So I bought the Anderson n-21 cam and I finally put it in. On their website it says "works with oem pistons" and "good for gt40 heads". So I go to do my ptv testing using the clay method. The cam is set up for 1.7 rockers, I have 1.72s which makes the lift come to .518. I know lift is not the only thing to consider when checking ptvc but just wanted to throw it out there. I used my Anderson valve springs and a stock lifter to check the clearance. The intake valve has plenty of clearance but the exhaust doesn't have but about 32 thousandths. My question is if I actually use a solid roller lifter like you're supposed to would this give me more clearance or less clearance on my exhaust valve.
Ptv Clearance
- Thread starter Roller1991
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A quote taken from this site after a google search: http://www.enginelabs.com/engine-tech/engine-blueprinting-how-to-check-piston-to-valve-clearance/
"So, how much clearance is enough? A safe rule of thumb is .080-inch for intake valves and .100-inch for exhaust, which requires a little more clearance because of the increased heat factor. Experts also suggest adding .030 to each valve if the engine is equipped with aluminum rods as they tend to stretch more than steel."
Given this info and what I feel, I'd look at cutting relief in the pistons. .032" isn't a lot of room for error in this instance....
"So, how much clearance is enough? A safe rule of thumb is .080-inch for intake valves and .100-inch for exhaust, which requires a little more clearance because of the increased heat factor. Experts also suggest adding .030 to each valve if the engine is equipped with aluminum rods as they tend to stretch more than steel."
Given this info and what I feel, I'd look at cutting relief in the pistons. .032" isn't a lot of room for error in this instance....
How much did the lifter compress? You'd be better off testing PTV clearance with a solid lifter to eliminate that variable. Here is a Summit video about checking PTV clearance. If you skip to about 3:50, he explains about checking clearance with a solid lifter. But if this is your first rodeo rebuilding an engine, it might not be a bad idea to watch the entire thing. The only thing I have to offer that he doesn't mention is I'd spray a light film of oil (WD-40) on both the piston and the chamber to help the clay peel nicely when removing the head.
View: https://www.youtube.com/watch?v=Y66lvdHbm60
And to answer your original question, if the hydraulic lifter compressed AT ALL during your test (which if you used actual valve springs vs. a light spring to only hold things together - it probably did), the solid lifter will give you LESS clearance.
View: https://www.youtube.com/watch?v=Y66lvdHbm60
And to answer your original question, if the hydraulic lifter compressed AT ALL during your test (which if you used actual valve springs vs. a light spring to only hold things together - it probably did), the solid lifter will give you LESS clearance.
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