Cam Problems

[kwhizz]

Well, the Saga of the Devil Engine continues.....To Make a long story short....two years ago I had the Engine in the 66 Convert rebuilt to take it on the Power Tour, had problems, took it out and back to the guy that rebuilt it....and.....let's just say that we aren't friends anymore....got it back aftert 6 months and finally got around to putting it back in the Convert about a month ago..........EOS,Rotella, Pre-lubed, started on the first revolution, ran it at 2400 RPM for a 1/2 hour......Life is good........Stock 360 H.P. hydraulic Cam........Took it out for a ride last week and put about 30 miles on it, by the time I got back home it sounded like I was running an out of adjustment solid lifter engine..........It ate the Camshaft.........Don't you just hate when that Happens

http://i13.photobucket.com/albums/a251/kwhizz/66%20Chevelle%20Convert/DSC04244.jpg

Ken http://www.yenko.net/ubbthreads/images/graemlins/mad.gif

Cam and Lifters "were" New..........

[nuch_ss396]

Ken,

This is becomming all too common. I think I'm going to use
EDM'd lifters in all my SHP cars from now on. Anyone got any
real data on EDM'd lifters vs. standard lifters? http://www.yenko.net/ubbthreads/images/graemlins/hmmm.gif

Steve

[Xplantdad]

That so sucks...what's the address of the guy that originally rebuilt it...LOL http://www.yenko.net/ubbthreads/images/graemlins/mad.gif http://www.yenko.net/ubbthreads/images/graemlins/grin.gif

[Charley Lillard]

A new LS style engine already has roller lifters in it :-)

[Motion Camaro]

<font color="blue">I here that you cannot even use
High Volume/Pressure Oil pumps any more.
It pumps the (crappy) oil past everything too quickly.
http://www.yenko.net/ubbthreads/images/graemlins/dunno.gif This is making me crazy! http://www.yenko.net/ubbthreads/images/graemlins/no.gif </font>

[markjohnson]

I did a cam/lifter swap a little over a year ago in my LS-6 454. I used a very large Comp Cams solid lifter grind along with Comp's own flat tappet solid lifters with the EDM hole in the bottom of them. Quite expensive at $180 just for the lifters but worth it in the long run to avoid any problems. I'm not a fan of Rotella either because diesel oils are known to be next on the horizon for the reduced zinc content if it hasn't been reduced already! I used the Valvoline Racing Oil 20W50 along with GM's Cam/Lifter break in additive and so far have no problems to report. I probably should have broke the camshaft in properly by using the outer valve springs only, but my '55 Chevy ex-C/Gasser has the engine set back very far under the windshield and dash and this would require total engine removal. One more thing, I've never been a fan of the half hour/2500 RPM thing. Just seems to hard on everything. I like to run them at 2500 RPM for just a few minutes several times with COMPLETE cool-downs between each session. That's probably what you don't read in the magazines, but it has been very successful for me for a long time. Good luck.

[RamAirDave]

How common is it to have a cam failure after the initial 20-30 minute break-in period has been completed?

[VintageMusclecar]

What brand is(was) the cam and lifters?

How much spring pressure on the heads?

Eric

[kwhizz]

It was a OEM plain old 360H.P. Hydraulic cam with stock springs............

Ken

[3macs1]

Hi Ken:
Is the block a 1966 casting??

[VintageMusclecar]

What brand were the lifters?

What was used for assembly lube, the red "taco sauce" or moly paste?

Did any of the lifters go into their bores tight?

If I may offer a tip for future reference...during mock-up I always use a brake cylinder hone and lightly "kiss" the lifter bores to make sure there aren't any boogers or left-over varnish that can hang the lifters up in their bores and keep them from rotating during operation.

http://www.yenko.net/attachments/267136-A5_Lifter_honeB.jpg

If the lifter can't spin it will go flat.

Eric

[kwhizz]

It is the original 66 engine in the car with grooved Rear Cam journal...........
Eric.....I didn't put the Engine together so I can't answer those questions, but it was a detail oriented shop that put it together this time.......No matter what.....It's my problem.......Again

Ken

[Charley Lillard]

I think it was the carbs fault. Who rebuilt it ? :-)

[kwhizz]

[ QUOTE ]
A new LS style engine already has roller lifters in it :-)

[/ QUOTE ]

Then I will be blamed for cloneing the Chevelle into a Corvette...................LOL

Ken

[3macs1]

Hi Ken:
Having the 3/16" wide X 7/64" groove in the rear cam journal is only half of the correct set up for 65/66 BBC from what I can remember.Please correct me guys if I am wrong since it has been many years and I am only going by memory. It has been a few years since I rebuilt a 66 engine. You also have to make sure you have the old style grooved rear cam bearing also and not the 67 and up flat one. The old style has 3 feed holes to supply the cam journals and the two lifter galley passeges vs one hole on the flat 67 and up style. You can use a flat If I recall correctly but as I said it would have had to be soldered and redrilled special for the 66 which I would be suprised the engine overhaul shop did. To me it sounds like the rear cam bearing may not be the old 66 style. If so, you will get some oil but not enough and end up losing the cam, etc.
Do you know if the rear cam bearing was grooved also with the cam.
Joe

[budnate]

Dang..Ken that is terrible..did ya sit down and cry a little I think I would have after all this... http://www.yenko.net/ubbthreads/images/graemlins/frown.gif

I am sure you double checked but Mac is right on the groove deal..did YOU lay eyes on the right bearing in the back?? the cam should have been grooved already if its a factory replacement piece.

I had similar deal years ago, truly tests your love for the car.

Mark a GTO guy I know does your method and claims it works fine as well...I set them a tick above 2k and let them go and lightly rpm up a little and back to the throttle stop at 2k in 3/5 min intervals, but have not broke a new came in lately and have been watching everyone under the sun have problems...my used cam stash is looking really good about now.

[ANDY M]

I had to replace my cam after the SCR last year, it wiped a lobe. It was a Crane MuscleCar cam, factory grind, less than 2 years old with less than 1500 miles on it.
My engine builder hates Crane, so he told me to go with a Lunati. I ran over to Jegs, (helps to live in Columbus), and the Lunati didn't even make it through the break-in.
The shop had to eat 10 hours of labor and put a Clevite factory grind in. Good thing for me it happened in their shop, and Jegs took back the Lunati, no questions asked.
Runs strong now, with Rotella oil in it.

[RPOL88]

Taking 3MACS1 a bit further, the 66 distributor also has an oil groove all the way around. 1967 and up is only about half way.

[RPOL88]

I said it backwards. 67 up is 360 degrees. 66 is only half way. Sorry for my mistake.

[Verne_Frantz]

If the groove is all the way around there will be no oiling problems no matter how how f'd up the distributor install is, but if it's only half way around, make sure the gear dimple is lined up with the rotor contact. If a distributor is rebuilt and the gear is put back with the dimple 180deg out of phase with the rotor contact, it will result in about a 16deg timing offset. (That position will also affect oiling) To get it to run right, you'll have to twist the distributor WAAAY out of it's normal position to get it timed. (or just switch the plug wires by one tower on the cap). But it will still be pointed the wrong way.

http://www.yenko.net/ubbthreads/images/graemlins/wink.gifVerne

[3macs1]

Agree Verne. Looks like Ken has a couple of items to check before looking at the cam manufacturer.
Joe http://www.yenko.net/ubbthreads/images/graemlins/smile.gif

[nuch_ss396]

Verne,

You may recall that there was a discussion on the NCRS site
some months ago about using early BBC ( rear journal grooved )
cams on later BBC combinations as long as the rear cam bearing
was modified to restrict oil flow to the rear of the cam.
I don't however recall anything mentioned about the distributor
issue that was mentioned here. Care to elaborate on that more? http://www.yenko.net/ubbthreads/images/graemlins/hmmm.gif

I was considering this avenue for a planned L-88 build as
I have my eye on an early build L-88 cam. However, after
reading this post and many more like it, I'm petrified of
the down-side of cam failure. It seems that this is getting
out of control these days. http://www.yenko.net/ubbthreads/images/graemlins/frown.gif

Steve

[3macs1]

Hi Steve:
Running a grooved cam in a 67 up block is no big deal really. We used to solder the rear cam bearing hole and redrill. Don't ask me the size, very small I remember. It is the bit in the top drawer of my tool box with tape on it LOL. The size is actually given in the how to hot rod BBC book.On the dist I am not sure. I never mixed them. My 66's were l-72's and I always used the 66 TI dist in them so had no issues. I did bake two cams like Ken however before I discovered I had the wrong rear cam bearing.Second one almost cost me the engine.