Considering Big Bore on the 1100E to an 1166

[Guyver]

I also posted this in GS Discussion. Just in case anyone hits here, where it is more applicable I thought I'd post here too. I'm seriously considering installing a Big Bore kit in my bike. It's used with the block and Wiseco 1166 Hi-Comp pistons for $400.00. It seems to be a decent deal given that the piston kit alone is $421.00. I'm not sure how much it would run to have my block bored out and this way I can always swap back if I want to. Anyone here have an 1166 kit installed? How is the power increase? Would it combo up with my RS36 Flat Slides well or would I need to go up to RS38 or even RS40 carbs? With this small of an increase in displacement I think the strength of the block would still be nearly as strong and the bike would remain streetable. I would just love to twist that throttle and feel all that power still on tap and then twist some more and Shazam!

[rosco15]

That 1166 is a nice upgrade. Works well with 36 flat slides. I don't think you would want the hi-compression kit for street use. Maybe better to hold out for a low compression kit.

[Boozy Creek Beast]

I but an 1166 Kit on my 80 1100 E. I went with the 10:25 comression since I am not planning to race it. It has been some of the best money I have spent so far. Before doing the upgrade my bike had over 60K+ on it and the up grade made such a differance in my tired engine that even though it cost me upwards of $600.00 to $700.00 dollars I can't think of a better way to bring my bike back to life. I was lucky and found a retired mechanist that bored my head for $100.00. The top end speed of my beast did not go up much but getting to top end speed sure did. With that much torque I go through a rear tire a year. I use a soft tire for grip which dose not help the issue but again with that much torque I prefer staying on the road reather than sliding across it.

The Beast

[80gs1100]

I too installed a big bore kit on my 1100, only it was the 1133 kit. Looking back on the whole thing makes me wish I would have just bought another bike that was already faster. It will end up costing much more than just the cost of the kit itself. Your looking at atleast $100.00 to get the block bored and honed, new gaskets, larger studs, while your at it change the cam chain and guide, you might as well have some porting work done, and higher lift cams. This alone on a twenty plus year old bike is pretty much just maintenance. And as anyone will tell you, it's not cheap to build these motors, especially if your on a budget. I hate to be pessimistic about the whole thing because I love my old gs and all, but it ends up costing a lot more than you might think.

[RacingJake]

Well if it's a street bike you could just retard the intake cam one tooth. That will drop the compression... say40- 50 psi. Maybe end up with all 4 cylinders at 170psi to boot?????????????

[rapidray]

Why not just get a stock 1150 cylinder & bore it the SAME 3 mil over & get a 1229 instead?!!! The cylinder drops right on & I can get you 18 mil pin 1229 pistons made for it. I just finished one of these for KATANAGREG & even put GSXR cams in it. Ray.

[RacingJake]

That sounds good too, I think for my Birthday I'll get some of those gixxer cams for my mutant rat bike.

[rosco15]

There is a low compression 1166 kit on ebay right now. low compression, pistons and block. Used

http://cgi.ebay.com/ebaymotors/Wiseco-Big-Bore-Kit-wth-Block-GS1100-Dragbike-GS-1100_W0QQcmdZViewItemQQcategoryZ35595QQihZ003QQitemZ130107144833QQrdZ1

[Hap Call]

I've been running an 1166 kit with 10.25 CR for several years and really like it. I have the old style 33mm Mikuni smoothbores and run a little on the rich side due to the higher compression ratio. I've been very happy with it. Total cost was about $450 which was a lot less than a new bike.

The 1150 cylinders will not always "bolt on". You will need to clearence the cases for the larger outer diameters of the cylinder sleeves.

Hap

[pano]

My planned 1166 mod has morphed into a 1260 mod. One way or the other I plan to make the commitment and have the machining done this winter.

I have a street ported 1150 head and RS36flatslides to put on it. The 1150 head came off a well built 1229 bored bike so I figure the 1260 will be the better match.

Either way I will be watching your build.

[rapidray]

I've been running an 1166 kit with 10.25 CR for several years and really like it. I have the old style 33mm Mikuni smoothbores and run a little on the rich side due to the higher compression ratio. I've been very happy with it. Total cost was about $450 which was a lot less than a new bike.

The 1150 cylinders will not always "bolt on". You will need to clearence the cases for the larger outer diameters of the cylinder sleeves.

Hap

Sorry to argue Hap but I have NEVER found a set of 1100 cases that the 1150 stock sleeves didn't go right onto. I am an actual engine builder who builds & races GSs. Ray.

[Hap Call]

http://www.thegsresources.com/_forum/showthread.php?t=72686&highlight=1100+CASES+1150

[Guyver]

Thanks to all the read and read and responded to the thread.

That 1166 is a nice upgrade. Works well with 36 flat slides. I don't think you would want the hi-compression kit for street use. Maybe better to hold out for a low compression kit.

I appreciate all of the feedback everyone had to offer. The used kit on Ebay is the one I was considering. Instead I think I'm going to go with an 1150 head for now and consider upping the block later on. Any comments, thoughts or suggestions?

[rosco15]

The pistons would get you about 15 HP. I have dyno charts on that. With 1150 head, drop in cams, you may get about 20 HP. No dyno chart on that, but I'm going off my MPH gains in the 1/4. Seems the pistons would be the cheaper way to go for close to the same gain. By the time you buy a head, do a valve job, buy cams, new springs, porting. You could put some big money into that head for only a couple more HP.

My thought would be more bang for the buck with pistons. Especially if you can get a good set used. Just my thoghts.

[Guyver]

My thanks again

Thanks Ryan and to everyone else. Ryan that is one sweet dragbike you have there. The engine is enough to make you start drooling.