Experience with Alusil cylinder repair shops

[diva.varadam@gmail.com]

Hi ProjektAutoScott - are you successful in doing the one cylinder rebuild with allusion sleeves. Can u share the shop information pls and the process you followed with your bmw. Thanks

[Chrisyphus]

The lack of responses here makes me think this didn't go well?

[JellyStyle]

Originally Posted by Chrisyphus

The lack of responses here makes me think this didn't go well?

we did it with about 250 of supplies from;;;

FYI, In case your tech team wants to partner with Goodson or offer their products, I see an opportunity here, especially with the number of folks sleeving their engines because of bad information out there, so here goes.

A few smart folks and I finally cracked the code with Alusil for BMW blocks. Working with Sunnen and Goodson, along with some engineers in Germany, we found that the process is actually not that difficult at all—you just need the right information and materials. I plan to share this information and the instructions.

Instructions on how to hone/bore to .10 over or simply polish and recondition Alusil can be found here: [Reconditioning High-Silicon Aluminum Alloy Engine Blocks](https://goodson.com/blogs/goodson-ga...-engine-blocks) for merely polishing the cylinders for new pistons.

For Polishing:
- Finishing Stones - MM33-J85
- Polishing Stones - MM33-CO5
- Felt Conditioning Set - MM33-FO5
- Silicon Compound - AN-30

For Hone/Bore to .10 over:
- Roughing Stones - MM33-J63
- Finishing Stones - MM33-J85
- Polishing Stones - MM33-CO5
- Felt Conditioning Set - MM33-FO5
- Silicon Compound - AN-30

You'll need to buy some Honeing oil to Bore/Hone or Soak the Felt pads, but you won't need a large qty, you can get that anywhere or at Goodson.

Any machinist with the right Sunnen or Goodson hone can perform this with the roughing stone and then move on to the finishing and polishing steps. It's surprising how many keep this information to themselves, claiming there's a secret recipe. It's often just a gimmick to sell sleeving services or instill fear. With the right information, it's much less costly and easier to do this than to sleeve and get new pistons.

You can still opt for either BMW OEM stock forged pistons or center-lined CP pistons. Note that BMW/Mahle also makes OEM .10 over (.25mm) pistons, indicating BMW anticipated the need for boring their blocks and running decent pistons. I have sourced OEM Mahle pistons for about $650 for 8, a fraction of BMW's price, which is about $350 each. I found a source at the Mahle factory to assist with this request. The 89.25mm oversize .10 over BMW Mahle pistons are available in Germany, with about 100 in stock, but no direct access to Mahle for deeper discounts yet.

Regarding the choice between BMW forged versus CP pistons, unless you are building custom CP pistons with offset pins, you might encounter some knock issues on some motors (due to piston slap). Custom CP pistons with offset pins would be ideal but are more expensive.

This knowledge should be more widely available online to promote honesty and transparency about how Alusil works and how manageable it is once understood. In Germany, every decent shop can do this, but in the USA, it's often shrouded in fear, uncertainty, and doubt. That’s why I’m sharing this information.

Just thought to pass this along in case anyone else ever asks.

[rcracin]

Thank you for sharing.

[a5m]

I feel this post won't get appreciated as much as it should. Great work and contribution to the community, thank you.

I thought people wrongly assumed OEM pistons were forged but they weren't? With the information you just shared I trust you know what you're talking about so, another thing that makes the S65 that much more special!

[Chrisyphus]

Originally Posted by JellyStyle

we did it with about 250 of supplies from;;;

FYI, In case your tech team wants to partner with Goodson or offer their products, I see an opportunity here, especially with the number of folks sleeving their engines because of bad information out there, so here goes.

A few smart folks and I finally cracked the code with Alusil for BMW blocks. Working with Sunnen and Goodson, along with some engineers in Germany, we found that the process is actually not that difficult at all—you just need the right information and materials. I plan to share this information and the instructions.

Instructions on how to hone/bore to .10 over or simply polish and recondition Alusil can be found here: [Reconditioning High-Silicon Aluminum Alloy Engine Blocks](https://goodson.com/blogs/goodson-ga...-engine-blocks) for merely polishing the cylinders for new pistons.

For Polishing:
- Finishing Stones - MM33-J85
- Polishing Stones - MM33-CO5
- Felt Conditioning Set - MM33-FO5
- Silicon Compound - AN-30

For Hone/Bore to .10 over:
- Roughing Stones - MM33-J63
- Finishing Stones - MM33-J85
- Polishing Stones - MM33-CO5
- Felt Conditioning Set - MM33-FO5
- Silicon Compound - AN-30

You'll need to buy some Honeing oil to Bore/Hone or Soak the Felt pads, but you won't need a large qty, you can get that anywhere or at Goodson.

Any machinist with the right Sunnen or Goodson hone can perform this with the roughing stone and then move on to the finishing and polishing steps. It's surprising how many keep this information to themselves, claiming there's a secret recipe. It's often just a gimmick to sell sleeving services or instill fear. With the right information, it's much less costly and easier to do this than to sleeve and get new pistons.

This knowledge should be more widely available online to promote honesty and transparency about how Alusil works and how manageable it is once understood. In Germany, every decent shop can do this, but in the USA, it's often shrouded in fear, uncertainty, and doubt. That’s why I’m sharing this information.

I agree with almost everything you've said here, except for the last two points- I firmly disagree that any shop in the States can do it, and that any shop in Germany can do it. Here's why:

Here, in the forums and in general, there is an obscene amount of misinformation regarding alusil reconditioning. We at Partee Racing do this every day. Actually every day we have Alusil blocks being bored, honed, and exposed in our machines in our shop. we see everything everyone says/does regularly and the vast majority of the time, it is wrong.

As I said, you are nearly dead on with your points and it sounds like your rebuild was successful, but that makes you the exception, not the norm. I cannot tell you how often we get calls from potential clients who had a shop do work for them, and then their cylinder walls disintegrated.

The fact of the matter is that if you do not have the right machines and equipment in addition to the Goodson products, the machinists are guessing. We verify every single cylinder with a profilometer before we pull the block out of the hone. The crazy part is that, even though we do multiple blocks per week, it's usually a two- or three-step process to get the cylinders perfectly in spec with the profilometer because they all behave slightly differently.

Sreten of E39M5 restorations had an EXTREMELY reputable shop in Germany do his block for his project Frankfurt build, and that engine ate itself in less than 10,000 KM. He flew here to our shop last fall to have a new motor reconditioned and blueprinted by us, and showed us the video he took at the other machinist's shop, and we could tell just by the speed the hone was moving that it was wrong. I had already spotted the issue when I watched his video before meeting him and saw just how rough his bores looked. Goodson says a dull matte finish, but the profilometer says a semi-gloss/satin finish is right.

We have observed that the vast majority of shops that claim the ability to do Alusil are guessing while they are doing it. They are guessing because the how-to guide on Goodson's website is simply incomplete.

My whole point with all of this being: there absolutely is public information that will get you most of the way there. But if you want to nail the perfect spec for cylinder finish every single time across hundreds of engines like we have, there absolutely is a recipe for success.

Originally Posted by JellyStyle

You can still opt for either BMW OEM stock forged pistons or center-lined CP pistons. Note that BMW/Mahle also makes OEM .10 over (.25mm) pistons, indicating BMW anticipated the need for boring their blocks and running decent pistons. I have sourced OEM Mahle pistons for about $650 for 8, a fraction of BMW's price, which is about $350 each. I found a source at the Mahle factory to assist with this request. The 89.25mm oversize .10 over BMW Mahle pistons are available in Germany, with about 100 in stock, but no direct access to Mahle for deeper discounts yet.

I would LOVE to discuss this further. We do not offer a basic rebuild for the S65 because OE oversized pistons are so obscenely expensive that it just doesn't make sense. I would love to be able to offer a far more cost-effective option for rebuilding to the community than starting with our Tier 2 engine, which comes with a completely forged rotating assembly.

[darren p.]

Originally Posted by Chrisyphus

Sreten of E39M5 restorations had an EXTREMELY reputable shop in Germany do his block for his project Frankfurt build, and that engine ate itself in less than 10,000 KM. He flew here to our shop last fall to have a new motor reconditioned and blueprinted by us, and showed us the video he took at the other machinist's shop, and we could tell just by the speed the hone was moving that it was wrong. I had already spotted the issue when I watched his video before meeting him and saw just how rough his bores looked. Goodson says a dull matte finish, but the profilometer says a semi-gloss/satin finish is right.

It doesn't appear Sreten has addressed this but that is a wild revelation that the motor from H2 ate itself so quickly and you guys built him another one. I can only speculate why he hasn't addressed this but am hoping he does in a future video. Didn't you guys host him and have a meetup when he was around? Can't imagine he wouldn't create any content from that trip or maybe he doesn't want to point the blame at H2 for the failure? Can you elaborate on this anymore?

[Chrisyphus]

Originally Posted by darren p.

It doesn't appear Sreten has addressed this but that is a wild revelation that the motor from H2 ate itself so quickly and you guys built him another one. I can only speculate why he hasn't addressed this but am hoping he does in a future video. Didn't you guys host him and have a meetup when he was around? Can't imagine he wouldn't create any content from that trip or maybe he doesn't want to point the blame at H2 for the failure? Can you elaborate on this anymore?

So there are a couple of things going on. First of all, I don't think he wants to throw anyone under the bus directly... It's just not his style. He is genuinely great people. We had a great time with him, an awesome time hanging out and machining his block, etc.

The motor we did for him was an S62 (we will also be doing an S65 at some point I think) and he is kind of in limbo on that video because he has a lot of stuff in the air with a new shop space and wants the video series to happen in a tight timeline. As far as I am aware, once he gets his shop space sorted out, we will ship him his block and components, and he will build the motor there (I should note here that this is an extreme exception that we've made- we do not typically supply machined components for customers to build themselves, as it opens us up to too much liability of a build gone wrong. The minimum we will ship is an assembled short block). Peter, at minimum, will fly to Germany to assist with the building process, but there is talk of all of us going for the video and to drive the Nurburgring. It's been nearly a decade since I was in Nurburg last, so I am really hopeful we all get to go lol.

[darren p.]

Thank you for that explanation and is pretty much what I was figuring. Been watching his channel for a while and he seems very genuine. I understand him not wanting to throw anyone under the bus but I'm baffled how such a reputable BMW specific machine shop could have made such a mistake?

I'm very grateful you guys are on the east coast, I've been contemplating a full stroker build since before I had an S65 and its nice to know shipping to Carbahn isn't the only option.

[S85 builder]

Sreten is a professional YouTuber, he is maximizing for views and engagement. Transparency is not his thing, he would have mentioned this by now. Simply put it's embarrassing. Sreten was the builder. H2 indeed did some suboptimal machining/honing but that is not why engines fail. I highly doubt that any post mortem analysis will find the alusil process was the root cause of the engine failure. If he does attempt to falsely blame H2, they are very well within their right to sue him for reputational damages. Germany is serious about this. Anything other than the truth won't suffice (as it should).

You guys might know that I had a few extensive posts critiquing him WHEN another forum member asked what my opinion was. Of course I was then brigaded and attacked by his rabid fan base. I'm glad you guys actually straighten him out as his response to my critique speaks volumes about what he actually knows. There are some misguided folks on here think he is god because he's a big youtuber.

This is exactly what you are up against as a shop that actually does things right. This is where myths and bad practices propagate. The guy claims he builds OEM plus engines and doesn't measure a G*Damn thing, doesn't think balancing the rotating assy is important, didn't even know what I meant about pre-lubing pressurizing the engine. He's rebuilt 3 or 4 engines that have failed. Shocker! It's interesting you're willing to send him things that you would not send to anyone else though despite the fact that they actually might know what they are doing. It is good exposure for you guys though.
You guys should have him buy your team tickets to go there rather than giving him free services.

Originally Posted by Chrisyphus

So there are a couple of things going on. First of all, I don't think he wants to throw anyone under the bus directly... It's just not his style. He is genuinely great people. We had a great time with him, an awesome time hanging out and machining his block, etc.

The motor we did for him was an S62 (we will also be doing an S65 at some point I think) and he is kind of in limbo on that video because he has a lot of stuff in the air with a new shop space and wants the video series to happen in a tight timeline. As far as I am aware, once he gets his shop space sorted out, we will ship him his block and components, and he will build the motor there (I should note here that this is an extreme exception that we've made- we do not typically supply machined components for customers to build themselves, as it opens us up to too much liability of a build gone wrong. The minimum we will ship is an assembled short block). Peter, at minimum, will fly to Germany to assist with the building process, but there is talk of all of us going for the video and to drive the Nurburgring. It's been nearly a decade since I was in Nurburg last, so I am really hopeful we all get to go lol.

[OmairK]

Quick question. Does that part number for the new engine block with pistons actually ship?

[THEROK]

Sorry for slightly off topic, but I plan on picking up a 4.6 Carbahn at some point soon. Need to do more research on the total BOM cost and what's exactly involved to do it right for me, but I trust Steve Dinan's motorsport experience. I don't know of any better for S65 owners.

I'm curious how the stock DCT handles the added power.