Broken Cam
Thread Starter
Racer
Joined: Sep 2007
Posts: 493
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From: Eden Utah
Broken Cam
OK--I was driving the Vette to meet with Jim for coffee. About a 100 yards from the coffee shop my car just quits. When Jim got to my car we started checking for the problem. I have a Multi/Sync distributor and I asked Jim to Turn the engine over so I could check the light in the dist. As he was turning the motor over I noticed that the rotor was not turning...BROKEN CAM!!!
I called my friend Vince who has a shop to see if there was any trick to getting the broken piece out. He said pull the engine as you will need to check the bearing for any possible damage. Ok-engine is out, and I now need to purchase a new cam. Some other cam manufactures told me that Comp uses Chinese cores and they have had some problems with breakage. Comp says the problem is due to the design of the SBC and they are prone to breaking cams.
The question is before I purcahse a new cam I would like any input from you guys out there on cam breakage, as pulling your engine in your garage is a PITA. Photos below
I called my friend Vince who has a shop to see if there was any trick to getting the broken piece out. He said pull the engine as you will need to check the bearing for any possible damage. Ok-engine is out, and I now need to purchase a new cam. Some other cam manufactures told me that Comp uses Chinese cores and they have had some problems with breakage. Comp says the problem is due to the design of the SBC and they are prone to breaking cams.
The question is before I purcahse a new cam I would like any input from you guys out there on cam breakage, as pulling your engine in your garage is a PITA. Photos below
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Comp says the problem is due to the design of the SBC and they are prone to breaking cams.
Is your distributor shaft intact?
Sure comp still makes some good products but Ive had failures too. From now on it will be a private grinder or something like Isky Crower etc. Someplace that hasnt gotten to big and has better QC
Race Director
Joined: Jan 2005
Posts: 10,641
Likes: 13
From: Slidell Louisiana
OK--I was driving the Vette to meet with Jim for coffee. About a 100 yards from the coffee shop my car just quits. When Jim got to my car we started checking for the problem. I have a Multi/Sync distributor and I asked Jim to Turn the engine over so I could check the light in the dist. As he was turning the motor over I noticed that the rotor was not turning...BROKEN CAM!!!
I called my friend Vince who has a shop to see if there was any trick to getting the broken piece out. He said pull the engine as you will need to check the bearing for any possible damage. Ok-engine is out, and I now need to purchase a new cam. Some other cam manufactures told me that Comp uses Chinese cores and they have had some problems with breakage. Comp says the problem is due to the design of the SBC and they are prone to breaking cams.
The question is before I purcahse a new cam I would like any input from you guys out there on cam breakage, as pulling your engine in your garage is a PITA. Photos below
I called my friend Vince who has a shop to see if there was any trick to getting the broken piece out. He said pull the engine as you will need to check the bearing for any possible damage. Ok-engine is out, and I now need to purchase a new cam. Some other cam manufactures told me that Comp uses Chinese cores and they have had some problems with breakage. Comp says the problem is due to the design of the SBC and they are prone to breaking cams.
The question is before I purcahse a new cam I would like any input from you guys out there on cam breakage, as pulling your engine in your garage is a PITA. Photos below
Looking at your pics seems like your engine is not stock.
I've used a few comp cams over the years with no problems I wonder if something has changed IE "the chinese core rumor". If I was in your shoes I'd call a quality shop and order a custom cam IE from AI, or one of the other shops....
(been running a custom AI cam for a couple of years ....lots of 7,000+ rpm run time with no drama.......Good luck
Mike
Thread Starter
Racer
Joined: Sep 2007
Posts: 493
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From: Eden Utah
the distributor is intact, it looks like the cam broke right in front of 7-8 cylinders, so there should only be a short stub left, which we will pull from in back, I will remove the freeze plug and then I can see if there is any damage to the bearing. I am look at a custom grind and the 4-7 swap from Isky. A little more money, but you get what you pay for and pulling the engine is crappy. After what I am hearing, I am a llittle gunshy of Comp. The Isky has a two year warrantee for what thats worth.
Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
the distributor is intact, it looks like the cam broke right in front of 7-8 cylinders, so there should only be a short stub left, which we will pull from in back, i will remove the freeze plug and then i can see if there is any damage to the bearing. I am look at a custom grind and the 4-7 swap from isky. A little more money, but you get what you pay for and pulling the engine is crappy. After what i am hearing, i am a llittle gunshy of comp. the isky has a two year warrantee for what thats worth.
Race on!!!
Jim
Last edited by CFI-EFI; Sep 4, 2010 at 12:22 PM. Reason: TYPOS
Race Director
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From: WI
Race Director
Joined: Sep 2000
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From: The Top of Utah
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Drifting
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From: Tampa Fl
Thread Starter
Racer
Joined: Sep 2007
Posts: 493
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From: Eden Utah
Just checked it and it turned easly..
Wow how do yoi break a cam?????
Were you just driving normal ?????????
30 miles per hour just shifted into high and convertor locked up, normal as you can drive.....Have no idea unless comps cores made by the Chinese are crap....
Wow how do yoi break a cam?????
Were you just driving normal ?????????
30 miles per hour just shifted into high and convertor locked up, normal as you can drive.....Have no idea unless comps cores made by the Chinese are crap....
Team Owner
Joined: Oct 2004
Posts: 81,241
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From: altered state
St. Jude Donor '05
Team Owner
Joined: Dec 1999
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From: Lacey WA RVN 68-69
NCM Sinkhole Donor
The distributor gear is weaker metal so if the oil pump froze or there was damage to the gear on the distributor, the gear should have broken long before the cam.
Of course it's entirely possible that it was a bad casting or forging, or even some bad metal. But Comp's comment about SBC cam breakage is
When you get a new cam. install new cam bearings. Not worth risking a new cam if there is a chance one of the existing cam bearings has any damage or has spun in the bore. With a break like that, it's a good idea to clean out the oil passages to get rid of any small pieces or shavings of metal.
Melting Slicks
Joined: Nov 2008
Posts: 2,765
Likes: 5
Everything is being made in China under the sun it seems anymore.
I used to use Competition Cams Camshafts in the 1990's.
I have been using Iskenderian and Crower Camshafts and valvetrain parts exclusivily.
Thats a shame, Comp Cams used to make excellent camshafts, lasted for many of thousand of miles for me. Often turning 8,000+Rpm's.
After seeing your broken camshaft in your Corvette, I will definatley stay clear of them.
China Metal Sourced Cores is what they are buying. I have heard that from others in the Racing Business last few years.
China ='s @$^&*(*()(^$ !
I used to use Competition Cams Camshafts in the 1990's.
I have been using Iskenderian and Crower Camshafts and valvetrain parts exclusivily.
Thats a shame, Comp Cams used to make excellent camshafts, lasted for many of thousand of miles for me. Often turning 8,000+Rpm's.
After seeing your broken camshaft in your Corvette, I will definatley stay clear of them.
China Metal Sourced Cores is what they are buying. I have heard that from others in the Racing Business last few years.
China ='s @$^&*(*()(^$ !
Thread Starter
Racer
Joined: Sep 2007
Posts: 493
Likes: 0
From: Eden Utah
What about the rest of the valvetrain? Any indication of a bad lifter? bent pushrods? Does the timing chain look like it may have stretched/ jumped? Any indication of valve to piston damage?
The distributor gear is weaker metal so if the oil pump froze or there was damage to the gear on the distributor, the gear should have broken long before the cam.
Of course it's entirely possible that it was a bad casting or forging, or even some bad metal. But Comp's comment about SBC cam breakage is
When you get a new cam. install new cam bearings. Not worth risking a new cam if there is a chance one of the existing cam bearings has any damage or has spun in the bore. With a break like that, it's a good idea to clean out the oil passages to get rid of any small pieces or shavings of metal.
The distributor gear is weaker metal so if the oil pump froze or there was damage to the gear on the distributor, the gear should have broken long before the cam.
Of course it's entirely possible that it was a bad casting or forging, or even some bad metal. But Comp's comment about SBC cam breakage is
When you get a new cam. install new cam bearings. Not worth risking a new cam if there is a chance one of the existing cam bearings has any damage or has spun in the bore. With a break like that, it's a good idea to clean out the oil passages to get rid of any small pieces or shavings of metal.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Seems like an anomaly to me? Considering all the different Forums I visit I don't recall a post similar to OP's. A cam that just broke.
Who knows? I mean who REALLY KNOWS where these cam companies get their cores?
At one time COMPCAMS was credited with getting their cores from CRANE which were supposed to be the best cores available, but what about now? Where was CRANE getting them?
Where are Lunati, Isky and others getting theirs? Are they now buying cores from COMPCAMS? If cores are like so many other parts for our engines there are only a very few companies that manufacture them.
Think about valve springs while you're at it: Where's the wire coming from; who actually mixes the alloy; who actually winds it? Take the catchy name like "Patriot Gold", ask yourself, what part does the company that sells "Patriot Gold" springs actually play in their manufacture. Do they just buy 'em and put them in their box?
There's a LOT we don't know. What we end up doing is putting our trust in the company we buy the cam from. However, when it comes to valve springs, at least CompCams gives all the details about their springs right in their newest catalog.
Nothing yet on cores though, but I'll keep looking.
Jake
Who knows? I mean who REALLY KNOWS where these cam companies get their cores?
At one time COMPCAMS was credited with getting their cores from CRANE which were supposed to be the best cores available, but what about now? Where was CRANE getting them?
Where are Lunati, Isky and others getting theirs? Are they now buying cores from COMPCAMS? If cores are like so many other parts for our engines there are only a very few companies that manufacture them.
Think about valve springs while you're at it: Where's the wire coming from; who actually mixes the alloy; who actually winds it? Take the catchy name like "Patriot Gold", ask yourself, what part does the company that sells "Patriot Gold" springs actually play in their manufacture. Do they just buy 'em and put them in their box?
There's a LOT we don't know. What we end up doing is putting our trust in the company we buy the cam from. However, when it comes to valve springs, at least CompCams gives all the details about their springs right in their newest catalog.
Nothing yet on cores though, but I'll keep looking.
Jake
Race Director
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From: The Top of Utah
Race Director
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From: Database Error Indiana
Comp needs to replace that cam. SBCs do not break cams, thats BS. Word gets around and they will lose a lot of sales. Pretty sure I wont buy one after seeing this thread. I actually have one on the shelf and it will probably stay there.