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Super73 · 04-27-2010, 02:11 PM

Not sure if this will help you or not but I was running a cam with 243/250 duration at .050 on a 108 intake center and a 111 lsa. I was able to run power brakes. But I only have 347cis..

I think the thing you need to look at is how much overlap the cam has and where the valve events are against static compression (leading to DCR). There is a lot that determines vacum at idle/cruise.

I'm assuming you will be running a hyd cam for maintenece reasons? Flat or roller? The lobe profiles will differ..

If you give me some more details I can put in it performance trends and give you an idea of vacum at idle. It may not be spot on, but might help a little.

04-27-2010, 02:11 PM	#2
Super73 Registered User Join Date: Nov 2007 Location: Bay Area, Ca Posts: 2,841	Re: How much cam is too much cam for power brakes Not sure if this will help you or not but I was running a cam with 243/250 duration at .050 on a 108 intake center and a 111 lsa. I was able to run power brakes. But I only have 347cis.. I think the thing you need to look at is how much overlap the cam has and where the valve events are against static compression (leading to DCR). There is a lot that determines vacum at idle/cruise. I'm assuming you will be running a hyd cam for maintenece reasons? Flat or roller? The lobe profiles will differ.. If you give me some more details I can put in it performance trends and give you an idea of vacum at idle. It may not be spot on, but might help a little. __________________ ------Motor---------------Bottle 60'---1.53---------------1.41 1/8---6.58 @ 105.92----5.87 @ 118.41 1/4---10.38 @ 126.97----9.24 @ 142.49 Last edited by Super73; 04-27-2010 at 02:13 PM.