Jeff95TA

I read an incredible amount about this last night! Maybe we can get all of this answered in one place.

1) When using the pushrod checker should a solid lifter (or one made to be solid) be used? If so should it be the exact same brand so the geometry remains the same? The lifter plunger does compress when opening the valve if the regular springs are used.

2) Can a checker spring be used instead of using a solid lifter? It may be hard to get a pattern mark though?

3) If using a checker spring, should the lifter be preloaded?

4) Car Craft had an article on checking pushrod length where you get the lifter on the cam base circle, put the rocker arm on, and just move the roller enough to mark where it's hitting. They recommended it be on the inboard 1/3 of the valve stem. This won't show the full marking pattern but it should show the start of the pattern. Thoughts on this?

SStrokerAce

1) this is the method I prefer, to use a solid version of the hyd lifters in the motor. You need to make sure the length from the roller wheel to the pushrod cup is within .010" of what you are running. It helps to have a machine shop to make these things!

2) yes you can do it that way as well, you don't get as much of the deflection in the system when you are checking it though.

3) yes you want to setup the system exactly how you are going to run it.

4) I shoot for the narrowest pattern that is in the middle of the valve, there are a lot of ways to do this but once I saw that Warren Johnson argeed with my way I'm sticking to it.

Bret

Colin91Z

Bret, what is your opinion of these:
http://store.summitracing.com/egnsea...115+4294859056


I have an adjustable pushrod from comp cams that I usually use, but I saw this and was curious so I bought one (seeing how it was pretty cheap) I figured I'd give it a try in conjuction with my adjustable pushrod and see how I liked it. Have you ever used one?

SStrokerAce

yeah I don't get the point of those.....

Colin91Z

Yeah I didn't either. I figured I'd take a $12 gamble just to see what its all about...My guess is that I'll be using the adjustable pushrod to determine the length like I always have in the past


FWIW, here is my thoughts on it: It says to slide it over the stud while the pushrod is in place, (and while the lifter is on the base circle of the cam of course) and if the checker contacts the pushrod first to measure the gap between valve stem tip and the checker and then order a pushrod that is that paticular length shorter. Of course its vice-versa if it contacts the valve stem tip first.
So I figure I'll try it and use my adjustable pushrod to figure what length pushrod it says I need, and then install one of my rocker arms and see if its right....I guess I'll let ya know how close it is

Jeff95TA

Messed around for a few hours this morning.

Tried a checking spring but still got a good bit of movement in the lifter, and it didn't want to make a mark on the valve real well.

I already had a solid lifter that I had made with epoxy, but it was an OEM lifter, not a Comp like I'll be running. Don't have a good way to measure the wheel-to-cup distance, but I compared the base circle valve tip mark between the two and they were close but not exact. Two extra discs under the cup of the OEM got it darn close to the Comp one.

Checked the marks starting at 7.200 and went down in 0.050 increments to 7.050, which looks the best. 7.050 got it closest to where it belongs (pretty much centered over the valve, maybe a little biased to the intake side). But the mark got wider. I was confused by some earlier stuff I read - is it possible to change the mark width without moving it's location? Changing length always moves the location, correct?

SStrokerAce

For the most part it changes the location but the narrower the better since it's less side loading on the valve/guide.

Bret

Jeff95TA

Lateral placement won't be a problem since I have adjustable guide plates.

This is what I ended up with.

7.100"
http://home.comcast.net/~jsaccani/DSC02675.JPG

7.050"
http://home.comcast.net/~jsaccani/DSC02676.JPG
http://home.comcast.net/~jsaccani/DSC02679.JPG
http://home.comcast.net/~jsaccani/DSC02681.JPG

7.050"(base circle mark)
http://home.comcast.net/~jsaccani/DSC02677.JPG

7.000"
http://home.comcast.net/~jsaccani/DSC02682.JPG
http://home.comcast.net/~jsaccani/DSC02683.JPG

Debating between 7.050 and 7.000.

One other thing. I noticed that sometimes the roller tip didn't leave a mark across the whole valve tip. Maybe the marker just didn't want to come off or could it be a problem with flatness of the valve stem or roller? Or am I worried about nothing?

A/G

Actually, based on the pics, I prefer the 7.100.

Jeff95TA

I'll try it on a few more valves to see if it's consistent. Does seem a little narrower.

What do you make of the marks that aren't across the whole stem?

SStrokerAce

7.100" is the best looking one to me... you don't want to go to small or you can have problems with the valves on the seat.

Bret

Jeff95TA

Checked several more with the 7.100" length:

http://home.comcast.net/~jsaccani/DSC02684.JPG
http://home.comcast.net/~jsaccani/DSC02685.JPG
http://home.comcast.net/~jsaccani/DSC02686.JPG

There's still that one pesky valve with only a partial mark. I tried rotating the valve 180 degrees, same thing. Also tried changing the rocker arm stud and a different lifter, no change. Could the hole for the stud not be lined up with the valve? The edge of the roller is just BARELY not touching. Almost can't even get an 0.001 feeler in there. And this is with the regular spring not a checker spring.

SStrokerAce

That looks good.

It's something goofy but if you can't get a feeler guage in there it's not a big deal.

Bret

Javier97Z28

Hrmm.. I ordered and have some checker springs with an adjustable trickflow pushrod and I was going to do this tomorrow so I could order new pushrods since I don't think my 7.2's are gonna work with the zero decked block.

Hopefully these will work in my case...

1racerdude

Yea your stud is out of line causing the rocker to coc* a little in relation to the valve. It's not a big issue as a lot of heads do this. What ya have to watch for is the rocker pushing hard on the guide plate on the opposite side of the way the rocker wants to twist. Have seen the roller tip eat up into the rocker body from this also but that was after 25/30,000 miles. I wouldn't worry about it,just something to keep a check on in the future.