7-11 swap, 8v 750 vs 16v vs gs1100e - Rickman CR900

[GregT]

I'm sure custom sleeves are available. Until you pop a sleeve out of the 650 block you won't know what you're looking at in terms of how much meat is around the sleeves.
Close flanges...I've just swapped a couple of sleeves in a ZXR400 Kawasaki, they are so close std that they have flats on the sleeve flanges to fit alongside each other...
It's all do-able, but until you pop a 650 sleeve out, you won't know really how involved it is. Oh, and the OD of the protruding piece of sleeve is usually less than the portion in the casting.

[Chuck78]

When I get some down time in January, I'm going to have to pull the head off the 550 on the shelf (673cc candidate for wife's ) & compare the combustion chambers side by side to my collection of 750 heads... if slightly smaller, maybe a stock 750 piston with deeper valve recesses machined would be sufficient... but at 741cc, it wouldn't have much of an edge over a 673cc gs650 top end with its more advanced closed chamber raised port head and piston design. A CP custom piston set for 789cc on the gs650 head would be by far the ultimate... but $1000+

[Chuck78]

I may pry at Wiseco this winter and see if they still have any records or CAD drawings of their old 741cc GS650 65mm big bore pistons, as the closed chamber 650 head would be the most efficient and highest horsepower for sure, although similar horsepower and more torque could definitely be achieved with the 789cc hemi head and 798cc GS750 NOS aftermarket pistons, but not the combustion efficiency/fuel economy that the 741cc GS650 Wiseco pistons could give.

The Rickman tank has a fuel tap on each side. I need to see if one is a reserve, or if it is truly a dual feed setup (considering the performance nature of the Rickman's). The Keihin CR31 smoothbores on my buddy's 1132cc KZ1000 has dual fuel inlets between carbs 1&2 and the 2nd between carbs 3&4, so the CR setup definitely hits a home run there. The only doubts I have are the application vs venturi size. The Mikuni BS32cv carb heads have much larger intake ports than the tiny vm22 gs550 heads. the GS750 VM26 engine has smaller intake ports than the 550 BS32 head (80+). Am I okay running a CR31 on the BS32 GS550 head, or will this only be good for higher rpm's and potentially kill my crisp low end response?
If running a CR26 or CR29, will the adapter stepping down from a 26mm/29mm carb venturi and adapter have negative impacts on the performance and throttle response when it dumps into a larger intake port made for BS32's?????? Will either scenario (or both), be it CR31's or the smaller CR's, make it so that I would have to roll the throttle on more gently than I would a VM22 GS550 or a VM26 GS750???

[Chuck78]

Wiseco GS550-650 740cc pistons - FYI

I may pry at Wiseco this winter and see if they still have any records or CAD drawings of their old 741cc GS650 65mm big bore pistons, as the closed chamber 650 head would be the most efficient and highest horsepower for sure, although similar horsepower and more torque could definitely be achieved with the 789cc hemi head and 798cc GS750 NOS aftermarket pistons, but not the combustion efficiency/fuel economy that the 741cc GS650 Wiseco pistons could give.

FYI Wiseco said will gladly make a new run of GS650-740cc pistons based on their old designs from the 1980's Wiseco K740 kit they offered, but they have a minimum run of 12 pistons at $125/each piston w/pin/clips/rings. 25+ pistons manufactured and they can be had for as low as $95/each piston. There is a group purchase thread going on elsewhere in this forum stated by Ace07 I believe his username is. This is quite possibly the best combination of GS's to build for best all around good handling corner burning twisties machine with a great amount of power in a rigid lightweight chassis with a 2" narrower and 35lb lighter engine than the GS750/1000/1100.
The exhaust ports didn't really align well with the Rickman frame like the GS750/1000 ports did, so this was unfortunately not the likely candidate to swap into the Rickman for me, but I hope to be building one of these for my wife's GS550 with 650 cylinders and head this year soon.