Cam Bearing Issue?

[Touch Nicks Thing]

Ok, here is the problem. Coming back from Bulli Brigade my motor, 1600 SP, started running hotter and hotter as I went. It was a fresh rebuild, less then 1000 miles on it before heading to Florida. Everything was good.

I get close to home, about 2000 miles later, and the motor is running extremely hot, 260+. I pull over and I hear a "whirring" noise like metal on metal.

Anyway, I let it cool down a bit, 30 minutes and head down some backroads. This is when I start to here a clacking noise. I got scared, thought I was gonna lose my motor so I filler it up with some gear oil and proceed home. No problem, make it 30 miles clacking and running like shit.

Ok, so, I just get the motor disassembled and I don't see anything wrong with the crank, there were no metal shaving in the oil, piston and cylinders all look fine. All I can see is that the cam bearings are worn badly (all are bronzed and scratched on the inside) and this front bearing is worn badly on the outer sides from hitting the cam (I presume?).

I guess my question is, could the cam bearings have been my issue all along?

Thanks for any help!
Nick

[kielbasa]

cam gear loose? that makes a funny noise in the motor
_________________
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[MURZI]

Did you check cam endplay when you built the engine?? Most new cams are tight as heck on new cam bearings.
_________________
62 vert
2276
Tim’s welded heads
45 Dells
A1 sidewinder
Fk44 cam

[Touch Nicks Thing]

I didn't build the engine, I bought it from Cali. Cam gear doesn't appear to be loose.

[oarse]

Hey Nick, longtime no see. Sorry to hear about your troubles.

What do the oil pump and tang at the end of the cam look like? Perhaps the oil pump was not correct for the cam. I've seen this before when pairing an early style oil pump with a later (4 bolt/rivet) cam. Also, is there any crap jamming the oil pump gears?

This is a long shot, but do you have dual springs on your valves? This could also put more strain on the cam. Do the lobes and lifters look ok?

I'd also check the distributor drive pinion to make sure it's in good shape.

[mark tucker]

not just the thrust the bearing is dead too. check to see if the oil gally is clear going to that bearing.almost all cams are ruff on the bearing journels,I always polish them with 800-1000 grit wet.is there any speckels in the other bearings? was it a new cam?I have a old cam somebody gave me many years ago that has about .010 wore off 1 side of it, due to the lobes being on 1 side always putting presure on 1 side of the cam.but if the oil had been good it would not of done that.it dont take much to kill these bearings and the cam bearings are way to small for what we are doing with them.I still cant beleave Jcee hasent made big journel cams for these things. a lot has been learned about lobe size&type & what size journel is needed for it. we need bigger journels&biger lobes for these motors even roller bearings like the v8 shit is using nw (and a good bit bigger too) the bearing speed gos up a lot but the aera is what make it work much better, kinda like using a higher wrist pin, less rock/pivot.and you dont need no pivoting cams.
I think there is an oil supply problem with your motor. does it have a fulflow filter? how many times has the oil & filter been changed? does the case have screw in plugs? check that gally.I have seen some with a sleve in the there,I presume from the factory, I think that gally intersects with the main&the small main bearing gally, easy for crap to get in from not cleaning good, or a silocone blob.

[Touch Nicks Thing]

I'll have to get some more pics tomorrow. The cam does have some wear on it at every bearing. The oil pump was fine and is doesn't appear damaged. The slot in the cam gear is larger then the oil pump, it does have some play.

Lobes look fine, lifters look great. Everything in the motor looks good except for these cam bearings and the wear on the cam. It was a zero mile, new motor.

Like I said, I'll have to get some more pictures after work tomorrow.

[mark tucker]

could of been dry bearings,I dfl coat mine, and use a few different lubes mixed to stay there on the bearings (molly,red engle type cam lube,a little synthetic gear lube)it stays there wont run out dont goo up.also use zinc moly on the lifters&lobes with the thick red cam lube. bearings are extreamly soft, and it takes a bit to get oil to them all and there too small to start with.always prelube a unknown motor.

[MURZI]

So the case got that dirty in 3000 miles?? Crazy..... What oil are you running??
_________________
62 vert
2276
Tim’s welded heads
45 Dells
A1 sidewinder
Fk44 cam

[modok]

Need to check
cam gear backlash, and make sure it's round

Runout of cam and gear area of crank

[mark tucker]

as nasty as the case it probably wasent properly cleaned.hmm whats the runout spec modoc?