i've changed my mind (about engines)

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jae said:
Not sure if it makes a difference or not, but wouldn't an adaptor plate or transmission swap be needed if going from the Buick 3.8 to the Chevy 350? Do they have the same rear bolt pattern?

Not trying to cause any problems or give misinformation but was wondering... :?:

very very rarely will you ever get a th350 on a 3.8, and IM not sure if mine came like that or if it was rigged to work, but my 3.8 had one. But usually the tranmissions will not line up.
 
Adjusting solid cam valvetrains is the vodoo, hydraulic is pretty easy. All you do is adjust it until the slop is out and the pushrod rolls with some resistance between your fingers on a closed valve. When you adjust all the closed valves, move the crank and adjust the rest.
 
At least you can adjust yours! On Oldsmobile engines there is no adjustment, you have to get new parts if it is out of spec. 😀
 
Yet another area where Chevy has a technical advantage over BOP engines. I looked at several factors when I went with a Chevy 350 to replace the worthless 3.8, and the rockers were one of them, as was the oil pump design. The only real negative to the Chevy was the lack of a high nickel block like Olds uses, but the low cost of parts and ease of use more than offsets it. My other hot rod is an AMC with an AMC engine, and after that wallet draining exercise I was sick of being different and just wanted something that worked.
 
Olds motors can be converted to run an adjustable rocker... you just have to pony up the dough to buy the parts... Oiling issues are also easily resolved with a higher volume oil pump.
The best part about an Olds motor is you don't need to wind it up to 7,000 rpms to make your power. In fact, with peak numbers usually in the 3500 to 5500 rpm range, there's no need to run it past 6 grand... which is coincidentally right about where the stock oiling system has a hard time keeping up.
 
Yep, low rpm torque. The stock rockers are good to at least .500 lift. My car launches raelly hard even with 2.56 gears. Make sure you up your gearing with a sbc. My sbc 350's were gutless turds with 2.76 gearing in my 78 1/2 ton. A stock 307 vin Y killed either for power with that gearing, in the same truck.
 
Low end and mid-range torque sure do make Olds and Pontiac engines nice and fun for a street car. I know a lot of people withSBC in their cars(myself included) and they just don't have the off the line punch that the others do.
 
Blake442 said:
My '83 wagon had a 3.8 V6 and a TH350... not only that, but it was a dual bolt pattern bellhousing as well.

Yes, I was thinking there was a dual-pattern TH350 but couldn't remember. My '81 Calais had the 260 mated to the TH350; I was kind of shocked :shock: when I did the motor swap, figuring the puny motor had the crap-tastic TH200 metric.

I just wanted to make sure in case there wasn't any thinking about possible extra cost. But since the plan is to go with the TH200-4R it's not an issue on that front at least.
 
My 350 has more low end torque than I can ever hope to use. I ran a computer sim on it, and it has 380+ ft/lbs from just off idle to around 5k. Mine is spec'd out to have low end torque, and you really need only barely touch the throttle to get it moving. Even a quarter throttle off the line barks the tires. I have accidentally peeled out so many times I can't count, and it gets frustrating because there is a fine line between being able to cross 3 lanes of traffic and going up in tire smoke. It's all in the combination of parts. A reasonable mechanical compression ratio and a wide LSA cam coupled with a Quadrajet can work wonders for low end. It's all in how the engine builds dynamic cylinder pressure.
 
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