Duncan_GT

Just got all of my valve train components delivered yesterday along with the custom cam. Heads are ready to be picked up after being milled. I was driving home today and randomly thought of PTV clearance. My new cam has more lift and duration than my previous Comp cam and the valves now sit lower. I'm still going to measure clearance..

But, what happens if I run into clearance issues? Fly cut the pistons? The pistons are made specifically for the twisted wedge head. I don't remember how much clearance I had originally, but I know I had quite a bit. How does fly cutting affect engine balance?

mjr46

I have probe pistons in my 347 and they will accomadate twisted wedge or inline heads, I have run inline and now tisted wedge with a .600+ lift cam and still had tons of ptv, I think you'll be fine, just measure and verify it

Duncan_GT

I was thinking i would have enough. But just in general, what happens if there is interference issues?

tinman

Same deal here.
I'd just check to see you have clearance and go.........

mjr46

you'd fly cut but I don't think you'll have an issue

Duncan_GT

One last thing. Is there a good tech write up on how to change valve springs? I got new springs, locks, and retainers. I know you have to know the install height etc

mjr46

do you have a special micrometer that'll measure installed height?? also it's not just installing the springs at said height, you first install them in a spring compressor and measure the open and closed pressures that the cam card says and see at what installed height they reach those pressures. In a perfect world both would match up...lol I usually just take mine to my local machine shop = quicker

Duncan_GT

I may do that then. I was just trying to cut costs w the machine shop, but i dont want to deal w the headache

tinman

Buy that special mic and one of those spring testers you use in a vice like I did and you'll have them for the rest of your life, thats what I did, saved a lot of money over the years....