How do you measure lifter bores?

[rang-a-stang]

I am getting ready to check for wear in my lifter bores. I see a few videos about using a dial bore gauge but it looks like a decent DBG is a solid $100. I hate to spend $100 on a tool I will use once. Is there another way to do it?

[Cliff]

I never heard of measuring a lifter bore. I have always just dropped in new ones. Can they wear to the point that you would need to make a repair?

[rang-a-stang]

Maybe? I have low oil pressure and one of the places it could be sneaking out is the lifter bores so I hope to check mine.

[rws31]

I've put lots of motors together and been around even more being done and checking the lifter bores has not been something to worry about. With a stock cast iron block with lots of miles on it, lifter bores should be the least of your worries. If your building a serious hi performance motor with a crazy cam and flat tappet lifters, maybe, check the bores.

I had a lifter break in half in a motor about 6000 rpm and the rest of the motor was toast. The lifter bore was fine. The #6 cyl lifter broke in half, then the bottom half fell out of the lifter bore, then got caught in between the #6 rod bolt and the block, and then twisted the rod off just above the crank, then the broken end of the rod slammed into the camshaft which in turn broke the cam into 4 pieces and of coarse that bent all the valves but 5 of them.

The lifter bore as fine. That block is in my Jeep now.

[babywag]

it's not as much a wear issue as knowing actual measurement & checking clearance on the aftermarket lifters.
some lifters are not correct o.d.

marc lemme dig around I have bore gauges and all that just need to find 'em.

[rws31]

I would definitely worry about cheap aftermarket lifters. That's what cost me an engine. After that episode, good name brand lifters only for me.

[SJTD]

Telescoping gauges. Sometimes called snap gauges.

You squeeze them down and lock them with the knob. Put them into the bore and release the knob. Wiggle around a bit so they're on the diameter and handle is parallel to the bore and lock them again. Pull them out and measure with a micrometer.

Repeat several times. Also check different heights. You check for roundness by turning the gauge once you lock it to see if it gets looser or binds then reset it at loosest and tightest spots.

Can be very accurate. It's all in your technique.

https://www.amazon.com/Pc-Precision-Telescoping-Gage-Set/dp/B00R5E5PI6/ref=sr_1_1?crid=2PGA4E1D0E714&dchild=1&keywords=snap+gauge+set&qid=1601442760&sprefix=snap+gauge%2Caps%2C215&sr=8-1

[tgreese]

Maybe? I have low oil pressure and one of the places it could be sneaking out is the lifter bores so I hope to check mine.

Do you have the block apart? I would be more suspicious of the cam bearings than the lifter bores. As mentioned previously, wear there is not typically a concern.

[rang-a-stang]

I've put lots of motors together and been around even more being done and checking the lifter bores has not been something to worry about. With a stock cast iron block with lots of miles on it, lifter bores should be the least of your worries. If your building a serious hi performance motor with a crazy cam and flat tappet lifters, maybe, check the bores.

I had a lifter break in half in a motor about 6000 rpm and the rest of the motor was toast. The lifter bore was fine. The #6 cyl lifter broke in half, then the bottom half fell out of the lifter bore, then got caught in between the #6 rod bolt and the block, and then twisted the rod off just above the crank, then the broken end of the rod slammed into the camshaft which in turn broke the cam into 4 pieces and of coarse that bent all the valves but 5 of them.

The lifter bore as fine. That block is in my Jeep now.

Hahahaha! I hope you took pictures of that carnage! That sounds amazing!

I hear you. I think the chances that I have a lifter bore problem are low but my oil pressure is low and I want to verify every clearance I can to figure out why. I do not suspect I have one smoking gun that is bleeding all my pressure; I suspect I have a few problems and lifter/bore clearance could be one of those problems. I guess the lifters most kits have for AMC these days are the Mopar lifters and have a .904 body but AMC should be .905. So if I have a little wear on my bores AND a slightly smaller lifter body than I should, that could be one source of lost pressure.

it's not as much a wear issue as knowing actual measurement & checking clearance on the aftermarket lifters.
some lifters are not correct o.d.

marc lemme dig around I have bore gauges and all that just need to find 'em.

Agreed. rgr, standing by.

I would definitely worry about cheap aftermarket lifters. That's what cost me an engine. After that episode, good name brand lifters only for me.

I have Comp Cams lifters in there, now. My reading about them finds a mixed bag of info. When I mic them, if they are .9035 or less, I may fork out some bucks for AMC specific lifters. I would rather spend money on quality lifters then damage my 401 crank because of low oil pressure. If this was a 360, I would run it until it blew up, then put a Hemi in but these 401's sell for $$$$$$ and I am scared to damage it.

Telescoping gauges. Sometimes called snap gauges.

You squeeze them down and lock them with the knob. Put them into the bore and release the knob. Wiggle around a bit so they're on the diameter and handle is parallel to the bore and lock them again. Pull them out and measure with a micrometer.

Repeat several times. Also check different heights. You check for roundness by turning the gauge once you lock it to see if it gets looser or binds then reset it at loosest and tightest spots.

Can be very accurate. It's all in your technique.

[LINK]

Copy that. Tony found a good one in his tool stash. A controlled exchange will be done soon!

Do you have the block apart? I would be more suspicious of the cam bearings than the lifter bores. As mentioned previously, wear there is not typically a concern.

Not yet. I am still planning for when it comes out (probably mid October). I want to have as many supplies and tools ready so I can pull it, do my bidness, then put it back in. I do plan to inspect my mains, rods, and cam bearings as well as the oil pump.