Hydraulic lifter / cam lobe issue

[CJim7]

Since you are installing the cam into another block with existing bearings.....I would strongly and definitely suggest the use of break in lube on the bearing surfaces as well as the lifter galleys.

It would be good insurance to treat this like a new cam/lifter set and use the break in lube on the lobes as well. At least use assembly grease. Anytime you crack open an engine and change something, you produce changes in running surfaces and this creates heat and material shedding which will require break in.

 

[jeepboy45]

Since you are installing the cam into another block with existing bearings.....I would strongly and definitely suggest the use of break in lube on the bearing surfaces as well as the lifter galleys.

It would be good insurance to treat this like a new cam/lifter set and use the break in lube on the lobes as well. At least use assembly grease. Anytime you crack open an engine and change something, you produce changes in running surfaces and this creates heat and material shedding which will require break in.

Thankyou... I'll be liberal with the oil, and assembly lube. Waiting for my sons to wake up. I am gonna drive the Jeep for a few minutes to get a good idea in their minds of how it is running, and yank the carb,intake,WP,TC cover,rad, grill, and make this happen today. Hopefully be done by this evening. Will give report if it was a benefit or not. "I mean, how could it be worse?" (hopefully I dont regret that statement)

brian

 

[CJim7]

take great care in removing the Cam...and even greater care installing it. There is a cam installation tool that bolts to the end of the cam, but you can do it without the tool. Just dont knick up the bearings.

Before you install it, mic the bearing surfaces on the old cam and compare them with the new one....just to be sure.

 

[jeepboy45]

I wouldnt have believed it if I hadnt seen it for myself!!! There must be 4-6 cam lobes COMPLETELY round... No lobe at all....

Its a miracle it ran at all!

Got everything taken apart, including removing the grill, electric fans, radiator, and everything on the enging to get to the lifters...

Couldnt put it back together since my Edelbrock intake has a corrosion hole and need to have it welded back up.. Put in the good cam and lifters and everything else but the intake..

I still cant believe it had sooo much cam wear.. And the lifter were concave on the bottom surface. I bet if I mic it there will be .200 of metal missing.. !!! I'll put up pics for anyone who doesnt believe that a cam can wear so fast. I swear, the last night I drove it a year ago, it DID NOT knock and had plenty of power. I revved the heck out of it that night. Wonder if I did the damage all in one night??? Like I said, if i didnt see it with my own eyes, I wouldnt have believed it.

 

[coldair]

Hope you dont have burnt valves with it having the lobes worn all the way off.

 

[jeepboy45]

Hope you dont have burnt valves with it having the lobes worn all the way off.

Uh, yeah me too....Is that a possibility from the worn lobes???

 

[jasonmark1993]

Not likely, valves normally get burnt when they get held open.

Ive never seen what you are describing either. I might have missed a post but not sure if you mentioned that the lifter was stuck. I would guess that it was after sitting for a year and you wiped it out shortly after start up. Maybe as it warmed up the lifter started moving again?

 

[coldair]

Uh, yeah me too....Is that a possibility from the worn lobes???

Ive seen it in small motors like 4 wheelers the fire has to go somewhere. but never have seen it in a truck motor.

 

[jeffgtoman]

There's nothing wrong with sticking in an old cam and getting some more life out of your engine. The discussion about break-in is a little flawed. I hope I don't upset anyone but here is an explanation about break-in.

When you break in a new cam, you are only breaking in the lobes. The cam bearing surfaces and the lifters have a hard shiny surface. No break-in required. The cam lobes have a rough porous surface from the factory. During break-in, the bottom of the lifter and the special break-in lube polish the lobes. This is done by running the engine around 2000 rpm for 30 minutes. It's kind of like applying a chrome finish. This hardens the lobes and makes them align with the lifter. It's not uncommon to actually loose part of a lobe during break-in. This can happen more often if break-in procedures are not followed. Idling the engine during break-in can cause lobe loss.

Now, if you reuse a cam in a different block, the new block lifter bores may not align the same and you may loose a lobe because of the mis-alignment. Technically, from a cam engineers point of view, a cam is not reusable because of this.

That's just the nit-pick of it all. I thought you and your sons might enjoy knowing the whole story.

The fact that you lost lobes on an old cam means you have lost lubrication to the lobe area. The only way the lobes get oil is from the crank throwing oil around and what runs down out of the lifter bore. Try to find out why you are not getting enough oil to the lifters. Maybe a stuck relief valve in the oil pump. I hope this helps. Wish we were neighbors. I love to build engines.

 

[jeepboy45]

There's nothing wrong with sticking in an old cam and getting some more life out of your engine. The discussion about break-in is a little flawed. I hope I don't upset anyone but here is an explanation about break-in.

When you break in a new cam, you are only breaking in the lobes. The cam bearing surfaces and the lifters have a hard shiny surface. No break-in required. The cam lobes have a rough porous surface from the factory. During break-in, the bottom of the lifter and the special break-in lube polish the lobes. This is done by running the engine around 2000 rpm for 30 minutes. It's kind of like applying a chrome finish. This hardens the lobes and makes them align with the lifter. It's not uncommon to actually loose part of a lobe during break-in. This can happen more often if break-in procedures are not followed. Idling the engine during break-in can cause lobe loss.

Now, if you reuse a cam in a different block, the new block lifter bores may not align the same and you may loose a lobe because of the mis-alignment. Technically, from a cam engineers point of view, a cam is not reusable because of this.

That's just the nit-pick of it all. I thought you and your sons might enjoy knowing the whole story.

The fact that you lost lobes on an old cam means you have lost lubrication to the lobe area. The only way the lobes get oil is from the crank throwing oil around and what runs down out of the lifter bore. Try to find out why you are not getting enough oil to the lifters. Maybe a stuck relief valve in the oil pump. I hope this helps. Wish we were neighbors. I love to build engines.

You're only in Indiana... I've got an extra room for a couple of weeks!!!

Thanks Jeffgtoman. I appreciate the information.

There is one snag though. While waiting to see what I'm gonna do with my corroded intake, we decided to drop the pan just to take a look...It had a good amount of shiny sludge in it. I am assuming it is cam / lifter residue and what YOU told me before about crank bearing havok. The snag is this. While I was looking at the crank, my son was cleaning out the oil pan. He found part of a cam bearing! At least that is what I believe it is. And I dont mean a small piece.

I also put up a pic of my corroded intake...

BTW: can anyone tell me why there is no water passage on the drivers side rear of the intake. When I first got it 15 yrs ago, I wondered, but figured there was a good reason. I havent really looked at a stock manifold except while lugging it to the scrap pile to see if there is a passage on it.

 

[CJim7]

Since you are installing the cam into another block with existing bearings.....I would strongly and definitely suggest the use of break in lube on the bearing surfaces as well as the lifter galleys.

It would be good insurance to treat this like a new cam/lifter set and use the break in lube on the lobes as well. At least use assembly grease. Anytime you crack open an engine and change something, you produce changes in running surfaces and this creates heat and material shedding which will require break in.

I stand by this.

 

[jeepboy45]

I stand by this.

A tube of break in lube was cheap...
Coated all surfaces , but my major worry is that piece I found in the oil pan. It may make any / all precautionary lubing a moot point !! AARG!! If it is what I think it is, there could be a cam journal with no bearing surface to mate with... But if I refuse to think of the possibilities of this, nothing bad CAN HAPPEN!!

Oh well, it should run better than it did with 4 lobes worn down and lifters to match... Hopefully it will run till at least September, my goal for a 360 build in the works... Sooner if $$$$ allow.

 

[coldair]

What kind of oil pressure is the motor running?

 

[jeepboy45]

What kind of oil pressure is the motor running?

Before I took it apart, it would sit at approx 40 lbs at startup. Then slowly back off over the next 5 or 6 minutes to darn near 2 lbs....

I have a corroded intake manifold, and just tried to braze it tonight to fix it. So hopefully after grinding it down, I'll have it back together tomorrow.

 

[coldair]

ya that doesnt sound good betting thats a cam bearing it spit out. You know you might be able to limp by with that motor by running a heavy oil like 80 wieght gear oil. I had a friend with a motor that was so worn out it would blow the dip stick out. He drained the oil out of it and ran 80-90w and it lasted 2 years before it blew up.

 

[jeepboy45]

ya that doesnt sound good betting thats a cam bearing it spit out. You know you might be able to limp by with that motor by running a heavy oil like 80 wieght gear oil. I had a friend with a motor that was so worn out it would blow the dip stick out. He drained the oil out of it and ran 80-90w and it lasted 2 years before it blew up.

Can an engine just "spit one out" like you said???

My fear was that I knocked one out when installing my new one. But I was being DAMN careful. And when I pulled the old one out, was being equally as careful. So it amazed me when my son found it in the oil pan.

I might have to try running thicker oil if it doesnt change with the new cam....

I had a buddy with a baja bug back in the late 80's. His engine was so worn out, he ran 140 weight gear oil in it... and STILL burned oil!!

 

[coldair]

Can an engine just "spit one out" like you said???

My fear was that I knocked one out when installing my new one. But I was being DAMN careful. And when I pulled the old one out, was being equally as careful. So it amazed me when my son found it in the oil pan.

I might have to try running thicker oil if it doesnt change with the new cam....

I had a buddy with a baja bug back in the late 80's. His engine was so worn out, he ran 140 weight gear oil in it... and STILL burned oil!!

I dought you knocked it out. I wonder if it had a lack of oil spun and fell down into the oil pan. That motor i was talking about actually broke the cam in half because it lost the bearing.

 

[jeepboy45]

I dought you knocked it out. I wonder if it had a lack of oil spun and fell down into the oil pan. That motor i was talking about actually broke the cam in half because it lost the bearing.

Coldair. you can delete what you just said.!!!! It goes against my state of denial....!! haha ... I had a fear of breaking a cam because it wasnt supported due to lack of a bearing..! And that refers back to what I said earlier. "But if I refuse to think of the possibilities of this, nothing bad CAN HAPPEN!!

Thanks coldair, you and Murphy are ganging up on me... LOL

 

[coldair]

DELETE DELETE I think you will be ok run that bad boy and keep us informed.

 

[jeepboy45]

There were 5 lobes that looked bad.
4 of those were nearly completely round, causing nearly no valve movement. 5 lifters shot, 4 of which are severely dished in, on the bottom.





I have the donor cam / lifters installed. 2 nights ago I put on the intake using the old gasket.. Yeah, I know...MISTAKE.. I discovered the mistake when there I saw steam coming out of the dipstick tube and the oil filler tube breather.!! AARG!!! On the plus side, I now have all 8 cylinders firing the way AMC intended. And not suprisingly-- much more power.

Pulled and reset the intake yesterday afternoon. I was forced to change the disgusting oil / water mix...(against my normal 15K whether-it-needs-it-or-not-policy.. haha..) Also threw away $12 of zinc additive I just put in the night before...AARG again

Seems to run good. There is still a lot of rod noise going on. Probably from all the cam metal that ran around the oil system... AARG again x3

I'm still unsure of the cam bearing in the oil pan. So far the cam hasnt broken due to the unsupported journal.. I want this engine to last me through the summer and fall, when I hope to have a new 360 done and ready to install. AFTER the new one goes in, I'm actually looking forward to tearing this one down to see what was really going on in there.