intake that is. and has anyone ever considered or even accomplished a dohc swap onto one of these 60degree engines? but either way i would love to run some aluminum heads on this engine to bring it to life a little more.

Blue1989RS

Do some searching. It would be extreemly rare for you to have aluminum RWD heads. Maybe you need a stronger magnet? And the DOHC V6 wasn't that impressive. Woohoo, 200hp. I have a white paper on it somewhere. Not to mention that supposedly it won't fit in the engine bay. If you go through all that hassle you might as well do an LT1/LSx V8 swap. Way more bang for the buck. If you are determined to stay V6, then do a FWD Gen III head swap.

firstfirebird

iTrader: (3)

What exactly do your rules specify in your class? Perhaps we can help you use a different combination and still be sanctioned.

redlinex

hrmm, i been reading alot on that hybrid engine setup (perhaps this isnt the right thread for this anyways, i just failed to ask this question though) going from stock iron heads to the aluminum heads(and of course the intake) what kind of power could be acheived?(and maybe the help of p and p the heads and intake, and cam and using the 3.4 displacement block) you know the whole hybrid setup.

bl85c

iTrader: (2)

300+ hp n/a, more with fi or n20.

auto-x1990RS

i've got a question. will the 3.5L heads (off the Pontiac G6 v6) fit on the 2.8/3.1 block??? i'm trying to get my little 3.1 up to 250whp and thought i could get to that number by doing that swap (and other work too)

grimmcs

iTrader: (1)

No they wont. I think that you can only use the 3.4 (or 3.5) with those heads. I believe that the valves will hit the block on the 2.8/3.1...the 3.4 bore is big enough to work with them though.

(Im sure FF will be here soon and confirm or deny that)

firstfirebird

iTrader: (3)

Just did in another thread. The 3.1 has an 89mm bore and the 3500 heads have chambers that are just over 91mm at the widest point.

I doubt the valves would hit the block deck, but definately dont want the chambers to over hang the bore.

mrfixit123

Hi, can one of you senior members with engine biulding experience call me 517 285 5236 about 3.4 swap Glenn

charlie 1

I want to put a set of aluminum head, and intake for carb, and a point distributor and coil, can anybody tell me what year, and car or truck these come in.

bl85c

iTrader: (2)

None. No carb/al heads ever.

charlie 1

what year would I find 3.1 heads and intake with a card, and points distributor for a v-6-60 engine

AM91Camaro_RS

I don't believe there was a 3.1 with a carb, either. you can use a 2.8 carb manifold on a 3.1. I really wouldn't bother with a factory one, though. Edlebrock made a carb manifold, though. They're not very common. I do happen to have one, though. PM me if you're interested. (this is for the iron heads). Why do you want a points dist? why not run HEI??

charlie 1

I would be interested in your manifold, is it for a 2 or 4 bbl. and how much is it? The reason that I perfer vacuum points distributor, I have run them before and can get parts for them and good luck with them

AM91Camaro_RS

It is for a 4bbl. I'll PM you so that we're not hijacking the thread about heads...