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Looks like since I got it down this far I’m just going to do it right . I don’t need it to mess up 6 mo the to a year from now and I’m back in the same boat I’m in now. Any recommendations for bigger cam combo that I should run? Thanks for all them help and suggestions
"Got it down this far"? You have not done 10% of the work that will be involved with a complete engine removal / rebuild. But its your money & time.
Just want people to know, that wiping a cam lobe or two is not the end of the world. It does not always justify a complete tear-down. It does not always justify a expensive roller cam purchase.
What is a MUST DO, is to use the proper oil right from the get-go. And that is what somebody failed to do. And that's why you have the pictures you show. The removal of Zinc years ago, would likely be one of the best kept secrets our Govt did to the automotive industry. And even then, only the pre 1990 vehicle owners would be of any concern to the lack of Zinc issue. Its not like this oil alteration event was on the front page news and on TV across the nation.
There are tens of thousands of Flat Tappet Cams running around with zero issues.
Good Luck
Last edited by HeadsU.P.; Mar 18, 2019 at 10:01 AM.
Nice in-between cam. GM ZZ502. 1 hp per inch. Sounds radical. .544 lift. Enough without having to redo valvetrain every few months. GM builds their components and engines to last thru the warranty. So, they are a little more conservative in cam lift and spring rates. Comp 911 springs work well. 122 install pressure. About 325-330 over the nose. You pick your own hyd roller lifters-as long as they aren't 125 buck ebay lifters. https://paceperformance.com/i-625508...zz502-502.html
Last edited by derekderek; Mar 18, 2019 at 10:37 AM.
There's no way in hell that an engine with a lifter that has the complete bottom worn off isn't full of metal shavings and particles. Your main, rod and cam bearings all have metal embedded in them and I can guarantee there are marks/ridges on crank journals. With the factory bypass in place, that engine has already pumped that crap through the entire oil system.
Upgrade to a hydraulic roller when you have it apart, it's a no-brainer.
There may be tens of thousands of flat tappet cams running around, but no factory engine has had them in almost 30 years. They didn't upgrade because it's cheaper...
If you have a shop do the work, the "fix" will cost more than upgrading to a roller cam now. Bite the bullet now and have the peace of mind that you're not going to have this happen again.
The most important question I have is how do you intend to drive it? How fast do you intend to spin it? Other questions are what CR is your engine, what trans do you have, what is your rear ratio?
My 73 454 wiped the cam and I am going with a Lunati 20010711 (60211)Voodoo roller because I don't want to deal with another wiped cam. Cam has an 1800 to 5500 RPM range and good low end torque and vacuum. Still putting the engine together.
Last edited by 2mnyvets; Mar 18, 2019 at 11:55 AM.
The cam lobe grinds itself off and falls straight into the pan. Some particles may have gotten picked up but how much is unknown of course.
Pull the pan and some main and rod caps and inspect.......that will tell you how far to go. A particle has to be pretty small to get past the pickup screen......
If the bearings look ok then throw out the oil pump and pickup......install a new one with steel collar shaft and a stud to hold it on the main cap. Braze the pick up on the pump after checking pickup depth. Now do as Jim said and block the bypass. Install your new cam and lifters and go.
Make sure you pick an old school grind from Comps Magnum series or similar.....Isky has a lot of old grinds that work awesome as well....this is added insurance over flat lobes.
How old is this engine? May want to check your valve springs......a lot of dual spring stuff requires the inner spring to be pulled before break in and reinstalled.
Jebby
Last edited by Jebbysan; Mar 18, 2019 at 11:56 AM.
Agree, that ones been going bad for a long time just redo the whole thing at least youll know what youre working with.
Thats a chiload of metal being pumped, bearings I bet the farm are exposed copper.
Catching one when its first starting to go sure change the cam/lifters and motor on not this time. Youll be glad you did..now you got an excuse to do a little porting and experience more power.
Just doing a stock rebuild it wont feel much better.
Put the lifter back in and measure the lift on the cam. If the cam lift is gone- then so is the cam. If the lift is not gone, the lifter could have failed. Replace the lifter, flush the pan and drive on.