Roller cam advice, please.

[counterman]

I have been chasing a miss in my recently rebuilt motor. It appears to be getting more pronounced, and it has started popping at 4k or so. Idle quality is going away also. I verified 150psi in all holes today, so no bent valves. I pulled the valve covers and cranked her up. Exhaust pushrod on #6 is no longer spinning. That plus the fact that I am still getting grey dust in the oil at this point leads me to believe that I have a bad cam. I had a new Edelbrock flat tappet unit. Anyhow, I am planning on pulling the motor for a clean out and check up. What hydraulic roller cam or kit would you guys recommend? This thing is a basic .030 over motor with billet caps. I have the iron Champion heads, and am running a TE44 now. I am planning on a an upgraded turbo soon. I upgraded to the 60 lb Delphi injectors already, and just got my tranny bombproofed by Mike Kurtz. I am running the Speed Pro forged pistons in the motor, and I don't want piston to valve contact problems, for sure. Thanks, Counterman.

 

[TurboBuRick]

Hell ya, put a roller in it and forget about it. IMO, flat tappets in these motor's are a problem waiting to happen. Today's oil just can't support them by itself. Were you running any additive?

Rick

 

[counterman]

Hey, Rick, I sure was running additives. I used Crane cam break in sauce for flat tappets, plus, I did the Zddp, too. I have changed the oil 4 times in less than 100 miles, and I added the Z stuff each time. The break in appeared to go well. The motor was smooth, and, in fact, I was amazed that the 60 lb injectors with the TT chip idled better than the stockers early on. I had other problems, caused by a poor local rebuild on my tranny. I over revved the motor screwing with the trans, and popped a head gasket. No piston to valve contact, and no coolant in the oil. I then sent the tranny over to Mike Kurtz, and the trans is an animal with no bad manners, now. I have noticed the idle quality degrading, and I have been watching a constant amount of grey material turning up in the oil. It is super fine, and cannot even be felt by hand. Now, it is popping under boost at 4k on up. For me, the fact that the pushrod is no longer rotating seals the deal. I am going roller. Counterman.

 

[TurboBuRick]

The one thats not spinning, does it appear to have the same amount of travel as the others. I would not seal the deal based on the pushrod not spinning. Do the rockers all still have the same amount of travel (up and down)?
Another thing I'm thinkng, if the miss at 4000rpm and up was related to the cam, it would not effect idle unless the cam lobe was completley worn flat. You would notice that for sure and it would miss all the time.

Have you tried running in batch fire mode to see if the miss goes away? Unplug the cam sensor while the motor is running. The CE light will come on and set a cam sensor code. No big deal. Leave it unplugged, take it out for a little blast and see if the miss is still there. Maybe you have another issue.

Rick

 

[counterman]

Rick, the miss is noticeable across the rpm band from idle on up. The popping is at 4k or so on up. I have the T&D rockers, and verified the lash adjustment a few weeks ago. I now have extra valvetrain noise on the pass side that I didn't have earlier. It is quite audible with the cover off, especially. Last time I had the covers off, all pushrods were spinning freely, and, now, #6 exhaust is stationairy at idle and when free revved, too. I do plan on doing some more exploration before yanking the motor again. The popping could easily be unrelated. It could be a coil pack, control module, crank sensor, or maf related, too. Thanks, Counterman.

 

[mygn276]

If its the dreaded #3 lifter bore that GM messed up on, The cam needs to come out. Drop the pan and clean it out and check a few bearings.they should be ok if the filter catches everything get a ducttile roller cam set somewhere around 212-212 and dont look back

 

[TurboBuRick]

Counterman, are you running a (turbo saver) remote oil filter?

Can you visually tell if any rockers are not moving (up and down) like the others? I mean if the cam is worn to the point to create a miss, you would be able to tell just by watching the valvetrain while the engine is running. The culprit would be pretty obvious. The rocker arm would hardly move at all (up and down). Take a close look at the rocker shaft too. They are known to crack.

Rick

 

[counterman]

Rick, I did not notice how much travel the rocker had on #6. It was still moving up and down, so I know the lobe is not completely gone. I was short on time, and should be able to get a better look at it this weekend coming, I hope. Counterman.

 

[Phoff]

PM sent.....

Pete