[25stevem]

Not having the poly lock on the flat as got a lot of folks messed up , some for days even after swapping heads and or cams so don’t beat yourself up too much.

[Gach]

Easy enough to do, especially when you’re in a confused state. I’ll bet it won’t happen again, that’s how we learn.

[Gach]

Some times, it’s the manufacturer who makes silly mistakes. On my second rocker Shaft set up, I went crazy for a week no matter what I did, I just couldn’t get the push rod geometry correct. Thinking adjustable push rod wasn’t long enough I ordered another one. Rocker Shaft mount has Pontiac stamped on it, in the instructions it says to put a Pontiac stamp towards the intake. Luckily enough for me I had pictures of the shaft set up that I sold, still on the motor. Which shows the Pontiac stamp facing the exhaust. I called the company, and guess what The instructions were incorrect. As soon as I switch shaft mount BINO ! I had correct push rod length, which was the ones I already had.

[chuckies76ta]

I ran these same lifters in one of my engines that I sold and the guy has never touched the adjustment and they are still operating fine for years. I was told by the manufacturing Tech that preload was very important. I believe .30 like you mentioned. I used a dial indicator to measure it. You can always replace your studs to longer ones if you don't have enough thread for the poly lock. I don't like some of the 7/16" studs that come with some heads and I always change to longer ones. I like more thread in the polylock. Make sure to check the rocker to retainer for clearance on full lift. Ya, machined surface on rocker is for polylock seat. I know you know all this, just throwing it out there. If you decide to use a stud girdle, make sure to use the one with the snap rings on the ends to keep the girdle in place. https://butlerperformance.com/i-2691...tegory:1234830
I also used the Staub measuring video and I found worked very well.

[rohrt]

Originally Posted by chuckies76ta

I ran these same lifters in one of my engines that I sold and the guy has never touched the adjustment and they are still operating fine for years. I was told by the manufacturing Tech that preload was very important. I believe .30 like you mentioned. I used a dial indicator to measure it. You can always replace your studs to longer ones if you don't have enough thread for the poly lock. I don't like some of the 7/16" studs that come with some heads and I always change to longer ones. I like more thread in the polylock. Make sure to check the rocker to retainer for clearance on full lift. Ya, machined surface on rocker is for polylock seat. I know you know all this, just throwing it out there. If you decide to use a stud girdle, make sure to use the one with the snap rings on the ends to keep the girdle in place. https://butlerperformance.com/i-2691...tegory:1234830
I also used the Staub measuring video and I found worked very well.

I don't know sh!t. LOL.

Measuring bores, degreeing cams and measuring for pushrods is all foreign to me, so I always appreciate the comments and experience others provide on this forum. Youtube and TV makes it all look so simple but until you try it with the tools and parts you have you never know what you will run into.

Yeah I measured my studs and they look to be 1.9" long. I see the ARP 334-7203 are longer stud. 2.1 tall. That would make the straub measurement a bit easier. I ran out of time but it looked like I could just barely get a 1/4 turn of thread on with the rocker at the 90 deg point.

When I get back to it I will see how close the Straub method is to the 8.75 pushrods I have in there..

Here is my math on that.
Gross Lift on the stump puller .570/2 = .285
7/16 stud 20 TPI .05 per Turn
.05/.285 = 5.7 Turns past baseline


Being ignoratn is not so much a shame, as bing unwilling to learn
-Benjamin Franklin

[25stevem]

Are you running 389/421 heads to be coming up with a needed push rod length so short?

[AG]

Originally Posted by rohrt

I don't know sh!t. LOL.

Measuring bores, degreeing cams and measuring for pushrods is all foreign to me, so I always appreciate the comments and experience others provide on this forum. Youtube and TV makes it all look so simple but until you try it with the tools and parts you have you never know what you will run into.

Yeah I measured my studs and they look to be 1.9" long. I see the ARP 334-7203 are longer stud. 2.1 tall. That would make the straub measurement a bit easier. I ran out of time but it looked like I could just barely get a 1/4 turn of thread on with the rocker at the 90 deg point.

When I get back to it I will see how close the Straub method is to the 8.75 pushrods I have in there..

Here is my math on that.
Gross Lift on the stump puller .570/2 = .285
7/16 stud 20 TPI .05 per Turn
.05/.285 = 5.7 Turns past baseline


Being ignoratn is not so much a shame, as bing unwilling to learn
-Benjamin Franklin

I'd be surprised if you need 2.1" studs. That's what I have on my race motor with 1.95" spring installed height.

[rohrt]

Originally Posted by 25stevem

Are you running 389/421 heads to be coming up with a needed push rod length so short?

The pushrods were supplied by SD Performance with the stump puller cam and ComCam roller lifters I initially had.

[25stevem]

Thanks for the reply, but that was not my question to you.

I can’t tell from your photos if those iron heads are 67 and up or not?

[rohrt]

Originally Posted by 25stevem

Thanks for the reply, but that was not my question to you.

I can’t tell from your photos if those iron heads are 67 and up or not?

Sorry, Heads are 1971 #96.

[25stevem]

Thanks!

[rohrt]

The Straub method will not work here.


I wanted to see how close the straub method was to my existing pushrods that have a nearly prefect contact pattern.

I did the math to figure the # of turns on the pollylock (see above) and there was a huge difference. like a 1/4" or more of gap between the rocker and pushrod.

I can visually see why. If I look at the 90 deg relationship of the rocker to the top of the valve face the roller is not centered. It looks like its going to roll of the end of the valve tip.

These are HS rocker, purchased for Pontiac. Although they were purchased in the mid 90s I believe.

Is this Normal geometry? Any reason to not run it as it is. with the pushrods I have?


1st pic on left - Rocker 90deg to the valve tip
2nd pic - Same 90 deg to show the roller to the valve tip
3rd pic. - With the pushrods on the base of the cam
4th pick - Valve lift on the top of the lobe

[zippy]

Doing the Straub method will look like the roller is not right when doing the setup. But it will be fine when everything is pumped up and running. The videos I have watched even explain this. I, personally, have never been able to fill a lifter with oil and not have it bleed down somewhat during testing when using the actual valve springs. If you have a really light spring, that will not collapse the lifter then you will see. Just did the Straub method on my 455 a little while ago. And worked perfect.
https://www.youtube.com/watch?v=o5is9BsH5OU

[rohrt]

Zippy what rockers do you have?

Are you able to show the same pic I posted, with the rocker at 90 deg and where the roller sits at the valve tip?

[zippy]

1.65 scorpions. And not really now. It is all buttoned up. But because you are at 90* before taking the lift into account, the polylock is up high, and the roller tip will be over the valve. Once you screw down the pollylock half your lift, it pulls the tip toward center of the stem. Look at 4:29 in the video link I posted above. You can see the roller is WAY over center when settng the 90* initially. But once it is tightened to proper location, 1/2 you gross lift, then when lifter is pumped up, and the rocker actually opens the valve, the valve drops down, thus the roller rides in center. Remember, the rocker stud and valve are canted closer at the top. The more the valve opens, the further apart the spacing gets. So when setting the 90* with valve fully closed, the distance is the closest and roller is over the stem. But it won't be in operation as rocker is tightened, and valve opens, this spreading the distance.

Want to add, that with this method, at 1/2 lift when running, rocker will be 90* to valve, and tip a tad over center. At 0 lift and Max lift, the tip should be just on stud side of center. And you have even geometry. You will be getting the max valve lift you can because the roller tip rides in an arc, but valve moves vertical. Arc to vertical travel is max at 90* the further off 90, the less valve motion you will have. Thats why mid lift, 90*. Even arc in first 1/2 lift as the 2nd 1/2