ok, this is a rebuilt block, (sbc) and im using hydraulic flat tappe lifters, but i cant get them in the hole. I was able tog et one in sofar, but i took a carbide bit that i used for porting my heads, and ran it, by hand of course, along the innner edge of the lifter hole (probably has a proper name, but i dont know what that is), but it is in there very very snuggly, like when i turn the cam i have to push the lifter back down. Now is this going to be a problem because its going to get pshed down anyways, and its not that much force, maybe 3-4 lbs of force to push it back down.

 

No, that's not a problemo. They should fit in their bores very snugly. The machine shop should have deburred the top edge of the bore. Unless you want to pull the engine all apart and clean it like an Egyptian princess, I wouldn't be running a bur on anything. That's the stuff you do before sending it to the machine shop. I'd make sure to clean it thoroughly now that you've done this...... for cleanliness is truly next to godliness where engines are concerned.

-Mindgame

 

I've seen on used blocks where the old lifter mushroomed at the bottom and they damaged the bottom of the lifter bores when someone pulled them out by force instead of pulling the cam and dropping them down. So the new lifters won't work up and down smoothly.

A little work with a fine tooth rat tail file takes care of it.

 

I've had a couple blocks that didn't want to take lifters for some reason as well. The best thing to do is get a brake cylinder hone (sears) and lightly hone the lifter bore using liberal amount of WD40 or similar. Just a couple seconds per hole will do the trick. You should know that a ball hone won't work well, and will change the shape of the bore.

 

I'd try chamfering the top of the lifter bore first with a soft stone. If that doesn't work, then try the hone. Just keep in mind that most engine builders I've talked to recommend no more than .0025 clearance in the lifter bore so as to provide adequate pressure.

As always... clean everything thoroughly before you reassemble. That can't be stressed enough.

-Mindgame

 

I had a problem with my truck moter liffter bores..What I did was take an old lifter and put it in upside down about 1/4 of the way into the bore(The one I hade was slightly tapered on the top)

Then I taped it firmly left and right and front and back with a 1 once ball peen hamer.

On a flat tappet cam the lifter must be able to spin or you will kill the cam

25k miles and going strong

Ed