Quote from: killinprixs on November 12, 2008, 03:22:48 PM
1990 NA 3.1s have different heads, the 91-93 comes with the same head as the TGP.

Just very curious as to I never had the chance to really compare that...  How do you know?  There's a few things I'm curious about with these engines and the n/a version...  I know the cr's are the same.  I have a book for a 1990 cavalier and beretta and they both say 8.8:1...  which iirc is the same for the tgp, correct?

Quote from: R Dubya on November 12, 2008, 02:44:09 PM
realistically it can be done but there are several major and probably dozens of minor details to deal with.  The oil pan would need to be swapped, the oil pump upgraded, intake and exhaust manifolds changed, I'm not 100% on the heads, mainly top end stuff.   It's not a direct drop in, but it can be done. 

After relaying this info to my mechanic he has decided to pull the heads and see what is going on. Hey, "In for a penny, in for a pound!" I always say! Hmmm..... That may explain why I'm broke! LOL! I'll keep everyone posted on it's progress.

the 511 casting heads were first introduced on the 89-90 turbo 3.1, they are better flowing heads compared to what the aluminum 2.8s and 1990 3.1 NA were using.  This cylinder head became standard for the 3.1s after 1990.  The combustion chambers were leveled out a little instead of the ridget heart shape found on 88-90 NA heads.  Not sure about the compression ratio, i always thought NA was 8.9:0.

The GM shop manual states 8.8:1.

looks like the 2.8s say 8.9:1 and 3.1s say 8.8;1 even tho they had the same 2.8 heads on the first 3.1s??  Must be in the pistons. 

Eh who cares about the 2.8... lol.

yea i dont give a crap im pretty sure my 3400 car is 9.5:1.

The compression difference IS in the heads. It's been discussed before. As far as listed #'s, they vary from source to source.

Quote from: killinprixs on November 13, 2008, 08:37:31 AM
looks like the 2.8s say 8.9:1 and 3.1s say 8.8;1 even tho they had the same 2.8 heads on the first 3.1s??  Must be in the pistons. 

I thought it was in the stroke

Anyone have a spare engine they want to sell?  :icon_cry:

Where are you located?  There are several engines floating around for sale.

Just re-ring it, clean up the bores, check tolerances and install some new bearings.  Probably cost the same a buying that nasty looking "TGP" engine off ebay.

or go to the local pick a part and get a low mileage 3.1 out of a 93 w body or better yet a 3400 ;) 

Or is it using antifreeze?  to have all 3 that consistently bad makes me think you might have a bad headgasket?  Are you getting bubbles in the overflow tank when the car is running?  Someone correct me if I am wrong on this one..........

From my very recent blown head gasket encounter, if you have your radiator cap off and try to start the car anti freeze will shoot out of the radiator. And yes there wil be bubbling in the overflow bottle and consistent air in the system. And mine was a small head gasket blow. LOL

Quote from: cobracmdr on November 20, 2008, 05:34:37 AM
or go to the local pick a part and get a low mileage 3.1 out of a 93 w body or better yet a 3400 ;) 

Is the 93 motor a drop-in replacement? Is the 3400? If not, what is involved with either? Thanks!