whats the limit for a sbo (gas block)
#41
I'm not saying you can't get 700hp on a stock gas smallblock but the question is certainly for how long! If you have a mega light rotating assembly then it might live but imo you better have a full girdle cause it's gonna blow and blow big eventually without one!
#42
Did I read that right, 1200hp and only mid 11's? Something is not right there.
Less than 600hp will get you into the 11's. I was putting somewhere between 320-330hp to the rear tires and doing low to mid 12's and that was with my grenade of a 455.
He's toying with you with that BBC
Less than 600hp will get you into the 11's. I was putting somewhere between 320-330hp to the rear tires and doing low to mid 12's and that was with my grenade of a 455.
He's toying with you with that BBC
#44
#45
It'd be great to come to a good value for:
1A) cast crank limit stock internals
1B) cast crank limit forged internals
2) forged crank forged internals (gas block limit)
3) diesel block with forged crank and forged internals limit (who cares about stock components with a D/DX build)
The only really way to determine it is to get 4 blocks, prep them, and overpower until you blow them all.
Then keep re-doing it for each scenario for a decent sample size.
#46
If I ever get a turbo back on my 350 I expect to find the limits of the stock short block, it’s .030 over and balanced but stock/factory otherwise. Btw, I never ended up racing the nova, dad moved back home to Iowa and I sold my 66. I did race the 66 against his big block 4 speed 1955 handyman wagon though. Beat him so bad he put two holset h1c turbos on it( not to long ago he told me the crowns broke off the top of all 8 pistons and took the heads with them)
Last edited by young olds; December 8th, 2020 at 07:19 PM.
#47
Some missed contributors to this forum in this thread. At least we gained Vortecpro since, a champion of the Olds V8. The stock pistons and rods are playing dangerously under boost. Hell I bent a rod by filling the cylinders trying to free up rings. It did work, 15 psi in the bent rod cylinder and 25 psi in the other, at a large cost including a bearing and no doubt a journal. We see so many less failed 350's, even when pushed hard. With more cubic inches easily available now, more should consider the Olds 350. In the 70's to the early 80's when sbc had flat cams and worn valve guides/seals, Ford had the garbage M series knocking away and Dodge's were running like, well Dodge's. The Olds 350 ran circles around the rest in reliability. I saw failed TH350's in those years, our 75 included, in the Cutlass, the HEI distributor died on 75 but the Olds 350, you could count on for a ton of miles. Our 75 after a ton of miles, some very hard thanks to my Sisters Boyfriend and friends, after 300,000+ had a knock. The brake caliper seized on and our 75 was hauled away for scrap. Someone bought it off the wrecker, Pat the Rat. They drove it another 5 years, so much better than nearly any other car on the road at that time.
#48
Also remember, there is two cast cranks. The "N" crank is much stronger than the later grey iron, lightweight cranks. There was a later crank in a 400+ hp 403 with a 6 spd manual, it did not go well, unless you like your crank in many pieces.
#50
If I ever get a turbo back on my 350 I expect to find the limits of the stock short block, it’s .030 over and balanced but stock/factory otherwise. Btw, I never ended up racing the nova, dad moved back home to Iowa and I sold my 66. I did race the 66 against his big block 4 speed 1955 handyman wagon though. Beat him so bad he put two holset h1c turbos on it( not to long ago he told me the crowns broke off the top of all 8 pistons and took the heads with them)
I'm planning a similar build, but I'm garage limited right now. I'm working to get the 330 it came with running so I can get the car out of the garage and back into the driveway; then I'll probably get another donor engine and do a full build-up for a boosted 39 degree 330 or 350. 330 would have fewer piston options but should be a bit better (cooling/structurally) for a turbo build. Still kicking around whether I'll want to replace the rods, or just the bearings and boost it until the first thing breaks. That would at least create one data point
I think part of this still being an unknown for OSBs is that the diesel block is a thing that exists. The guys chasing quarter-mile records and dyno numbers probably migrate to that block at a certain point, whereas the Chevy guys were stuck with the early SBC blocks as their strongest option for 30 years, so those power chasers blew a few motors on the way to IDing a rough range of 650-800HP block limit with the two bolt setups.
#51
Good point -- probably best to throw that in the pile of Jetaway transmissions at the junkyard.
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cutlassefi
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November 29th, 2019 05:07 AM