Hello Everyone,
I just got done measuring my pushrod length with my new morel lifters. I measured a required pushrod length that was 7.277 inches which includes the .030 recommended preload for the morel lifters. I have 7.325 in pushrods, so that makes them .048 too long. How would go about taking care of this? Could I just shim my stock rockers that .048 in length, or would a preload of .078 be fine or way too much? Should I just call it good, and torque and go?

Thanks!
Adrian

 

Why not order custom pushrods?

 

Because all the shops around here are closed the whole week....aka, livernois which is 3 miles from my house, and I need to get the car put together as soon as possible. I'd like to finish it tomorrow if possible. I already have my cam degreed perfectly using the ICL method ,and now I'm onto pushrod length and PtoV clearance. I just want to know if a .078 (or more realistically a .080") preload would be too much on the morels, and if I can just shim my stock rockers to make up for the difference.
Also, I already have 2 sets of pushrods, and I don't want to buy more haha....

Best,
Adrian

 

I would shim before I added that much preload. Best would be buy the right pushrods, don't hurry, do it right!

 

well, I guess I could just shim for now, and order the new pushrods for later, its a 10 min job swapping out the pushrods. So, thats where I htink i'll go for this, I'll shim first, sell off all my remaining parts, and then get the custom lenth pushrods...

Best,
Adrian

 

Adding shims will throw off the swipe on the valve tip which will cause it's own set of problem if it's way off and left that way for to long. If it was me, I would order the correct pr's shipped overnight and be done with it and then sell the extra stuff. Sometimes finding the right size shims can be a pain.

 

Yeah, I'd just order a set of shorter pushrods man. You'll save more time and headaches doing it the right way first!

 

Alright, I will be able to get some 7.275 in pushrods today!! That will give me a .028 in preload on the lifters with a recommended .03 from Morel.

Will this .028 preload suffice?!

Thanks,
Adrian

 

I would say yes, your measurements are likely not accurate to 0.002 anyhow. Also, which pushrods? I think Comp uses gauge length and Crane and Manley use OAL so be careful.

Which adjustable pushrod did you use?

 

I ran into this with pushrods. If you bought a guage length 7.325 it will actually measure 7.338-7.340. That was why I had to send them back. Morels, heads milled .035, and .040 cometics needed a short rod and .055 shim. The .055 shim got the swipe right and then I had a 7.325 custom OAL pushrod made from Manton Pushrods. Had a set made from Crane and they were total GARBAGE. Varied .030 from shortest to longest and was told that is as good as it gets. It is been a hassle!

BTW...... .025-.035 is perfect preload. Some even run around .015 on the morels. Mine is set up to about .025-.030 across the board.

 

why wouldnt you use adjustable rockers too?

 

Sam:

Money

 

Agreed. But if I had $$$ I would be running both.

Glad you found the PR's you needed. Really sux having to do a job twice.

 

If I had the money I'd be running Jesels on my new motor. It's the last place I ran out of cash and ended up with stock rocker arms.

 

spent the coin on the best lifters and skimped on the rockers...ok
Let us know when you find needle bearings in the oil...

 

FWIW, TrickFlow can do some custom length prods quick, if that size isnt already in stock. I got mine in two days from time of ordering, and they checked out dead on across the board.

Reading this, I finally found the recommended pre-load for my Morels, yeah yeah yeah....too bad I already been running them with .XXX pre-load. Guess I need to get back home and do some measuring. Also, I am looking into the Crane adj. rockers, not for bearings sake, but the fine tweaking of prod length/pre-load etc, hopefully quieter in the end.

 

the only thing with the Cranes is their varible ration. It goes to like 1.79 on the nose of the cam, then back to 1.7 in some areas. If you cam is big (I think it is a donkey dick) you are in the same boat at me. I don't want anymore lift, and the comps and Cranes both are larger than 1.7 ratio.

John

 

The actual ratio of the "Quick-Lift" Crane rockers is 1.72. The rocker starts the valve off its seat at a ratio of 1.79. As the rocker oscillates, the ratio decreases so that by .200"-.300" net valve lift, the rocker ratio become 1.72:1. The 1.72 ratio is maintained through the rest of the lift profile until the valve returns to .200"-.300" from returning to the seat at which point the ratio increases to 1.79:1 as the valve goes back on the seat.

 

John, as read from above in Joe's post, as well as my other readings on it, the rockers were designed to produce that extra little lift at the bottom and then tapers off as it lifts up to avoid the issues your worried about. My cam is by far not a donkey dick @ only 231/242 .637/.622 114*LSA It idles just a hair more aggressive than the CheaTR cam . But anyway, combined with the ETP 11* heads, I am sure I have way more than enough clearance.
For me, I'd rather have someone setup the valvetrain to get me into an approx ballpark. Currently running 8.100" pushrods with stock rockers, .040" gaskets, ETP unmilled heads. From my understanding when going to the Vinci rockers, the pushrod gets shorter? If so, that would make me feel a little better than having such long pencils operating the valves. Bad part is, it would take me another week to get the vinci's in, check length, order custom length p-rods, get them in and finally install and adjust...ok, more than a week.

 

CAT3,

What preload do you have on the Morels now? I have .075 ( if a 1/4 turn on a stock rocker = .015, then 1.25 turns = .075, search is down ) but need to bring it down to .030.