At least for the short term, the inline 8-cylinder that has been under the hood of my '51 Buick Special from its creation is going to stay right where it is. That being the case, I'm going to be interested in maximizing the engine's power output while also boosting it's reliability. With the understanding that, often, increasing power and making an engine able to not beat itself up do not easily go together, and using cost-effectiveness as a guideline, are there specific things that the Buick I-8 responds well to in either category? To be sure, the universal principles will be applied - making certain that ignition and fuel delivery and distribution are optimum, that the oil can get everywhere it needs to be and at the correct pressure, et cetera. But beyond that, what kinds of things make the Buick 8 a happier engine? Any thoughts?
Provided your engine is the 263 version, a 1941 dual carb manifold with matching carbs would help. Make sure the flapper in your exhaust manifold operates or remove it, and at least 1-3/4" exhaust pipe with a good flow thru muffler. That is about all you can do without going into the engine. That dual carb manifold is a hard find, but they are out there. Keep in mind you are looking at a 120 HP engine, but with a fair amount of torque.
Thanks, 'oldtin. The Special did come with the 263 in '51. Twin carbs in 1941, from the factory? Two singles, I would assume. I would also guess there wouldn't be a bunch of carbs that would bolt right up to it, so I would need the factory units (Carter, Rochester, Zenith?).
1941 was the only year factory installed, and I believe Stromberg was the most used carb. And yes, two singles with progressive linkage that opened the second unit under acceleration. Finding a complete set-up would make it easier.
They are actually 3 bolt carbs that bolt up to that manifold. Stromberg and Carter are both options. A complete manifold setup will have a spacer under the rear carb that has a vacuum-actuated flapper. My understanding is that it brings the rear carb online as needed, sorta like a q-jet. I also understand that a lot of guys remove the flapper and run the carbs non-sequentially for better fuel distribution. Bear in mind that there are two versions of this setup. The 320 (big block) and 248 (small block, which shares the same manifold with your 263). Measure the length of your current manifold, that is the length you are looking for. I picked one up at a local swap meet this spring (sans carbs), and saw another at Iola this summer. So they are out there. If you do see one, look it over for cracks. They aren't as fragile as the stock exhaust manifold, but they are 83 years old at this point. I am on the fence at the moment, as I do have all of the material to build a 3x2 intake and tubular manifolds (headers). If I use it, I am planning on trying it on a pair of Stromberg 97s (that I have for the 3x2 project) EDIT: You may have to modify the driver's side engine mount to use the factory setup. I know that I will if I do use it on my 50. The front manifold dumps pretty much on top of that mount.
Also, good on you for running the S-8. My original plan with my car was to swap in a 455, but once I got the fireball tuned up, I tossed that plan out. The engine is remarkably smooth and quiet, with plenty of torque. It will most likely end up with the 322 out of my 55, but that is several years down the road.
Duel carb was 1941 and 1942 option on the 248 engine. Carburetors are same mount, 2 barrel, as one carburetor. I did a full blown "hop up " build on the 263 I swapped into my 1950. A bit pricy. Glad I did it though. Even before the 263 I went to fuel injection and HEI ignition. Ben
Ben is right and I had forgotten about the dual carb set-up as an option in 42. Buick stopped production in February of 42, so probably not many out there. By 1950 Buick had improved the 8 quite a bit with bearing inserts and hydraulic lifters, so rebuilds are a little cheaper than the earlier ones.
I've always wondered how difficult it would be to swap a 320 ci Roadmaster engine into one of the smaller Buick's. It's probably too much longer to be practical. I used to vintage race against a couple of them and they were fast! The owner told me they bored them out a full 1/4" and used IH tractor pistons to end up with 356 ci. They added 5 or 6 Stromberg 97's and some high lift rocker arms and called it good.
The Roadmaster engine is much longer and would require a radiator move. also the larger engine would need a marching bell housing. If your car has a Dynaflow transmission then a change to std trans would do a world of help.
I had toyed with the idea of an I-8 in my second coupe, but since I don't have a complete engine, I opted for a 292 Chevy instead. The first coupe is getting the 401 Nail Head I pictured in your other thread. And the expertise of folks here on the HAMB will help you get your project going.
Sure can't go 1/4 [.250] on 263. I went .125 [ 1/8th] and that was too much. One cylinder wall cracked and had to sleeve. Besides which the .125 brings the bore to the same "bore" as the head gasket opening. Ben
My Buick shop manual gives the max overbore for a 248 @ .080". I would imagine a 263 would be the same, although I have seen .100" done.
What's the compression ratio of these engines? If it's low bumping it up may help both power output and fuel economy. One of those good modifications that only costs money once, and save money the rest of the time.
FYI. Stroll on over to Antiquated forum and @carbking has a factory dual carb set up for a 248 for sale.
I believe the CR had gotten into the sevens in the later years, still quite low. Decking some off of the block and head would raise it, but then other requirements associated with that gets pricey.
Your car, your build, but the smaller engine is always going to be somewhat of a disappointment. Maybe consider doing it like Buick did when wanting more performance; a traditional hot rod, their largest engine in a shorter and lighter body. During the late '30s/early '40s the Century was Buick's companion to the top level Roadmaster and was offered as a 2-door and 4-door sedan and convertible. jack vines
The following has always been my philosophy. I got this from a set of 1961 Popular Mechanics encyclopedias. H for Hot Rodding. I read those when I was a kid. Mom would help me with science fair projects out of those books. We won some ribbons too! I miss you Mama! OK H for Hot Rods...... Most new factory cars come out of tune from the factory. The factory does not have enough time to tune these cars to their full potential. The first step in Hotrodding is to get the factory engine tuned up to it’s potential. A stock engine tuned to it’s potential should be the base of any hot rodding project. A well tuned stock engine will perform better than most new cars. A well tuned stock engine often will perform much better than many engines with hundreds of dollars of speed parts if the mechanic has not properly prepared and tuned those engines for those parts. A good running and well tuned stock engine is the base line. With a great running stock engine the mechanic can see how the engine responds as he makes modifications. My advice..... Get the shop manual. Get the engine squared away stock. Then go from there. I own Fords from the period. I dare say this and it’s true. My stock 1951 Coupe runs better overall than the vast majority of the dual carb or triple carb bling machines. Why? For one thing I have a functioning timing advance. ^^^^ It’s a 8BA thing but it’s a great example of really knowing your engine.
At different times, I owned a '50 Special with a standard transmission and a '51 Special with a Dynaflow. BIG difference in performance. The '50 felt much more powerful, since whatever power it did make wasn't being sucked up by a swamp in between it and the differential. Also, the Dynaflow got half the fuel mileage of the stick car.
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