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Discussion in 'Old's Cool' started by norton73, Jan 7, 2011.
Vierventilköpfe für BMW R50S
Click on the pics for close ups.
Pretty damn cool!
Can you give me a hint or just outright tell me?
Looks like good clean track hooligan fun to me... just wear your leathers and a damn good helmet.
Look at the heads
Are they Krausers with stock covers or modified stockers?
Nothing wrong with 4 valve heads. Might be Krauser or Luftmeister heads, or something totally different. Looks like a good design to me.
Two words: all custom.
Who said that's an "S"? Not anymore. Anyway- it's got the wrong rocker covers for an "S".
Am I to believe he put a spark plug in the middle? Is that even possible?
Why not just do a dual plug get-up? And if that IS an "S", it seems dumb to ruin a useless but never-the-less valuable lump when you could have found a normal 500 for cheap. I mean, the "S" was a little faster, but faster than what? A 12yo on a Schwinn Sting Ray?
That's an amazing piece of work- custom heads, crank, rods, and pistons to make a higher revving motor with a modern 4-valve head design. Low domed pistons, narrow included valve angle, centralized plug.... I'd love to see a dyno chart on his final tuning results. This could be a 70 HP mill or better.
It is a lovely machine with all kinds of fancy machining.
I am wondering at the wisdom of the square slots ventilating the clutch area. This is not the first old BMW race bike where I have seen this, I just wonder why.
How do you install the roller bearing crankshaft into the case with the rods already installed?
No matter which HP rating you're using, an increase to 70HP is a stretch for that engine which is ~500cc and has just those mods. My comment here in no way pans the devotion they've placed in their design. The doubling of horsepower on 55-69 BMW twin engines is serious biz.
Very nice work!
Its called an R50S but the bore and stroke work out to 896cc. If true I think he may well get much more than 70 hp.
I must be missing where the bore and stroke increase on that engine is 896cc. From the pics it does not seem like the geometry and positional placement of the cylinder to engine case interface has been modified to have an increased bore to make it just south of a liter engine.
The site has this: Bohrung 70mm Hub 64mm 500ccm. Visually the pistons look like a large bore and w/ a shorter stroke. So is it a 1/2 liter or 1 liter engine? Time for an e-mail to the builder.
Using the translator built in to Firefox, the first page of the site lists the bore as 64mm and stroke as 70mm (64*700= 448cc per side). Maybe something lost in the translation? Bill.
That's how "/2" engines are assembled. The crank and rods go into the crankshaft tunnel, then the assembly gets rotated onto its back, then finally goes vertical to drop through the rear bearing counter bore. Just to add pleasure to the job, the case has to be hot enough for the rear bearing to drop in.
Thanks Wrench! I could not see how they would fit. I've never seen a /2 motor up close, I will need to fix that!
I'll tell ya what's wrong with those pictures.............
they weren't taken in MY garage!
That thing is sweet.