Trashed Roller cam. Be sure not to do this!!!
Thread Starter
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Trashed Roller cam. Be sure not to do this!!!
I installed this Hydraulic roller cam 2 years and about 15k miles ago. I took the intake off yesterday for some porting and noticed this:
Notice the orientation of the link bar on the cylinder with the arrow compared to the one next to it. I installed it backwards! I've been driving all this time with those to rollers about 30 degrees twisted.
Here is a pic of the cam lobe.
There's a deep groove cut into the lobe from the lifter roller digging into it. The lifter housing is also very close to the lobe which means most of the roller wheel is gone.
I am very impressed with the quality of the cam and lifters. Over 2 years and 15k miles like this and it is still in one piece. These lifters must be top quality, and the cam material very tough. I also think running synthetic oil helped. I can't even imagine the stresses and heat that must have been present on these two lobes.
The cam and lifters are Comp Cams.
Notice the orientation of the link bar on the cylinder with the arrow compared to the one next to it. I installed it backwards! I've been driving all this time with those to rollers about 30 degrees twisted.
Here is a pic of the cam lobe.
There's a deep groove cut into the lobe from the lifter roller digging into it. The lifter housing is also very close to the lobe which means most of the roller wheel is gone.
I am very impressed with the quality of the cam and lifters. Over 2 years and 15k miles like this and it is still in one piece. These lifters must be top quality, and the cam material very tough. I also think running synthetic oil helped. I can't even imagine the stresses and heat that must have been present on these two lobes.
The cam and lifters are Comp Cams.
Drifting
Joined: Jan 2000
Posts: 1,612
Likes: 0
From: Phoenix Arizona
Re: Trashed Roller cam. Be sure not to do this!!! (zwede)
Zwede,
Sorry to see that this happened. What are you plans with the new camshaft- go with the same specs or change things around??
BTW- My motor is done! And I should be able to get it back to the house by the end of the week...... I will post some pics....
Bob :cheers:
Sorry to see that this happened. What are you plans with the new camshaft- go with the same specs or change things around??
BTW- My motor is done! And I should be able to get it back to the house by the end of the week...... I will post some pics....
Bob :cheers:
Le Mans Master
Joined: Mar 2002
Posts: 7,056
Likes: 40
From: Life is Messy, Bring a mop
Re: Trashed Roller cam. Be sure not to do this!!! (zwede)
Zwede,
thanks for posting this. I always prefer to learn this kind of lesson from someone else :eek:
I'm considering a roller cam for my car and when I see instances of them failing, my curiosity is peaked.
thanks for posting this. I always prefer to learn this kind of lesson from someone else :eek:
I'm considering a roller cam for my car and when I see instances of them failing, my curiosity is peaked.
Burning Brakes
Joined: Jul 1999
Posts: 923
Likes: 164
From: Hudson NH
Re: Trashed Roller cam. Be sure not to do this!!! (zwede)
Hi Markus,
Well it certainly could’ve been a lot worse! I too have installed roller lifters backwards, but fortunately caught my mistake before installing the intake. It *is* easy to do.
Did you have any idea anything was amiss prior to removing your intake? What are your cam specs and attendant spring pressures? What synthetic oil and weight do you run?
Are you taking this as a SOI (Significant Opportunity For Improvement – a Noel Carboni saying) and changing anything else? Agree there was some hellacious heat and stresses on that lifter and lobe for 15K miles!
Take care,
Mark
[Modified by ML67, 12:22 PM 5/6/2002]
Well it certainly could’ve been a lot worse! I too have installed roller lifters backwards, but fortunately caught my mistake before installing the intake. It *is* easy to do.
Did you have any idea anything was amiss prior to removing your intake? What are your cam specs and attendant spring pressures? What synthetic oil and weight do you run?
Are you taking this as a SOI (Significant Opportunity For Improvement – a Noel Carboni saying) and changing anything else? Agree there was some hellacious heat and stresses on that lifter and lobe for 15K miles!
Take care,
Mark
[Modified by ML67, 12:22 PM 5/6/2002]
Thread Starter
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Re: Trashed Roller cam. Be sure not to do this!!! (ML67)
Well, I had some indications something was amiss, but it was very subtle. It tended to wander a bit in idle speed, but the EFI kept most of that in check. I noticed the vacuum wasn't as steady as I wanted. It had the slightest of chugs below 2000 rpm, but again it was very minor. It also didn't put down the power I expected it to on the dyno. Only 366 rwhp and 420 torque. I expected about 20 more hp and torque. I heard some clacking, but figured it was the injectors.
I took it apart to port the intake.
I considered changing the cam specs, but decided to stick with my old specs. They have worked very well.
The cam is a hydraulic roller. 224/232 duration, 573/585 lift. 114 lobe separation.
Oil is Mobil 1 10W-30.
I ordered the cam & 2 replacement lifters today. I may have it by the end of the week, but probably early next week. Comp Cams needs about 3 days to grind it (custom specs).
I took it apart to port the intake.
I considered changing the cam specs, but decided to stick with my old specs. They have worked very well.
The cam is a hydraulic roller. 224/232 duration, 573/585 lift. 114 lobe separation.
Oil is Mobil 1 10W-30.
I ordered the cam & 2 replacement lifters today. I may have it by the end of the week, but probably early next week. Comp Cams needs about 3 days to grind it (custom specs).
Le Mans Master
Joined: Aug 2000
Posts: 6,362
Likes: 7
From: Brazos TX
Cruise-In IV Veteran
Cruise-In V Veteran
Re: Trashed Roller cam. Be sure not to do this!!! (zwede)
Yikes! Sorry to hear that. I am amazed that it ran that long. As you said, tough equipment (and quite impressive). That 20 hp you expected was being used to turn the cam. It should run really good once it's back together.
Pro
Joined: Dec 2000
Posts: 531
Likes: 0
Re: Trashed Roller cam. Be sure not to do this!!! (zwede)
They are pretty tough. In the racecar once I came back in from qualifying with some pretty serious valve train noise. I pulled the valve cover and found the #3 exhaust rocker very loose (.100"+). Since it was a points race and we had just qualified to start on the outside front row of the heat race, I adjusted it and ran it. That was Friday night. I then ran it Saturday and Sunday nights as well. I tore the intake off on Monday and found that the bearing in the roller lifter had failed. That had caused my increased lash. The cam lobe was fine but the roller lifter had several flat spots! This was with .645" lift, triple springs and a rev kit. I was pretty impressed with the synthetic oil. Also since I suspected something wasn't right with the cam, I tried not to let it idle for any period of time the whole weekend. I ordered a new pair of Crane lifters and went racing again Friday. It's amazing what will work when you pray to the engine gods.
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