I need some input! Cam button?

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wigsplitter74

wigsplitter74

The Mopar Kid
Joined
Feb 9, 2009
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Location
Janesville, WI
Well one day I lost spark and oil pressure in my 360. Pull the dist. out and I find out that the gear on the shaft that drives the dist. and oil pump is totally chewed and shot and the cam gear shows a wierd wear pattern. My guess is that the cam was walking, right? My motor has less than 6k on it and has always run good with no wierd noises. At this point I know I need a new shaft/gear and I'm going to put a new cam in it. Does anyone know if anybody makes a cam button or something to keep the new cam from walking and doing the same thing as this cam? It's a MP .430/.450 cam in it now and I'd like to step up to the MP .484 cam. Any input is appreciated as always.
 
The cam retainer plate is what holds your cam in position. Mopars don't need buttons like SB chevys. Is it trashed? Check to make sure your oil pump didn't sieze causing the gears to strip, can you turn the oil pump by hand?

The drive gear bushing might be trashed too.
 
Is it a retrofit roller cam? You need a bronze dist gear for those...
 
It's a MP hydraulic flat tappet cam so it should be the right gear. I pulled one out of a motor at our shop, a 70k mile 360 totally stock never torn apart and that gear shows a wierd pattern too. WTF? Who makes a good retainer plate? I'll have to check and make sure I can turn the pump.
 
Also check the drive gear bushing in the block. If it's loose it'll let the gear slap back and forth against the cam and trash it.

BTW: Over the last 25 yrs. of owning small block mopars I haven't seen many wear blocks very worn. It's possible of course but I sure haven't seen many.
 
I WOULDN"T use the current wide lobe separation .484 with your current combo. Its gonna kill what little cylinder pressure you already have. You need something with tight lobe separation with your current combo. Trust me on this.If you can find the old 108 lobe separation version of the .484, that would work ok.
 
You know, considering this guy says hes been around Mopars all his life, he kinda talks like a chevy guy...:bootysha:
 
Just kidding you wigsplitter, but like moper & I and a few others have already told you, cam buttons are strictly chevy parts. Mopars are better engineered than that.
 
Look down into that hole you just pulled the distributor and oil-pump drive out of. Theres a bushing down there. Shine a light down in the hole & you will be able to see it. If your oil-pump drive can slop around in that bushing, it will kill the distributor gear. Check that, like Moper & Ramcharger told you, & check to make sure that the distributor isnt pushing down on the cam gear/drive like I said. Your problem is almost certainly one of those two things.
The cam is held in place by a thrust plate that bolts to the front of the block after you slide the cam in. It keeps the cam from walking forward. You DO NOT need a button in a Mopar, thats why no-one makes one.
 
If the block/heads have been cut alot, its a possibility the distributor is bottoming on the drive, not on the manifold. If you put the distributor in the hole, and it doesnt seat all the way down on its own, DO NOT pull it down by tightening the clamp, as it will push down on the drive-gear, and usually damage both the cam gear & oil-pump. I am trying to really describe the two possible conditions that could be causing your problem here.
 
the wide lobe separation will give HIGHER cylinder pressure due to decreased overlap. They sell it as more street friendly.
 
No, this is incorrect. Tight lobe centers give more cylinder pressure. Common miscomception. I know you arent likely to take my word for it(although I have actually tried it) so here a dyno test you can look at.June'99 Car Craft, they tested 3 otherwise identical cams in a SBC 110, 108, 106. Cranking compression was as follows 110=155, 108=165, 106=180. maybe someone on the board has a scanner and the magazine and can post it.
 
Hummmm...... In everything I've ever read wide lobe centers (110~114) were always said to produce more low end torque due to less overlap as DusterDon said and tighter lobe centers (106~108) were more race oriented for higher hp but make less low end torque. I played with it on my Desktop Dyno program and it showed that also.
 
george said:
If the block/heads have been cut alot, its a possibility the distributor is bottoming on the drive, not on the manifold. If you put the distributor in the hole, and it doesnt seat all the way down on its own, DO NOT pull it down by tightening the clamp, as it will push down on the drive-gear, and usually damage both the cam gear & oil-pump. I am trying to really describe the two possible conditions that could be causing your problem here.
Click to expand...

why would they mill on the top of the block? The distributor on a small block sits on the end seal boss on the back of the block. This isn't a Small block chevy...if it was, then heads/manifold machining would matter
 
Theres a difference between Lobe Seperation Angle and Intake Center Line. The MP "new" cams have a tighter LSA (The amount of degrees between the intake and exh lobe centerlines), and a retarded ICL. You're confusing the two. IMO, there's at least 50 grinds I'd use long before any MP offering. Especially if there is a need for street manners and torque. Also, on a side note... where do you think all the schrapnel went? Not a good thing...
 
I'll get a buddy to scan the dyno test in question & post it. Tighter lobe separation always increases cranking compression. Dont have time to get into a long-winded tutorial on this as I am workingg now, no time during the week. if I remember, i will do one next weekend.
 
moper said:
Theres a difference between Lobe Seperation Angle and Intake Center Line. The MP "new" cams have a tighter LSA (The amount of degrees between the intake and exh lobe centerlines), and a retarded ICL. You're confusing the two. IMO, there's at least 50 grinds I'd use long before any MP offering. Especially if there is a need for street manners and torque. Also, on a side note... where do you think all the schrapnel went? Not a good thing...
Click to expand...
Moper, I havent looked at the "new" MP Cams, Someone else had posted that the new version of the 484 was on 114 lobe separation, I took his word for it. I know the old ones were 108 lobe separation. Gotta go eat my lunch, i will try to find time to check in on this thread when I get home from work, if my baby will let me.
 
I'll fire one more thing out here. You guys are confusing cranking compression with "streetability" there is no direct correlation between higher cranking compression and more manifold vaccum. & My Performance trens engine analyzer disagrees, not that I would pay too much attention to what software tells me. I actually ran two cams in a 427 chevy. Big roller 278/284 @ .050, 12.7/1 compression, one cam on 108, the other on 110 lobe separation NOT Centerline. Both cams in 4 deg. advanced the 108 cranked 15 psi higher than the 110, same result as the Car Craft dyno test.
 
WoW this thread got a lil' jacked up loL fishy's right on the money with the bushing for the intermidiate shaft,they sell a bronze one that works awesome,any time you have a block hot tanked the caustic solution will eat at the material the bushing is made of and it must be replaced,sorry to hear of your misfortune,go thru the engine thoroghly...there will be metal shavings everywhere that will need to be cleaned out.
 
Cant speak for anyone else, but I'm certainly not "jacked up" no reason I can see for anyone else to be either. Personally, I jump on an opportunity to learn something new, I guess there are some guys who put ego ahead of that, but I hope thats not the case here. I will contact my buddy tonight, if he has the issue in question, I will ask him to scan it & forward it to me, & I will post it. Then I'll leave it to you guys to suss out why, you can email me off board with your thoughts if you wish. I have no interest in online pissing matches, so I will post the dyno test in question, and the guys that are willing to put some thought into what they see are welcome to take it off-board with me.
The answer is fairly obvious if you really think about what is going on in the combustion chamber at overlap. Gotta get back to work now. I'll follow up with the dyno test info in a couple days. In the meantime, think about it.
 
http://www.moparmusclemagazine.com/howto/mopp_0506_camshaft_specs/lsa.html

This is a link from a mopar mag that might help things make sense. As opposed to simply saying we just can't grasp the theory. George, just my observation and opinion, but you tend to overgeneralize and make opposing viewpoints seem wrong based entirely on your experience. Not to mention the incomplete thoughts expressed... and then re-expressed and tangents that appear in some posts. So just as i do with most other guys I have respect for, I simply request more than some dude on the 'net telling me otherwise. I'd be very interested in real theory, not graphs from a dyno. Tell me why it is as you say. I can tell you I understand the physics involved as well as most, better than some. That beign said, the subtleties of cams and the dynamics of a running engine have yet to be duplicated for study. Without profiling the cams in question, I'll stay on the simple side of the lesser overlap with an earlier closing intake valve will always make more cylinder pressure at lower engine speeds. Not all cams are measured the same, there is no apples to apples on many of these, and Mopar has never published good numbers. On the subject of MP cams... The reason I wouldnt use them has no more to do with the LSA and duration numbers than the purple rustproofing coating they run. They are manufactured with no regard to quality. So I don't use them.
In regard to the OP, I honestly would be concerned over the oil contamination from the debris in addition to the oil pump drive and bushing. Also, you lost oil pressure... if the cam timing was affected, you may have bent valves too. I think I would at least pull the valve covers and intake and snoop a bit.
 
Id rather wait until we get the dyno test posted, so you can take a look at it. Be patient...all will be revealed,theory included. that having been said, it is probably more instructive if we take this off board, but we can adress that after the dyno test goes up.
Like I said, in the meantime, really THINK about what is going on. First, suspend your disbelieve for a moment & accept that I MAY be right, then contemplate what happens in the chamber around tdc with a given amount of duration when you tighten the lobe separation angle. And remember, I was VERY specific, I said the cylinder pressure goes up. I didnt say anything about torque, but we will address that later on. I believe you are a "thinker" and fairly experienced, so I think you can grasp this.
 
Getting back to wigsplitter, yes, absolutely, he should tear it down and clean out the debris. I would also take a look at the back of the cam plate, as when the gear packed it in, it could have chewed up the backside.
 
Ooop's I think you took me all wrong,when I said jacked up I meant that this thread was hijacked to something other than it's original intention(see original post)how it got jacked to talking about camshaft overlap and combustion chambers and dyno sheets I'll never know,We are all here to help and certainly ain't here for no Pi$$ing matches,I seriously didn't mean to offend I'm a good DAWG and I'm waggin :grommit: quote=george;514285]Cant speak for anyone else, but I'm certainly not "jacked up" no reason I can see for anyone else to be either. Personally, I jump on an opportunity to learn something new, I guess there are some guys who put ego ahead of that, but I hope thats not the case here. I will contact my buddy tonight, if he has the issue in question, I will ask him to scan it & forward it to me, & I will post it. Then I'll leave it to you guys to suss out why, you can email me off board with your thoughts if you wish. I have no interest in online pissing matches, so I will post the dyno test in question, and the guys that are willing to put some thought into what they see are welcome to take it off-board with me.
The answer is fairly obvious if you really think about what is going on in the combustion chamber at overlap. Gotta get back to work now. I'll follow up with the dyno test info in a couple days. In the meantime, think about it.[/quote]
 
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