My Pete rebuild

[Rawze]

no need to pull the crank to counter-bore. just wrap the crank throw to protect/seal it + make cups/plates just below the liner step to catch shavings and clean thoroughly before removing them. As a safety measure, pull and wash out the rod and main bearings and cavities with some brake cleaner and an air line.

[Nostalgic]

If I'm pulling the main bearings to wash out the passages, I might as well lift the crank out of the way, and if I need to do that, I might as well pull my new crank before any more machining. If apex wasn't sold out, I would have already purchased the tool at this point. It's NOT going back to the place that did this, and at the least, I better get a refund + cost of wasted shims.

When I dropped the first liner in (#6 as I was working backwards), I ran the gauge on a couple spots, and it was .013-.014. When it was compressed, then everything went to hell. Granted, my homemade press is not equal to the one you use - I can side load pretty easily if I'm not careful lining up my plate, but even in that case, I should see discrepancies showing high readings in spots and the lowest reading I should see would be .014 if it was cut correctly, right?

[Rawze]

(07-07-2018 )Nostalgic Wrote:  If I'm pulling the main bearings to wash out the passages, I might as well lift the crank out of the way, and if I need to do that, I might as well pull my new crank before any more machining. If apex wasn't sold out, I would have already purchased the tool at this point. It's NOT going back to the place that did this, and at the least, I better get a refund + cost of wasted shims.

When I dropped the first liner in (#6 as I was working backwards), I ran the gauge on a couple spots, and it was .013-.014. When it was compressed, then everything went to hell. Granted, my homemade press is not equal to the one you use - I can side load pretty easily if I'm not careful lining up my plate, but even in that case, I should see discrepancies showing high readings in spots and the lowest reading I should see would be .014 if it was cut correctly, right?

your liner compression tool looks to be as good as any cummins tool would be. Be sure to use a torque wrench and torque the compression tool to 100 ft/lbs. You should be getting a consistent measurements to 0.0005" variance or less. That is if whoever cut it is worth their salt and as long as the top of the engine block + all other surfaces are very clean and washed with acetone. Don't know about after-market kits but I have never seen any variation in liners themselves from cummins, nor a variation in shim thickness. BTW: the brass shims from cummins are "hardened" brass shims. I was not so sure about apex or others, so I go with OEM when helping someone here.

If I had had gotten a shim that was 0.021", I would have taken it back and demanded a new one. You should NEVER have to cut the block for varying length shims or incorrect liner sizes, it is bad practice. Assume the shim could have been defective (incorrect hardness, etc. -- I.E.> something went wrong during the manufacturing process). I would not trust it.

Start by pulling the liners out and measuring the consistency of the step in the block itself. Same thing, there should be less than 0.0005" if you want them consistent.

(These numbers should be valid for the CM870, CM871, CM2250, Cm2350-X101 engines) ...

A depth of 4.724" results in 0.011" with the new OEM anti-carbon liners (no added shims). - THIS Is TOO LOW!- and NOT recommended!.

An OEM shim of 0.020" and a depth of 4.741" results in 0.014" height. <- Acceptable.
An OEM shim of 0.020" and a depth of 4.740" results in 0.015" height. <- OPTIMAL HEIGHT!.
An OEM shim of 0.020" and a depth of 4.739" results in 0.016" height. <- Max height safely possible.

An OEM shim of 0.032" and a depth of 4.753" results in 0.014" height. <- Acceptable.
An OEM shim of 0.032" and a depth of 4.752" results in 0.015" height. <- OPTIMAL HEIGHT!.
An OEM shim of 0.032" and a depth of 4.751" results in 0.016" height. <- Max height safely possible.

-- This all assumes your measuring tools are calibrated and measuring practices are accurate + consistent. At 4+ inches depths, I have been bitten by digital depth gauges, so I use only trust a mechanical gauge when doing the counter-bore depth measurement itself. - Ask if whoever counter-bored it used a digital depth gauge on it when checking it.

Tags:

counter-bore depths, liner height, 0.015", 0.014", 4.724", 0.020 shim, 0.032 shim

[Nostalgic]

I have both digital and analog calipers, but I really don't trust myself to get an accurate reading down the hole without using a micrometer. It would have to be perfectly level and straight, something I don't trust myself to accomplish freehand. I didn't price Cummins shims and I guess they're probably twice the price, but at this point, I'll pay the extra and get them. I'm leery of even having the local shop cut them without me hovering over them the whole time.

I torqued the press to 50 ft lbs - 100 may take some of the discrepancies out of each hole, but it's not going to grow my liner any. In other words, if I'm seeing an 11, it's not going to get any better lol.

[Nostalgic]

I've learned a lot the last 6 days.

1- Checking deck flatness, even with a precision straight edge certified within .001" can hide .002" of variances. Doesn't make sense, right? Shining a bright LED at the back side, I couldn't see light between it and the deck. It only took .002" to flatten my deck, but it made a world of difference while checking liner protrusion, which brings me to

2- If you are using anything with a dial indicator, at best, your accuracy is already at least .001" compromised. Including my brand new sled style liner height gauge.
I checked the Apex shims with my my (calibrated, with certificate) dial caliper, and you know, every single one of them read dead nuts .020". Long story short, I dug my severely missed dad's micrometers out of his aviation box. One measured pretty close to .0200-.0201, most fell around .0202-.0203", and low and behold, one is .021 exactly.

Big difference between something certified and accurate to .001" and something certified and accurate to ±0.00005" with increments of 0.0001"

Shims vary .0002" on average around the perimeter, captive shims on the liners vary .0003-4", and the one liner we checked had a .0004" variance in height.

3- My home made liner press is crap, so a slight hold up to my last step, which is trust, but verify.

4- I can't wait to be done spending time and money on this crap and get on to the more important things in life, like chrome and fuzzy dice lol.

[Nostalgic]

#6, reading .014" all around. After the last week I ask, what is the real protrusion? .01279? .01493? My answer is, if that little needle shows .014 on all 6, on all 6 points, I don't give a crap what the "true" protrusion is, I'll be eating roller dogs in a year.

Anywho, only 5 More to check lol.

[Nostalgic]

Well, I find myself at a point where I'm running out of patience.

6,5,4 solid .014 (going by sled dial)
3 - .014- ~.0145
2 <.0145- <.015
1 <.0145 -<.015

At this point, there's no way I'm taking it somewhere and dropping it off.

So, I'm left with 2 options:
1- Have a local shop come here and put up with me. I'll make the call in the morning. "Yeah, uh, I need my counterbores cut, but I only need less that .001" taken off 3 holes". We'll see.
2- Use an old liner, weld a handle on, and lap them. I'm tempted to try it out on the highest one if I get a 2nd wind this evening, but that's a lot of twisting, and I never did get a depth micrometer shipped, so it'll add a lot of time checking.

In all reality, I already have something that likely exceeds what I would have likely got for a Cummins short block, and has much tighter tolerances than allowed - heck first time around MET Cummins specs, but I know me, and I don't know if I could slap it together like this and not lose sleep.

On the bright side, I'm getting a 10 year, 1 million mile warranty on parts & labor (non-transferable), but what did Tommy Boy say about warranties?

[pearce trucking]

Did you eat paint chips as a kid?
"Yeah, WHY?"

I'm starting mine and will be using the Monaco tool rawze shows in his videos. I'm a perfectionist too. I think your numbers are probably good enough. But if I had those same numbers, I'd probably be trying to get them exact too. See what others say though. I dunno for sure.
Oh btw, did I read correctly that you had .002 taken off the deck?

[Rawze]

(07-15-2018 )Nostalgic Wrote:  Well, I find myself at a point where I'm running out of patience.

6,5,4 solid .014 (going by sled dial)
3 - .014- ~.0145
2 <.0145- <.015
1 <.0145 -<.015

At this point, there's no way I'm taking it somewhere and dropping it off.

So, I'm left with 2 options:
1- Have a local shop come here and put up with me. I'll make the call in the morning. "Yeah, uh, I need my counterbores cut, but I only need less that .001" taken off 3 holes". We'll see.
2- Use an old liner, weld a handle on, and lap them. I'm tempted to try it out on the highest one if I get a 2nd wind this evening, but that's a lot of twisting, and I never did get a depth micrometer shipped, so it'll add a lot of time checking.

In all reality, I already have something that likely exceeds what I would have likely got for a Cummins short block, and has much tighter tolerances than allowed - heck first time around MET Cummins specs, but I know me, and I don't know if I could slap it together like this and not lose sleep.

On the bright side, I'm getting a 10 year, 1 million mile warranty on parts & labor (non-transferable), but what did Tommy Boy say about warranties?

it will run there, looks to be progressive and not more than 0.0005 form cylinder to cylinder. With it at 0.014 - 0.015, your likely never to have issue with it.

Just make sure you let th head settle over-nigh after you get the bolts torqued to 300 -ft lbs, then torque again the next day,-- Than after that, do your 90-degree on the bolts for the final torque.