Technical Max rpm before stock sbc blows up real good?

I have a 1959 283, completely stock internally. How high can it be revved before I can expect something to break? I never rev it beyond 5000, which from what I've read seems ok, but I was wondering.

 

How long is a piece of string ???
All of you out there with 283's, get into it, take note when it pops, and report back.

Would depend on a lot of variables, even though it is stock, but 5000 rpm should be ok as long as it is not constant and the engine load is not high.
NO RESPONSIBILITY TAKEN.

 

fair chance it will valve bounce before it snaps something, but continued valve bounce will eventually blow it.

 

Yes, valve float is usually a great rev limiter, which has saved a many stock engines. Usually low, to no oil showing on the dip stick, will cause engines to scatter.

 

Why blow it up???..... I'd rebuild it or stick the crank in a small journal 327 block with matching pistons.... Sell the 283 block to a restorer and make some $$ back....

 

We used to exactly that back when those motors weren't worth anything . My buddy owned a junk yard and we would take old engines and rig them up to run setting on the ground and stand around and drink beer and pull the throttle wide open and see how long they would run before they blew up.
We would bet and the loser had to pull the next victim. Great fun. We liked small block Chevys and 289's because they would go to 6 grand pretty easy with no accessories on the engines.

 

did the same thing during my " tenure " as a junk yard dog, we'd laugh when they started popping back out the carb( a waste now, fun at the time)

 

Crane cams or one of the cam manufacturers had an article out that said that the OEMs at one time purposefully installed somewhat weak valve springs for just this purpose, to prevent warranty service returns from "over enthusiastic" motorists. Valves bouncing several times before closing bleeds off compression and power, acts as a rev limiter.

 

The limit will vary but 5000 should be pretty safe. The valve springs are probably pretty weak if original. That would be the first thing I would replace. If oil pressure is good, replace the springs and keep enjoying it.

 

I had buddies in high school that wound 283's wayway faster than I would have and they just kept running...

 

I had an SBC back when I was in high school. I built it out of a 400 block, and a 350 crank, with bearing spacers (before you could get thick bearings for said purpose), that came out to about 377 inches.

That pulled hard all the way to 7000rpm, thanks to some seriously hogged out heads that a retired racer neighbor hooked me up with. This went into a car with 2.56:1 rear gears.

Stupefyingly irresponsible for a 17-year-old.

 

We've all been there................

 

Friend of mine had a 283 short track engine.
Balanced and built with quality stuff.
made a couple races living in the 7500 + rpm range.
He said it dang near split in half.
I always figured Gm designed valve float as a rev limiter for stock engines.

 

HA!

Pretty much exactly that!

 

My uncle had a 62 Chevy 2 wagon. 283 PG.
he let me and my cousin drive it to school every now and then.
I thought you always shifted out of first when the valves floated.
That 283 survived my me, my cousin and my uncles little brother

 

Had a blown 283 , in a 55 p/u an regularly ran it up over 7, 7300 broke a valve spring once, (something to be said about lathe turned Lock's) My blown 327 6500 with no issues... I also assembled both engines , So I knew what I Honestly had...
Your results may vary

 

Had a 58 Vette in the mid 60s....wound it to 7,000 with no damage. Only did it one time....no fan belt sure let it rev quick. Wish i had that one back.........ah; the good ole days.

 

Stock 400 SBC 5000 RPM is a death sentence....I know..I killed it....

 

The question might be how many times can I rev it to xxxx rpm's. Or what gear it's taken to max rpm's in. Any engine can rev higher in 1st gear than it does in higher gears, as it takes less time at high rpm's to get there, and you're there less time in 1st than in higher gears.

 

Where was the weak link, one of my friends told me not to wind up my stock 400, he said it can't take it?

When putting together a 400 using the longer 5.7 rods, the cam lobes start getting close swinging by rod bolts at 1-3 and 5-6 starting at around .480 lift, I could see where a larger cam could meet and greet the rods when the crank flexes at higher r.p.m.s,
Don't know how much clearance there is using stock rods, but thinking it has to be close, the crank is still at the same place.
Always thought maybe that is why 400s got the bad reputation.
A Low budget build I got on the stand now is a stock bottom end 400 ( good non smoking runner out of my coupe about a month ago) using A.R.P. rod bolts along with a Howards 6000 rpm small base circle hydraulic cam/kit.

 

Agree that valve float will limit the rpms before catastrophic failure. It is pretty hard to actually scatter and engine, low oil usually just will cause spun bearings and the engine stops running once the parts start getting stuck together. True mechanical failure, like a rod breaking, valve dropping into cylinder, crank cracking and breaking (quite rare), and similar is needed to really have one scatter much.

 

Have had 60yrs of experience revving 283". I have no fear going to 6k with one with solids and stock internals.
Built, I have revved them to 7500 plus many, many times with no damage.

 

Not with stock points, the engine will act like it has a rev limiter..

 

The thing you should think about is whether you can afford to blow the engine up.....or not. While lots of engines will rev high, you only get to find out where it will blow up.....once! You don't get a "do over" at that point. So while many Chevies have reached these upper limits, many have not

 

I say go for it and report back! You'll experience valve float rapidly I'm sure. Banking on 5500-6500 tops.

 

Depends, does the engine have oil in it, or a brick lying on the gas pedal? And again, why? I am butch/56sedandelivery.

 

When I was in my late teens early twenties I had a fairy built up blown 327 in my OT 69 nova. I spun that engine way past 6000 rpm at the track and on the street constantly . Then my luck ran out and she spit a piston out the side. You never know exactly when they will give up the ghost . Some may disagree but SBC are pretty damn tough .

 

MAX RPM BEFORE STOCK SBC BLOWS UP REAL GOOD?
Only the Shadow knows!

 

I don't understand why you would want to destroy such a nice engine.