Guess The Problem Is Cam Is Bad - Need Advice

[QuikRick]

Well, my GN was running bad. We thought it might be a valve problem but apparently a cam lobe for the #6 cylinder has flatten out. Car had 7K miles on it since engine was assembled and not alot of racing miles at all. Mechanic is not a Buick guru but thinks that maybe they didn't break the cam in properly originally. Says that to break the cam in you have to run car at 2000 RPM for 20 minutes and then change the oil & filter after letting engine cool completely down. I'm not really a guru myself when it comes to these engines. We have talked about going back with roller lifters and I assume that means using a roller cam. He said a soft cam would run about $350 max and to do the roller cam set up would be about $1K (this doesn't include labor of course). I guess with the roller cam they use hardened steel and they don't have to be broke in like the soft steel cams. The car has had extensive mods done to it and I may sell it eventually but not really sure but I want to make it right as possible. He is talking about Comp Cams. I guess I'm just looking for anybodys thoughts on any of this?? What cam (brand) anyone would recommend, roller vs soft, etc etc. Thanks, Rick

 

[Brer Rabbit]

Check the supporting vendors.

All of them sell complete roller cam kits. I think there under 900.00. Comp Cams is the brand that I have and have no issues, with 4k on the motor and beating on it daily. U will need to know all the details to ur rebuild before U buy the cam. Ive heard it said that a roller cam is good for a 100hp compared to the flat tappet cams. Good luck.

 

[BlackBandit]

I would go roller. You really should have the engine torn down and cleaned out. basically a bottom end rebuild. If you caught it quick and the cylinder walls are ok then I would just do all the bearings and scrub the block and do any machine work needed to the crank and leave the pistons alone. Also, someone on here (blazer406 ?????) posted on how to go to a roller setup using gm stuff which is cheaper, and IMO a better setup. You might look into that. I guess it partly depends on who's doing the work. So, in summation, get the metal out, go roller, don't look back.

EDIT: Keep an eye out in the for sale section and maybe post in the part wanted section. I good used roller/lifters set will save you a bunch of money and work just as well as new ones.

 

[QuikRick]

Thanks for the input

Guess I'll go with the roller cam. I really don't know why a roller cam wasn't used in the original rebuild. I mean this was orignally done by a well known GN mechanic in Dallas and was pretty much "no expenses barred" type deal. As far as what was done on the rebuild, it is the invoice and lists everything piece by piece, to wit: HD intake & exhaust valves, steel rods, bosch sp calb injeco, dbl rld timing chain, ta49 turbo, alum drive shaft w/loop, etc etc. As for the metal shavings, so far it is just real fine particles and the mechanics think a good flushing will be just fine and no need to redo the bottom of the engine. Thanks for your input and if anyone else has any comments, I'm all ears. Thanks, Rick ..

Questions: This car has an in front of the radiator intercooler, can anyone tell me if the cam can be removed without removing the radiator and/or intercooler? It has double electric fans also. Can cam come out without removing fans? There seems to alot of room between the engine and the fans (with no intercooler) and I know the cam is kind of short being a V6. They started out at $3K and now are at $2,600 . I was thinking it should be more around $2K to install a new roller cam kit. He said $1,140 for the Comp cam kit but I saw what I think is the same cam kit for $908. Of course there is shipping and Uncle Sam. I want to be fair but I don't want the cam put up my you know what.. LOL Anyone familiar with this I would appreciate your input. Thanks, Rick

 

[Brer Rabbit]

Suggestion...

Find a new mechanic, its easy for him not to "think" a complete tear down is not really necessary, because its not his car. That plus the fact that hes trying to mark up the roller cam kit by $200.00, tells me hes gonna beat u down on labor also. The part of the country U live in depends on who could be recommended to U.

 

[QuikRick]

Find a new mechanic, its easy for him not to "think" a complete tear down is not really necessary, because its not his car. That plus the fact that hes trying to mark up the roller cam kit by $200.00, tells me hes gonna beat u down on labor also. The part of the country U live in depends on who could be recommended to U.

I'm kind of agreeing with what you said and even considering doing it myself. You know, if you want a job done right - do it yourself... I'm on the central coast of California. I think most of the decent GN mechanics are down south around LA.. Thanks, Rick

 

[chrisgarrett]

I wouldn't invest the time and labor of a new roller cam in an engine without rebuilding the whole motor.

 

[turbo nasty]

Shavings went all through the motor pull and check everything