Dmn cam.

[corsair231]

Got home yesterday morning and I heard a hard ticking from up top. I pulled the oil fill tube and it got louder. Pulled the cover today and guess what? Yep, the #3 exhaust rocker was only moving about 1/2 of what the rest of them were. I pulled the pushrod hoping for the best but, no dice. D@mn . Into the engine again. This comp cams only lasted about 4 months. This makes the second one since the build. I know I am doing things right. I checked preload, proper assembly, proper break-in. I don't have excessive spring pressure. I don't really beat on the car either. The one from Postons made it a little over a year and a half, which is bad enough, but 4 months, wtf. How do you make a flat tappet cam live in these things. Do I try a Lunnati now, go back with a Poston's or a Comp cams. Or should I just put a $89.00 stock replacement from Autozone in it? I know the best thing would be a roller set-up but it really is not in the budget. This thing is my daily driver and I can't afford to let it sit and I can't keep putting cams in it three times a year.
Sorry for the rant but I had to get this out of my system. But really, does anybody have a 100% fool proof way to make a cam live or a least a suggestion for one that will? My bottom end is in good shape with good oil pressure so I don't suspect oiling/mechanical problems.
Looks like I may really have to shoot Santa Claus this year because if I don't have a car then I can't get to work. If I can't get to work then he will have no place to deliver toys to next year. :frown:

 

[DMan]

Lotta talk about this lately. Do a search on camshaft failure.

Basically, #3 exhaust is a problem because its a bit misaligned with the lifter bore. To deal with that problem, GM engineers *reversed* the taper on the #3 exhaust lobe only. Now I would have figured that by now, most aftermarket mfgers had done so as well, but perhaps not.

I've only just rebuilt my first (GN) engine this year so I'm no expert. But from what I read the best insurance against this is when you do your break in, be meticulous about the procedure. Crane Cams outlines a very rigorous procedure on their website. Finally, remove a valve cover when the engine is running and verify that #3 exhaust push rod is in fact spinning. At least that's what I read.

 

[corsair231]

My push rod is still spinning. I havent pulled the intake yet so I am still hoping that I may just have a collapsed lifter, but with my luck, it's probably the lobe. The only hope I have is that it gave no indication prior. The last time the car would burp back in the intake and had no tick. It also had boost flutter, similar to compressor surge, which started at higher boost and as it got worse started coming on at lower boost. This time there have been no burps and it started suddenly with the flutter at low boost. I guess I have to pull the intake to see for sure.
I'm expecting/preparing for the worst but hoping for the best.

 

[turbo2nr]

A few popular TR shop owners have told me they will not work on a motor without a roller cam installed. Pretty strong words.

I read in a Stage motor book about blasting a cam with glass beads to give a little texture for the rollers to grab on. Otherwise, the rollers may just slip and slide and wear away material instead of rolling.

One of my friends here in Richmond has a GN with a factory corrected lifter bore in #3. Ground out bore and had a bushing in there. 87GN

 

[DMan]

I've always wondered if its possible to change a lifter without removing the intake. Here's what I envisioned in my fairy tale:

1. remove valve cover, remove rocker and pushrod.
2. using a telescoping magnet through the pushrod hole in the head, pull lifter from lifter bore and lay it in the valley
3. remove turbo oil drain on front of block.
4. using telescoping magnet again, extend into lifter gallery, poke around, find lifter and remove it through the oil drain hole.

possible?

 

[Lee Thompson]

maybe

Possible, but what is the plan to reinstall lifter?

 

[DMan]

Yes - good point. It will be harder to put a new lifter back in than pull an old one out, but it would be possible with the right tools.

Maybe a long thin-wall plastic tube that you could insert into the oil drain and then slide the new lifter down, close to number 3 cylinder. Then back with the magnetic tools to drop into place..

 

[SloGN]

check

corsair 231

check the rocker arm itself to see if it has wore a oblong hole in the rocker/and also check to see if it has wore andgrooves in the rocker shaft.


inspect all moving part on the top side of the engine before tearing it down.


when you get it running keep adding GM EOS to the oil for quite a while say 10k miles.

the problem with flat tappet cam is that the facot is the oil companies are removing the zinc thats is added to the oils. Zinc is what helps keep metal waer down on flat tappet cams.

the next time i go back into my engine i'm going roller so i don't have to worry about it wiping a lifter.

 

[DMan]

What is GM EOS?

What is this zinc in the oil story?

 

[49-blues]

Engine Oil Supplement or engine assembly lube- i just bought a case -almost $120. from GM-if you need a bottle- i will send for $10. plus $1.00 for shipping or go to your local GM Dealer. Its needed to break in flat tappet cams.

 

[Jerryl]

Scary stuff.
Check out the link in my sig.

Guess I am "rolling the dice" with the Flat tappet stuff.
I may just take the motor back aprt on the stand, install a roller and not look back.

 

[NCTURBOS]

Engine Oil Supplement or engine assembly lube- i just bought a case -almost $120.

You got ripped off!! GM retail is only $7.65 a bottle. Next time you need some let me know. I can get you a case for less than $60.00 plus shipping.


K.

 

[49-blues]

Will do- i wish i knew that earlier. thanks

 

[m233roller]

Hi,
You say you don'y have excessive spring pressure. What is it? MOST of the flat tappet cam failures is from to much spring pressure, Period !!!

 

[Glenn_A]

cam

Dam it all to hell fellas...ur scaring me now....I just finished a rebuild with a 204/214 flat tappet cam and 100 lb springs :frown: :frown:

 

[m233roller]

Glen,
Yeh 100 lbs. closed pressure but it's that 300 to 320 open pressure that wipes these fast ramped cams. Been ALL threw it.

 

[corsair231]

I replaced the rocker arm/ shaft assm. with a spare I had. The tick did not change so I'm sure I have to go into it again. I could try the magnet thing but I want to check the cam lobe as well. My spring pressure is 95 lbs closed but I must admit I don't know the open pressure but the cam lift was supposed to be well within the spring specs so I should be safe. Thanks for the EOS tip. I'll definitely try it.

 

[DMan]

Dam it all to hell fellas...ur scaring me now....I just finished a rebuild with a 204/214 flat tappet cam and 100 lb springs :frown: :frown:

They don't all fail Glenn, but hopefully you followed break in procedures meticulously.

I just finished a rebuild as well and I think I screwed up because I let the engine idle for about 30 seconds; started and stopped the car about 5 times (had a fuel injection problem) before I ramped up the rpms. I did have lifter lube on everything but still..I'm probably in trouble.

 

[VadersV6]

This may sound like an extremely stupid question, but are all you guys using brand new GM lifters everytime you put in a new cam? Are you soaking them overnight in a little tub of oil and manually actuating the little plunger in the lifter while the lifter is submerged? Are you coating everything with moly? Are you changing the oil before start up to single viscosity dino oil for the break in? Are you dumping the break in oil right after break in? Are you sticking with dino oil for about 500 miles and then switching to a good synthetic? Royal Purple uses zinc and moly in their oil. I used to fire up my cobra in the middle of winter, let it run for 30 seconds and then go out and powershift at 7500rpm through the gears. I beat the hell out of that thing but never had any type of engine failure. Everything wore beautifully and compression stayed perfect. I only ran royal purple in that thing. I could drain it after 8000 miles and it still loooked almost new. Mobil 1 looked like tar after 4000. Granted, this car had roller cams, but the crosshatching (scope) in the cylinders looked like a fresh hone after 65000 miles. 5000 of those miles was with a blower and 600hp. I saw some independant tests of Amsoil, and after 5000 miles, things started going wrong with the oil in a hurry. My cousin has a 5.0, and he overheated the hell out of that motor...something like 280-290 degrees. He didnt know he was supposed to check coolant level when the engine is gtting hot (dumbass). Anyway he was running RP, and the compression is great. No engine damage at all. Sorry, didnt mean to turn this into an oil commercial.

 

[blown okie]

wanna fix your cam problems? Install a roller and never flatten a cam again. they dont call them flat tappet cam for nothing.