Some Questions



I'm new to the Turbo Buick motors and I was wondering if someone could give me a run down on the different types of blocks available. Which were odd-fire/even-fire and on-center/off-center etc. Also, the newer SeriesII (3800) Buick engines are similar but I hear they can't share any parts from the older engines, what makes them different?

Does anyone have a FAQ page with some details? I would like to read as much info as I can so I can start my project.
Quick run-down: Buick V6s were odd-fire (two rods share a common journal) until mid 1977. 1978-up engines are even fire; the rod journal was split 30 degrees to allow an even firing order. Some race builders later ran odd-fire cranks in their Stage motors as the oddfire crank is stronger (especially for stroker cranks where the split pin becomes a thin point).

The Buick racing program got into high gear in the 82-83 time frame; Buick began working on the Stage parts. The Stage 1 and Stage II blocks began production around 84-5; they were heavy duty, race-only versions of the production blocks with a revised, better casting.

The Stage 1 and Stage II share a common casting but differ in finish machining; the Stage 1s are machined the same as production blocks (wet sump, 2 bolt mains, 8 head bolts per side). The Stage IIs got 4 bolt steel mains, relocated pickups and later dry sumps, relocated cam oil galleries, and 14 head bolts.

The split pin for even firing motors resulted in a rod offset in the bore; this "off-center" design carried through for all production V6s. In 1987 at the power levels the Stage blocks were producing, this became a problem and the blocks were revised with shifted bores to eliminate this offset, creating the "on-center" blocks. The on-center blocks carried through into the early 90s with various production revisions including revised rear main oil seal, cross-bolted front and rear mains on later blocks, etc.

Corresponding to the Stage II block was the Stage II head development; this was a fresh design, race-only head. It shares no parts with a production head, requiring a different intake, valves, rockers, headers, valve covers..even the cam is different as the valve layout was revised.

This excellent head was the biggest factor in the success of the Buick V6 in circle track cars; it has a very small, efficient chamber, ports that easily flow 300+ cfm on the intake, and 14 bolts to match the S2 blocks. 274 ci circle track motors with a single 4 bbl carburetor made in excess of 525 hp; twin turbo race Stage IIs have made at least 1400 hp and run 6.90s@200+mph! :eek:

For pictures of various blocks, heads, cranks, etc., see and look at the picture guides. OK...I am an insomniac and I need to go to bed now. :)
My plan is to do something unique, so I've been looking into building a newer Buick motor (3800SeriesII) for use w/ turbo(s). I figured this would be a cheap way to start into the Turbo Buick world and I wanted to know where it stood in its V6 family. My plan at the moment is to do this as cheap as possible because I know engine buildups always cost more than planned.

The 3800 has cross bolted mains, even fire crank, I believe 8 head bolts per side. Not sure if it's on center or not. So given your info, should place this block somewhere close to stage I motor in strenghth? The 3800 also has decent heads from what I have read, but I haven't gone too far into my research on them.

I think a Stage II motor might be a little overkill, I assume I wouldn't need to go that route until I want to go sub 10s.
There has been talk about this at various times on this BB and elsewhere. If you want to do it cheaply, unless you're a skilled fabricator, I'd stick to a production earlier 3.8. The 3800 shares almost no parts with the older 3.8. It has a different intake, exhaust headers, ECM, etc.

Therefore, if you want to make a turbo 3800, you'd have to do custom headers, intake piping, invest in an aftermarket ECM or some sort of aftermarket fueling system, etc.

If you want a good plug n' play 3800 for a project, consider the SC3800 motor from the 97-up Regals and GTPs. It makes 240 hp stock, is a very throttle responsive and smooth motor, and there are modification parts available. I have a 97 Regal GS and love the motor.

In closing, if you want to ask further 3800 questions, it might be better to post them in the tech forum or the 3800 forum to widen your audience.