How many RPMs?...

[jcharliem]

Spidey's comment in the "350 redline" thread about a 327 leaving the line at 11,000rpms got me wondering...

How many rpms are possible in an overhead valve mill? I know Pro Stock are in the upper 9,000's and into the 10,000's. What's the most you've personally witnessed other than watching NHRA?

For me it was a modified Boss 302 - pushing 8,600rpms.

[Barry Donovan]

what I learned to be a chevy 302 a long time later (the guy who built it helped with a monte carlo some years later - small world)

anyway, 11000. his build + factory stroke.

That is actually where I got a whiff of the 3 main subarus, that same guy.
I am indeed limiting to 6500, it would go until exploding (I guess 10000+ on 2.65 inch stroke)

I have heard my own at buried tach, 9k.

A lot of myths out there.
short strokes can go far on regular people fuel... hearing stories of big strokes + gas station = big rpm, its most likely the hoaxes you may be digging at.

[VTJUNK]

A friend of mine has a log book from a Ford Thunderbolt, one of the ones that is no longer around due to a trailering accident, and it documents the runs the car made, from tire pressures, track conditions, clutch techniques etc. It says leave at 7,000 and shift 7500.

There was a well known Rochester NY area Falcon drag car that had a small block Ford in it, and was run to over 10,000 according to a few people that knew the car and a few guys who drove it.

Personally, I've run my 289 Falcon to 7500 many times

[Beagle]

I don't bother trying to rev an OHV... it's too expensive for my blood. OHC, I've had over 13k time after time. The R6's were redlined at 14,500. We put 20% nitro RC fuel in a 21cc Hoffco weedeater motor and tached it with a 8" prop at just over 21,000. That was a little spooky.

[68scott385]

7000rpm flash on a 6000 pill

4:11 gears & 3.06 1st don't really work together...

otherwise keep 'em under 6500

[Thumpin455]

I shift the 467 at 7000, but all the others at 5800.

[jcharliem]

...OHC, I've had over 13k time after time...

Ya, the OHCs are insane. F1 buzzing +18,000rpms.

I'm curious about automotive OHV mills (not motorcycles). I don't believe I've ever heard of 11,000 rpms. I think Pro Stock is about the highest spinning OHV mills out there... and you need some wicked valve train components for that speed. Equally impressive are the continual rpms in NASCAR... 7,500 - 9,000! Sheesh.

[silver_bullet]

Honda 125 one lunger at 10500 RPM; the factory GP Honda cycle prototypes would pull much higher but that was like a 6 cylinder 250 cc engine

[NewEnglandRaceFan]

Ya, the OHCs are insane. F1 buzzing +18,000rpms.

I'm curious about automotive OHV mills (not motorcycles). I don't believe I've ever heard of 11,000 rpms. I think Pro Stock is about the highest spinning OHV mills out there... and you need some wicked valve train components for that speed. Equally impressive are the continual rpms in NASCAR... 7,500 - 9,000! Sheesh.

nascar run up to 9700 safely..
and over that to win if needed..
RCR has engines that ran in testing for 2 hours straight at 11000rpm, but kept breaking valves

[Beagle]

nascar run up to 9700 safely..
and over that to win if needed..
RCR has engines that ran in testing for 2 hours straight at 11000rpm, but kept breaking valves

Yep. Safely. That's why so many used parts are on ebay. Rod sets of 6, lifters for a seven cylinder... and there is never any smoke or oil on the track from that safe 9700.

Uh huh.

lol. Impressive none the less, but that is some hairy edge they live on.

[Scott Liggett]

My buddy's '71 Vega with a 331 would hit the lights at 8900 on the 1/4. I loved to sit down at the end of the track to hear it come screaming by.

Nascar's engines still use flat tappets and spend a lot of time above 9000 rpm. Pretty amazing that they spend the entire race above 7000 rpm and bounce off the rev limiter on the straightaways closing in on 9500 rpm.