Problem with Comp Cams |
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AWhite70
Senior Member Joined: March-05-2004 Location: United States Status: Offline Points: 242 |
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Posted: November-17-2004 at 9:21pm |
I just wanted to make everyone aware of the problems I've had with Comp Cams on the cam for the engine I'm rebuilding in my '79 Nautique.
I ordered a custom grind reverse rotation camshaft this spring and rebuilt the engine. Everything seemed good until I had to tear the engine down for reasons other than the cam. Upon teardown inspection of the cam and measuring of the lobes I noticed that the intake and exhaust lobe lifts were backwards from my desired specs on the cam card. I called Comp Cams and they told me this was impossible, but to send the cam back and inspect it. When Comp inspected the cam they confirmed that the lobes were backwards and promptly ground me a new cam and shipped it out within a week. When I received it I measured it only to find that it had been ground exactly the same as the first cam. I called Comp again and have been going back and forth with them for the past 2 months. They supposedly know what got messed up and are going to grind me a new cam to the correct specs and ship it to me. Meanwhile I'm waiting. I just wanted to warn anyone that's rebuilding an engine with a Comp Cam to make sure they measure the lobes to ensure they actually got what they wanted. |
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Jim_In_Houston
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I just got off the phone with a comp cam rep getting recommendations for a cam for my 1968 289 Ford engine. I was told Comp Cams does not offer a reverse rotation cam for a 289 but that they do offer a reverse rotation cam for a 351 Windsor and all I have to do is change my firing order to use the Windsor cam. Does this sound right or make sense?
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AWhite70
Senior Member Joined: March-05-2004 Location: United States Status: Offline Points: 242 |
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I'm not sure about a 289 but I know that's the case for a 302. In the automotive world there are a lot of 302 running 351 firing order's and vice versa. I'm not sure exactly why they are different but they are interchangeable.
Since on a 4 stroke engine there are always 2 pistons in the same physical position but on different strokes (i.e. compression & exhaust) you can have multiple firing order's that work fine. |
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882001
Senior Member Joined: October-21-2003 Location: United States Status: Offline Points: 332 |
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did it run with the first cam? i just got a cam from them a couple of months ago. seems to run great.
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kemah texas
1988 skinautique "2001" |
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GottaSki
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A 302 is only an overbored 289, and the same firing order, so a 289 can be converted to the 351 firing order like the 302.
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AWhite70
Senior Member Joined: March-05-2004 Location: United States Status: Offline Points: 242 |
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The engine ran great with the bad cam grind. I degreed the cam when I installed it so the #1 intake was in the correct spot and the durations were close enough that everything ran ok. The intake and exhaust lobe lifts were different but not different enough to detect a problem in engine running. The one problem I did have is pushrod wear. I attribute this to the fact that the opening and closing ramps were backwards (i.e. I was opening the valve by going up the closing ramp and closing the valve and closing the valve going down the opening ramp) I suspect that this caused some increased loading on the valvetrain and caused the pushrods to wear.
In short, there was no detection of the cam being wrong in running the engine. I would have never known if I didn't measure the cam |
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882001
Senior Member Joined: October-21-2003 Location: United States Status: Offline Points: 332 |
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so should i call comp cams? how long have they been screwed up? whats gonna happen if i leave it.i wasnt looking to disassemble the motor again, but if i need to i will.
need to change your name to eagle eye. i could study that cam for a month and not figure that out. |
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kemah texas
1988 skinautique "2001" |
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captan1
Senior Member Joined: June-02-2004 Location: United States Status: Offline Points: 180 |
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Damn Correct Craft and their reverse rotation setup, that's one of my biggest dilemmas,, cam selection for RH motors. You buy a reverse rotation cam from one of the marine engine parts people and no cam specs come with it.
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Jim_In_Houston
Platinum Member Joined: September-06-2004 Location: United States Status: Offline Points: 1120 |
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So, do any other cam grinders make a reverse rotation cam?
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SS 201
Senior Member Joined: October-20-2003 Location: United States Status: Offline Points: 232 |
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Crane,
I have two of them |
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SS 201
Senior Member Joined: October-20-2003 Location: United States Status: Offline Points: 232 |
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Crane,
I have two of them, firing order 18456273 |
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captan1
Senior Member Joined: June-02-2004 Location: United States Status: Offline Points: 180 |
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For reference purpose this web site has a OEM RH cam spacs http://engineparts.com/motorhead/techstuff/2003marine/Camshafts_Lifters_TimingComponents.pdf
I'm not sure if Lazer cams did but I Crane probably does. What was the specs or part number for the one you got SS201? |
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Stan C
Newbie Joined: February-18-2004 Location: United States Status: Offline Points: 38 |
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If you have an existing rh rotation camshaft, isky cams in calif will regrind it with any new cam profile you like for $78.00
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Stan C
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SS 201
Senior Member Joined: October-20-2003 Location: United States Status: Offline Points: 232 |
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Crane is the largest suppler of cams, they not only grind but manufacture the blanks. They supply most of the automotive industry. Call this person, Roy Griffin 386 527 8385 leave a message he will get back to you. Just tell him Bill B told you to call, he is special event person for Crane. He will take care of your needs.
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Jim_In_Houston
Platinum Member Joined: September-06-2004 Location: United States Status: Offline Points: 1120 |
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Good info.
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882001
Senior Member Joined: October-21-2003 Location: United States Status: Offline Points: 332 |
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what do you think i outta do? is there a way to tell?
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kemah texas
1988 skinautique "2001" |
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SS 201
Senior Member Joined: October-20-2003 Location: United States Status: Offline Points: 232 |
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Look at your cam card and use the firing order is was ground for. Also it tells you what it is should say left hand rotation. long as the dist goes in, just use the firing order it was ground for on the card.
The different firing orders were used to take the load off the front journal of the crank. CC engine were 18456273 Some Ford engines had three different firing orders. |
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AWhite70
Senior Member Joined: March-05-2004 Location: United States Status: Offline Points: 242 |
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882001-The easiest way to tell if your cam is right would be to pull one of the valve covers, remove a couple rocker arms and check pushrod lift with a dial indicator. This will tell you if you have the correct lift on the correct lobes. There is no way to tell if the ramps are right without some pretty sophisticated equipment and a detailed drawing of what they're supposed to be.
Other than that if the engine runs ok and you're happy with the performance I wouldn't worry about it. You're not going to damage anything that you wouldn't replace in a cam swap anyway. Like I said I never would have known mine was ground incorrectly until I took my engine apart for other reasons. As far as other suppliers for RH marine cams I couldn't find anyone other than Comp that would grind a high performance RH cam. Crane used to but no longer does as I understand. Federal Mogul and Dana (Clevite) sell cams ground to OEM specs. The custom grind cam from Comp was still have the price of what Ski DIM wanted for an OEM replacement PCM cam. |
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SS 201
Senior Member Joined: October-20-2003 Location: United States Status: Offline Points: 232 |
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First,
If it was the wrong rotation and the transmission pump wasn't changed the boat wouldn't move.The boat with the wrong prop would go backwards instead of forward. Water pump if not flipped wouldn't work ,etc. You need yor cam card and dial indicator, top dead center plug,degree wheel, etc and the knowledge to do so. Cam card will tell you everything you want to know about your cam, if it's a left or right rotation, and all other pertent information.. |
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captan1
Senior Member Joined: June-02-2004 Location: United States Status: Offline Points: 180 |
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This is the response I got back from Lazrecams after requesting info on reverse rotation cam grinding. The cam I chose to reference was a Ford 351 1962-1992 Hyd grind of 215 degrees @50 intake/exhaust and .486 lift both sides, a bit more than stock marine grind. I've never used them so don't come to me if the lobes are bass-ackwards.
"Yes, indeed Cap'n! We certainly can. $188.11 for most hydraulic and lifter grinds. And it's typically only 2-4 working days from order to ready to ship." Cam Wizard captan1@pacbell.net writes: Can you grind me a cam like ( 2650137 ) a or b? for a reverse rotation ford 351 1977 marine engine? Steve |
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SS 201
Senior Member Joined: October-20-2003 Location: United States Status: Offline Points: 232 |
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I would choose a dual pattern cam rather than a single pattern cam. Single are used in conditions that require wide open all the time ,dual pattern gives more low end torque, and on off throttle responses.
When used on a track and wide open throttle is constant they are great. In my opinion |
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captan1
Senior Member Joined: June-02-2004 Location: United States Status: Offline Points: 180 |
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I'm no cam wizard but I have researched the different profiles and why they are. One comment I remember is this guy wrote a tech article about dual pattern cams, he wasn't against them he just said there is a purpose and a place for them. He said sprint cars sometimes used a dual pattern cam to soften the "getting back in it" and consequently lowering the compression for rookie drivers because on dirt the rookie would stab the throttle half way through the turn and bust loose the tires and usually spin out and the dual pattern cam would help prevent this. He also said that now days the exhaust systems in cars are better and the need for longer exhaust duration wasn't so beneficial, boat exhaust systems at 3" and short distance have to be fairly free flowing. I've had dual pattern cams and just wanted to try a single, might note even notice the difference.
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SS 201
Senior Member Joined: October-20-2003 Location: United States Status: Offline Points: 232 |
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That is a good analysis and If it doesn't work you can alway's mix the rocker ratios. I would agree with the exhaust however older marine systems are not free flowing, unless you have changed exhaust. Expensive way of going back. I guess seeing is believing, have fun.
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David F
Platinum Member Joined: June-11-2004 Location: United States Status: Offline Points: 1770 |
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Has anyone ever thought about coverting a RH engine to a gear driven camshaft. This will allow the use of conventional LH rotating cams, distributor and oil pump. The 350 Chevy in my old 64 Chris Craft was set up this way and made it very easy to get the cam I wanted. I actually used a cam spec set up for RV's to get the most low end torque possible. Just a thought.
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captan1
Senior Member Joined: June-02-2004 Location: United States Status: Offline Points: 180 |
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I thought of that too, I don't think it would fit. The cam gear would have to be so big to eliminate the idler gear like the old Chevy six had that it won't fit in the Ford timing cover. You have to eliminate the idler gear to reverse the rotation of the cam, the gear drives used on car engines have an idler gear that keeps the cam rotating in the same direction as if using a chain.
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David F
Platinum Member Joined: June-11-2004 Location: United States Status: Offline Points: 1770 |
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The 350 that I rebuilt had the camshaft gear driven directly by the crankshaft gear. This setup reversed the rotation of the camshaft, distributor and oil pump relative to the the crankshaft. Allthough I have rebuilt several 351 Windsor's, I never really studied the cam chain cover to see if there was enough room for a gear drive setup. However, you are probably right.
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SS 201
Senior Member Joined: October-20-2003 Location: United States Status: Offline Points: 232 |
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There is none.
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AWhite70
Senior Member Joined: March-05-2004 Location: United States Status: Offline Points: 242 |
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An update on my Comp Cams story:
Yesterday I received my cam (the 3rd one). I measured it and it matches the spec. card and is the specs I wanted. Comp said they had their "Master Grinder" (the guy who does cams for Nascar) do my cam and that they know what mistakes they were making and assured me it won't happen again. Aside from this taking a little too long I have been happy with Comp's service. Along with the cam they sent me a new set of lifters and pushrods. Hopefully I'll get the engine put together in a couple weeks and maybe get it in the boat so I can clear up some garage space. |
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captan1
Senior Member Joined: June-02-2004 Location: United States Status: Offline Points: 180 |
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For the rest of us that might be interested in swapping cams,, what are the spec's of your new cam and did Comp Cams give you a part number for the new cam?
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AWhite70
Senior Member Joined: March-05-2004 Location: United States Status: Offline Points: 242 |
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If you do a search on this forum for Comp Cams you'll be able to find a couple old threads with my cam info, but here it is:
Cam Blank: 35-000-5RR Grind # FW 5442/5444 H112 +2 Duration: 218/226 @ .050" (I/E) Lift: .308"/.320" (I/E) (0.493"/0.512" w/ 1.6 rocker) Lobe Separation: 112 The cam performed great with the lobes reversed. Hopefully it will be as good or better with the cam ground correctly. |
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