Most HP a KR has shown on a dyno?
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Most HP a KR has shown on a dyno?
As topic title suggests.
I would be of the opinion that a disc valve non-pv engine would be able to see 55-60RWHP. Has anyone tried to develop the engine/ignition? Has anyone ever stuck RGV carbs on a KR?
Just wondering
I would be of the opinion that a disc valve non-pv engine would be able to see 55-60RWHP. Has anyone tried to develop the engine/ignition? Has anyone ever stuck RGV carbs on a KR?
Just wondering
crochet & croquet
- the KR kid
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- ScottaKR
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The RGV carb conversion is a bit tricky (got a pair sitting in the shed), as the manifolds curve about 90deg meaning a custom adaptor setup would need to be made which is out of my budget atm .
The main problem for us Tandem owners is the lack of replacement pistons available. I recently purchased a pair of KMX125 pistons @ 2mm o/s (dimentions match nicely), only to find they are massively heavier than the KR item, so I'm loath to use them as I'll have to rebuild/balance the cranks so it dosn't shake itself to death (would rather use RG150 slugs and bore it to 300cc, but need longer rods).
I remember someone saying that increaseing the disc valve opening duration has shown good results on a standard motor, but don't think anyone has bothered to dyno test this.
The main problem for us Tandem owners is the lack of replacement pistons available. I recently purchased a pair of KMX125 pistons @ 2mm o/s (dimentions match nicely), only to find they are massively heavier than the KR item, so I'm loath to use them as I'll have to rebuild/balance the cranks so it dosn't shake itself to death (would rather use RG150 slugs and bore it to 300cc, but need longer rods).
I remember someone saying that increaseing the disc valve opening duration has shown good results on a standard motor, but don't think anyone has bothered to dyno test this.
KR250 Tandem Twin (Naked)
KR1 Red/White
KR1S Track Bike (has been put on hold for now)
ZXR750 H1 (Winter project)
KR1 Red/White
KR1S Track Bike (has been put on hold for now)
ZXR750 H1 (Winter project)
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You want to make an omlette you have to break some eggs.
A KMX isn't a performance engine stands to reason it wouldn't have a performance piston.
Problem seems to be the 25mm comp height of the piston, making it a prime candidate for a rod/and piston swap to something that can handle some HP(YZ,KX,TZ or Cagiva Mito SP). Does anyone know the standard rod length? Is it the same rod as the KR-1? 106mm centre to centre???
If the standard disc lokks like it has less than 180 deg of duration it needs all the help it can get. For some boogie around the 200-210 deg is needed.
So I suppose the answer is nobody has had a serious attempt at tuning one?
Hopfuly have a set of cylinders her to look at shortly
A KMX isn't a performance engine stands to reason it wouldn't have a performance piston.
Problem seems to be the 25mm comp height of the piston, making it a prime candidate for a rod/and piston swap to something that can handle some HP(YZ,KX,TZ or Cagiva Mito SP). Does anyone know the standard rod length? Is it the same rod as the KR-1? 106mm centre to centre???
If the standard disc lokks like it has less than 180 deg of duration it needs all the help it can get. For some boogie around the 200-210 deg is needed.
So I suppose the answer is nobody has had a serious attempt at tuning one?
Hopfuly have a set of cylinders her to look at shortly
crochet & croquet
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Yes. *ASSUMING* the stock rod is 106mm centre to centre.There is 2 readily available and cheap options
RD 350 110mm rod with a TZ 4DP piston.
110 + 8(half of the gudgeon)+20.5(compression height)=138.5mm installed height
or
RD 400 115mm rod with cagiva Mito SP piston
115+8+17=140mm
v's
Stock
106* +8+ 25=139mm
If it were me the 115mm+SP piston is the ideal as this is very similar to what an Aprilia GP bike runs.
RD 350 110mm rod with a TZ 4DP piston.
110 + 8(half of the gudgeon)+20.5(compression height)=138.5mm installed height
or
RD 400 115mm rod with cagiva Mito SP piston
115+8+17=140mm
v's
Stock
106* +8+ 25=139mm
If it were me the 115mm+SP piston is the ideal as this is very similar to what an Aprilia GP bike runs.
crochet & croquet
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There have been a few raced but no-one's ever been forthcoming with what they've done to them or what the results where. And I have asked.TwoStroke Institute wrote:So I suppose the answer is nobody has had a serious attempt at tuning one?
Kawasaki issued their own KR tuning manual (in Japanese) but I've never been able to get a hold of a copy.
Looking forward to seeing how you get on. =D>
Kawasaki KR250 Tandem Twin (x4) & KS-II 80,
Yamaha RD350LC,
Suzuki GSX-R750RK & RB50 Gag.
Yamaha RD350LC,
Suzuki GSX-R750RK & RB50 Gag.
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I suppose you would know Stroker boy has anyone put a KR engine into a more 'ahhem' modern frame?
I have been playing with a ROTAX 256 engine recently and seeing some very good results (lets say a number above 74HP and below 80HP) and think there is MASSIVE potential in this engine.
Running it as a 'twingle' seem to be the go, and even with 28 or 34-6mm carbs should see mid 60's HP, probably to much for the frame to cope with.
I have been playing with a ROTAX 256 engine recently and seeing some very good results (lets say a number above 74HP and below 80HP) and think there is MASSIVE potential in this engine.
Running it as a 'twingle' seem to be the go, and even with 28 or 34-6mm carbs should see mid 60's HP, probably to much for the frame to cope with.
crochet & croquet
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Like this one below ?TwoStroke Institute wrote:Stroker boy has anyone put a KR engine into a more 'ahhem' modern frame?
Not really heard of any. Bloke I bought my rolling-chassis off kept the engine with a view to putting it in a Spondon chassis (one designed for a Rotax tandem-twin) but as far as I know he never got round to it.
Kawasaki KR250 Tandem Twin (x4) & KS-II 80,
Yamaha RD350LC,
Suzuki GSX-R750RK & RB50 Gag.
Yamaha RD350LC,
Suzuki GSX-R750RK & RB50 Gag.
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After cracking open a few covers I found some odd ball things, a second dummy flywheel, a dampened primary, ah yes the crank dampers and reed valves.
Positives are think a dry clutch would be do-able, well made engine and globs of potential.
Wishlist would be a cylinder with stud spacing similar and a powervalve.
Is that back lash in the primary normal?
Positives are think a dry clutch would be do-able, well made engine and globs of potential.
Wishlist would be a cylinder with stud spacing similar and a powervalve.
Is that back lash in the primary normal?
crochet & croquet