Pushrod Length: 351 heads on 302

[lucheski]

has anyone here run 351 heads on a 302, for those who have what pushrod length are you running?

I have 69 Windsor Heads (Casting=C90E G) for a '89 302 Block.

What pushrod length should I use?

stock 302 pushrods were too short

the next step up from federal mogul parts were too long...the rockers kept coming off until i shimmed the studs...and then one would pop off only every once in awhile

[Rev]

Have you got adjustable poly-locks on studs or fulcrum mount rockers? I think you would want adjustable poly-locks and stud mounts, and at least roller tip rockers. I ran 351W heads for several years on my 306 with no problems. I think I still have the push rods that I used and could measure the length if I can still find them.

The best bet is to get an adjustable length push rod, use a solid lifter, and find the length that keeps the roller tip right in the middle of the valve stem face when the engine is cranked over. That gives you ideal valve train geometry and best performance and least valve guide wear. You would have to order the correct length push rods after that ideal length was determined.

Rev

[~The Jester~]

Originally Posted by Rev

The best bet is to get an adjustable length push rod, use a solid lifter, and find the length that keeps the roller tip right in the middle of the valve stem face when the engine is cranked over. That gives you ideal valve train geometry and best performance and least valve guide wear. You would have to order the correct length push rods after that ideal length was determined.

Rev

Yeppers! I have a set of Canfields on a "302". I'm running 6.905" pushrods. No two engines are the same, so do like Rev said. Measure for yourself. Ya want the rocker tip to be a bit towards the intake when the cam is on the base circle. Right in the middle at mid lift, and a bit towards the exhaust at max lift.

On this one, it's best just to measure for yourself. Valvetrain geometry is THAT important. Get an adjustable pushrod (I'm guessing you'll need Comp Cams part #7702) and go from there.

Valvetrain geometry really is THAT improtant. Improper geometry will cause all kinds of problems, and have you chasing your tail around in circles.

[Capri306]

I think I had some small combustion chamber 302 heads (D0OE I believe, without air injection ports) on my 1984 block when I put it into my '79 Capri. If memory serves correctly, I think I went bonkers trying to get the pushrod length correct (as the cam was non-standard base circle ). I ended up shimming and getting some locknuts so I could adjust the rockers to get the proper geometry. Yeah, not the most scientific way to do it, but I was 17 and just wanted to get my car on the road!!!

[HotRoddin]

Originally Posted by Capri306

I was 17 and just wanted to get my car on the road!!!

Ahhh the good ole days You could do something you knew dam well you shouldn't do, then when it went wrong, which you knew it probably would in the first place, everyone just excused you because you were only 17 ! lol

I have a web site here somewhere, that had plans for an adjustable pushrod (very easy to make) for checking proper length. I'll post it if I can find it, although depending on what the cam co's charge for theirs, it might not be worth the effort ?

Rod