Supercharger Help

[cranknut67]

I finally found a B&M supercharger, and was wondering if anybody knows about timing issues that I should know about ?
I am going to be using a mallory comp 9000 unilite - currently I have not seen a way to get the timing controller ( MSD ) that I have to work with the 6al and the mallory dist.

I will be running the stock pulley (7 lbs of boost) with 8.5 - 9.0:1 compression - I want to keep the static compression down to 12 if possible.. and the cam - 272 crane w.454 lift ( advertised duration ) will this be ok to run with it - just afrais that I will screw this up and be rideless because I missed an obscure fact..

[PR454SS]

I think I remember reading on the MSD website or in the directions with my MSD box about how to hook up to different distributors, you may want to check there. I do know that with a supercharger you'll need to watch the boost carefully to avoid detonation/preignition as the boost climbs you'll need to back off the timing. Here is a couple of ignition setups from a Street Supercharging manual: 10 degrees dist. advance in by 3000 rpm with 18 degrees initial lead for a total of 38 degrees for the street.
Another says:to slow the dist. advance through the use of stiff advance springs and have all the advance in by 3500-3800rpm with 12 degrees initial advance.
There is really no way to tune it before you start, also you'll probably want to go to a colder heat range spark plugs to compensate for the increased combustion temps.
Sorry for the long post, I'll bet it will be Bad A$$ when you get it done

[Randy70C-10]

I run mine around 36 degrees of total advance, but the best thing that works for me is to advance it until it knocks a little then I back it off, turn off the engine and start it back up. If it sounds like the starter is having a hard time turning the engine over, then I back the timing off a little more. Fire it up and take it for a spin. If you floor the pedal and it still knocks, back it off a little more. You don't want detonation, especially with a blower motor. You'll go through head gaskets every 100 miles. Also, have you done your homework? You can't put a blower on a stock engine. Some will tell you differently.

[cranknut67]

350 ci 4 bolt main block bored .40 over w/ flat top pistons (steel) w/ a steel crank,(standard stroke ) brand new world sportsman 2 heads 1.6 - 2.02 w/complete race springs/screw in studs
roller rockers, mild cam. headers MSD 6al / MSD timing controller..
think that will be ok to run with the 177?

[Rooster's 67]

Quote:: ((I want to keep the static compression down to 12 if possible.. and the cam - 272 crane w.454 lift ( advertised duration ) will this be ok to run with it))


AHHHHhhhhh .........

NO

Sorry, do you mean that you are going to set the base motor up with a caculated compression if 12:1, If so this is very high for a blower motor. Even a small huffer like the 177.

You could go 12:1 static but you would have to go to a much larger cam than the 272 crane camshaft. in the order of 298 adv. duration or larger or much more overlap like in a special blower camshaft. And the streetablity of this setup would suffer Terribly

please elaborate.

[cduster]

You can't put a blower on a stock engine. Some will tell you differently.

Why not? I was told that you could on a lower compression stock motor if you used a larger pulley on the blower to run less boost.
I have never had a blower, but would really like one so any info on this would help. Thanks, Dan

[Chevy67Tk]

cranknut67

Which timing controller are you running


I’m running an MSD9877 with the distributor locked out. I’m still experimenting a lot but the last setup is 16 initial advance with total 38 all in at 3200 rpm.

Like randy said do your homework and take your time it may cost a little more now but will pay off in the long run.

[Randy70C-10]

cranknut67- Flat tops will eventually crack under any kind of boost. You need to run forged/dished pistons designed specifically for blowers and turbos. Also, you should run a milder cam with a little more duration on the exhaust side, and the heads should be ported a little on the exhaust side as well. If you have the stock harmonic balancer, you should think about getting a Fluid Damper.

Rooster- Static compression is the end result (engine compression plus blower boost) The calculated static compression ratio in my Model A is 18:1.

Here's a good pic of the engine in the Model A:

[Rooster's 67]

yup went back and re-read the first post....duh
he should follow Randy70-c10's suggestions for engine build rather than mine based on the way I read it at first.

[Randy70C-10]

Rooster- If it can be broke, I've broke it. Rock on!