That is also my understanding, although most of the press announcements did mention the gasket as one of the different parts, and so I would like to have a final answer, which means parts manualsMy understanding is the head gaskets are the same and the crank cases are different suggesting there is more material in the H2R. I assume ( ass u me ) the compression ratio is lower on the H2R. Our H2 do develop more torque at low rpm that backs this up. This means that the H2 can never be full blown H2R spec. The only way forward is variable compression which means a 300cc could rev to 18k and be tractable for road use. I'm quite happy that this bike is RIDICULOUS as it is and does have the scope to give a reliable 250 -275 which apart from drag racing applications REALLY IS ENOUGH.
Makes sense on two levels, firstly as you have stated the valve piston clearance. Secondly the lower compression ratio to allow more boost. By telling us this was achieved by a different head gasket suggests a bit of naughtiness on the part of Kawasaki , problem is what they have given is so rude anyway.I have posted it before but this is DIRECT from Kawasaki's dealer site.
On the note of the head gaskets I had a thought today, the crank, pistons, rods head, gasket are all the same. The crankcases are not, I wonder if they had to raise the deck height to accommodate the larger camshafts to give a little more room for piston to valve clearance.
Below is a screen shot of the k-dealer site with the part numbers and what bike the gasket fits.
Thank you Garth! This settles it once and for all.I have posted it before but this is DIRECT from Kawasaki's dealer site.
On the note of the head gaskets I had a thought today, the crank, pistons, rods head, gasket are all the same. The crankcases are not, I wonder if they had to raise the deck height to accommodate the larger camshafts to give a little more room for piston to valve clearance.
Below is a screen shot of the k-dealer site with the part numbers and what bike the gasket fits.
Indeed, and in this case I have to admit I am rather annoyed that this is the case. They paraded the two engines to be identical but for very few parts, upgraded to handle the increased performance, but the crankcase is no small part, and it certainly was not what has been communicated to people, including the press.The difference in compression ratios between the two designs is very small. The R is 8.3:1 and the H2 is 8.5. From a performance standpoint it will not limit either engine. There are plenty of blown gas motors that run fine at 20 or 30 psi at 9 or 10:1 compression, so either bike's compression is not a limiting factor. I doubt if valve clearances are that close either, as I routinely find huge piston-valve clearances on stock bikes and I seriously doubt this will be any different. The R does have different cam specs with much more duration and probably more lift, but is easy enough to check if anyone decides to try R cams in their H2. I am still puzzled why they would use different crankcases when they could have just used a thicker head gasket or bigger valve pockets, there must be some other design difference in the cases besides just the deck height.
The h2 and h2r have all the same rotating components like valve and springs and crank rods and piatons... The h2 and h2r does not have a base gasket as the cases are a "top case" configuration...So can the H2 rev up to 14,000 safely with the higher compression, and make a considerable amount of top end horsepower? If not, can we measure the deck highth's and make up the difference on the H2's cylinder base gasket?
yes they have the same screens - they look like they are flame arrestors though.Garth or anyone else , does the H2R have the velocity stack screens ?
mesh and airflow usually are not in the same sentence and i expect its only on the H2 for economy
Garth what are the cost differences between the 2 cases H2 and H2R. We know what the cam prices are, and head gaskets. To me the cases is the big question mark. I think the differences are for the extra clutch parts. Side by side will tell.
Clutch baskets are the same inner and outer and pressure plate. Its all in the clutch plate stack, they have more plates to handle the power most likely as well as stiffer springs.Garth what are the cost differences between the 2 cases H2 and H2R. We know what the cam prices are, and head gaskets. To me the cases is the big question mark. I think the differences are for the extra clutch parts. Side by side will tell.
In looking at the H2 parts diagram, it is not difficult to put together a clutch stack with an extra plate. Various thickness options.Clutch baskets are the same inner and outer and pressure plate. Its all in the clutch plate stack, they have more plates to handle the power most likely as well as stiffer springs.
I wouldn't worry to much about the clutches though as you can increase spring pressure if needed.
In looking at the H2 parts diagram, it is not difficult to put together a clutch stack with an extra plate. Various thickness options.
Is it confirmed that the springs are a different PN? Is the slipper mechanism the same? Sorry, not trying to make this your full-time job, but appreciate the help.
Do you have access to the stack height info? I saw different thickness steels on the H2 fiche...some options.The clutch springs are same part number, same goes with the slipper mech.
The fibers are what seem to be "special" to the H2R the steels actually are the same part number for ninja 250/300's lol....
I'd shim the stock springs and see how it goes before trying to add plates. but that just me! I'm sur the extra plate will help with clutch life?