Larger engine in Kat...1127 overbored to 1350?

[KatBusa]

I just bought a 1992 GSXF1100 katana motor 1127cc, the engine I.D. # is V706-110345.

I am very serious and interested in getting as much out of the motor performance-wise, without actually turning it into a dragbike(would like to keep it a good street bike).

I am putting this engine in a 2004 katana 750 frame. According to the sticky I read, It should be possible right?

I would like to know what big bore kits are out there that would work for me. I would like to overbore it to 1350cc, is that even possible?
Just give me your recommendations. I am also interested in performance camshafts,
valves, pump, etc., the WHOLE NINE YARDS!!

[KatBusa]

I do not have the wiring harness or the carbs for it, i will be need them as well, but I figured that boring it to a much large size, would probably mean the stock carbs wouldn't be used anyways, even if they were rejetted...(assuming), but I think I can get some real good aftermarket ones that would be better. Any recommendations on that?

And as for the harness, I guess that has to be the stock one, and so far I've come up empty handed on ebay and 2 other sites for it. Not to mention I check temacula sports a suzuki dealership and they dont list it as available anymore. HELP me....on the harness please!!!!!!!

[The CyberPoet]

(A) Visit wiseco.com to see what overbore kits are available for that engine. There should be several. Look at the compression ratios as well -- more compression = more top end HP, less compression but more displacement = more bottom end torque.

(B) Use the wiring harness from your existing engine and search the forum for how to make it work.

(C) The stock carbs will work if rejetted (and work well if they can be jetted to match, since smaller carbs=higher velocity air-fuel mix going into the cylinders), but if you are looking upgrade for pure performance, look for flat-slide carbs. They're not as reliable as CV carbs during altitude changes (tweaking required if you change 3000 feet of altitude with CV carbs), but they are the top of the heap in performance carbs and standard in racing applications.

Cheers,
=-= The CyberPoet

[Waltari]

The largest overbore you can go on stock liners is 1216cc which will give you about a 12:1 compresson ratio. Some people use stock hayabusa pistons (also 81mm and slightly shorter) as opposed to aftermarket 81mm pistons as the busa piston will drop your compression ration slightly (better if you want to run a turbo).

Everything above a 1216 you'll need to resleeve and honestly, once you start to go that large your getting into the range where it will be less and less streetable. I may be wrong but you may need a different block to go as large as a 1340cc.

How much HP are you looking to gain really? With a stock motor, jetting, and exhaust you can get into the 115-120hp range. Add gsxr cams and add a few more HP. I've seen B12 motors with a 1216 overbore, gsxr cams, porting, jetted cabrs, and exhaust work putting out around 160hp. Do a 1216 with busa pistons, the above mentioned work and a urbo and you're over 200hp.

Then comes the question...do you need that much power in a katana and can it handle that much power? If you're just looking for a 1300cc sport touring bike, why not just buy a busa?

[loudnlow7484]

http://www.oldskoolsuzuki.info/patrick/articles/supertune/st1100.htm

Apparently an article asking several shops about upgrading the different models of GSXR1100. It's from the UK, I believe. Some informative stuff, as well as some rough HP numbers with the mods.

[Mojoe]

Like Waltari said, you will definately need to re-sleeve if you go that big. personally, I thought you could go as high as 1250 before doing this, but I could be wrong. and if you do re-sleeve and go that big (over 1250), it also requires the block being bored as well.

I have an 1127 engine that was built by Vance & Hines racing. It is supposed to have roughly 200hp, but I can not confirm this because it is still dismantled. I can not give you exact specs on what it has because all the documents are at the shop and I haven't looked at them in a while, but it is bored out to 1216 I believe. It has competition racing cams, oversized valves (a must if you want to really tap into the resources from bigger bores), undercut tranny, completely polished and ported, and the head has been planed. it also has a dyna2000 ingnition and dyna racing coils. the hp it is stated to have was with 41mm lectrons, but I only have 40mm mikuni flatslides for now.
according to the bills...labor, parts..etc, etc....this engine costs in excess of $10k US to build. If you really want to re-work an 1127 to gain this much hp, expect to pay close to that if you do not do at least 50% of the work yourself. a piston kit is cheap....anywhere from $250-400. however, getting them into the engine can cost you another $2k if you just haul the engine off to a shop and tell them to install them.
you would be better off just buying my engine.
(just kidding....it aint for sale...YET).

[KatBusa]

BIG cc ENGINES in KATs

I want to thank all of yall for the informative responses. Right now I am torn between getting a b12 instead, or spending A LOT of $ to get what I want out of an 1127. The strange thing is the bandit 1200 actually is an 1157cc motor. You wouldn't think that extra 300 cc would be all that big of a deal, but it is set up completely different and from what I've been told it had a great deal more at the midrange than the 1127, so the potential for more high end is there, since you have a little more mid to sacrifice and still be alright.

So for now, I am just glad to hear from all of you and your personal experiences. Oh and thanks for posting the newsletter, it kinda lays it all out.

Please keep this thread going. I think big or overboreing these large cc engines is very interesting, yet tricky!

[KatBusa]

MISTAKE

meant to say 30cc instead of 300 on last reply. this was a typo!

[Mojoe]

I don't know much about the B12 engine, but the 1127 oil/air cooled is one of the most popular engines out there for tweaking and tuning. and the reason i suggest going with the 1127 is the availability of parts....used and new. sites like www.stripbike.com and www.dragbike.com always have parts for the 1127 in the used classifieds. it is the cheapest way to go with the same results in the end.

[KatBusa]

how available are parts for the bandit? I wouldn't assume too hard since it is still in production right? Although I dont think they made one in 2006. But with it being more recent wouldnt parts still be available?

[Mojoe]

how available are parts for the bandit? I wouldn't assume too hard since it is still in production right? Although I dont think they made one in 2006. But with it being more recent wouldnt parts still be available?

I imagine new parts OEM are plentiful, but have no idea on aftermarket parts. the thing with the 1127 is that it is one of suzuki's most popular engines for modifying. you might have to search around on some other forums to get a good answer to your question. is the B12 a popular engine to modify? do they use them for drags? it all boils down to "supply and demand". you might be able to get aftermarket parts such as cranks, cams, valves...etc, etc, for the B12, but they might cost more because the demand is lower.

[KatBusa]

makes sense to me, I appreciate the tip!

[The CyberPoet]

I have a tuning & mod guide from Yoshi on my website that applies to the old oil-air cooled engines (86-88?). Might be worth a read for some of you -- talks about cam timing, ignition advance, valve mods, carb settings for different types of racing, etc.

http://www.motorcycleanchor.com/kata...hop_up_kit.pdf

One of our members was nice enough to send it over to me so I could host it. Enjoy...

Cheers,
=-= The CyberPoet

[KatBusa]

OK..I THINK I MADE MY MID UP! I want the bb12 engine instead of the 1127. Even though parts maybe harder to come by, and even the engine for that. But I think StevieB has one for me LOL!

[DooD]

Keep in mind that if you DO decide to go for the B-12, that you'll be dealing with a torque motor, and a 5 speed. It's not for everyone - a lot of people are used to the newer style of I4 that is meant to rev high and build power - the B-12 just plain out has it, though peak numbers may be somewhat more limited.

On my Holeshot build, I'm looking at about 135-140WHP, and about 90-95WTQ....and that was a VERY expensive build. I have pretty much every option Holeshot offers, aside from the stage 1 cams - I just went with the Gix intake cam....It's not cheap - jets, filters, piston kit, exhaust, gaskets/etc, advancer, cam.....it adds up fast! Not to mention the porting, teardown and build time....

All things aside, if you WANT a built motor, both the 1127 and 1157 are going to cost a TON of cash. Also, with the 1157, you MUST note that you could end up getting a motor that has the oil consumption/piston problem and run into problems there. That will only cost you more money and time. I don't know anything about the '27, so I can't really say anything about it.