Technical Can anyone tell me if I'm on the right track?

I'm working with a free goodwreanch 350 block cast everything. And a 142 roots supercharger. It has the worthless 462624 heads but luckily with the 76cc chambers it's a dished piston low compression setup. A summit k1102 cam kit we will be locking out the vacuum advance and recurving the distributor with an 18 max initial stop bushing and two light silver springs to get a total of 30 to 31 all before 2,800 a 4150 750 hp that's setup for a roots applications. Will I need to install the cam with 4 degrees retard at the chain?

 

why such a small cam?

I've had decent results with big blocks with blowers with 230ish at .050 cams, with 112-114 LSA and built in 4 degrees or so advance.

If you can spin it up to 5500 rpm you'll make more power, etc.

 

Are you saying the cam you used had 4 degrees advance out of the box? Did you install that/those cams with the 4 degrees retard at the chain? Or did you set the timing chain/cam to the stock position? Would the cam I listed work on a 142 supercharger without that 4 degrees retard at the chain?

 

I would probably run it "straight up" at the timing marks, so it would have the amount of advance that's already ground into the cam.

But it's still a pretty small cam for a blower motor.

 

I'll install the chain to the straight up timing marks and see how it does then. Also the smaller cam might limit a bit of power? The 350 will be bolted to a t90 4wd transmission\t-case that I'm guessing wouldn't take much to break. It's more for looks and hopefully a torque gain.

 

Then it will probably be OK. Listen for pinging, crank back the timing or get better gas if you hear any!

 

If I can't find the sweet spot on the distributor could I just delete the vac can flip the weights and lockout the whole distributor? Then drop it in and set it to 31 degrees throughout the whole rpm curve? I heard this would be hard on startups but as like a last ditch effort?

 

kiss your t 90 goodbye

 

I would keep the advance curve in the distributor. If you do have pinging problems, figure out what RPM they happen, and see if you can change the timing setup to retard it in that RPM range, only.

 

We have a gas station that sells 110 octane at the pump I'm hoping a mix of that and 93 will help keep pinging to a minimum.

 

I would try 93 by itself first, and see how it does.

With a longer duration cam, in a big block with 8ish compression, I can drive on 87 just fine.