Ok guys....wondering about putting 1.6 rockers on my 383. I believe I have plenty of room....just wanting to run it by y'all as well. Flat top pistons with 4 valve reliefs....3.4cc. .010 piston to deck clearance with a .041 thick gasket and 65cc AFR heads and the GM 847 cam.

I have 1.52s right now...just something I'm thinking about....probably won't gain much going to the 1.6s though.

What's your opinion?

 

Very unlikely to be a problem, but the way to know for sure is to check.

 

Most of those types of pistons only have valve reliefs for 2.02" valves, while the most recent AFR 195 heads have been getting 2.055" valves, and the 210s have long been getting 2.08" valves. So if those are the heads you have, then you'd better pull one, get the clay, and check it the right way.

 

I ran flat tops from SRP with 5cc total valve relief and there were only 2 reliefs. With AFR 65cc chambers, 0 deck with .041 gasket. I ran a cam with 286/306 advertised duration 230/245 at .050, .603/.613" lift on a 109 lsa, installed ona 108 ICL.

I had around .120" on intake and .080-.090 exhaust which is bare minimum clearance.

You should be fine on the 847 cam with .010 deck/.041 gasket. But its nice to check to be sure.

 

I have the Canfield 195's which also have the 2.05 intake. My intake valve would hit the side of the relief. The depth was fine, but I had to have the reliefs for the intake valves widend.

 

Thanks guys...that's what I was thinking as well. If I pull the heads to check, then I'll probably go to a smaller gasket in thickness to get a better quench and just add a tiny amount of compression.

When I was building the engine, I took the edge of the valve reliefs and rounded/smoothed them from there jagged edge to reduce detonation so I did clearance them a tiny bit for the bigger valve without thinking about it....lol.