I'm putting together a 327 backed with an M-21 for my '67 Chevelle. The engine will probably put out 300-350HP. I have a new flywheel, new clutch and pressure plate. I may run it down a strip a time or two to see what it's capable of but I will not be racing it with any regularity. Also, I doubt it will ever exceed 6,000rpm. That being the case, do you think a scattershield is necessary? I currently have a GM aluminum bellhousing. Since GM sold millions of cars with similar powertrains I'm thinking I'm within a reasonable safety range.

Thanks.

John Ladd

Depends on the facility. I know here for "show-n-shine" days at the strip, you can get by without it (but not without a helmet). If you step up from there, you will need to have it, along with additional requirements, installed before passing tech.

If you value your feet it can't hurt even on a one or two time pass....JMO

Right, it "can't hurt" to install a scattershield...or a six point roll cage, etc.

What I'm wondering is, given the engine in question and the type of operation it will see, is it likely one could look forward to clutch or flywheel failure?

Put another way, GM sold millions of Corvettes, Camaros, Chevelles, Novas and B-bodies with similar engines/transmissions. Do you know if flywheel explosions were a problem with them?

Thanks, again.

John

The odds are that you will be fine with the setup and useage you describe.

But there is no guarantee of safety except with a blast shield.

All it takes is one time to have a bad day.

After grenading a motor that I thought was pretty safe up to 7000 I have new found respect for 120 mph and what can happen when the engine is reved up pretty good.

I will always recommend a scattershield for safety. It only takes one time to do a lot of irreversible damage to your car or yourself.

If you only plan a pass or two down the strip. search the classifieds or ebay for a used scatttersheild. I have NEVER run without 1. I got my first 1 from the local buy& sell paper for $50.

NHRA requires an SFI bellhousing if you're faster than 11.50 in the quarter (they also require an SFI flywheel and pressure plate).
With a 327 and less than 400 hp you won't be that fast.

What flywheel are you using?
If it's the stock size GM (10" ?) I've read in several books that they are safe to as much as 10,000 rpm!
I believe it's the larger 11" and maybe some of the old time 30-40 lb heavy flywheels that are not as safe at high rpm's.

My advice would be to stick with the stock bellhousing, install a rev limiter and set it to about 6500 rpm.
That way you won't over rev the flywheel and you'll also protect your engine from over revving.

My Chevelle also has about 350 hp and I've raced it with slicks and I dump the clutch at 5000 rpm and shift at 6000 rpm with no problems.

if your not putting in a scatter shield then I would at least run a billet flywheel.

Wow its your decision, but i will tell you i have seen 2 go. 1 was at high rpm and he sent it out the windshield, but the other was just as he hit second gear at about 5000 rpm on street tires, made a big mess and convinced me few hundred on a blowproof is just the smartest thing to do. Ralph

Thanks for all your thoughtful replies. You've given me much to think about.

John