hey guys. last year i put gn1 aluminum heads, ported intake, and comp 218/212 flat tappet cam in. car hasn't run right since. after much discussion and reasearch, i found i have 3 lifters that are collapsing, along with pushrods that are too short. yes, i did a search and now know about all the measuring. i was told that a 8.870 length is usual for this combo, but not the case for me. i'm coming up with about 9.100 inches. i have a friend with the same set up, but with a roller cam, and his pushrods are the 8.870's. the difference is in the height of the lifters, which is about 1/4 inch, the difference that i need. anyone else ever come up with 9.100 ? other question is, should there be ball ends on both sides of the p rods? there is on my stockers, but not the 8.870's, only on one end. if it's only on one end, where should it go?
pushrod questions
- Thread starter trbojo
- Start date
- Joined
- Feb 18, 2006
If your measuring right then thats what it is.
Whats on the other end of the push rod? They are usually identical. Can you post a pic?
Whats on the other end of the push rod? They are usually identical. Can you post a pic?
- Joined
- Feb 18, 2006
Damn, chewed up your rockers. :frown: Who set them up originally?
As long as the other end of the rod is round it shouldn't be a problem. I would use the ball end on the rocker side but looks like your getting new ones anyways.
As long as the other end of the rod is round it shouldn't be a problem. I would use the ball end on the rocker side but looks like your getting new ones anyways.
- Joined
- Feb 18, 2006
Roger that!
Well you are allot smarter now. :biggrin:
You confident you measured right for the new ones? Did you get a adjustable rod?
Well you are allot smarter now. :biggrin:
You confident you measured right for the new ones? Did you get a adjustable rod?
i just got the adjustable rod today....haven't actually checked yet...saw the 9.100 figure when i did a search on pushrod length... 8.870 which is what i got, plus .250, or 1/4 inch, which is about the difference between the roller lifter and the flat tappet the i saw, comes out to 9.120..i'll know for sure tomorrow when i measure
- Joined
- Feb 18, 2006
just finished checking. how crictical in closeness to the center of the stem do you have to be? here's 2 pics. the first one is with length at 9 1/8 which translates to 9.125..second one is at 9 3/32 which is about 9.094. i did measurement with a combination square and a straight edge. i'll have machine shop at work double check measurement for me tomorrow.
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Paul69camaro
Member
- Joined
- Mar 24, 2009
I just posted about this exact issue on another thread I started, http://www.turbobuick.com/forums/engine-tech/343522-first-buick-build.html
I talked to Tom this morning and said that just recently he started having a problem with the pushrod length with aluminum heads and flat tappet cams. I just bought the pushrod checker and will check the size in the next couple of hours. I'll post the results to see if the match with yours.
Aggie,
I read the thread you posted recently about your current motor build. Looks like we are currently building similar combos. Post up your results also if you can.
Hook em!
I talked to Tom this morning and said that just recently he started having a problem with the pushrod length with aluminum heads and flat tappet cams. I just bought the pushrod checker and will check the size in the next couple of hours. I'll post the results to see if the match with yours.
Aggie,
I read the thread you posted recently about your current motor build. Looks like we are currently building similar combos. Post up your results also if you can.
Hook em!
comp measuring tool should be here tomorrow. I won't be able to measure till this weekend. I'll post up what I find.
Paul69camaro
Member
- Joined
- Mar 24, 2009
Trbojo,
I came up with 9.111 actual length measuring with calipers and still was a little high on the valve, since you have to add about .016 for the oiling hole difference and the fact that pushrods come in .05 increments I ordered 9.150 pushrods from Tom at Champion. Looks like we are all in the same ball park. BTW, I made a solid lifter to keep my hydraulic plungers from collapsing, what did you use to measure yours?
Paul
I came up with 9.111 actual length measuring with calipers and still was a little high on the valve, since you have to add about .016 for the oiling hole difference and the fact that pushrods come in .05 increments I ordered 9.150 pushrods from Tom at Champion. Looks like we are all in the same ball park. BTW, I made a solid lifter to keep my hydraulic plungers from collapsing, what did you use to measure yours?
Paul
Paul69camaro
Member
- Joined
- Mar 24, 2009
You absolutley right, I forgot to add .004 to my measurement since my home made solid lifter was .004 taller. Comes up to exactly what you measured, 9.115. Just remember that when you order the pushrods, they don't account for the oil holes in the end. Look at the bottom part of this site.
COMP Cams® - Valve Train Geometry
Paul
COMP Cams® - Valve Train Geometry
Paul
i think you subtract for the oiling hole difference...i was told that the actual length of the rod you order is shorter...i.e.... 9.150 spec rod is actually 9.135.....oiling hole difference...if you were high on the valve (mark more towards exhaust side) you would want to shorten the rod....am i correct here??
NicksTurbo6
Member
- Joined
- May 25, 2006
The second picture with the 9.094 measurement has a better contact pattern than the first pic. You want the "sweep" to be on the center of the valve tip, just slightly favoring the intake side. This is how I set up the shaft mounts on my old 396 LT1, as directed by Jesel.
Nick
Nick
