pushrod/ valve question
pushrod/ valve question I had Ed at FTI spec my cam, provide pushrods and all valve train. The cam is 111lobe sep, .622 lift on int with 231 deg duration. 7.4 inch pushrods. I put a test spring on the intake and bolted head on to check ptv clearance. Rotated engine over and of course, it hit (ed said we would probably have to cut). but while doing this check, I looked into the int port and noticed the valve never closes. Even opposite of the lobe, the valve is still open about 1/8 inch. the lifter was made solid and i had a weak spring on it, but I grabbed the retainer and the valve would not move. You back the rockers off and it closes. I asked ed about pushrod length and he said 99% of the time its right, but to double check. I am figuring the pushrods are too long, but not sure....
On The Tree
Joined: Mar 2009
Posts: 175
Likes: 1
From: shrewsbury, ma
Got ya. It sounds like they are too long like you said. I got one of Ed's cams but I'm using morels and came out needing much shorter pushrods, 7.25. I tried using the 7.4s as a baseline like you and realized right away it wasn't right.
Get an adjustable pushrod. Find 0 lash, spin motor over while checking ptv. Then add desired preload to you're 0 lash measurement and get the right pushrods
Get an adjustable pushrod. Find 0 lash, spin motor over while checking ptv. Then add desired preload to you're 0 lash measurement and get the right pushrods
Well i am hoping Ed gets back with me and we can just get these swapped out. I appreciate your help tho. I was hoping since the weather was in the 60s this coming weekend to maybe get this thing together and put in, but dont look like that will be happening. I got a nice pile of parts here laying in the floor. I may go back out again tomorrow night and try it one more time to be sure, but i am pretty sure it was set up right. I did it twice with the same result.
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Verdad Gallardo At first i was using a actual spring, but then, for ease of install, I swapped to a "test" spring I made that is just enough to pull the valve snug against the seat. I read some more on here, gonna try the adjust to zero lash and go down to 22 lbs ft and see how many turns that is and see if its anywhere close, if not, i will have to go another route.
To measure the preload you need to have the correct lifter and spring installed then check preload. Zero lash then should torque 22lb at about 1/2 turn. Takes more that that shorter pr . Less is longer
Tim
Tim
Gotcha Tim. i done some research on it and that was the method i was gonna try now. I emailed Ed and he said by the ammount the valve was open, it seemed like they were too long, he is sending me out some 7.350 length to try both and see which ones are the best fit. Thanks for your info tho.
