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Old August 13th 2019, 04:35
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Wally Wally is offline
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Join Date: Nov 2002
Location: The Netherlands
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Quote:
Originally Posted by $aint View Post
Haven't seen these Deutz cylinders before. Are they for a type4 or for some other engine and repurposed?

If you want to share I'd be interested to know why you're going with 102mm vs the 98mm you had (or anything else for that matter).
I still have a bunch of these decisions to make as well (2056, 2270, etc)

And 9000 RPM is quiet a bit, do you make that regularly?
Deutz is a tractor manufactorer and is always a diesel engine...The older jugs are better to use, but harder to find and as the word seems to be out about these (old autocrossers used these 25 years ago already..), prices on ebay for used barrels are up. They used to be 'free' (tossed from old broken engines)

With Original head castings I would always keep as small a bore as possible as the heads warp originally already, even more so when fly-cut and even more so when 'openend up' for big bore. Everything you cut away is a weakening...

However, the Original 98mm bore idea had a long history from when friends made a set of custom made alu-'nikasil' cylinders and the were in 98mm, no choice there, but enough for a turbo engine

However again..., with the billet heads I now use, warping is not an issue anymore, but I also want to keep the case openings as small as possible as opening that also weakens the case (spigot). The edges where the cylinders rest are extremely small on engines that run the standard 103mm bore cylinders. I don't like that for a (really) big hp engine.

As one doesn't always have free choice and everything is a bit of a comprimise, I got a very good 'deal' on the cylinders which were 102mm to begin with, so I'll have the bottom turned down a little to minimize wall (2mm) and keep case strength up a bit.
I'd rather had 100mm and keep that 1mm more in the case, but sometimes you also go with what you have and its probably not really that much of an issue and the extra cc's give a bit more bottom torque (spool), so that nice as well.

Long story, but considerations for decisions are never simple nor single
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