I blew something in my 8k dollar motor!! I have a feeling the oil pump is gone and I will have to take out the motor. I am still in the process of determining what is going on. If I take the motor out I am going to go from 11.5:1CR pistons to 8:1 CR so that I can supercharge the car. I am considering a 6-71 blower.

Do I have to change my camshaft to a blower cam?
What else do I have to change besides the pistons?
The internals are pretty bulletproof... see sig.

Thanks

 

you dont have to change cam, but it will help if your wanting power, also you will need another carb, as far as carb sizes thats not my area but my guess would be 2 650's, or you could convert yours to blow through and go with an ATI/vortec supercharger, i like ATI personally... check out ATI's website and look at their nova if you have doubts bout em not making enough power or something... got 1200hp on pump gas on a "slightly modified" crate 427 bbc, 1500 on race gas if i remember correctly, and a guy round here (denver, co) has a 64-67 nova with a 355 and the p1sc running low 11's

 

What is the LSA of the cam?????

 

That cam you have will leak off a lot of boost. I'd look for a cam with a lower duration (230ish?) and a 112-114 lsa.

 

I will have to check the lobe seperation.

Any cams you can reccomend that will go with my setup and a blower?

 

This is a must-read if you are thinking about doing this......

http://www.holley.com/HiOctn/TechSer...fo/SCTech.html

Can't say my limited expereince with roots blowers lines up 100% with what they say, but it's REAL close.

 

If the cam you have was right for the NA setup it will need to be changed to work with the 6-71. Blower cams are usually much smaller overall, because you don't need a lot of cam with boost. As the RPM climbs the supercharger make more and more boost, cramming more and more air and fuel into the cylinders, which accomplishes the same thing as a cam with a lot of overlap, long duration, and high lift.

Comp Cams makes a nice line of blower grinds, one of which should easily fill the bill.

Other mods depend on boost levels. Head and main studs are alwasy a good idea. You'll defiantely want a full forged rotating assembly, which I would assume you already have. Keep in mind that ring endgaps are different for blower engines than they are for NA engines, because the cylinder temperature is greater.

 

Thanks for the info. And yes my internals are pretty much bulletproof to an extent. All forged and nitrided to handle the nitrous.