Idle late night musing: Sensible, streetable engine mods?

[morthrane]

If money was a minor barrier to buildling a streetable* hot GS11xx motor, and you had the ridiculous motivation to build it up instead of buying a hayabusa, what would you do?

For example...

Displacement: How big can you go before heat becomes a possibly deadily issue on hot days? Just under 1200cc? 1260? Big block stuff? Balance and weld the crank if it hasn't been done?

Everything else-- cams. What kind of valves and work done to the valvetrain and head. Top end oiler, oil cooler? What kind of ignition, coils, etc.? What bore size carbuerators?

Worst question of the night: how about mildly turbocharging the engine? Too much?


Just to clarify, I don't see myself having such money anytime soon... but it really doesn't hurt to sorta plan ahead in case you see an amazing deal-of-a-lifetime part that can fit the grand plan, right?


















*streetable defined: possibly cold blooded but easy enough to start; runs on 91 octane or under; quirky is ok, but tempermental is not; won't crap itself sitting at stop lights and slowly lane splitting... at least for 15-20min.
You get the idea-- a reliable runner, not just a strip queen or show bike.

[Dink]

Haha to easy!!
best capacity is 1166cc, just bore the stock block out, cheap too only need ot buy the piston kit, they even supply most of the gaskets.
Rejet to suit, maybe de- restrict the intake side; I recoomend removing the stock air cleaner box and replacing it with a single pod filter, dial in th estock cams, or fit 1150 cams. Suzuki were notorious for the stock cam timing being out and sometimes by a large margin.
Dyna has always been considered the best option for ignition, I dont think it is worth it unless your stock setup has problems.
An oil cooler and/or a topend oiler kit is also not necessary but is a good idea.
The clutch hub is always worth an upgrade, at least have the springs in the back changed and it re-rivetted together to take the rattle out.
It is easy to pour cubic dollars into any motor, but is often unnecessary, unless you are after a specific target i.e. 1/4 mile times.
this would give an extremely strong streetable motor without over streesing anything that would then require the cubic dollar approach to keep it all together.
Dink

[robinjo]

Haha to easy!!
best capacity is 1166cc, just bore the stock block out, cheap too only need ot buy the piston kit, they even supply most of the gaskets.
Rejet to suit, maybe de- restrict the intake side; I recoomend removing the stock air cleaner box and replacing it with a single pod filter, dial in th estock cams, or fit 1150 cams. Suzuki were notorious for the stock cam timing being out and sometimes by a large margin.
Dyna has always been considered the best option for ignition, I dont think it is worth it unless your stock setup has problems.
An oil cooler and/or a topend oiler kit is also not necessary but is a good idea.
The clutch hub is always worth an upgrade, at least have the springs in the back changed and it re-rivetted together to take the rattle out.
It is easy to pour cubic dollars into any motor, but is often unnecessary, unless you are after a specific target i.e. 1/4 mile times.
this would give an extremely strong streetable motor without over streesing anything that would then require the cubic dollar approach to keep it all together.
Dink

I like it when you talk sexy Dink =P~ :mrgreen:

My plan for the future is to find a 1150 engine, do some mods (1230 kit) and put that in and saving the stock motor.

[lecroy]

I used to run a Mr. Turbo on my 1100 street bike back in the mid 80s. No real problems. Lot's of power.

I think I would buy the Hayabusa, put a turbo on it and forget the old GS!

[morthrane]

I used to run a Mr. Turbo on my 1100 street bike back in the mid 80s. No real problems. Lot's of power.

I think I would buy the Hayabusa, put a turbo on it and forget the old GS!

Yes, but a Hayabusa isn't as cool as having a dinosaur of a bike :twisted:

Perhaps I should commit the ultimate heresy and source a 'busa motor and put it in the (braced and gusseted) Katana frame... hrm. 8)

[robinjo]

I used to run a Mr. Turbo on my 1100 street bike back in the mid 80s. No real problems. Lot's of power.

I think I would buy the Hayabusa, put a turbo on it and forget the old GS!

Yes, but a Hayabusa isn't as cool as having a dinosaur of a bike :twisted:

Perhaps I should commit the ultimate heresy and source a 'busa motor and put it in the (braced and gusseted) Katana frame... hrm. 8)

If you do that I will have to come and flog you personally! [-X

[lecroy]

Yes, but a Hayabusa isn't as cool as having a dinosaur of a bike :twisted:

The dinosaurs gave way to evolution and are now extinct. They were big and slow, just like the old GS bikes when compared with a modern sport bike.

[robinjo]

Yes, but a Hayabusa isn't as cool as having a dinosaur of a bike :twisted:

The dinosaurs gave way to evolution and are now extinct. They were big and slow, just like the old GS bikes when compared with a modern sport bike.

The point of your reply being?

[Anonymous]

The dinosaurs gave way to evolution and are now extinct. They were big and slow, just like the old GS bikes when compared with a modern sport bike.

I'd say that jake and a few others would totally disagree with that statement. [-X

[lhanscom]

Check out my site, it has a list of mods, and IMHO is pretty much the perfect bike. I may be biased?

http://www.ctel.net/~lhanscom/gs1150.htm

[oldschoolGS]

Sometimes less is better. Unless you are going to carry around an ample supply of 100+ octane fuel, 10.5-1 compression for a year round, street ridden bike is about max. My experience has been that any higher than this on a motor with a combustion chamber designed for the GS standard compression ratio of 9.5-1 is not pratical for street riding. Heat and detonation will be a problem, only severe retarding of timing (this defeats the purpose) or high octane race fuel will cure this. Look at the early 80's Suzuki GS endurance racers, they used fairly mild engine mods to increase performance but prevent the motor from becoming a hand grenade. A good starting point is an aftermarket intake and exhaust system with a set of mild drop-in cams. This will greatly increase performance with out turning the bike into a trailer queen. Good Luck, Ed.
1983 GS750ED
2001 TL1000S

[RacingJake]

Did someone lite the night sky with the beacon again.

New tech is great but being raised in the 60's I still like doing it the old fashion way without a laptop. Electrons should only go to the sparkplugs but I think lecroy may have other ideals \/ Give me a old 302 or 351 with a carb and I can have fun all day long just like the old GS. Keep it simply and you can fix it anytime, nowdays you need to plug it in just to get the fault codes.

With just a few minor mods a Busa can run high 8.90's and the GSXR 1000 9.10's and were talking no bars here. Just check out Super Streebike mag. But my bike is bought and paided for, so I dance with the bike that brought me to the track.

But my next new bike will be a Busa in the next few years.

[lecroy]

An example of an old relic.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=2479924833&category=6027

I like the looks of it.

I'd say that jake and a few others would totally disagree with that statement.

With just a few minor mods a Busa can run high 8.90's and the GSXR 1000 9.10's and were talking no bars here. Just check out Super Streebike mag. But my bike is bought and paided for, so I dance with the bike that brought me to the dance.

Jake has spoken. I agree, the old bikes can be bought cheap and are a lot of fun. There just slow.

[cbxchris]

Got to disagree about slow. My last year of competition I had a GS based turbo/nitrous funny bike that ran mid 4`s in the 1/8 at around 152 to 155. In the quarter high 190`s were common with low 7`s. I have had several hayabusa`s....I sold them. They have no soul. These old GS`s are still the sh*t. I can ride sitting up where my back doesn`t kill me. I can take the top end off without a pain in the as*. I can degree the cams without wanting to commit suicide....PLUS it has rockers....NO underbucket SHIMS!!!! Ah don`t get me wrong the hayabusa is a heck of a bike. I`ll get another one day ...maybe soon but this summer I`ve decided just to have fun on my classic`s..the GS and cbx. As for the ultimate street bike engine. I would base it off the 1150 engine. I would do the normal ignition upgrades. In the bottom end I would do the hub,weld the crankshaft,undercut the tranny,turn the oil pickup around and modify the cases to remove the forks through the oil pan area. On the top end I would tke a stock 1150 cylinder and put in liners for a 1325cc and bore it to 1230 or 1260 with J&E pistons set to around 170 pounds of cylinder pressure(probably around a 11 to 1) Any more and you`re going to knock.. I would use a billet cam chain tensioner. I would also o ring the cylinders and have the block milled for gsxr o rings to go around the studs. Ape studs in cases and cylinders. I would not use a external oiling kit nor 750 gears. On the head I would go 1mm over on both sides on the valves. I would use pm springs and retainers with long adjusters. I like megacycle cams but webs are OK also. Around a 355 lift would be max for good street life...maybe even a touch smaller cam. You would need adjustabe cam sprockets. Good port work would be a must. Carbs would be buyers choice. I like kiehns and mikunis. No bigger than 38 mm max. Heck I`ve forgot a lot. Bigger oil cooler off a gsxr,billet output shaft,hard weld rockers.....good way to spend several K. Be fun but I wouldn`t do another GS engine. I just like to ride and not work on them anymore.

[oldschoolGS]

Thats a pretty mean looking ride. The old bikes do have charactor and class and are very easy to work on. My 2001 TL1000S is a perfect example of modern tech. at its best or worst. 15 years ago who would have thought of a 400lb. V-twin bike making 100+ hp with a 10,000 rpm redline. The only problem is it is a nightmare to work on. The small front fairing is actually about 8 different pieces that all fit together in a certain way. To get to the front plug, the radiator must be pivoted out of the way. Valve adjustments- anyone heard of shim under bucket? By now you get the picture. It is like the difference between a 1967 427ci Corvette and a 2004 C6 Corvette. Both make 400 hp. but in very different ways. Me, I will take the 67' any day of the week. Ride On, Ed.