pschif8480

Hello all. This is my first post. This past December, I got a 1971 Coupe with a 496 Stroker, Solid Roller Lifter Cam, .700" lift, TH400 automatic with a Hurst Quarter Stick, and 5:13 gears. I have taken it out about 5 times since this brutal winter here in NY. Getting used to the car, really enjoying it. Anyhow, after going for a long drive, I was getting ready to move it into the garage and I was about to put the shifter into reverse from neutral but instead of putting my clumsy big foot on the brake, I floored the accelerator. The engine roared and before I could get my foot off the gas and check the tach, within two seconds, the rev limiter cut off the engine completely. I don't think I even got to redline but I am not 100 percent sure. After a minute, I restarted the engine and took it for a ten minute drive; everything seemed okay.

I can't shake the concern that I might have done some damage. Any feedback would be appreciated. Thanks.

Paul

U17

It's shot !!! Just send it to to me....

pschif8480

Hey man, thanks. What can I tell ya'? I am neurotic. So where am I sending it and to whom?

harris1507

If the Rev limiter was working properly it should be just fine

Gordonm

that is the purpose of the rev limiter.

drwet

Relax. They're tougher than that. Besides if you had done some damage, you would know it by now.

68/70Vette

I know it's a matter of personal choice, but 5.13:1 gears is, to me, pretty restrictive. My 68 ZZ4 had a 3.73:1 (?) rear end and it drove on the freeway at about 3000 rpm at 60 mph. I installed a Tremac TKO 600 trannie and now cruises at 2000 rpm at 70 mph. 3000 rpm at 60 mph just drove me nuts..just me.

My 1970 project car also has a 3.73:1 rear end ratio..all Tom's Differential stuff. It'll have a 496 pr 502 cubic inch engine. It's a Keith Black aluminum block and aluminum Brodix heads. It now had a TKO 600 trannie also. Should be looking at 2000 rpm at 70 mph also.

Back to your 5.13:1 rear end. A stone stock Corvette C3 IRS cannot tolerate more than about 550 hp with the stock tires, even racing tires, that were available in the early 1970's. This is 550 HP that the L88 engines developed for road racing with road racing tires. 550 hp with drag racing tires will destroy the rear end differential as I understand it, If you really have a lot of HP, and a 5.13:1 rear end, you could well be reaching the limitations of the rear end. Check out Tom's Differentials. Enjoy!!

Jerry Curl

I've done that myself. It should be fine. I think you'd have seen any problems at this point had there been any actual damage at this point.

joewill

with that engine specs and those gears, i expect that your car has seen alot more exercise than you have given it.. i bet it has been well past the red line alot.. by the way, how do you know what the redline is?

tokim

With a '71, you'll have plenty of opportunities to be concerned over real issues/repairs..this isn't one of them.

pschif8480

You're probably right. I think it has seen alot more exercise and RPM's than I have yet to give it. I am not clear on what determines redline on a particular engine. The engine was rebuilt on March 29, 2013 and I have the dyno sheet. Peak Torque is 623.97@4700 RPM and Peak HP is 655.11@6100 RPM. From what I can gather, redline takes into account bore and stroke, rod/stroke ratio or whatever is a little passed (+500 RPM) peak HP RPM. Maybe someone here knows of a concrete formula for redline.

540 vette

I would guess with the engine and parts he has listed, the person that built the car probably beefed the rear up some and didn't just throw some 5:13's in there.

Dustup7T2

Were you wearing steel-toed engineer or hiking or motorcycle boots?

If your foot doesn't quickly learn the difference between stepping on the brake vs the throttle, you may end up hurting reciprocating parts in that 496 if the problem continues. I'm guessing, your event was a one-time and rare occurrence, correct?

I agree with the others: no harm, no foul. I'll guess that the motor is fine.

Stout package installed in your car. Is it licensed for the street or strictly a racer?

pschif8480

I know...bonehead move. I'd like to say I was wearing Doc Martens but I was wearing New Balance sneakers. I have been driving for 36 years and I don't remember ever doing that. I also have experience driving a manual stick on a car and a farm tractor though it's been many years since. So I can pretty much say with 100 percent surety that I will do my best do not do that again. The car is street legal; I got it December 2013 (through a consignment) and just really started to take it out last month. Getting used to everything; the cockpit, the quarter stick, the handling (it has power steering, disc brakes and MT ET Drag Radials on the back). It has decent street manners but it definitely was a racer at one time because the engine appears to have a vestige of a nitrous system and it appears to be a somewhat detuned racing setup.

Sunstroked

Wow, someone built a monster. Yeah, I'm pretty sure that rev limiter was set up as a safe guard. If he blew a drive line part while getting on it, the rev limiter protects the engine.
Curious, what possessed you to acquire this beast? I mean nothing negative, it's just not a car for everyone.

pschif8480

Well, over the years I had developed an interest in classic muscle cars, especially the Chevrolet, Dodge/Plymouth and Pontiac lines. I spent lots of time on the internet perusing different muscle car sites for info and to see what was for sale. Well, I always really liked the C1 to C3 body styles (especially the C3 being a teen in the 70's) and I really liked the modified pro street/street machine builds and this one caught my attention--right price and stats. I really did not realize how much car it was (maybe a bit too much), but I had it checked out at a local muscle car shop when I took possession and they cleaned some things up on it (like new front tires, new Weld wheels, electrical work, tune, etc.). The first time I heard the engine fire up, I was taken aback at how loud it was. It turns out to have excellent handling, has good street manners, goes nicely at 60 mph on the highway, and is a lot of fun to drive. I have not taken it over 5000 RPM's and I stay in the right lane on the highway. But I have launched from a dead stop and it is exhilarating. To me, it is nice to know that I have the awesome power under the hood, not that I would drive irresponsibly all the time. Anyway, to cap off this long story--I am too old for a midlife crises and I guess I was communing with my inner Walter Mitty (Danny Kaye not Ben Stiller). Thanks for listening.

540 vette

You go 60 MPH on the parkway with 5:13 gears. How high is the RPM's.

I had a Firebird with those gears and used to cruise about 40 on the parkway at around 3000 RPM.

pschif8480

60 MPH looks to be about 3500 RPM.

ryanmh

With that build, the rev limiter is probably set well below what it can tolerate. Your "redline" doesn't have much to do with peak horsepower. It's going to be defined by mechanical failure or valve float. Assuming that's a really stout build, it's probably valve float. Around 7000 RPM would be my best shot in the dark for a solid roller.

MMH2009

1971 Coupe with a 496 Stroker, Solid Roller Lifter Cam, .700" lift, TH400 automatic with a Hurst Quarter Stick, and 5:13 gears.

Nice set up! I bet it roars.