Are N/A 3.8 blocks the same as Turbo 3.8 blocks?

[rd122481]

Is the NA 3.8 block the same (apart from the rotating assembly) as a Turbo 3.8 block? Basically, can I go to the scrapyard and pull the block from a NA 3.8 Regal & rebuild it to see 10 second boosted use in a GN?

 

[corymc]

i know you have to put in the oil return drain in the front of the block. and im not sure about the oil pan thing being 14 or 20 and whats years are good. i read if you can find an sg block those are good

 

[jhanson1750]

I think that there the same other than the return line fitting hole in the front of the block in the valley. Other than that they should be the same. Some folks with more first hand knowlege chime in and verify this. Jon Hanson

 

[Blazer406]

Welcome to TB.com.

For all practical purposes, a n/a 3.8 if it is the 109 block casting is the same. The only difference is the turbo blocks have a 1/2" NPT tapped hole in the front of the block below the intake. This is a drain line for oil coming from the turbo. The boss is there for the hole on the N/A blocks.... all you have to do is drill and tap it out.


As long as it is a 109 casting (approx '86 and '87) it will work. There might be a few 109's in late '85 and possibly a few if you can find an '88 Cutlass....... but most were in the '86 and '87 cars.

 

[Blazer406]

Dang I type slow....

two replies from the time I started typing.... :redface:

 

[rd122481]

So where can I go to find a turbo 3.8 block(for cheap)that I can build while leaving the car drivable?

 

[corymc]

try a local junk yard they are in alot of the late 80s cars

 

[turbofish38]

The 109 block is used on every 1986-1988 G-body with the 3.8. I still see plenty of them in the boneyards. Yep just drill the drain hole and you're ready. The only model of G-body you wont find a 109 in are the Chevys. An easy way to tell if it is a 109 block without getting dirty is to peek in through the wheelhouse opening. All 109 blocks have drain plugs on the side of the block and you can see them through the wheelhouse opening. Just look by the motor mounts.

 

[BlackBandit]

Also you can look for the boss where the oil drain line would go.

 

[CParman]

the 109 blocks have a higher nickle content in the castings I think? Which should make them stronger.

 

[SloGN]

The 109 block is used on every 1986-1988 G-body with the 3.8. I still see plenty of them in the boneyards. Yep just drill the drain hole and you're ready. The only model of G-body you wont find a 109 in are the Chevys. An easy way to tell if it is a 109 block without getting dirty is to peek in through the wheelhouse opening. All 109 blocks have drain plugs on the side of the block and you can see them through the wheelhouse opening. Just look by the motor mounts.

i just learned something new


thanks

pat broughton

 

[turbotman]

Found mine in an 87 Cutlass, factory stock bore and mains, perfect 109 block once the oil return was drilled and taped. Oh ya..........it came with a rolled fillet turbo crank from the factory as well. GM used up almost all of their turbo cranks in late 87 in both turbo and non-turbo 3.8s.

PS- as far as I know, all G-body 88 cutlass's were v-8 cars, so your best hunting will be in 86-87s.

 

[bison]

the 109 blocks have a higher nickle content in the castings I think? Which should make them stronger.

No higher nickel content. They are not proven stronger. They all have the same meat in he webbing area which is not much. Go for the heaviest casting you can find. Stage 1 and 2 have a different alloy and thicker mains. I just threw away 4 blocks of which 3 were easily useable. They are very common and cheap in junk yards.