ebr-1190-rxsx-cylinder-closed-deck-conversion

[EBRRider]

https://ebutik.nccr.se/ebr-erik-buell-racing-3/ebr-engine/ebr-1190-rxsx-cylinder-closed-deck-conversion-machining-your-cyl

[Brian S]

I had seen a pic of these cylinders before and wondered WTF supported the the top of the cylinder. At minimum I thought it should have been o-ringed. BTW price for this conversion is approx $355 US. I'd like to find out if iron sleeves are another option...he didn't seem to know if it would help.

[Cooter]

An O-ringed head gasket doesn't support the top of the cylinder sleeve the way you think. Only supporting the sides of the cylinder (closed deck) would do that. Iron sleeves have been discussed and the stiffness would probably help a little, but it's much more effective support to brace the sleeve against the cylinder wall. Cheaper too.

[TerryS1980]

US version is here at $531. https://ebutik.nccr.se/ebr-erik-buell-racing-1/ebr-engine/ebr-1190-rxsx-cylinder-closed-deck-conversion-machining-your-cyl-1

[Cooter]

Very nice of them to offer!

[LeesEBR]

Those are semi-closed.

https://shopcdn2.textalk.se/shop/4830/art30/h7697/175297697-origpic-9ccb91.jpg?max-width=540&quality=70

https://www.subaruoutback.org/attachments/blockdesign-jpg.379865/

I had seen a photo, somewhere, of someone that had made an insert to make it a proper closed deck. I thought it was NCCR, but I can't find it anymore.

[LeesEBR]

You can see in this image, the whole deck can be closed except for these eight (?) coolant passages.

https://www.badweatherbikers.com/buell/messages/713493/808875.jpg

[Cooter]

Meh. Semantics.

What it needs is sleeve support, and thats what it's getting. Some support > No support. I wouldn't be too fast to adopt the weight and complexity of overkill.

[Brian S]

It's not the head gasket that provides support, it's the cylinder head. It does so by increasing the clamping force directly around the top of the cylinder. See below.

Misheard what he was saying about the iron sleeves. What he said is he wasn't sure if he could do his deck modification on them. US version $531?


Those are semi-closed.
I was thinking the same. Didn't want to say it.:smirk:


I had seen a photo, somewhere, of someone that had made an insert to make it a proper closed deck. I thought it was NCCR, but I can't find it anymore.
He mentioned they tried to do that but after a while realized would have been less work to design a whole new cylinder.

[Cooter]

I agree o-ringing would help them seal, but thats not the problem. The problem is support.

I disagree that the copper head gasket squished in a void would support the piston sleeve any amount big enough to matter in this example (this aint no boosted Cummins;)) and probably make a mess of the head gasket as the head and sleeve are moving around so much. Did you SEE where the valve marks were?! Wild guess at 200 thou, Holy Hell thats a LOT! Can you picture what the gasket would look like after being mashed around almost a 1/4" back and forth? Yikes. My opinion of course, no offense meant.

[LeesEBR]

Meh. Semantics.

What it needs is sleeve support, and thats what it's getting. Some support > No support. I wouldn't be too fast to adopt the weight and complexity of overkill.
It's not semantics, it's a technical and structural difference. Some > None, agreed, but a closed deck is drastically different than a semi-closed deck. Proper terminology should be used.

[Cooter]

Yes, I agree you are technically correct. But with re-engineering a casting being the only way I could see a closed-deck conversion to this engine, my point is the elegant NCCR solution has more support than a typical semi-closed deck.

So can we agree with "mostly-closed deck"? :) LOL

[LeesEBR]

Yes, I agree you are technically correct. But with re-engineering a casting being the only way I could see a closed-deck conversion to this engine, my point is the elegant NCCR solution has more support than a typical semi-closed deck.

So can we agree with "mostly-closed deck"? :) LOL
Yes, we can agree, what they've designed should be an improvement.

I would worry about heat expansion making the cylinder out of round at the top.

I'd like to see closed-deck still an option, but would obviously expect a higher price. I think it would serve the purpose much better, and costs could be brought down.

[Cooter]

A true closed deck cylinder would be the best for sure, but with such limited EBR production, and only a few brave souls who either ride hard enough too 'need' or have enough wallet to 'want' that upgrade, I'm not sure it would ever be a reasonable cost. Reasonable is subjective of course:whiver:

We all know how the might-as-wells add up when theres a split case on the bench:cry: