Msd 6al2? (plz help me)

[Fastorange]

I seen you guys put the new 6al2 on the crusher camaro(on youtube). How is the box working? I was told by the guys at summit that msd was recalling them because they did not work right(headsoking). So I bought the 6al. I just bought a 67 camaro myself. it has a 388 in it. I'm not the best when it comes to motors. I'm trying to build a street strip car(12sec goal) that i can run on the road with pump gas. here in Ohio they sell 94 oct. The car now has a comp cam's 520 lift with a 280 duration. has lots of low end power but nothing on the top end. I need an idea where I should start. it has a 10:1 compression with the heads (76cc gm smog heads dunno what the runners are. but i know i have 2.02/ 1.60 valves )
other mods
750 cfm Holley crab
Weiand Stealth intake manifold
cast crank and rods. Hypereutectic pistons.
compcams roller tip rockers (will be replacing them with a set of hartland Sharp i have)
headers
rearend out of a 69 dodge dart 355 gear.
thanks for you help or ideas. I'm asking because in the video you guys said that your built a lot of camaro's and this car seem to be set up pretty good for a rookie such as myself.

[fahrenschnell]

Re: Msd 6al2? (plz help me)

You might want to post these questions up in the Tech Section....

There are a lot of knowledgeable guys who can help you out in there...

Good Luck and Welcome Aboard....

Seth

[min301]

Re: Msd 6al2? (plz help me)

There.....moved. ;)

[VTJUNK]

Re: Msd 6al2? (plz help me)

Seems like you have a pretty decent combo in the works there. A 388 with those heads and that cam is going to make good torque, not be a high winding motor. I would think it would be all done by 5400-5600.

You didn't mention what distributor you're using, but I would check to see what kind of curve you have, and make sure the timing is somewhere in the ball park, say 10-12 degrees, with 34-36 total just to start with.

I would change the heads, and that could be a whole 'nuther thread, what heads to use. With all you have in place, good heads will really wake this thing up.

[min301]

Re: Msd 6al2? (plz help me)

I would assume, since you noted you had 76cc heads,
that the pistons are domed, am I right?

VT is right about the heads, much better are available
to suit your needs, and make gobs more power everywhere.

[Fastorange]

Re: Msd 6al2? (plz help me)


As for right now the car has a stock points distribtor. I have an msd pro billet waiting to go in with a msd 6al. I was told by my good friend an his motor builder that i can only run 10:1 compression and run pump gas. they keep telling me if i go any higher ill have to much spark knock because the fuel will burn too fast.

I have these heads siting in the shop http://store.summitracing.com/partde...5&autoview=sku

But i was also thinking about going this way too http://store.summitracing.com/partde...5&autoview=sku

I have not pulled the heads yet on the motor to see what the part number is on the pistons. Im just going by what the other owner said.

[min301]

Re: Msd 6al2? (plz help me)

Then those heads choices won't work.

If you have 76cc chambers, and 10:1, then putting 64 or 67cc heads on it will only hike it more.

[VTJUNK]

Re: Msd 6al2? (plz help me)

Without knowing what you have for pistons, it's hard to say what you'll end up with for compression with those heads.

Your second choice for heads, the aluminum ones, will allow you to run slightly more than 10:1 compression and still run pump gas. With 94 available to you, I wouldn't worry about going over 10:1. With the 200cc runners, the engine will be more lazy down low than the other Summit heads you have, but they aren't a bad choice for a street engine, and I doubt you would really feel the difference between the two.

The 165cc runner heads will work well with what you have already, and provide lots of low end torque. Put that MSD setup in there, and add a 1900-2200 rpm stall if you have an automatic. That will go along with your 3.55 gears nicely, and will put you really close to your goal of 12's

[Fastorange]

Re: Msd 6al2? (plz help me)

I know that without what pistons i have in the motor I'm pretty much shooting in the dark here. So i guess the question is what kinda of compression can i run and still be able to use pump gas and run it on the street. reason why i wanna keep it more of a street car is because its a really nice car. I can bring it to myself to put a cage in it or to strip it out.

[Fastorange]

Re: Msd 6al2? (plz help me)

I got off the phone with the guy that did own the car and he told me that it has a dish type piston in it so that would mean that I have a lower compression than 10:1 Right? thats with a 5.7 rod.

[min301]

Re: Msd 6al2? (plz help me)

I they are dished, you have way low comp ratio with 76cc heads.

If you can get the part number, and ask if it was decked, and what that spec is right now,
we can give an accurate calculation of what you have w/ 76cc heads.
We can also calculate what it would be with the 64-67cc units.

[Fastorange]

Re: Msd 6al2? (plz help me)

I drove her home tonight. seems like I had a miss. when i stoped she smoked alot. so im guessing a good tune up. its got a race 750 holley on it. im going to just replace all gaskets and check everthing out. try to get a part number for the pistons and go from there. Ill keep ya guys posted.

[min301]

Re: Msd 6al2? (plz help me)

We'll be here. ;D

[smallblockjay]

Re: Msd 6al2? (plz help me)

Even with dish pistons and a 76cc head, comression might not be all that bad. It's not 10:1, but depending on the dish and the gasket compressed thickness, it could still be around 9:1. With the 4.060 bore and longer stroke, you have a little more volume compressing, so it's not like having a 4.0 bore, 3.48 stroke 350 with dish pistons and 76cc chambers. I think 64cc heads would be fine. I had 64cc Sportsman II heads with flat top, two valve relief pistons running near 11:1. And replacing those heads and the distributer along with adding the 6al will help a lot.