Technical Caddy lifter preload?

How do you guys check lifter preload on a caddy 472/500?
My fresh build is making a rocker arm noise.
I’ve never had to check a preload. Just adjust. These guys are different.

 

Do the Cadillac engines even have single adjustable rockets? Going from memory, I thought they had nonadjustable valvetrain. At least factory GM, unless you have the aftermarket roller rockers?

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Non adjustable.
Pedestal mount. Seems like a mystery, haven’t found much info. Even the cad co stuff is vague.
I was told to remove .020 from the pedestals.
The caddy needs .020 preload.
I used a lunatti cam and lifters. This thing sounds like a solid lift engine.

 

• https://cranecams.com.au/pdfs/pp1110c.pdf
• http://cad500parts.com/tech/Rockers_Stage1S.pdf

 

Thanks. I’ve look at the cad500 info.
I guess I’m looking for someone that has done it. I’m spoiled with SBC adjustments.
Seems like it’s a guessing game or buy the adjustable rocker arms.

 

Every rocker loose?

 

Several.

 

Couldn't be just that the lifters aren't fully pumped could it?

 

That’s possible.
The caddy set up is weird.
If my cam has a lower base circle, the rockets will be loose.

 

Yeah I've never messed with one. If you need preload, would it be easier to go with a longer pushrod? Or would it screw up the geometry?

 

That or machine the rocker arm stands.
But how much is the question

 

Caddy rocker supports are marked intake IN and EX make sure they are in the right location. https://www.bing.com/images/search?...d738a7d83756f0f?rik=I81GAsM1UkR2Qg&pid=ImgRaw

 

I'd give it more run time, recheck the torque on the rocker stands, and see if it helps before i went too crazy lol.

 

Thanks

 

check edited post

 

Yep. Thanks again

 

You mentioned the possibility of a smaller base circle in post #9 and that has to be your problem. For some reason the base circle on Lunati’s Cadillac cams must be smaller and that eliminates the lifter preload. As Lunati tech’s suggested the easy (and cheapest) way to correct your problem is to mill .020 off the rocker stands. It sounds like they have experience with this issue on Cadillac valve trains using their cams and you could use longer push rods but it will be more economical to mill the rocker stands.
If .020 doesn’t sound like enough you could go .030, that would be the same as 3/4 of a turn on a Chevy rocker nut.

 

I was suggested that. I have extra stands
Is that Lunatti info?

 

I suspect the problem is because there are no high lift cam blanks made for that engine. They are taking a stock lift cam and regrinding it. So essentially they are giving the cam more low instead of more lift. That is why you need to machine the towers.

 

Well, I bought some lifters from the Cad Company. They are confirmed US made.
The Cad Co lifters are .011 taller than the Lunatti lifter. The push rod cup is .009-,010 higher as well.

the Cad Co lifter is on the left

 

New lifters in. Scared me at first. Took a little bit to pump em up.
A lot quieter now

 

Great outcome !

 

Well, we ain’t done yet.
Idles great. Runs a little rough around 1500rpm.
Set timing with a vacuum gauge.
Gonna investigate carb base gaskets. I used a 68 intake. No EGR. That has a stainless plate under the carb. That’s there but I’m not sure if we have it all figured out yet

Is seems it’s a gasket followed by a stainless ‘shim’ then the carb.
that seems odd.

 

all of them i have seen have a gasket on bolth sides of the shim

 

I was wondering that. A gm manual I found online says only one gasket between the intake and shim plate.

 

You should go to the Cadillac-Lasalle club forum and ask this question there, there is a special way to install that spacer? A lot of smart guys there that could help you out.Harvey

 

Glad you got the lifter situation resolved, Tony. I had the same situation on a small block Olds. Wanted to use original pushrods/lifters after a cam change to a "original type grind" cam. I probably had .040 clearance on all rockers when fully tightened. I had some adjustable Mondello pushrods and had to use them and set all individually. It was a PIA! I wonder if those longer lifters you got are available for other engines that don't have a adjustable valve train?

 

If your intake manifold has the exhaust cross over to heat the carb - would a exhaust type gasket be required between the intake and stainless block off plate?


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I think the longer ones are maybe the correct ones and the other ones were too short. I still have an original I could compare them with

 

I’m going to order a 68 intake gasket. I’m using a 68 non egr intake.
I’ve had a similar issue with ford once