Cam/Kit replaceement

timkins · September 18, 2007, 09:18:54 AM

I have what I believe to be a stock 78 2 bolt main Chevy truck block in my street rod. A couple of the guys at a local cruise night indicated that this motor has a tendency for the camshaft to go bad on one or two lobes.
They claim that when this happens the motor would start to use oil in those cylinders only and run a little bit rougher. I seem to remember in my younger days that guys with Chevy power would change the stock cam for one with a little more oomph directly from GM. The reason for the question is I have started to use a little bit of oil in the number one cylinder. Not enough oil to foul the plug but enough to show on the plug as oily deposits. All of the rest of the cylinders a burning clean with no oily deposits. Any thought or suggestions would be appreciated.

enjenjo · September 18, 2007, 10:02:34 AM

Well, first I would do a compression check, and if that is ok, then check the cam. If that's bad, I am a big fan of Edelbrock performer cams. The kit with cam, lifters, and springs is a good deal, and I've never had a problem with them.

chimp koose · September 18, 2007, 12:06:37 PM

If you do decide to go with a new cam be careful of what oil you use on break in.newer oils dont have enough zinc to properly break in a new cam. oils like shell rotella ,valvoline racing oil,diesel oil that has an 's' prefix rating and any oil intended for motorcycles should be used for breaking in a flat tappet cam. If you are in doubt about what oil is good call a cam company tech line to be sure. A friend of mine broke in a cam with the wrong oil and it destroyed the cam before the break in was over.he was fortunate enough to get warranty replacement because the cam company didnt have specific oil requirements listed on the break in info. (i think they were just finding out about the oil problem themselves)

timkins · September 18, 2007, 03:17:48 PM

I did a compression check on the motor for other reasons about a month ago and the numbers were; #1--115lbs, #3--115lbs, #5--100, #7--100lbs,#2--100lbs, #4--110lbs, #6--100lbs, #8--110lbs. I will admit up front that these numbers mean very little to me. Any other suggestions?

Okiedokie · September 18, 2007, 03:27:06 PM

My advice would be to relax and enjoy. How many miles a year do you drive it? 3,000? Plan on drag racing it? Gonna do any 5,000 mile trips? If the answers are no, relax. Most likely it will serve you for many more miles.

Bib_Overalls · September 18, 2007, 03:44:08 PM

If this thing is keeping you awake at night I have a suggestion. Pull your valve covers and eye ball the rockers while you crank the motor over (with the coil wire discnnected). If you have one or more flat lobes on your cam you should see a difference in the amount of lift.

Changing out a cam is a big job. You can do it in the vehicle. But you have to pull the intake, radiator, and pan. And then you have to work leaning over the fenders. Not something you want to do unless it is necessary. Or you absolutely just have a need for more speed.

I also use Edelbrock Performer cams in my street motors. Good power, good idle characteristics, and reasonable economy.

UGLY OLDS · September 18, 2007, 05:40:00 PM

How many miles on this engine ?? Any clattering noise from the valve cover area :?: :?: This could be something as simple as a worn valve seal...As was previously suggested....My vote goes for drivin' it & see if it becomes worse......( Normally when a Chevy starts to loose a cam lobe, you will hear the clattering from the valve cover due to the excessive rocker arm lash.....)

wayne petty · September 18, 2007, 05:47:21 PM

a little clarification...

the grades on motor oils with gasoline engines in mind are

sa,sb,sc,sd,se,sf,sh,si,sj,sk,sl,sm,sn

sa and sb oils are non detergent and are really cheep. i put some in one day and it turned to black pudding...i though i broke the oil pump... when i went to drain the oil it took two days to drain... back to it... the newest oils are have less zink which protects the cam and lifters.. new cars all have roller cams.. even the new batch of rotella has reduced zink levels... check the back of the bottle.

each step up in sa, sb,sc is a newer standard or type of oil..

for compression ignition engines the rating is ca,cb,cc,cd,ce,cf,,,,

there are some additives athat can be added for breaking in cams.. and most smarter people have started using lifters that have an edm hole drilled in the bottom to direct more oil at the cam lobe.. you can barely see it.. look close...

i also put cam failures out to unproper hardening of the lobes after grinding..but i used a lot of reground cams as i could get the grind i wanted.. this is metal to metal rotating contact..

the face of the lobe has a tiny angle ground into it... the lifter has a convex face... so the lifter rotates slowly in the bore do to offset friction on the lifter face.. )/
when the cam lobe has failed.. the pushrod will also rotate really fast compaired to the others or back and forth...

i have also started installing the new style neodynium super magnets in the bottom of the oil pan... this will catch any iron,steel particals...

tomslik · September 18, 2007, 07:32:59 PM

[quotei have also started installing the new style neodynium super magnets in the bottom of the oil pan... this will catch any iron,steel particals...[/quote]

where do a guy get those?
they the same as the ones in a hard drive?
love to find a source for those....

purplepickup · September 18, 2007, 10:33:02 PM

Quote from: "tomslik"
where do a guy get those?
they the same as the ones in a hard drive?
love to find a source for those....

Google them...there's lots of sources. The correct spelling is neodymium magnets. I think that's what hard drive magnets are.

We glue them in truck tranny cases at work to catch bearing rollers and things you don't want going thru the gear sets.

I'd email you a couple but they'd prolly get stuck in a server.

Crosley.In.AZ · September 18, 2007, 10:46:30 PM

GM has / had an additive EOS = engine oil supplement... I liked this stuff for new cam shaft break in..... unless you are going to a hyd roller lifter cam

some folks say GM has dropped the additive.

Bruce Dorsi · September 18, 2007, 11:09:05 PM

For what it's worth:

STP contains the ZDDP (Zinc additive) that has been reduced in most motor oils.

I know many people do not like STP, but it may have a useful purpose for them now.

My favorite assembly lube is a mix of 50% STP - 50% motor oil.

wayne petty · September 18, 2007, 11:53:36 PM

Quote from: "tomslik"[quotei have also started installing the new style neodynium super magnets in the bottom of the oil pan... this will catch any iron,steel particals...

where do a guy get those?
they the same as the ones in a hard drive?
love to find a source for those....[/quote]

http://www.permanent-magnet.com/
middle of the country

http://www.allelectronics.com/cgi-bin/category/370/Magnets.html
L A area or mail order

mcmaster carr also have some..

many new starters use these magnets also in a curved design.. if they are cracked they wont work.. so rebuilders may have a scrap pile to get rid of..this is why you dont hit starters any more.. especially the small ones.

tomslik · September 19, 2007, 05:06:02 AM

Quote from: "purplepickup"
Quote from: "tomslik"
where do a guy get those?
they the same as the ones in a hard drive?
love to find a source for those....
Google them...there's lots of sources. The correct spelling is neodymium magnets. I think that's what hard drive magnets are.

We glue them in truck tranny cases at work to catch bearing rollers and things you don't want going thru the gear sets.

I'd email you a couple but they'd prolly get stuck in a server.

i've got a few dead hard drives but i didn't know what the magnets were made out of...

timkins · September 19, 2007, 07:54:26 AM

I am experiencing some lifter noise that goes away after the car has run for several minutes. The car is running with about 60#s of pressure. I am not sure of the mileage on the motor or if it was rebuilt at the time it was installed as I am the second or third owner after the rebuild.