fresh cam, is my oil too thin?

My .02,
That cam looks fine. I would use it on my Bonneville engine. The wear pattern shows the lifter turning off the top of the lobe. Put it back in and set the valves cold at 1/2 turn. If the problem persists I would take a strong look at the valve spring pressure. I suspect you have too high a pressure for the lifters. Bleeds them down when the oil is hot and thinner. Measure the installed height and then pull a spring. Take it to your local machine shop and have them measure the pressure open and closed. Record the findings and call Comp.
Dan

 

if you know of any mechanics that mess with race type stuff see if you can borrow a portable valve spring tester...then kind that either bolts to rocker stud or pivots on top of the rocker itself. check open ans seat pressure. I always have one at Bonneville, unfortunately we had to use it last year....if not do what Dan above said, be sure to measure the installed heights so the machine shop knows what to check....maybe a good idea to check all the installed heights to mke sure the previous machine shop didnt fark things up...Hans

 

ok, so put the cam back in, im sure i mentioned that the groove in the distributor WAS blocking the oil passage, so i took it to my buddie and had him open it up on the lathe a little bit. put everything back together, ran it, still no dice.

put a straight edge across my rocker studs, there is maybe one that is a 1/16" off but i cant tell if there is fresh metal on the bottom of the stud were the stud gets pressed in (as if it would be pulling out). i dont think my studs pulling out would be an issue only because the cam i had in here before was MUCH bigger and i had zero issues with valvetrain noise.

im still wondering if its a lubrication issue. while adjusting the valves i saw that there was oil getting to the rockers, but nothing was really "squirting" hot oil pressure at idle is around 20+ checked all of my pushrods for some sort of blockage, everything looked good.


so needless to say this pos is not going to LSRU 2012 with me, but id still like to put some miles on it when i get back. any more ideas?

 

Oil passage to the lifters clogged?

 

how would i check that?

 

Are all the lifters claddering? or can you narrow down the ones that are, and then look for any inconsistency, like rocker height, oil volume out of the rocker, push rod clogged??? ANything.

 

First of all is there oil coming to all the rockers? is the pushrods
rotating when you run the engine? you had a bigger cam before
is the push rods the old ones? are they the right lenght? old cam
could have rquired another lenght pushrods. worn rockers?
old cam had higher lift rockers change direction at another place now
and is the pushrods straight

 

the pushrods ARE from the previous cam, however i didnt think that they would be a different length. what is the stock sbc pushrod length?

the rockers have less then 1200 miles on them, how could i check if they are worn (they are just 1.5 ratio stamped steel)?

oil is lubricating the valvetrain but its not squiring like some people have been saying it should be

 

Just my opinion and I am not a Chevy guy.

When my brother and I built his 350, we adjusted the valves while running. We were getting a bath from the oil squirting out of the rockers until we shut it down and got the little caps to cover the rockers. To me, it sounds like you are just not getting the oil where it needs to be. I'm kinda confused that you are still running that distributor at this point. Grab a stock one and throw it in there and see what happens. If you are blocking oil flow with the current one, you would know in 5 minutes if you just swapped it out with the one that came off the motor on the engine stand.

 

I dont have the stock lenght in my head but check so the rocker
have the corect contact on the valve

1200 miles should not wear out the rockers but check the tip
if you dont se any wear its ok

sounds like you have litle oil coming up to the rockers
most of the time you got oil squirting on the headers
and inner fenders but as long as its oiling the rockers
i dont tink its the problem...... i suspect wrong lengt
or bent pushrods

with high lifts sometimes the slot in the rocker is not
long enough so it bottom outs against the rocker stud
but you got a low lift cam

in the 80s when syntetic oils came out on the market
it made hydraulic lifters tic in some ford sb for me

 

ARE YOU USING POLY LOCKS OR NEW LOCKING NUTS?locking nuts are to be used once only.

To check pushrod length rotate your engine and make sure the rocker is riding close to center on the valve. If you have poly locks clean a valve tip and mark it with a dry erase marker. Rotate cam and pull it off again and see where the rocker is riding. Look up rocker arm geometry.

My comp cam looks the same... There is still nitriding on the lobes so it cant be worn much.

Maybe a bad head gasket letting water in one cylinder when hot coolant is under pressure?

 

Well I figured I'd lay this thread to rest. After speaking once again with comp on the phone, the tech guy said that some valvetrain noise can be common even on their high-energy camshafts. Was t quite enough for me so I had a buddie of mine check it out while he was over (one of the high performance Chevy types of guys) and he also said it was t much to worry about. As of now its been a few weeks of occasional driving and it hasn't gotten any worse, so I guess It was just me being nervous about my cam install.

 

HAHAHAH... I love it. AT least I a now know I am not the only detail freak when it come to engines......

Happy motoring, now all you gotta do is get by thinking about it an wondering while your driving....

 

The lobe to the left of the cam journal is about the same as the base circle. The corresponding lifter was also cupped about 1/8", When your cam fails like this one did the wear metal has to go somewhere. One wiped lobe on a BBC trashed the oil pump and metal filings became embedded in the bearings. My point is, if a cam or lifters are at all questionable, replacing them is cheaper and a whole lot easier than dealing with a catastrophic cam failure.

 

I agree with that 100%