maroonls1z

How snug are lifters suppose to be in the lifter bores in a new block? I'm have a set of Johnson link bars and when I put them in the new block they slid in but not very easily. I figured they might just need to be run and wear in and I wanted to confirm this. They are not super tight but if they stayed this way I would not be able to use a pen magnet to pull them up or anything.

WE TODD DID

iTrader: (2)

Moving parts aren't supposed to "wear in". Did you measure the lifter bore clearance? Probably going to have to get the lifter bores honed to size. Needs .0015"

maroonls1z

I didn't have a bore gauge. They don't stick or anything in the bores. They are just snug. They move up and down freely when I turn the crank over. Maybe I'll get a bore gauge and check it out to confirm. 0.0015 is a pretty small gap so that could be pretty much where I'm at and I'm just being paranoid

redtan

iTrader: (5)

They're supposed to be snug, just like pistons. Otherwise if they are too loose then would rock back and forth in the bore and/or spin around none of which you want.

maroonls1z

In that case I will just run them, was just thinking if I did a cam swap I wasn't sure a pen magnet would be able to grab them but they don't have oil all over them yet either

WE TODD DID

iTrader: (2)

What?

KiwiKid

Dont think of it as a gap, the gap would be half of that again, its a clearance on the diameter of the lifter in its bore, and WTD is spot on .0015"

Are you using an aluminum block?

maroonls1z

It's an ls7, I went ahead and ordered a bore gauge just to be sure

WE TODD DID

iTrader: (2)

Aluminum blocks can be tricky to measure. I would guess the lifter bores will get around .0005" or so bigger when up to temperature.

maroonls1z

I'm sure it's fine and I'm just over thinking it

KiwiKid

Agreed WTD, hence my question about the material of his engine block.

Measure it by all means, but if its neat sliding fit at room temperature it will be perfect at an engines normal operating temperature.

maroonls1z

I was just test fitting them dry, I'm sure after I simmer them in some oil and use some assembly grease they will slide better

Havoc40

Let me know how they fit in the block after you lube them a little. They should slide in with no effort, as clearance should be around .0015". I've ran across a few issues with factory GM blocks, usually roundness and taper. The lifters are ground to .8421"-.8418"

redtan

iTrader: (5)

What I'm saying is that they should be snug in the bore without being able to rock back and forth in there and thus having a bit of resistance going in is not an issue.

CAMSTER

iTrader: (10)

Just use them, don't put lifters in their bore dry, if hydraulic deep them in a jar in oil overnight or two then install them wet. be sure to squirt cam lobes with oil before you drop them in.

joyridin'

iTrader: (1)

The lifter bore diameters should be .8438-.8444" if you feel compelled to measure them. I wouldn't bother.