Let's talk ports- Stovebolt and Buick Straight 8

Are these engines similar in port design? I've never seen a Buick in "real life" but they intrigue me... alot!
I know that GM was all separate divisions back then, but I'm wondering if there is any "inbreeding" between the two?
Are the combustion chambers the same design? I'm talking middle generation Stovebolts-216/235/261 here.

Does anyone have experience with both? From a modified point of view?
I've been thumbing through a 1949 Motors Manual my Grandpa gave me, and cutaway wise, they "look" similar... With a cam change and block/head deck, what would a max RPM range be on a 263? Full pressure oiling too, right?

Thanks!
JK

 

I don't know the answer but I would suggest checking out www.inliners.org (if you haven't already).

 

Thanks for the tip.
Yeah, I've been there, and www.teambuick.com (when it will come up- it seems like my computer doesn't like it.
The talk on teambuick is that the heads don't flow well, but they appear to be the same as a Stovebolt, and there is alot of info out there for the Chevy's and flow numbers, tricks, etc. I'm just trying to see the difference, without having a Buick "in my hands".
I guess I'm looking for the potential on the Buick, as compared to a 216/235, other than "cubes".
Thanks!
JK

 

The ports are pretty much the same but not the combustion chamber. Buicks are more normal and like a later GMC head

 

Ok, that helps some. Thanks for the tip!
JK

 

Rich is correct; the buick, however is much larger in terms of chamber cc's than the 302 and substantially moreso than the later small-port gmc, so there is less quench and it's more difficult to build compression with a flat top. it has been said that either the gmc or the buick will accept a cut of up to 3/16" on the cylinder head deck face.

the buick could potentially have an advantage over the gmc and the chevrolet in its' non-siamese, 6 exhaust-port design. the gmc, chevrolet, and the buick all place the intake valve perpendicular to the deck face, however, the chevrolet has the inexplicably odd semi-pentroof valve inclination on the exhaust side. when the gmc engine was designed in the late 1930's, engineers essentially cherry-picked the best design elements of both the chevrolet and buick engine archetectures.

the 235 chevrolet casting is thick enough in the port area to ream to 1 7/16" diameter down to a 1 1/4" depth. later gmc small-ports (819 heads) are marginal on this mod, as gm was starting to experiment with thinner casting methods as designs progressed. one can only ***ume that the 263 buick would fall in this category as well, being the final design progression of the I-8.

 

That's good to know- the Buick doesn't have the goofy 1/2 chamber thing like the Chevy does. 3/16"- that's a helluva deck job! But I bet it'd raise compression a ton.
The info above gives me a good idea of what he cylinder would look like. Thanks!!
JK

 

...and to answer your question about the 263 buick oiling, yes, it has full pressure and insert mains and rods. a caveat: buicks oil from the top end, with the rockershaft acting as the galley, thus part of the reason why the top ends got so sludgy. cool operating temperatures, poor quality, infrequently changed oil and partial flow filtration all conspired against the top end.

the gmc and the full-pressure chevrolet's oil identically, from a central galley in the block

 

Ok, from what I understand, only the 263's and later 320's have the insert bearings.
I was looking at the 320, but I think I'm digging the 263 more. Thank you for all of your insight so far.
JK