Power limit on a 350

[G72Zed]

Acc0rding to Engine Masters O Motor Trend , if you want 8,000 RPM a 350 won't go their because of the stroke. A 283 has a shorter stroke and can get you their.

Huh, I'm back on the dyno later today, I'll have to tell the 358 SBC I'm going to tune on that it can't rev to 8k anymore !! , those little SBC are so head strong and stubborn, they don't listen very well LOL.

Used to turn them 8,300 for 100 laps 2 nights a week.....until they made the chip rule to 7,600

Amen to that or get somebody to sponsor you. Hard to earn that street notoriety nowadays, unless you're running deep in the 8s or lower in the 1/4.

Oh ya, there's big sponsor's alright, with big budgets too, but nothing "street-1/4 mile" in my cases.

One of my "customers" raked in over $80,000 in 20$ bills in 2022, and a very very small budget team, but that's an exception.

 

[NCCAMARO]

Can’t speak to a 350 per say but in the late 70’s we running first Gene Fulton and later Fred White 287cid small blocks with Doug Nash 5 speeds. My dad launched at 10,000 and shifted between 10 and 11,000. The sound of those S.B.s reving to the moon on a hot Carolina night made for a great childhood.

 

[hd_cat]

I'm interested to hear if there even is a limitation on a 4" bore block. I've heard it's 700 horsepower from old posts. More importantly I'm wondering at what point will factory internals truly fail?

When does the block give up?

Is it RPM? Is it horsepower? Or is it torque that will kill it? If it is rpm then what rpm. With factory rods and factory crank. I'll balance it. Looking to maximize some junk. As in can a guy rev a factory forged crank and regular rods to 10 grand? Probably not. Although I'm still going to try.

I'm probably gonna throw something together and prove any answer wrong but I am interested I'm the opinions.

I know. Why would you want to rev it to 10 grand? Well, to make more power.

It's not likely that a heavy reciprocating mass such as stock Chevy will live at 10K RPM, better to buy a lightweight crank, pistons, and Rods, then add billet main caps, head and main studs to increase durability. You might also consider adding threaded plugs to the larger water passages in the deck, drill them to allow water to pass, but the extra mass in the openings will increase the strength of the deck. I did this with the 377 when I built it in '87 and it's still in good shape. The valvetrain will certainly require exotic components to allow the engine to rev that high, I have yet to see a nascar engine rev to 10K RPM, I don't watch much, but last I saw was 8K - 9K RPM. I'd love to hear it, if you can make it happen, closest I've seen are the youtube videos of '69 302 Z/28s.

 

[Rustbucket350]

@Rustbucket350

What ever happened to your "Twin Turbo Tall Deck" buildup, did you dyno test it or run it at the track yet ??

Maybe I missed it, if so, how did it go ???

Still need to get the battery mounted, fit the hood (extemely time consuming since I have to cut and fiberglass the new scoop into the old fiberglass cowl), remember, I'm going from a 3 1/2" cowl to a 9". address a few minor things (oil and exhaust leaks) and tune it. It seems to be happy though. I should be able to get that all done pretty soon.

Sorry I do not have a dyno.

Kinda worried about low oil pressure but that's a different topic and probably related to sender and feed line location. Highly doubt if it made close to no oil pressure that I would have a valve cover or turbo drain line leak like I do. No matter what, she's getting ran since the whole idea was to see what that would do. Unlike everything I've seen on the internet it did not blow up at 5 grand. Does not blow up at 6 grand.

It actually seemed quite happy minus some raw fuel coming out of the exhaust. I do need to pull one thermostat out so I can have a water bypass. I was unaware that big blocks did not have an internal bypass like small blocks. I do believe the 366 is capable of way more rpms than people give it credit for. Especially if it lives long enough for me to install a solid cam like the good lord intended. Yes, I am quite aware of the valvetrain limits on a Gen V big block.

 

[Rustbucket350]

It's not likely that a heavy reciprocating mass such as stock Chevy will live at 10K RPM, better to buy a lightweight crank, pistons, and Rods, then add billet main caps, head and main studs to increase durability. You might also consider adding threaded plugs to the larger water passages in the deck, drill them to allow water to pass, but the extra mass in the openings will increase the strength of the deck. I did this with the 377 when I built it in '87 and it's still in good shape. The valvetrain will certainly require exotic components to allow the engine to rev that high, I have yet to see a nascar engine rev to 10K RPM, I don't watch much, but last I saw was 8K - 9K RPM. I'd love to hear it, if you can make it happen, closest I've seen are the youtube videos of '69 302 Z/28s.

This is the spirit and info I was looking for.

 

[Rustbucket350]

I had a 355, 74 4bolt main studded, Callie’s crank and Crower rods, forged pistons, and Brodix heads. 12 PSI of boost but only ran it to 6500, not 10K like you want to, made 652HP at the wheels. I was told by many people that I was on borrowed time, and wasn’t “if” it was gonna blow, but “when”. Every time at the track in the burnout box, I wondered if this was the last one? I pulled the motor and sold it while it still had value.

That combo is honestly something I'd think was relatively safe to run.

I didn't expect this many replies. I do have this 355 and I don't know what I'll put it in but I do think I'd like it to send some rpms. Maybe not 10 grand. Maybe 9 is a good redline. Personally, I don't think 9 grand is too high when I have revved engines with factory cast assemblies to 7500 and not worried. I am looking for another vintage vehicle (apparently I can't get enough punishment on my wallet). My "junk" 350 has been sitting on a stand for 7 years with billet main caps, a forged crank, and ARP rod bolts. When I said looking to maximize some junk, I meant my junk.

 

[G72Zed]

Still need to get the battery mounted, fit the hood (extemely time consuming since I have to cut and fiberglass the new scoop into the old fiberglass cowl), remember, I'm going from a 3 1/2" cowl to a 9". address a few minor things (oil and exhaust leaks) and tune it. It seems to be happy though. I should be able to get that all done pretty soon.

Sorry I do not have a dyno.

Kinda worried about low oil pressure but that's a different topic and probably related to sender and feed line location. Highly doubt if it made close to no oil pressure that I would have a valve cover or turbo drain line leak like I do. No matter what, she's getting ran since the whole idea was to see what that would do. Unlike everything I've seen on the internet it did not blow up at 5 grand. Does not blow up at 6 grand.

It actually seemed quite happy minus some raw fuel coming out of the exhaust. I do need to pull one thermostat out so I can have a water bypass. I was unaware that big blocks did not have an internal bypass like small blocks. I do believe the 366 is capable of way more rpms than people give it credit for. Especially if it lives long enough for me to install a solid cam like the good lord intended. Yes, I am quite aware of the valvetrain limits on a Gen V big block.

No need to apologize for not having a dyno....99.99% don't.

But even better is the 1/4 drag strip, it's real world, and the timing lights, trap mpg do not lie.

I live on the dyno, but you don't race dyno's, track is where it's at....Hope things go well, race safe and keep all of us updated.

 

[Rustbucket350]

No need to apologize for not having a dyno....99.99% don't.

But even better is the 1/4 drag strip, it's real world, and the timing lights, trap mpg do not lie.

I live on the dyno, but you don't race dyno's, track is where it's at....Hope things go well, race safe and keep all of us updated.

Thanks man. It's gonna get a bit wild (and fun).

 

[sandlapper]

--- I was unaware that big blocks did not have an internal bypass like small blocks. ---

Isn't that why OE BBC (and late sbc Gen 1e Vortec L31) have a bypass Hose ?
which connects top of water pump to front of intake manifold water Xover.

 

[procharged81]

That combo is honestly something I'd think was relatively safe to run.

I didn't expect this many replies. I do have this 355 and I don't know what I'll put it in but I do think I'd like it to send some rpms. Maybe not 10 grand. Maybe 9 is a good redline. Personally, I don't think 9 grand is too high when I have revved engines with factory cast assemblies to 7500 and not worried. I am looking for another vintage vehicle (apparently I can't get enough punishment on my wallet). My "junk" 350 has been sitting on a stand for 7 years with billet main caps, a forged crank, and ARP rod bolts. When I said looking to maximize some junk, I meant my junk.

It wasn’t the internals I was afraid of, it was the block puking everything out, me driving through the oil, and putting it in the wall