OK, now that my heads are installed as well as the timing chain, it was time to measure what length pushrods i would need.

Here is a link to the head install thread. http://forums.corvetteforum.com/c4-t...r-install.html

First off, I asked questions and did some research. I ended up buying this pushrod length checker from summit.

http://www.summitracing.com/parts/CCA-7702-1/

Then I read up on pushrod length checking procedure from people who had input in my head install thread.

http://www.biggrizzly.com/Lloyd_words.html

http://www.circletrack.com/techartic...gth/index.html

After research, I was ready to begin.

First problem is that I have hydraulic roller lifters. If you measure pushrod length with them installed you get a false reading. I took an old lifter apart, took out the guts, and ground down an old head bolt that took up all of the slack the hydraulic part used to. Then installed the cap and retainer clip.



The pushrod length checker has 2 marks which seperate when you thread it apart. Each full revolution is .05 " longer. My stock pushrods were 7.2" so I decided to start there. This left me 8 revolutions from snug on the checker.

I installed my solid lifter on the exhaust valve of cylinder 1. I colored the valve tip with a sharpie, installed my stock 7.2" pushrod, then my roller rocker. I tightened the rocker bolt finger tight, then went 1/2 of a turn tighter. The original pushrod gave me a wide wear mark which was towards the intake side of the valve tip. This means my pushrod was too short.

I unscrewed the checker one full turn from the stock side pushrod (9 turns from tight) , giving me a length of 7.25". I again colored the valve tip with a sharpie,installed my pushrod checker (taped up so it would not move at all), then my roller rocker. I tightened the rocker bolt finger tight, then went 1/2 of a turn tighter. This 7.25" left my wear pattern wide and still towards the intake side of the valve tip. This was still too short, but the wear pattern was more narrow and more towards the center than my stock pusrod length.

I adjusted the pushrod checker 10 turns out from tight, giving me a length of 7.30". I installed the rocker with the same 1/2 turn after finger tight and the wear pattern was perfectly centered and narrow.

I repeated the 7.3" test on the cylinder 1 intake valve. I got the same pattern as the exhaust valve and was happy.

Just to be sure, I screwed the pushrod checker out another turn, giving me 7.35" and ran the test again. The wear pattern was wider than the 7.3" test and was more towards the exhaust side of the valve tip. This means the 7.35" pushrod would be too long.

I hope this helps others measure their pushrod length, and if I did something wrong or if I could improve on something, please let me know.

I think I am going to purchase these pushrods. http://www.summitracing.com/parts/CCA-7609-16/

I am going to wait until I get some feedback and be sure I did this correctly.

Thanks,

Mike

 

Just a bump...hoping to order these today from summit...

Would like to get them asap before christmas. Plan on installing my intake the 26th.

Thanks,

Mike

 

These will save you ~$20, and are a very high quality pushrod.

http://www.summitracing.com/parts/TFS-21407300/

 

If I could ask a question on doing this. Did you check more than one for pushrod length, atleast one intake and one exhaust? I would think they could all be a little different in length, but I guess with hydraulic lifters that could even them out . I've heard of kits where you can cut body of each pushrod to a special length yourself so each one can be set up different for each cylinder,then you press the hardened pushrod tips back in place. That might be over kill for what we are doing though. Thanks Tim

 

My cam has the same intake and exhaust lift (219/219 Cam by LPE) so if i use the same ratio rockers they should be the same.

If you have a cam with different lifts I would think you would need two different length pushrods if the difference was drastic or you used different ratio roller rockersfor intake and exhaust valve.

I did my test on my exhaust valve then took my final length and did the test on the intake and was happy with that pattern too.

As far as the kits go, I'm sure they have a need somewhere in the industry. I do not think that adding some parts to a stock 350 will warrant it though.

 

This won't make a difference. My cam is 605/622 lift, same pushrod length.