Corbrastang

Ok, so i got the lifters installed and decided to test fit the cylinder heads and check the valve clearance. I quickly realized that the only mechanical lifters that i own are from a flat tappet camshaft. I gave them a try anyway and the clearance was fine. I then decided to order one pair of mechanical roller lifters. They arrived today, but they are far different than the hydraulic ones.
With the hydraulic roller lifters installed and my standard length pushrods I cant even begin to thread the rocker nuts.
Here is what i purchased
http://store.summitracing.com/partde...6&autoview=sku

With the mechanical pair that I purchased the standard pushrods work just fine.

Here is the link to the mechanical pair that i purchased

http://store.summitracing.com/partde...2&autoview=sku


Why are these lifters so different?? I tested the clearance with the mechanical roller lifters in place, but i since there is such a difference i dont think its accurate.

I guess i need to order pushrods that are a lot shorter.

Thanks

muncieman

OK, what year is your block??? Then what cam are you using, solid or hyd. roller??????

Corbrastang

My block is a 1965 327. I purchased a lunati retrofit hydraulic roller cam with .492/.492 lift and 218/218 duration.

AZDoug

The Comp Cams roller lifters instructions state you need .400" (or was it .500"?) shorter pushrods.

Since your block was decked so severely, I would buy an adjustable pushrod length checker and just order the actual length pushrods you need.

Doug

muncieman

I see why you are shopping for lifters, the rollers by Lunati are double the price of the cam.

Here is a less expensive alternative.

http://www.compperformancegroupstore...egory_Code=HRL

Corbrastang

Actually, i'm not shopping for lifters.

I purchased the Compcams Hydraulic roller lifters to be used with the lunati camshaft.

The reason i purchased the 50.00 single pair of mechanical lifters was to measure the valve clearance. However, apparently they will not work, so i guess i will send them back to summit.

I wonder how i should check the valve clearance with the comp cams hyraulic lifters-you cant turn the plunger upside down because the link bar is in the way.

Thanks

Hitch

Use light weight springs..

66BlkBB

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Doug,

I was reading through Summit's recommendations on what to buy to assist in installing these roller lifters and they don't even mention that you have to buy shorter push rods. You would think that an application that requires almost 1/2 inch shorter push rods would be mentioned in their literature on these. I have to assume that the lifters are taller due to the fact that they have to keep up the same volume area for the lifter to pump up. The roller is probably that .400 to .500 of an inch that makes it taller.

Steve

muncieman

There is nothing mentioned about the Lunati rollers needing a shorter push rod but I bet you need them as well for that roller.

I'm guessing the 87 and up push rod for a factory roller motor would work.

JohnZ

Yup, like this.

Hitch

Thanks John, I didn't have a picture of them from the last two times I used them. Dave

AZDoug

The instructions that came with my set of Comp rollers mentioned shorter pushrods, IIRC. I think it is mentioned on the Comp Cams website also. You may even find shorter pushrods for this application in teh Jegs/Summit catalogue

In any event, after reworking the valve train geometry, I ended up with shorter pushrods, that were real close to the suggested shorter length, but longer or shorter by about .030", IIRC.

The factory Rollers I believe are not tall like the retro rollers since they do not need the connecting bar to keep them from rotating.


Doug

silverado2005

Not to hijack, but I will. Why the light weight springs?

Hitch

You can either use a solid roller lifter such as the OP is tryin to use or you can use the light springs. I prefer the light weight springs because you don't have to keep 2 sets of lifters on hand. ie Solid and Solid roller lifters for checking depending on the cam you are using. If you use the light weight springs the spring pressure will not collapse the lifter's internal spring. The lifter will lift the valve and lower it with out collapsing and you can determine whether or not the valve will smack the piston

BTW you coming out my way anytime soon? IM when you come I'll shoot you my new address..


Oh I did have a few pics, it's important to make sure that you reach max lift when you are claying the pistons to determine if you are going to have a problem..

Corbrastang

thanks for all of the help!

As soon as i find my pushrod length checker i should be in business. I just wanted to confirm that these retrofit lifters really are supposed to use shorter pushrods before i started ordering more parts.

I've got soft springs in my degree wheel kit, but there is a new problem.

I tried to compress my valve springs with the head off the block with one of the valve spring compressors that is used to compress springs while the heads are installed and it bent my studs. So, i guess i will be ordering new studs and having them installed.
While i am at it should i just replace them all with screw in studs or should i just go with two replacement push in style units??

BTW, where do you buy the press in units?? I cant find them
Thanks

Scott Marzahl

Since you are running a roller which utilizes pretty high spring rates, IMHO you should really have screw in studs before they start to pull out. Any good machine shop should stock press in studs.

Corbrastang

Thanks! I will go ahead and get some on order-might as well.


Also, i cant find my pushrod length checker anywhere. Since the rods will need to be shorter what length pushrod checker do i want to buy??
ex. 6.5-7.5 and so on.


Also, which length studs should i purchase?? And can i tap the heads at home and install them or should i have the machine shop do it??

http://store.summitracing.com/egnsea...151+115+400295

Scott Marzahl

You'll need to have a machine shop mill down the stud bosses and tap your heads for screw in studs.