Cam Problem!

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Xstream_1

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Bad news. While in the process of taking the Cuda home (for the first time after rebuild) I wiped a lobe out on the camshaft. I am going to replace it this weekend and thought I might try a different cam this time. I was wondering if you guys might would give me some suggestions. These are the specs. The cam I have in it now is a Comp 20-214-4., 270 duration 470 lift. The rest is as follows
.030 over flat top pistons
1.6 roller rockers
Edelbrock Performer heads (63cc)
Dual Plane intake 1500 to 6500
600cfm carb (temp)
TTI Headers and Exhaust
904 Trans and 2500 stall
8 3/4 rear 3.55 gears
275/60-15 tires
We already know the compression is really low on this engine. I will be using it mostly as a street vehicle but like everyone else I want it to sound good and have decent throttle response. I don't want to have to change the converter if at all possible.
Thanks!
X
 
Don't know your displacement or compression, but the cam you had sounds like it was the right choice. I hope you figure out why you wiped out a lobe before you put in another cam, so you don't have a repeat failure.
 
Sorry I forgot to include that. It is a 318 bored .030 over. The compression according to everyone is probably really low,around 8.0 to 8.5 :1. I spoke to Comp earlier and the tech said it could have been due to several reasons, a piece of dirt stopping the lifter from spinning, adjusted wrong, improper break-in, etc., everything except a bad lifter or defective shaft. Those reasons may be correct, only one way I know of finding out! I also contacted Lunati and they suggest a 60401 Voodoo, 256/262 213/220 @.50 454/475
Thanks for the reply!
X
 
I think that Comp is to big and the Lunati sounds like a better choice.
 
I feel for you bud. I just went through the same thing. I was able to track it down to, to long of pushrods causing to much lifter pre-load. I hope you have better luck than I did.

Jack
 
AdamR said:
I think that Comp is to big and the Lunati sounds like a better choice.
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i agree with adam but i dont have as much knowledge as alot of guys here have but i have looked at the vodoo cams and i think the specs on them sound good:)
 
Coyote Jack said:
I feel for you bud. I just went through the same thing. I was able to track it down to, to long of pushrods causing to much lifter pre-load. I hope you have better luck than I did.

Jack
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I thought about the pushrods being the problem, but when I installed the cam, heads, and 1.6 rockers I checked the length on them with a pushrod length checker kit and came up with 7" and had the correct geometry, or at least thought I did, and had Smith Brothers make up a set. But then again this is the first engine I have ever put together. Live and Learn!!!
Garland
 
Xstream_1 said:
Bad news. While in the process of taking the Cuda home (for the first time after rebuild) I wiped a lobe out on the camshaft. I am going to replace it this weekend and thought I might try a different cam this time. I was wondering if you guys might would give me some suggestions. These are the specs. The cam I have in it now is a Comp 20-214-4., 270 duration 470 lift. The rest is as follows
.030 over flat top pistons
1.6 roller rockers
Edelbrock Performer heads (63cc)
Dual Plane intake 1500 to 6500
600cfm carb (temp)
TTI Headers and Exhaust
904 Trans and 2500 stall
8 3/4 rear 3.55 gears
275/60-15 tires
We already know the compression is really low on this engine. I will be using it mostly as a street vehicle but like everyone else I want it to sound good and have decent throttle response. I don't want to have to change the converter if at all possible.
Thanks!
X
Click to expand...

OK, I am getting everything ready to install the new cam. I thought I would turn the oil pump a little to make sure everything was getting oil so this wouldn't happen again. I noticed that oil is only coming out of the lifter bores on the passenger side of the engine and none coming out of the holes for the rocker shafts. I am assuming that the cam has to be installed before both sides will oil themselves???? Am I right or wrong? I did pull everything down and checked it and everything looks alright.

X
 
New oil filter!!!!! You could have some old cam debrise in there. The new filter "Should" get it all.
 
Oh Yeah! I changed the oil filter like three times while I was priming the oil pump. Do you know if I am right or not about the lifter bores or not? Does the cam have to be installed before both sides wwill get oil!
Thanks

Garland
 
Humm, don't know. I never tried to turn the pump without the cam installed.

Since the cam should be there with the lifters installed to get pressure everywhere, I think that the lack of lifters would just let the oil run out of the passage like a severed arttery. The passage being the one described in the MoPar engines book as the one to peen.
 
I know you don't want to hear this but here is my suggestion. I would pull the engine down, clean everything, and reassemble. I wiped a cam in my 340 and just put a new cam in. I did a couple of oil changes and even ran a "Flush" through it. In about 100 miles, I noticed a knock. This is on about the 5th oil change since the new cam. I had it towed home and pulled the engine. Spun bearing on #1 cylinder. The metal was circulated EVERYWHERE, even up in the lifter valley. The pistons are ruined as they look as if they were sanded with 40 grit sandpaper and I am out a crank and at least one rod. This car has been in the family since new and has a few years under it's belt on the current build. I believe the wiped cam had everything to do with the spun bearing. Even the oil pump pickup's screen is packed with metal and I will have to get a new oil pump and pickup. My car has been down all year because of this (happened in Dec.) When I get some money, I'll get it back together.
 
I just got off of the phone with Lunati and Comp and both are reccomending break in with Shell Rotella T oil, something about the zinc and phosphorus content, and both reccomend using 7 to 8 quarts initialy on break in, yet both still have standard motor oils listed in the break in prcedures on the paperwork that comes with the cams!
 
Comp recently changed the paperwork in theirs, to mention the Rotella/zink deal, checking for lifter rotation, and to remove the inner springs from dual setups for break in. I have only seen the updated paperwork once, and that was in a cam and lifter kit in one box about 2 months ago. I usually get my cams and lifters seperately, and the notes werent/arent in there yet. As far as the engien bbeing filled with debris, I'm sure it has some. If this doesnt bother you, go ahead and replace the cam. It may be just fine, it may not. You do not want to overfill the oil pan. You DO want to get the engine to at least 1500rpm immediately at fire up, and keep it over 2000 for 10-15 minutes. The cams are only splash fed, if the oil isnt whipping off the spinning crank, it doesnt get much oil. Overfilling can cause the oil to get frothy, and that just gets pumped thru everything..frothy oil cant work. You can run 1qt over the pan rating easy,. but putting 8 qts in a 6qt pan is asking for trouble, and leaks..lol. As for the preoiling, you need to have the cam and lifters installed, and you must rotate the engine over while prelubing, to get oil to the top end of both sides. The passages only line up for a short time during the cam's rotation, and never both sides at once.
 
moper said:
The cams are only splash fed, if the oil isnt whipping off the spinning crank, it doesnt get much oil.
Click to expand...

No sir, you are very much wrong.

And I qoute, from the "How to Hot Rod Small Block Mopar Engines" by Larry Shepard: "The #2 and #4 journals on the cam have a hole drilled through them. The oil pressure comes from the top of the #2 and #4 main bearing straight up to the cam bearing. The next step is to go to the valvetrain in the cylinder head. This passage is in the top part of the cam journal. Therefore , the pressure has to come in the bottom, around the sides of the cam and out the top (actually slightly to one side).
 
krabysniper said:
No sir, you are very much wrong.

And I qoute, from the "How to Hot Rod Small Block Mopar Engines" by Larry Shepard: "The #2 and #4 journals on the cam have a hole drilled through them. The oil pressure comes from the top of the #2 and #4 main bearing straight up to the cam bearing. The next step is to go to the valvetrain in the cylinder head. This passage is in the top part of the cam journal. Therefore , the pressure has to come in the bottom, around the sides of the cam and out the top (actually slightly to one side).
Click to expand...

You're referring to the camshaft journal lubrication, and Moper was referring to the camshaft lobe lubrication, so he is correct.
 
Yes, you are right. A buddy and I were just talking about this a little bit ago and he pointed out the same thing, I merely meant to correct the fact that the way he states it implies that this is the only oil the cam gets (via windage), which would be wrong, as stated. My bad for not realizing what he meant was refering to lobes. O:)
 
Xstream_1 said:
I just got off of the phone with Lunati and Comp and both are reccomending break in with Shell Rotella T oil, something about the zinc and phosphorus content, and both reccomend using 7 to 8 quarts initialy on break in, yet both still have standard motor oils listed in the break in prcedures on the paperwork that comes with the cams!
Click to expand...

This is all CRAP the cam grinders tell us to cover the fact that the current cam blanks are porous and soft, which is the real reason so many cams are going flat.
I've noticed a marked increase in this over the past 5 years.

It's hard to believe that even engine builders with DECADES of experience can't install a cam without it having a lobe go flat.
Insist to Comp Cams that it was a defect in manufacture and at least get another cam from them.

YES, definitely tear the engine down and clean the heck out of it, better replace the oil pump, too.

Mark.
 
Yeah, I was thinking lobes..since that's what goes flat...lol. What is mentioned is mentioned because they are talking about the difference of pushrod oiling and shaft(thru the head) oiling, and certain mods..(I have that book too..comes in handy)

Mark, the cam cores havent changed. Beleive what you want, but the top engine builders didnt put it right back to the oil at first. The first complaints were lifters with not enough crown (difficult to measure, but feasable because of the selling of a bad production run from somewhere..cant recall which company), or a soft cam. I never heard of any damaged cam being rockwell tested for hardness, and being compared to "an old hard one..". Being that there were only a few makers of lifters, and a lot more companies selling them, I'd hypothesize that many of the bad batch did get into other sets, and that's what caused to supposed cam issue. I know the buyer of the bad batch did sell them again. They should have been destroyed. Also, 5 years ago, the "fast rate" cams were just coming out. It's these fast rates that mean it all has to be perfect, or the cam wont break in, it just breaks.
 
You grinded off a lobe on your cam. Will the filter catch all that metal?
The problem with the all this cam problems? Oil is not what is was. Go to your local GM dealer, get a pint of their EOS engine break in lube. Use that with some cheap 30 wt, that will be fine, except that metal already in there.
Maybe it will be okay.
Did CoyoteJacks engine live through its cam problems? Didnt his do the same thing?
 
70Barracuda said:
Did CoyoteJacks engine live through its cam problems? Didnt his do the same thing?
Click to expand...

Yup he ate a lobe and replaced it with a Mopar 484" cam wich also took a dump I think. I know its lots of money but if I ever eat a cam lobe on the 340 Im stepping up to a roller cam.
 
Yup, I ate 2 cams. I took the engine apart and lucked out. No damage other than the two cams. I will say this though, I shut the engine down as soon as I detected that something might be amiss. The lobes on the 2 cams were not damaged that bad, just enough to make the rockers start to make noise. I have found the problem and will be getting a new cam, lifters and adjustable rockers this week.

Jack
 
I had comp cams cam go flat me also. I do the break in the same way every time. I use comp cams break in lube on the lobes,and oil-stp on the bearing surfaces. When i called comp about the cam they gave every excuss in the book but they warrentied the cam. They were very quick at replacing the cam for me. I flushed the system, new oil filter, oil and did the same thing i did the first time. I had no problems this time. changed oil and filter after break in and again at 600 miles. that 3 oil changes and 15000 miles ago. I think it was a bad camshaft first time around.
 
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