rebuilding a 390 for my 66 shortbed. had the engine tanked, boared, and crank turned. cam bearings were removed prior to cleaning and machine work. buddy of mine, who's done a bunch of FE's and shortbolocks in his day , helped me install the cam bearings...he has a bearing installer. i installed the cam the other night. well lubed and clean. i did install the rotating assembly before the cam, for what its worth. so the cam was tight going in. i have installed only one other cam and this was tighter than that one, thats all i know. i needed to coax it a little at every bearing, and the last 1/4" by smacking it with my palm. but it went in without a hammer. it did not rotate too freely. i figured not much i could do, new bearings new cam, so i put it together. dame buddy came by today and we took of the timing cover... he thinks its too tight.., and i agree. after priming it, we still cannot spin it by hand with the timing gear on it. we can spsn it with a swtandard 3/8 drive ractchet. its tight but when it breaks it seems to spin okay, a little snug, but consistnet. cam is new. meilling rv type.

so what do i do. its obviously too tight one one or more bearings but because the bearings are different sizes how do i tell where its hanging. how do i clearance the bearing once i know where the problem is (assumign i can find it) or do i have a bad cam or bad bearings?

i really need help. got a lot of time and money into this motor and have been without a daily driver for months now. thanks a lot guys.

 

It sounds like you either have the wrong cam bearings or they got screwed up while being installed.

 

thanks for the reply. we fit the bearings to the cam before install to ensure position and fit. the clevite bearings came with the rebuild kit and i verified the part number for the engine. the "bores" taper so the wrong bearing could not be installed at any location. there were 2 of us there helping with the install watching closely and inspecting the bearings. they didnt go in as easy as maybe they could have but the were installed straight in the right location.
lets assume the bearings are correct and installed correctly, what can i do to resolve this problem. i dont have a bearing scraper, can i use emery cloth?

 

Trying to correct boogered cam bearings in an assembled shortblock with emery is an invite to disaster- where do you think the bearing material and emery debris is going to go? Don't kid yourself that you can control and collect it all, some is going to go inside the oil galleries, and you might cut a little here and there for a while and probably never get it "right". I know you don't want to hear this, but just pull it down and let the shop check the bores and install the bearings, and they can check it before it leaves. There's a couple reasons why you install the cam first, you just found one, plus it's just so much easier when you can just reach down inside the block and guide it in place, instead of trying to fight it from the front

 

Start over

 

awesome. thats what i was afraid of. 6 weeks down the toilet. i get about an hour to work on it every other day. thank god its warming up, i actually start riding my motorcycle instead of walking and taking the bus everywhere.

i dont really have the money to pay someone to install the cam bearings let alone check the block let alone rebuy bearings and another gasket kit, so it'll just have to sit. anyone want an almost bitchin 390? some assembly required? i also have a nice 66 shortbed with no engine for sale.

just kidding. the truck is worth more to me apart than i could sell it for. it'll just have to wait.

 

Sounds to me like he nick'd a couple bearings ! or more ?