View single post by DonBurns
 Posted: 01-16-2017 04:31 pm
PM Quote Reply Full Topic
DonBurns

 

Joined: 09-18-2015
Location: Fullerton, California USA
Posts: 47
Status: 
Offline
Tim-

Thanks for the feedback. I did fit the "competition valve springs" that are sold specifically for use with 104 and 107 cams. The club store mentions they are necessary to avoid valve float (bounce?) but no mention of the binding issue, but I have to assume the springs are correct - the engine did not break when started anyway. I also fitted "big valves" , 1.450" Intake and 1.275" exhaust, and the upgraded studs to allow the newer torque specs, and new JE 9.5:1 pistons. I wonder if the final compression of 9.6 is due to the decking work.

I had not thought of the valve timing changing due to decking the block. I always thought decking was a standard part of any rebuild. When I have a moment I will do the math and calculate the degrees of cam shift that would go with the .1 compression increase. Although there are other factors going on, like CC'ing of the head and thicker head gasket, so I'll just calculate cam turn per mil.

I have another concern at the moment. The builder did so many things wrong besides decking the liners flush (no thermostat, no oil in the transmission and several more minor issues) that now I'm wondering if they put the cams in the right place. I told them (but I told them about the nip as well) and the boxes were marked, but... Anyway I was going to check the lift yesterday and took off the intake cover and was setting up my dial gauge, but realized mine is only a .25 maximum gauge. I think that should work as a way to verify once I get the correct gauge.