camshaft question

[dontknowitall]

When I got my engine back from the engine shop they told me they had problems fitting the camshaft / bearings. They needed to "scrape" the bearings or something like this.. I thought having new bearings for the camshaft would just fit. It cost me extra but I am not sure if this "scraping" was nessecerry:(

[Dave72dt]

Cam brgs are driven in and without the correct driver ( and even then sometimes ) the insides edgse of the brgs get swedged in a little. Also happens when the brg doesn't start stright and becomes a bit egg shaped. Result is the cam fits tight and doesn't turn easily so the soft aluminum inner coating is "scraped" a little for clearance. When it doesn't turn easily, it's hard on gears, usually spins the brgs in the block which gets the brgs and cam hot which makes them sieze which makes you cuss and do it all over again. Should have been part of the brg install but each shop has it's own policy on charging.

[Plymouthy Adams]

I would think that the scraping could very well be atrtributed to them not having the corect insertion tool thus damaged the edge a bit by possibily rolling the metal..I would be concerned if the camshaft does not now have a few tight spots due to this ..can they tell you the exact clearance now that they did this little procedure?

[dontknowitall]

I dont know Tim, they are not set up for older engines and the guy I spoke to first was all like we can do it mate, no problems etc.. but then he left..

So, what would you do?

Would you have some one else strip the engine down to check if all is done ok? I am insecure now as if I can trust this engine...

[Andydodge]

How did the engine turn over when you got it home?........how complete was it?......was the timing cover on ?.......andyd..

[dontknowitall]

Engine turns over as with the hand as I have not been able to start it yet. Timing cover was on but I removed it after reading up about the oilfeeder, only to discover the Oilfeeder thingy was indeed missing.. I made up a new one with the help of a mechanic.

When speaking with the mechanic who assembled the engine he told me that the camshaft took the longest because he had to scrape fit the bearings.. The crankshaft, new bearings, new pistons, rebored, new rings etc..were ok, they did have straight a conrod...

this engine shop is well established and has got good trades people

[Dave72dt]

I'm sure the shop, if reputable, has a warranty on their work. They found the bent conrod, something easily missed so chances are they did well on the rest of their work. Taking a guess, they assembled the motor for you which tells me you may be unfamiliar with this type of work and wouldn't know for sure what to look for or feel if you tore it down.

Cam journals and brgs can be miked to find clearances but rotating effort is largely a matter of "feel". Apparently he felt it was too tight and went back and got it right. I wouldn't be uncomfortable with it myself. Good mechanics really only want to do a job once so it needs to be right when it goes out the door the first time.

[Mike@DRH]

Most often when we see this in our shop it's the bore in the block thats a little under size.

If the bore in the block is too small the bearing, after install, will reflect that same amount, sometimes tolerable and some times not.

The best, or what we say is the correct way, to repair it is to line bore the block (cam bore). Some shops elect to take material (scrape) from the I.D. of the bearing after install. It's up for debate on which way is the best way to fix it.

We very rarely see more than one bore thats off in a block and it is much more common in older engines.

Mike

[dontknowitall]

Thanks all, the shop is very reputable and has a high standard of workmanship. They do mostly high performances engines and having this oldie in between may have put them off. I have desided to just instal and run the engine.. thanks again for your support:)