I have a set of Windsor Jr. heads w (1.94,1.60)s they have been milled just a little bit to true them up, and I was gonna put them over the top of some stock 87 forged pistons and was wondering how much lift I could use before I run into piston/valve clearance problems? Also what would having my pistons fly cut cost if I had to?
How much lift can I use and clear the stock pistons?
- Thread starter POWER302
- Start date
Boss351
New Member
You could use some sort of thin layer of playdo on the piston and slowly turn the engine by hand... measure the gap you have between the lowest point and the piston. Do people still do this?
5.0 HOtrain
Founding Member
Boss351 said:
People still do that
More about duration than lift, at peak lift the piston is at the bottom of the stroke I believe. FWIW, i ran afr165's with a .5344 lift cam, but duration was a little lower at 218/222 @.05.also you have to take into account when going the clay method (playdo) route on a hydraulic lifter the plunger travel has to b added into the equation measurement also. do to the lifter not being pumped up.
i frequently use this method but on a flat tappet cam i use a solid lifter for measurement purposes, and on the hydraulic roller lifters i have a few scrap roller lifters with the plunger assembly tack welded on inside upper lip.
or you can use some low tension springs in place of normal springs for measurement purposes.
the 1.94 , 1.60 valves will definitely need 2 be checked 4 p2v clearance just for piece of mind........if not youd be takeing a big chance.
then later down the road when the chain gets stretched out and the cam starts 2 go out of synch, that spells trouble with big valves.
i frequently use this method but on a flat tappet cam i use a solid lifter for measurement purposes, and on the hydraulic roller lifters i have a few scrap roller lifters with the plunger assembly tack welded on inside upper lip.
or you can use some low tension springs in place of normal springs for measurement purposes.
the 1.94 , 1.60 valves will definitely need 2 be checked 4 p2v clearance just for piece of mind........if not youd be takeing a big chance.
then later down the road when the chain gets stretched out and the cam starts 2 go out of synch, that spells trouble with big valves.
i made a tool to hook the rocker at the pushrod and land on the other side of the stud, then welded a bar to it. put the piston at tdc(at valve overlap) installed stock springs for one cylinder, put a dial indicator on the spring retainer for measuring. and checked the clearance every 2 degrees for about 30 dergees both ways.
