How much can a non welded crank take? If any?

[gorbys]

just curious about a stock gsx1100sz engine and a turbo. I've heard they break easily

[Blower1]

Unwelded cranks are prone to twist with higher power than stock.

Get the crankshaft inspected, rebuilt and welded. Then it´s good for bigger horsepower.

[TonyGee]

what year is your GSX engine ? 83's where mostly welded at the factory. 

[DAZ]

1 minute ago, TonyGee said:

what year is your GSX engine ? 83's where mostly welded at the factory. 

Is that mostly ef/efe ? 

[Gixer1460]

22 minutes ago, TonyGee said:

what year is your GSX engine ? 83's where mostly welded at the factory. 

All SZ Katana's were built between 1980 - 1981/2 ie. the early ones 1074cc - the new models 1135cc were semi welded in the factory, although that can be improved upon!

Any tuning that improves the engines breathing and thus increases the torque, really needs a welded crank. Only a fool would try a turbo without prepping the bottom end and if the crank is being pulled apart swapping in 493 Katana rods is a damn good idea before re-assembly and fully welding the pins (thats where the skill is needed!)

[clivegto]

I  asked Ian King (drag racing champion) the same question but for gsx1100efe. He said personally he would not put more than 120hp through a standard one. Did surprise me that but then again he didn't get to be the European champion without knowing his shit. 

[Arttu]

No personal experience about non-welded cranks but based on what I have heard and read they can twist even at stock power.

Suzuki started to weld cranks around 82' I think. So all 1135cc EFE engines have them and later 1074cc engines too. I have used a stock factory welded crank at 180-200hp on road for quite some time without issues.

[gorbys]

mine is a 1074, I believe its  an 82 from what I know, it doesn't have a welded crank

[johnr]

all the 1135 ef/efe cranks were welded but also came with 20mm small ends on the rods. 1075 motors were 18mm small ends. sz kats didnt have welded cranks, sd kats did. but before you start going down the welding route, kat 1000 had much stronger rods and if youre planning on long term use it might be worth investing in the stronger rods whilst youre at this stage as a good foundation for future upgrades. and whilst its apart, think about a straight cut primary drive as well, if youre investing time and cash in the motor, give it a good foundation.

[Blower1]

6 hours ago, johnr said:

all the 1135 ef/efe cranks were welded but also came with 20mm small ends on the rods. 1075 motors were 18mm small ends. sz kats didnt have welded cranks, sd kats did. but before you start going down the welding route, kat 1000 had much stronger rods and if youre planning on long term use it might be worth investing in the stronger rods whilst youre at this stage as a good foundation for future upgrades. and whilst its apart, think about a straight cut primary drive as well, if youre investing time and cash in the motor, give it a good foundation.

If wanting stronger/heavier connecting rods, you can buy new GN250 rods from bay of e or axpress of a. Only difference to 1075 /1135 rod big end bearing is that bearing surface on the rod is wider and bearing have one roller less.