Cam bearing failure (pics)

Performance mods and Advanced Stroker discussion.
User avatar
amcinstaller
I love JeepStrokers.com!!
I love JeepStrokers.com!!
Posts: 604
Joined: May 22nd, 2008, 11:57 pm
Stroker Displacement: 4.6L
Vehicle Year: 1980
Vehicle Make: AMC
Vehicle Model: Spirit
Location: Red Deer, AB, Can

Re: Cam bearing failure (pics)

Post by amcinstaller »

yea, those slots are really wierd looking, like someone cut tem by hand with a cutting wheel. have you checked the depths on them to see how cosistant the depth is? i see the picture showing the width, but not depth.
1980 AMC Spirit Restomod in Progress
SilverXJ wrote:Roller rockers won't help that mess you have created. Nor will God for that matter.
User avatar
SilverXJ
Global Moderator
Global Moderator
Posts: 5789
Joined: February 14th, 2008, 7:14 am
Stroker Displacement: 4.6L
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Radford, Va

Re: Cam bearing failure (pics)

Post by SilverXJ »

They do look like they were cut by hand. Which isn't a problem. I just don't like how big they are. For what its worth Comp Cam's lifter bore grooving tool only cuts something around .020" x .010" groove. If those grooves are as deep as they are wide, doing the math for all the lifters would be equivalent to a leak the size of a 1/4" hole. (sqrt((12X.065x.065)/pi)x2. That is a lot especially when you take into consideration that the pump only has a 1/2" hole to pass oil through to the block .

As for why they are there, the one thing I can think of is to increase oil to the cam because it is still a cast cam which is splash lubed. Which is a fine idea in itself.
6TIME
Consistent
Consistent
Posts: 241
Joined: October 4th, 2008, 10:53 am
Stroker Displacement: 4.6
Vehicle Year: 1993
Vehicle Make: JEEP
Vehicle Model: CHEROKEE

Re: Cam bearing failure (pics)

Post by 6TIME »

Agreed! Splash lubed cam's have survived just fine for a long time! Before this ZDDP deficiency thing has come to light in newer oils, lobes have been going flat in just about every type of flat tappet engine. I think that this has spurred a flurry of new methods to direct more oil to the cam...More is not always better. As I understand, oiling systems are designed to balance adequate oil flow to every critical part of the engine. There are many orifices in the lifter galley and valve train that help keep pressure down at the cam bearings and other critical areas. When lifters are grooved, and the amount of oil pressure/flow to the cam bearings isn't somehow measured after the modification, it could put the system severely out of balance. A HV oil pump could provide enough flow to protect the cam bearings? But who's to know until the motor is torn down or a failure is evident. Like Silver said! All of those grooves add up to a significant leak that robs oil destined for the cam journals.
scalper
Making Progress
Making Progress
Posts: 61
Joined: June 20th, 2009, 9:07 pm
Stroker Displacement: 4.7l
Vehicle Year: 1996
Vehicle Make: jeep
Vehicle Model: cherokee
Location: santa fe tx

Re: Cam bearing failure (pics)

Post by scalper »

like i have mentioned before i am running 2 roller strokers with no problems but i am using a hv pump.the groove in my lifters look just like those. i have been using 20w50 valvoline vr1 oil this summer.pulled the pan on my daily driver with 15000 mile on the cam and everything looked fine. i wouldent trip over weather the grooves look inconsistent are were cut with a wizwheel.
basscat
Making Progress
Making Progress
Posts: 53
Joined: December 28th, 2009, 6:28 am
Stroker Displacement: 4.6L
Vehicle Year: 1997
Vehicle Make: Jeep
Vehicle Model: TJ Sport

Re: Cam bearing failure (pics)

Post by basscat »

Scalper, I think you're right and am going to put it back together with the 505 setup. I have the money to get a flat tappet cam and lifters so the cost doesn't weigh into the decision.

Question for you, did you notch your rod bearings so oil could get to the squirter holes in the rods? The replacement bearings from Clevite didn't have the holes and I'm wondering how oil gets to the distributor gear otherwise.
User avatar
SilverXJ
Global Moderator
Global Moderator
Posts: 5789
Joined: February 14th, 2008, 7:14 am
Stroker Displacement: 4.6L
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Radford, Va

Re: Cam bearing failure (pics)

Post by SilverXJ »

The notch in the rod bearings supposedly help lube the piston walls and cam. I put the notch in the Clevite bearings myself using a dremel. Only one side needs the notch. The King bearings had the notch in them. I don't know if they are necessary though. The cam gear should get oil from a hole in the head dripping on it.
scalper wrote: i wouldent trip over weather the grooves look inconsistent are were cut with a wizwheel.
Its not how it was done, its the size that is the issue.

If it were me I would send those lifters back and ask them to send you some un modified lifters and either groove the lifter bore or groove the lifters much smaller.
scalper
Making Progress
Making Progress
Posts: 61
Joined: June 20th, 2009, 9:07 pm
Stroker Displacement: 4.7l
Vehicle Year: 1996
Vehicle Make: jeep
Vehicle Model: cherokee
Location: santa fe tx

Re: Cam bearing failure (pics)

Post by scalper »

basscat,i did not notch the rod bearings on my motors.good luck.
scalper
Making Progress
Making Progress
Posts: 61
Joined: June 20th, 2009, 9:07 pm
Stroker Displacement: 4.7l
Vehicle Year: 1996
Vehicle Make: jeep
Vehicle Model: cherokee
Location: santa fe tx

Re: Cam bearing failure (pics)

Post by scalper »

basscatt,were your rod bearings notched? i dont have a set of rods laying around so im not sure of the size of the hole in in the rod . i dont think the groove in the lifters is much bigger than the hole in the rods. imo blocking off the holes like most rod bearings do and even aftermarket rods should offset any oil pressure loss that the grooved lifters may cause.in fact your getting direct oiling to the lifter and cam lobe instead of slinging oil around like the hole in the rod would cause. im not saying that was a bad design it supplied oil to many 4.0 cams with good results. am i making any sence of this?
User avatar
SilverXJ
Global Moderator
Global Moderator
Posts: 5789
Joined: February 14th, 2008, 7:14 am
Stroker Displacement: 4.6L
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Radford, Va

Re: Cam bearing failure (pics)

Post by SilverXJ »

The groove in the lifters is much bigger than the groove in the rods. Also, the hole in the rods is at the end of the line for the oil.
basscat
Making Progress
Making Progress
Posts: 53
Joined: December 28th, 2009, 6:28 am
Stroker Displacement: 4.6L
Vehicle Year: 1997
Vehicle Make: Jeep
Vehicle Model: TJ Sport

Re: Cam bearing failure (pics)

Post by basscat »

The replacement bearings I used (when the cam bearings failed) did not have a hole in them so it seems the blocking off of the squirter holes does not provide an offsetting benefit to the pressure loss due to the lifter grooves. My thought was that the hole in the rod bearing lined up with the hole in the crank precisely when the rod was moving up and the squirter hole was pointing at the cam. When the holes aligned, there was a quick shot of oil delivered which may create a pressure drop pulse but is so quick in duration that it is insignificant. I was asking the question because I was concerned about oiling to the crank position gear only. One thing I am sure of, the lifter roller tips got plenty of oil.
scalper
Making Progress
Making Progress
Posts: 61
Joined: June 20th, 2009, 9:07 pm
Stroker Displacement: 4.7l
Vehicle Year: 1996
Vehicle Make: jeep
Vehicle Model: cherokee
Location: santa fe tx

Re: Cam bearing failure (pics)

Post by scalper »

yea that makes sense now.
User avatar
SilverXJ
Global Moderator
Global Moderator
Posts: 5789
Joined: February 14th, 2008, 7:14 am
Stroker Displacement: 4.6L
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Radford, Va

Re: Cam bearing failure (pics)

Post by SilverXJ »

basscat wrote:My thought was that the hole in the rod bearing lined up with the hole in the crank precisely when the rod was moving up and the squirter hole was pointing at the cam. When the holes aligned, there was a quick shot of oil delivered which may create a pressure drop pulse but is so quick in duration that it is insignificant.
Never though of it that much, but that makes perfect sense. Now the real question is if they provide any benefit or not.
One thing I am sure of, the lifter roller tips got plenty of oil.
LOL. I think so as well!
basscat
Making Progress
Making Progress
Posts: 53
Joined: December 28th, 2009, 6:28 am
Stroker Displacement: 4.6L
Vehicle Year: 1997
Vehicle Make: Jeep
Vehicle Model: TJ Sport

Re: Cam bearing failure (pics)

Post by basscat »

FINALLY got all the replacement parts from 505. Will try to get it together next week.
basscat
Making Progress
Making Progress
Posts: 53
Joined: December 28th, 2009, 6:28 am
Stroker Displacement: 4.6L
Vehicle Year: 1997
Vehicle Make: Jeep
Vehicle Model: TJ Sport

Re: Cam bearing failure (pics)

Post by basscat »

Update. 505 recommended I check the runout on the cam before putting everything together. Sure enough, it was at .007 which is out of spec. I sent it back to 505 and they straightened it (for free - I think). Anyway, just got the cam back yesterday and headed to the machine shop...
User avatar
SilverXJ
Global Moderator
Global Moderator
Posts: 5789
Joined: February 14th, 2008, 7:14 am
Stroker Displacement: 4.6L
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Radford, Va

Re: Cam bearing failure (pics)

Post by SilverXJ »

Check the run out again. It could have been damaged during shippping.
Post Reply

Who is online

Users browsing this forum: Ahrefs [Bot], Amazon [Bot], Google [Bot] and 17 guests