66 427ci. 425 hp lifter noise on cold start.
 

Hey Guys
I’ve had this 66 for going on two years now .
When I bought it I discovered I had a rear main seal leak so I pulled the pan and thought I would check for any metal of sort while replacing the rear seal. NOTE Car had Receipts of being rebuilt 500 miles before I bought it.
Good thing as I found bearing material in the pan. So we pulled the motor and found that on a rear main bearing was scored and the oil Journal on the crank had a very small bur . The crank Apparently didn’t get polished when they rebuilt the motor. Wasn’t able to find out the story why it was rebuilt but it is what it is .
Motor is all stock other the a mild comp roller cam and we added comp roller rockers the hydraulic lifters were good cleaned and reused.
We polished the crank and the cam looked great so used it.. We honed the out cylinders new rings and also put a new set of stainless steel vales as the ones in it were a from 2 different sets why I don’t know. I’m thinking someone wasn’t a Mechanic that did the repair or rebuild.
My first clue was the rear main seal is a two piece right the lower was in right the top was in backwards thus it leaked thank GOD .. Could of been a train wreak coming .
Got it back in and primed the motor and is running used Breakin oil ... and have changed oil twice no signs of any debris in the oil after 200 miles.
ive re adjusted the valve lash. Great oil pressure... Problem is when I do a cold start I get some noise not bad but it sounds like lifter or rocker noise till car warms up say 150 I’m running the Rotella 15 40 is this normal. I’m a little livery adjusting rocker lash again this is twice.
how far can I go. LOL. Is this just the Nature of this big block. I don’t know. Only had small blocks
Note once it warms up it sounds good. Any ideas on oil this is what I read to use Basically diesel motor oil.
I don’t want to go to much further until I find out why and get this noise sorted out .
any help or ideas would be appreciated thanks guys .

If it’s a 65-66 BB your cam shaft and rear barring need to have a grove to get oil to the top end

Looks like you may have come across what several others (including me), have using Competition Cams Roller Rockers.

I completed a build of my 427/435 motor. I installed a hydraulic roller cam along with the hydraulic lifters, and they were Comp equipment.

Unfortunately, I had significant lifter noise from at least two lifters. They wouldn't hold pressure, yet they were brand new!

I ended up ordering a complete new set and took another chance that they would be good. Fortunately, the new lifters operated as they should.

Another friend of mine suffered from the same problems with his roller rockers as well. He had to replace several lifters.

Unfortunately, this problem is not uncommon. Do a search on Comp Cams hydraulic roller lifters and you will find that many individuals suffer from the same problems. Looks like the problems became prevalent when Comp Cams mover their manufacturing to Mexico.

You may have to remove your valve covers and try pushing down on the rockers, and try to determine which one, or two is making the noise.

I will not use Comp Cams products again.

Pat

Thanks Pat
Dam just my luck..
When we tore down the block and checked the cam card it Was strangely and marine cam. Why not sure.
My machinist / builder said the cam looked great.
Was after the the break in I thought about going to comp roller rockers hoping this would help the noise and it did.
The rocker arms in the car when we took it down looked to be stock. Original.
I guess it was kinda a big shot in the dark but it did help quit a bit. Just not totally.
Pat if you don’t mind what did you go to on the lifters and what oil did you decide was your choice?

I went back and re-read the original post, and It sounds like you may not have the problem I had.

Does your lifter noise go away after it warms? Mine did not, and you could collapse the lifter with your hand by just pushing on the top of the push rod. And we adjusted the valve lash three different times, yet still couldn't get the loud "tapping" noise to go away.

I chanced it and purchased a second set of hydraulic rollers from comp. They wouldn't warranty my original ones, because they said the motor sat too long (14 months), after being rebuilt, yet prior to firing.

I'll have to look at my log to get you the exact oil I ended up going with. I do know it was a racing oil with zinc in it.

Pat

Thanks Pat. Yes once the heat exchanger in the exhaust opens it’s like someone hit a switch in noise goes completely away.
My Machinist - builder builds drag motors has a complete machine shop and races himself he recommended the Rotella diesel oil that it had everything in it I needed so I just want went with that.

Yes it’s a January 66 car I will have to check on what bearings were used. Thanks My Friend
I appreciate it Rick

I have had the best luck with Howard's cams hydraulic roller lifters for reliability, high RPM performance especially if you spend the extra money for the light weight ones, and especially noise.They are the quietest ones of all the brands I have tried which are many over the years of building engines.
Comp cams in my opinion is not very good anymore.

Are you sure you don't have an exhaust leak masquerading as a lifter tick - sometimes they can sound awfully alike...?

This is true and they often fade away as the engine warms up. Also could be some piston slap depending on type of pistons used and clearances. Maybe you could post a video with sound if you think it could record.

This AND you need to have a groove machined in the back cam journal. You'll get some oil to the lifters with just a grooved bearing shell but not enough and any be what's causing your noise. I don't know if the info shipped with BB Chevy cams these days has the groove specs any more. It did about 15 years ago. The groove should match the location, width and depth of a factory 65/66 cam.

Finally, the back cam bearing has to be oriented so that all 3 oil holes line up. They are not evenly spaced around the bearing and it's possible to line up 2 of the 3 oil holes. That will leave one bank of lifters dry. In an unbelievable set of foul ups, my motor was shipped to me assembled without the rear can groove. Only found that out after a cam failure. After that, my machine shop managed to put the back bearing in wrong. Roasted the whole drivers side of push rods and rockers.

Hey guys
No it’s definitely not an exhaust leak .
I have a stethoscope that gets me to the area with the covers on.
I may try taking the valve covers off and do some shielding and cold start it.
See if I can get my guy out to the house .
What doesn’t help maters it’s a side exhaust car so it’s dam loud and in the garage.

When I talk to my builder I will question him on the bearings . I didn’t see the Assembly of the motor .
I do have the parts list what he used. This may help .

Still - I'd be tempted to wire open the exhaust heat riser on the next cold start and see if eliminating the back pressure prior to warm up and the valve opening eliminated the noise. A 5 min check..... Just a suggestion..

the correct rear cam barring is only half of it. You need the proper grove in the rear of the cam

I had a tick and it was the rocket nut hitting the valve cover..check cover for marks...I put on thicker valve cover gasket, sound gone

Jack

I second this suggestion

is this even the orginal block?,

if not it might not even need the rear grooved rear cam bearing

Yep, I will definitely go with Howard's from here on out.

Pat

True it’s worth a shot who knows My friend ��