jensenracing77

i got the 215 block back for my Jetfire. they pressed the cam bearings in and after installing them the cam did not fit. they machined the bearing surface of the cam so it would fit. my question is, did it not fit because of the line bore is off or because the bearings crushed to much? how would i know? i got it home and oiled the cam and installed it. it feels like it spins nice but i just don't like how they did it. D&D told me to not change the cam bearings because i would run into trouble.... now i wonder if i should have listened to them.

jensenracing77

also, if the line bore is off and they machined the surface till it fit. does that mean i have a couple bearings with more clearance on one side than the other? if so, would that make the cam flex? sorry for uninformed questions but i am in new territory here. my machine shop is assuring me it is ok but i just worry about these things. i had this shop do machine work and several Olds engines and NEVER had a problem...

Dave Siltman

As long as they are willing to honor their word---I'd say "let 'er eat". I'm not familiar with those 215 engines, but if your machine shop is confident in their work, then I think you'll be OK. Aluminum is kinda weird and I hear ya' on the concerns. Good luck!

jensenracing77

i have called around to several machine shops and only got one that would look at it to give me a second opinion. they checked it all over and said they could do it right if i wanted them to but they also said it would be a wast of money because what i have will work just fine. i think the cam has been in and out of this engine about 20 times now. i am going to start putting it back together and trust what they are telling me. i am taking vacation next week and hope to have this car most of the way back together by the end of next week. i am still needing piston rings but i should have them this week.

rcrac3r

Being that the cam is brand new (I assume) it shouldn't have had to be machined to slide into new cam bearings. This is the first time I've heard of this having to be done. Any engine I've rebuilt I've always had the cam bearings replaced with no issue. IMO it saves issues down the road. Maybe the machine shop put in the wrong size bearings & that is why the cam had to be machined. As Dave said if they will stand behind their word then ok.

Oldsmaniac

I have no real advice only a comment....back in votech we had Buick 350's to rebuild. We put the cam bearings in ourselves and the cam would not go all the way in. The instructor came over and assumed we F -Up ed the bearings on installation so he got a new set out and installed them himself and had the same problem. He took out a bearing scraper and scraped the offending bearing and the cam slid in. I think I would trust your machinist and not worry.

11971four4two

The above scenario makes more sense to me , adjust the bearing to the cam. I have never heard of machining a cam to fit the cam bearings.

Good luck with the 215 Eric

ah64pilot

I agree...it seems like a bass ackwards way of doing it but I guess it works. If it spins freely I don't see it being a problem, the cam is not dealing with a side load like a main or a rod bearing. Maybe Mark will chime in...

jensenracing77

also, this engine is not likely ever going to see 5000 RPMs so even at 5000 the cam is only 2500.

Mark at D&D said that the cam bearings available for this engine don't have the correct outside diameter. when they are pressed in it will put to much crush on the bearing. he said there are only 2 correct ways to do it. one is to machine the block to the correct size before installing the bearings or getting a set of unfinished bearings and then honing the bearings to the right specs. the sad thing is, i told my machine shop about this before they started and they said they run into this from time to time and they know how to deal with it. i didn't know that was machining the cam.