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BBC Comp Cam Issue

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cam comp issue
5K views 28 replies 12 participants last post by  nelsont509 
#1 ·
Good day my fellow BOAT enthusiasts..... I recently started hearing a different sound coming from the left side exhaust while cruising. As my valve cover gaskets where leaking a little, I thought, no better time than to adjust the valves, right, glad I did!! With engine at idle, I began my rocker arm adjustment, starting with number one cylinder. That's when I noticed the number 7 intake rocker arm was barely moving....What follows is a series of pictures that I believe accurately shows the issue I found. The cam lobe in question is the second one from the distributor gear. I have yet to find out why... :wtf: :confused:

Auto part Suspension part Automotive engine part Suspension


Auto part Automotive engine part Suspension part Suspension


Auto part Suspension part Suspension Coil spring


Metal


Auto part Tool accessory Metal
 
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#2 ·
Ya lost a lobe. More often than not, the prime suspect for the cause is improper break in procedure for a new cam. However, there can be other causes too.

How many hours on that one? Fairly new? Been in the engine and working fine for a decade?
 
#3 · (Edited)
Hehehehe..... I've owned the boat for the last decade, 139.2 on the hobbs. Bought the boat with 89 hrs. The last 30 hrs or so, within the last 4 months (moved to Florida). Pry the same cam since a mid-nineties rebuild (original owner). I'm the third owner. Just seems awfully specific for a cam break in issue :)Unsure

I've got the new Comp Cam coming...any suggestions for break-in, or just follow manufactures recommendations?!
 
#7 ·
Oh yes!! I'm borrowing a bore scope, and a filter cutter from work this evening to look at the cylinder walls and oil filter. I ran a magnet down through the oil pan with little to no shavings...hopefully Wix saved my bacon!!!

Once I moved to FL, she sat for about two and half years without running, so a little rust, I'm sure, is to be expected...
 
#17 ·
I'll toss this out as a thought. I believe it was said the engine had been setting for a length of time. If so, is it possible enough oil drained off the various components including the camshaft to essentially make it a dry start-up resulting in that kind of damage.

I know that if my engine sits for a time, i'll pull the distributor and run the oil pressure up before starting it.
 
#19 ·
All the way down...

You MUST take the engine all the way down and CLEAN every nook and cranny.... Trash will be everywhere, so much so that even a hot tank may not get it out of the block.... The bypass, (unless you run an Olsen cooler) is what the filter screws on to. Another critical area is the oil pump it's self. The pump sees the oil BEFORE the filter and can really take a beating from very little crap flowing through it... The pressure relief piston needs to be removed and cleaned or it may stick. Stick closed and you'll blow the filter gasket out, stick open and you won't need to worry about cleaning that block again... I would highly recommend replacing the oil pump if there is ANY sign of damage to the impellers or the body.... (Don't assume an "out of the box" replacement pump is within desired specs)...
Too late now, but if you went to a roller cam there is no break in dangers..:D

Ray
 
#20 ·
You MUST take the engine all the way down and CLEAN every nook and cranny.... Trash will be everywhere, so much so that even a hot tank may not get it out of the block.... The bypass, (unless you run an Olsen cooler) is what the filter screws on to. Another critical area is the oil pump it's self. The pump sees the oil BEFORE the filter and can really take a beating from very little crap flowing through it... The pressure relief piston needs to be removed and cleaned or it may stick. Stick closed and you'll blow the filter gasket out, stick open and you won't need to worry about cleaning that block again... I would highly recommend replacing the oil pump if there is ANY sign of damage to the impellers or the body.... (Don't assume an "out of the box" replacement pump is within desired specs)...
Too late now, but if you went to a roller cam there is no break in dangers..:D

Ray
LMAO..... I did look at the roller cam sets, for a second. I though to myself...Damn, even for a cheap set, it's more than I paid for the whole boat!!! As I stated before, I'm no where near the same caliber boat owner, let alone, engine as you folks have... with that said, however, I defiantly what something reliable. Any particular brand of oil pump I should be looking in to??

I thank you all for the encouraging words and wisdom!! I will be possibly this summer looking to rebuild (or finding something different) the power plant in my float.

Boat safe, Float fast!!
 
#21 · (Edited)
Friends don't let friends run Comp products, especially flat tappet cams. This thread is the poster child of "why not".
Tear it down, clean it good, save your pennies and invest in a good hyd. roller. The cam is the brain of the engine. If it's not right, nothing else will be, no matter how much you spend. The right cam can make a bad combination of parts look good...the wrong cam can make the best parts look like a turd.
I would replace the oil pump. Period. I would go with Melling select series, either the 10774 (standard volume), or 10777 (high volume) if you are running any sort of oil cooler or remote filter. If the engine doesn't have a decent oil pan, you might consider one down the road at some point. Marine engines are hard on parts and a good oil pan is good insurance.
Also, stop running aircraft oil in your automotive engine. It's not air cooled and doesn't run on avgas. These days there are specific oils for just about every application. I would look at something like the Driven HotRod oil if you insist on running a flat tappet. There is no need for 50 wt, either. Old school, old school thinking, old school results. Plenty of good 30 and 40wt synthetics on the market these days.
 
#28 ·
Friends don't let friends run Comp products, especially flat tappet cams. This thread is the poster child of "why not".
LMAO...Now you tell me!! :secret:

Agree with everyone, tear it down to the bare block and have it cleaned professionally, You will prob need to re-hone the cyl walls and maybe new piston skirts. Really just depends on how bad the metal chunks (if anything of significant size) got into the bearings and pistons.

Definitely buy a new oil pump. Yours is probably contaminated. They are cheap, the Melling M77 standard volume pump is usually good for anything under 500hp, (I've ran one for 4 seasons)

I run a Comp cams unit in my FTC (flat tappet cam) BBC. I broke it in exactly according to the manufactures break in procedure...here is what I did:

*Gobb all the cam break in red goo on the camshaft before you bolt the intake on. This stuff is supposed to "stay" on the lobes even though it seems that most of it runs off. maybe it adheres to it microscopically, IDK lol.

*use a bottle of the cam break in oil. I filled up my oil filter halfway with this stuff, that way it got to the cam bearings and lobes immediately. The other half of the oil filter i filled up with the motor oil.

*Motor Oil - I broke it in with and run Valvoline VR1 20-50W. It has high zinc and phosphorous and is probably the best "off the shelf" oil for flat tappet cams. That other stuff you were running seems too thick and not really formulated for an auto engine.

*Remove the inner springs if you are running a dual spring setup. Re-install after break in. This is according to Comp. I actually ran a lake trip or two with the single outer spring only.

*Mark distributor location with the sharpie, remove and use a manual oil pump drill attachment and spin that oil pump for about 20 minutes to get the oil and cam break in oil flowing everywhere....till you see it coming out of the push rods up top. You will see your oil pressure rising on your dash gauge. Replace distributor. Do this the day you are going to break in the new cam.

*Fire that engine up on the lake, hold it at around 2000rpm for about 20 minutes, varying the rpm speed by about 500rpm up and down occasionally. Yes this is kinda scary but its really the way you break in a Flat Tappet cam. After 20 minutes, if your motor hasn't blown up, you did everything right!

*Change oil, never run synthetic in a FTC motor

NOTE: everything I did to break in this motor that wasn't stated by Comp Cams, was direct advice from the legend that this sub-forum is named after. Seemed to have worked :))THumbsUp
:))THumbsUp:))THumbsUp Thank you for the advice!!

FYI.................. AeroShell is also used with flat tappet camshafts, aircraft difference is they are a billet type, most are hydraulic mushroom lifters in horizontal apposed engines ............. We also run AeroShell with our Roll Royce Merlin engines in the P-51s they are liquid cooled. I don't suggest running AeroShell in these engines.......

To say synthetic oils won't work with flat tappets is a misnomer........... Amsoil, Lucas Hot Rod & Classic have oils designed around these types of engines!!

Good Luck with your problem............ Spudz
With the exception of this one cam lobe, I've had no problems running Aeroshell in numerous applications without issues... Maybe it caught up with me!!

I'm not one to give advise as I have received a lot of advice from these guys, just going to say I just broke a lunati flat tappet cam in and I used isky rev lube, its a moly lube and it sticks! sticks damn good I liked it way better than the other red stuff but that's my own experience and I used joe gibbs break in oil (its expensive but better safe than sorry) just my experience and good luck!
:thumb:

Do NOT use aircraft oil in your automotive or marine engine. It's not what it was designed for.
:D

Flat tappet cams are a roll of the dice even if you take all of the precautions during break in.

For a long time I refused to install a flat tappet cam in an engine and give it to the customer. Then as business got slimmer, I would install them with a disclaimer on the invoice. :)eh:) Even then I wanted nothing to do with breaking one in for them.

I can recall back in the day even when the oil was OK break in was sketchy. There were soft springs to use during run in and rockers with very low ratios to run them in with. Opened the valves just enough for the engine to run and put the least amount of spring pressure on the valve train.
When I get the engine back together, I'm following the manufactures recommendations... pretty much what Bonzen said...
 
#22 · (Edited)
Agree with everyone, tear it down to the bare block and have it cleaned professionally, You will prob need to re-hone the cyl walls and maybe new piston skirts. Really just depends on how bad the metal chunks (if anything of significant size) got into the bearings and pistons.

Definitely buy a new oil pump. Yours is probably contaminated. They are cheap, the Melling M77 standard volume pump is usually good for anything under 500hp, (I've ran one for 4 seasons)

I run a Comp cams unit in my FTC (flat tappet cam) BBC. I broke it in exactly according to the manufactures break in procedure...here is what I did:

*Gobb all the cam break in red goo on the camshaft before you bolt the intake on. This stuff is supposed to "stay" on the lobes even though it seems that most of it runs off. maybe it adheres to it microscopically, IDK lol.

*use a bottle of the cam break in oil. I filled up my oil filter halfway with this stuff, that way it got to the cam bearings and lobes immediately. The other half of the oil filter i filled up with the motor oil.

*Motor Oil - I broke it in with and run Valvoline VR1 20-50W. It has high zinc and phosphorous and is probably the best "off the shelf" oil for flat tappet cams. That other stuff you were running seems too thick and not really formulated for an auto engine.

*Remove the inner springs if you are running a dual spring setup. Re-install after break in. This is according to Comp. I actually ran a lake trip or two with the single outer spring only.

*Mark distributor location with the sharpie, remove and use a manual oil pump drill attachment and spin that oil pump for about 20 minutes to get the oil and cam break in oil flowing everywhere....till you see it coming out of the push rods up top. You will see your oil pressure rising on your dash gauge. Replace distributor. Do this the day you are going to break in the new cam.

*Fire that engine up on the lake, hold it at around 2000rpm for about 20 minutes, varying the rpm speed by about 500rpm up and down occasionally. Yes this is kinda scary but its really the way you break in a Flat Tappet cam. After 20 minutes, if your motor hasn't blown up, you did everything right!

*Change oil, never run synthetic in a FTC motor

NOTE: everything I did to break in this motor that wasn't stated by Comp Cams, was direct advice from the legend that this sub-forum is named after. Seemed to have worked :))THumbsUp
 
#24 ·
FYI.................. AeroShell is also used with flat tappet camshafts, aircraft difference is they are a billet type, most are hydraulic mushroom lifters in horizontal apposed engines ............. We also run AeroShell with our Roll Royce Merlin engines in the P-51s they are liquid cooled. I don't suggest running AeroShell in these engines.......

To say synthetic oils won't work with flat tappets is a misnomer........... Amsoil, Lucas Hot Rod & Classic have oils designed around these types of engines!!

Good Luck with your problem............ Spudz
 
#25 ·
I'm not one to give advise as I have received a lot of advice from these guys, just going to say I just broke a lunati flat tappet cam in and I used isky rev lube, its a moly lube and it sticks! sticks damn good I liked it way better than the other red stuff but that's my own experience and I used joe gibbs break in oil (its expensive but better safe than sorry) just my experience and good luck!
 
#27 ·
Flat tappet cams are a roll of the dice even if you take all of the precautions during break in.

For a long time I refused to install a flat tappet cam in an engine and give it to the customer. Then as business got slimmer, I would install them with a disclaimer on the invoice. :)eh:) Even then I wanted nothing to do with breaking one in for them.

I can recall back in the day even when the oil was OK break in was sketchy. There were soft springs to use during run in and rockers with very low ratios to run them in with. Opened the valves just enough for the engine to run and put the least amount of spring pressure on the valve train.
 
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