ACL rod bearings?

[Green-Eggs]

Originally Posted by Assimilator1

200!? Wow! I did wonder how much it would need .

It all depends on how wide the variance. BE has a 4-sigma variance in theory, but a 5-sigma variance in reality. ACL specs say a 4-sigma variance in theory too, and probably a 5-sigma variance in reality as well.

So yeah, I'd say 100 shells of each to do it right and not have any waste at the end.

[jvictormp]

Having removed ACL H-STD after 3,000km to inspect, now doing again with 6,000km, and one trackday. New reason this time.

They seem exactly like the first time I removed (before trackday).

As you can conclude, its first layer goes fast, then stays like that for more time (don't know how much, but I assume it can hold several thousands of km).

Anyway, the reason why I did it was that I heard a friend of mine lost a Honda K24 due to an ARP 2000 rod bolt breaking down. Then I remembered that two of my rod bolts (BE-ARP 2000) suffered impact on the head, and I reused them anyway (then I discovered that they were actually three). I didn't assume it would be risky at all, until that happened to my friend. We still don't know yet if his bolts suffered some impact too, but I thought I should minimize every risk and decided to replace them all for new ones.

And due to that contact marks on the ACL bearings, which leads me to think that I'll need to replace those bearings some day in the future, I decided to go back to BE Bearings again to have not to even think about opening that sump again.

Ask for details if you wish.

Recap:
I lost an engine with BE Bearings due to fuel hydrolock.
https://www.m3post.com/forums/showthread.php?t=1851485

Put ACL bearings and reused BE-ARP bolts from the broken engine on the "new" used engine.

Inspected them before the first trackday (3,000km done on them):
https://www.m3post.com/forums/showpo...&postcount=340

Now this.

[Helmsman]

Originally Posted by jvictormp

Having removed ACL H-STD after 3,000km to inspect, now doing again with 6,000km, and one trackday. New reason this time.

They seem exactly like the first time I removed (before trackday).

As you can conclude, its first layer goes fast, then stays like that for more time (don't know how much, but I assume it can hold several thousands of km).

Anyway, the reason why I did it was that I heard a friend of mine lost a Honda K24 due to an ARP 2000 rod bolt breaking down. Then I remembered that two of my rod bolts (BE-ARP 2000) suffered impact on the head, and I reused them anyway (then I discovered that they were actually three). I didn't assume it would be risky at all, until that happened to my friend. We still don't know yet if his bolts suffered some impact too, but I thought I should minimize every risk and decided to replace them all for new ones.

And due to that contact marks on the ACL bearings, which leads me to think that I'll need to replace those bearings some day in the future, I decided to go back to BE Bearings again to have not to even think about opening that sump again.

Ask for details if you wish.

Recap:
I lost an engine with BE Bearings due to fuel hydrolock.
https://www.m3post.com/forums/showthread.php?t=1851485

Put ACL bearings and reused BE-ARP bolts from the broken engine on the "new" used engine.

Inspected them before the first trackday (3,000km done on them):
https://www.m3post.com/forums/showpo...&postcount=340

Now this.

Big job again, well done mate! Yeah they seem a tad tight, guess they might as well come out. Whats up with the bolt heads, what happened?

[jvictormp]

Originally Posted by Helmsman

Big job again, well done mate! Yeah they seem a tad tight, guess they might as well come out. Whats up with the bolt heads, what happened?

The rod from cyl 5 of the old engine hit their heads, you know the history.

[Redd]

Jvictormp, thanks for sharing. You really like to take apart that engine lol.

[jvictormp]

Originally Posted by Redd

Jvictormp, thanks for sharing. You really like to take apart that engine lol.

I don't at all, trust me. I hope this was the last time.

[Assimilator1]

Originally Posted by jvictormp

Having removed ACL H-STD after 3,000km to inspect, now doing again with 6,000km, and one trackday. New reason this time.

They seem exactly like the first time I removed (before trackday).

As you can conclude, its first layer goes fast, then stays like that for more time (don't know how much, but I assume it can hold several thousands of km).

Anyway, the reason why I did it was that I heard a friend of mine lost a Honda K24 due to an ARP 2000 rod bolt breaking down. Then I remembered that two of my rod bolts (BE-ARP 2000) suffered impact on the head, and I reused them anyway (then I discovered that they were actually three). I didn't assume it would be risky at all, until that happened to my friend. We still don't know yet if his bolts suffered some impact too, but I thought I should minimize every risk and decided to replace them all for new ones.

And due to that contact marks on the ACL bearings, which leads me to think that I'll need to replace those bearings some day in the future, I decided to go back to BE Bearings again to have not to even think about opening that sump again.

Ask for details if you wish.

Recap:
I lost an engine with BE Bearings due to fuel hydrolock.
https://www.m3post.com/forums/showthread.php?t=1851485

Put ACL bearings and reused BE-ARP bolts from the broken engine on the "new" used engine.

Inspected them before the first trackday (3,000km done on them):
https://www.m3post.com/forums/showpo...&postcount=340

Now this.

Yea, seems to confirm that std clearances aren't enough for your engine (and likely most of our S65s).
And yea, seems sensible to replace those damaged bolts.

[Helmsman]

Originally Posted by jvictormp

The rod from cyl 5 of the old engine hit their heads, you know the history.

Ah, right, I forgot. Good luck!

Ps. Still strange that they already are "worn", assuming you didn't have cold start every km of those 3k... Thought ACL Standard was a little bit more open than the OEM 702/703. Ah well.

[Assimilator1]

Originally Posted by Helmsman

Ah, right, I forgot. Good luck!

Ps. Still strange that they already are "worn", assuming you didn't have cold start every km of those 3k... Thought ACL Standard was a little bit more open than the OEM 702/703. Ah well.

Nope, ACL std (H) bearings target the same clearance as OEM bearings.
You might be thinking of the single set of ACL Hs bearings that BE measured and posted in the S65 bearing wiki/thread, that set did have slightly bigger clearances than OEM.

[Helmsman]

Originally Posted by Assimilator1

Nope, ACL std (H) bearings target the same clearance as OEM bearings.
You might be thinking of the single set of ACL Hs bearings that BE measured and posted in the S65 bearing wiki/thread, that set did have slightly bigger clearances than OEM.

Yep I'm aware the "target" OEM but from chatting with them + reading about various measurements its seem they ended up a tiny bit more open?
Anyways, I didn't think even 702/703 would be that significantly "touched" after 3k km only but maybe the outer layer is meant to deal with the cold start. Or crank dimensions on the big side maybe...

[Assimilator1]

Actually, now that you mention it, Redish motors here in the UK fit ACL Hs, and they measure the clearance afterwards (although with plastigauge) and often find they get ~0.05mm.
But because you can't guarantee that, I went for mixed and measured ACLs.

[jvictormp]

Originally Posted by Assimilator1

Actually, now that you mention it, Redish motors here in the UK fit ACL Hs, and they measure the clearance afterwards (although with plastigauge) and often find they get ~0.05mm.
But because you can't guarantee that, I went for mixed and measured ACLs.

I did plastigage them too. They were all alike.

[Assimilator1]

Is that in inches and with the BE bearings?

[jvictormp]

Originally Posted by Assimilator1

Is that in inches and with the BE bearings?

Sorry, yes in inches and ACL bearings, brand new ones, back in December 2021.

[Helmsman]

Originally Posted by jvictormp

I did plastigage them too. They were all alike.

So still a good 0.05mm, shouldn't result in shown wear right, didn't realize plastigage that much off?

[Green-Eggs]

Originally Posted by Helmsman

So still a good 0.05mm, shouldn't result in shown wear right, didn't realize plastigage that much off?

The inaccuracy of Plastigage has been documented, repeatedly, with examples. It's one of those things that I've said so many times, that I thought I was beating a dead horse. It's one of those things that comes up so often, that Bert dedicated a small page at his wiki to discuss it.

http://wiki.rcollins.org/core/index...._on_Plastigage

[jra85]

Originally Posted by Green-Eggs

The inaccuracy of Plastigage has been documented, repeatedly, with examples. It's one of those things that I've said so many times, that I thought I was beating a dead horse. It's one of those things that comes up so often, that Bert dedicated a small page at his wiki to discuss it.

http://wiki.rcollins.org/core/index...._on_Plastigage

Green-Eggs Can you reply to my PM about my AutoTalent order for BE rod bearings and bolts? Nobody at the company has responded to my contact attempts via any of their communication channels, and my next step is to reverse the credit card charge. Thanks.

[Assimilator1]

Originally Posted by Green-Eggs

The inaccuracy of Plastigage has been documented, repeatedly, with examples. It's one of those things that I've said so many times, that I thought I was beating a dead horse. It's one of those things that comes up so often, that Bert dedicated a small page at his wiki to discuss it.

http://wiki.rcollins.org/core/index...._on_Plastigage

And yet as I have posted at least a few times, some engine shops have found it to be pretty close to measuring with precision gauges (which you seem to ignore). Although maybe it is more prone to user error?
And both BMW and Suzuki (cars) state to use it for e.g main bearing sizing. So your case isn't proven outright.
I'm not saying it is as accurate as precision gauges, but it's accurate enough to give a decent idea of clearances for 'regular' workshops and DIYers, if done properly. It's not useless as you're implying.

Two comparisons between precision gauges and plastigauge from engine shops, and 1 from a DIYer.
Papa dakis racing (table at 5m:26s) -

The Horsepower Monster (skip to 3m:42s for start of the article, 7m:10s for dial gauge results, 9m:07s onwards for plastigauge results)-

And a random DIYer on youtube comparing plastigauge to a precision gauge finds plastigauge is close too.
asquaregarden (skip to 9m:57s for results)

[Green-Eggs]

Originally Posted by Assimilator1

And yet as I have posted at least a few times, some engine shops have found it to be pretty close to measuring with precision gauges (which you seem to ignore). Although it is more prone to user error.
And both BMW and Suzuki (cars) state to use it for e.g main bearing sizing. So your case isn't proven outright.
I'm not saying it is as accurate as precision gauges, but it's accurate enough to give a decent idea of clearances for 'regular' workshops and DIYers, if done properly. It's not useless as you're implying.

Two comparisons between precision gauges and plastigauge from engine shops, and 1 from a DIYer.
Papa dakis racing (table at 5m:26s) -

The Horsepower Monster (skip to 3m:42s for start of the article, 7m:10s for dial gauge results, 9m:07s onwards for plastigauge results)-

And a random DIYer on youtube comparing plastigauge to a precision gauge finds plastigauge is close too.
asquaregarden (skip to 9m:57s for results)

And yet, there's this. There's also video to back this up, in a temperature controlled environment about 70-degrees F, but the video's never been edited or posted.

http://wiki.rcollins.org/core/index...._on_Plastigage

Just because BMW posts the Plastigage procedure in their service manuals, I'm highly skeptical that they use this method to assemble engines. I'd need to see some type of proof to believe it. Not saying it's impossible, but I would be left shaking my head if they did.

[Assimilator1]

Originally Posted by Green-Eggs

And yet, there's this. There's also video to back this up, in a temperature controlled environment about 70-degrees F, but the video's never been edited or posted.

http://wiki.rcollins.org/core/index...._on_Plastigage

Just because BMW posts the Plastigage procedure in their service manuals, I'm highly skeptical that they use this method to assemble engines. I'd need to see some type of proof to believe it. Not saying it's impossible, but I would be left shaking my head if they did.

It'd be interesting to see that video.

I think I saw BMW's recommendation to use plastigauge in the NewTIS website, which is no longer available (I think others have seen it at their own site though). However, now that I work for a BMW dealer I can look it up myself (when I remember!).

And I know for a fact that Suzuki recommend it to size main and rod bearings as I saw it in there online manual (Portal), and I took a photo. I would post it directly here, but my images at Imgur are unavailable for me atm. But anyway, you can see my photo of it here and here, that was for an AZG Swift Sport.
This is for workshop repairs/assembly, I've no idea what the factory does.

[Assimilator1]

Originally Posted by Green-Eggs

And yet, there's this. There's also video to back this up, in a temperature controlled environment about 70-degrees F, but the video's never been edited or posted.

http://wiki.rcollins.org/core/index...._on_Plastigage

Just because BMW posts the Plastigage procedure in their service manuals, I'm highly skeptical that they use this method to assemble engines. I'd need to see some type of proof to believe it. Not saying it's impossible, but I would be left shaking my head if they did.

Below are a couple of shots from BMW's AIR showing plastigauge use, the VIN in there is for my M3.
Pic 1, pic 2.

[2008M36MT]

Is BE in a shortage again? If not, the cost difference is immaterial, why do people bother even asking about VAC or ACL? Just get BE.