Hey guys... Going thru some of my parts books and catalogs, I noticed that several pistons carry the same parts # for both the 231 V6 as well as the 350 buick V8.... There are lots of "off the shelf" turbo pistons available for the 231... Does anyone have information on how these pistons would work in a 350???? Would, for example, a forged racing piston designed to give 7.6:1 compression in a 231 also give 7.6 in a 350????? These are things we will need to find out as we move forward with the supercharger and turbo applications for the 350. Thanks:grin:
WOW! That would be great! I just thought of that when I saw your post. I don't see why they wouldn't work, just need to buy two extra pistons is all. With plenty of parts out there for the Turbo 3.8L, prices shouldn't be as bad as I thought! Well off I go to see what I can find on this! Daniel
d, i have a little exp. with the turbo regals, how much boost you planning on running? i would start low,watch for detonation! its a motor killer!p
idea Just a thought...being that we've been throwing around info on the 350's weak point the rods...would the 231ci rods work with the buick 350??? Just an idea... Daniel I was just wonding how simalar are these two engines? I mean can you use the timing cover or pushrods? Just wondering how many parts could be used on each of these engines.
Although some things (like pistons) interchange, I don't think the rods do. I could be wrong, but I think the 231 rods are around 5.96" and the 350 rods are around 6.38". I'm not sure about other interchanges, but remember that the 350 has a 10.18" deck height, whereas the 231 has a 9.5" (???) deck height; that could mess things up a little. Darryl, I don't know about the compression ratio thing, so I guess you'll just have to look at the piston, combustion chamber and cylinder volumes of both the 231 and 350 and compare them. This should at least give you an idea of whether or not they'll work.
That's basically what I was asking... If anyone has *firsthand* knowledge about things like deck height, rod length, head CC volume, piston pin to deck height, etc, for the 231 and the 350, so wecould compare those numbers... The pistons that carry the "same" parts #'s are the "stock replacement" low compression models. I'm quite sure that when were talking about precision racing pistons designed for the 231, something will be lost in the translation when they are installed into a 350, but exactly how much will be lost is what I'm wondering. As for the rods, I know that both the 231 and the [later] 350's use very similar cap-screw type cast rods, but I remember reading somewhere that the rods would not interchange between the two motors... Cant remember exactly why, might have something to do with the different lengths.
I really have to take a closer look at my 350 pistons/rods...The even-fire crank has split-throws(one journal for each rod, not shared journals like the V8s and oddfire 231)...making the split throw crankshaft BUT still keeping the cyl bore spacing of the V8, required the engineers to offset the rod almost .100 in the cyl bore and piston... Found the info I was thinking of...Even-fire pistons can be retro-fitted into odd-fire motors, but not vice-versa...The distance between the pin bosses on the 350 piston and the odd-fire V6 is 1.230", where the distance on the even-fire V6 is 1.280"... If anyone is interested, the SA Design book, "V6 Performance(Buick, Ford, Chevy 90*/60*) by Pat Ganahl has some of the above info listed and goes into more detail on design differences between the odd-fire/even-fire V6 compared to the 350, which is what the V6 was based on(rods, cranks, pistons, etc)...Also has oiling system mod explanations of Jim Ruggles and Smokey Yunick's work on the V6s which can be adapted to the 350 as well...Good Book... Rod info... 350 rods... Rod length 6.380" Rod width .845" Big End 2.000" Small End .9398" 231 rods... Rod length 5.960" Rod width .844 (I think)o No: Big End 2.25" Small End .9391 - .9394
As stated the 350 pistons and the 231 pistons will interchange, the bore size is the same for both engines.. However the stroke is different, the 231's have a shorter stroke. If the stroke were the same the 231 would be a 4.3l vs 3.8l. (wouldn't that be fun!) The 7.6 compression pistons probably won't give the same compression in the 350 as the deck height is different and some other differences between rods/block/heads. Best way to tell is to put one in a 350 and take a bunch of measurements and calculate the true C/R... $.02 non professional OPINION. Dan
Yes, the stroke is different, BUT the 231's rods are shorter and the deck height on the 231 is shorter as well... As soon as I get my spare 3.8L turbo motor back from the machine shop, I'll check the dimensions on the pin heights to the top of the piston between a 350 piston and the 231 turbo pistons...And if possible, I will take a measurement of the deck heights of a 3.8L motor and a 350 motor...
Any updates on these 350 and 231 pistons? I noticed that the TRW (Fed. Mog.) piston L2452F is listed for the 78-87 231 non turbo and also 75-79 350. Badger also has piston B422A for the 231 non turbo and B422 for the 350 - not sure what the A is with the 231 pistons. Seems like something could be made to work here!:Brow: Scott
It's Brien (like Brian, not Breen or Breanne). I find that the Keith Black website is good for reference. The Silvolite section isn't as detailed, but it gives you the bore and compression height and has some less popular engines too. BTW, the buick 300 and 340 have the same compresion height, so with a .050 overbore you might be able to use standard 231 pistons (if they go .050 over).
