Cam problem

[Dmax97]

Just curious if anyone used this cam from lunati?Pn: 10700901Advertised duration: 296/306@.50: 244/250Lift: .454Lsa/lcl: 111/110I had 2 different engine builders assemble this cam in different heads both purchased new, it would run like a raped ape for one race then the lobes and followers would waste right away. Any ideas?

[Jb35]

I havn't run that cam, but lunatis are usually pretty good cams. Are you breaking the cam in correctly?

[engineczar]

Dumb question but is the pipe plug installed in the back of the cam?

[Dmax97]

Yea the plug was installed, and yes the recommend cam lube was used. Was broke in using the same way everyone one else does and what I have done many times before, possible the followers could be the incorrect ones?

[Jb35]

Call both builders and call lunati. If they are good experienced builders, not saying they arn't, they should be able to tell u what went wrong.

[1195]

Can you post pictures of the failed followers?

[Dmax97]

Yea this is all I have

[Jb35]

Geometry isnt correct one follower shows too much lift another shows too little. Hard to tell from pic but if there are grooves wore in followers spring pressure is off too.

[Dmax97]

Ok thanks alot! Guess I'll have to find a new engine builder

[Browndog]

Wow that's not even close to being right. Ask around other racers in your area and find out who can help you out. The guy that did your work should be giving you a refund for sure.

[Jb35]

My opinion if at all possible learn to do that kinda work yourself. It requires very little special tooling, you will save money in the long run, and u will be more exact on ur stuff then someone else will. Its not very difficult.

[Browndog]

There is a little more involved unless he has valve grinding equipment. Valve height is Very important. Depending how the seats are ground you can end up with different valve heights which you don't want. It would take more than a few sentences here to explain how to do all that is involved with setting up one of these heads so find someone that can do it properly. There is nothing wrong with learning how to do it but unless you have someone to teach you chances are you are just going to keep wrecking parts and that can get expensive. Find someone that knows what they are doing.

[1195]

I have had 2 new cams with new followers that had follower failuer that looked simalier to that.
Both had correct geometry. I polished the lobe and put a "good" used follower in and ran them for many races. Looked like problem was a soft follower to me. I have also torn down a few heads that had a badly warn follower and lobe that the oil hole in the lobe was pluged
Bottom line on these heads is that they are very complicated to set up and even when they are right they sometimes give trouble. Finding quality followers is a challenge also.
Valve length, guide height, spring installed height, spring pressure (open and closed), coil bind, stock type bearings or full groove, straps, milling, port and polish, std or oversize valves, cracks, hard seats, hla preload, solid conversion, mouse traps.
And so on and so on. Just a few things to consider when setting one up.
Demax97 if the lobes on your cams survived they may still be usable.

[Browndog]

Look a little closer at the pictures. The cam was running off the end of the pad. It is not starting to lift where it should. That is a setup problem. Now there could still be other issues like too much spring pressure or bind as well as soft followers. Lots of things it could be that is why I'm suggesting he finds someone that knows what they are doing to help him. We can keep coming up with reasons why it may be happening but that is not really helping the guy out.

[Dmax97]

thanks guys, I was looking for input on what could cause the problem. Looking at maybe trying to have another head built with the same cam, man does it pull down the straights compared to other cams I've ran, were only allowed up to .460 lift