Sbc cam bearing replace with crank still in? Can it be done?

[Golddredger]

I have 1975 4 bolt main 350 that was overhauled and they did a very bad job with the cam. 2 lobes went flat. So I got the engine cheap. I have pulled it apart but am hoping to leave the crank and pistons alone. When I pulled the cam there was big chunks of the 3rd cam bearing falling out and the front bearing has a chunk missing and a hole knocked into the surface along with gear marks from when they put the cam in. Worse cam job I have ever seen. so I am going to have to put some cam bearings in. I have never attempted to do them with the crank in. I read it can be done. But how hard is it? Worth pulling the crank? Any tips would be great. The engine is on the stand so easy to work on. Just in hopes of saving time to get this put back together and in my 27'. Getting closer everyday with the car. Engine will be needed soon.

 

[junker39]

There may be metal shavings or particles all thru that thing. I'd pull the whole thing down and clean it real good. A set of gaskets are fairly cheap but, probably worth it to prevent something from getting screwed up. Just my 2￠worth.

 

[studebaker59]

It can be done, but i agree with junker39. Take it all apart and give it a good cleaning.

 

[bruno]

Since it's on the stand pull it apart. It'll let you check all of the rod and main bearings. If the previous builder screwed up the cam bearings there's no telling what else he did. Better to be safe than sorry

 

[62ChevyII]

Like everyone else said, take it all the way apart and check everything out... where there's smoke, there's fire. If they screwed up the cam install, what makes you think they didn't totally screw up the rotating assy install too?

Also if you are putting a hydraulic flat tappet cam in it make sure you use the right lube on the cam and lifters... make SURE it has ZINC in it. Then make sure you follow the correct break in procedure per the cam manufacturer.

 

[Old Iron]

I'd install a HV55 Mellings oil pump too!!!!!!!!
When changing oil, always put the zinc additive in.

 

[Golddredger]

Ok done deal it will come apart all the way! I was trying to cut corners and get her back together but I sure would be bent if I got it back together to only have to pull it back out of the car and start over. I am there now. Thanks for the kick in the pants! Thanks for the zink tip as well. Yes going flat tappet so I will get the additive. Also going with a melling pump. Got my list ready to order from summit.
Thanks again!

 

[Old Iron]

Our pleasure [ddd

 

[bruno]

Yeah! We love to kick butt

 

[sgtpontiac]

What can I say??

You guys have said it all...

 

[Yankee Transplant]

if your going that far just go ahead and get new bearings and rings I only had about $350 in a cam,, lifters,, rings bearings and gaskets and a HV pump .. this way you will (know) you have a motor .. them shavings could be bad if trapped in the journals . then brake loose after you run it a while. My engine looked great when I took it down , but I didnt want a re-due on nothing .. A chevy is cheap to build if you only have to build it once ,, if you have to re-due then you pay for it twice,, JMO...

 

[Golddredger]

Alright I popped it the rest of the way apart tonight. Glad I did... bearings are shot from the metal from the cam lobes going through it. Crank looks good no bad joournals both rod and mains are looking good. So a simple rebuild is what it is going to get. Also had a broken compression ring on one piston. Cylinder is not damaged thank goodness so I will hone them and she should be good to go. Have a great evening gents!

 

[bruno]

Happy to hear their wasn't damage to the expensive parts. Sounds like a straight forward rebuild.

 

[sgtpontiac]

Good thing you tore it down....

avoid some headaches down the road....good luck with the build...[P