I got the top end tore down this weekend and fitted some parts just to make sure they fit. My main concern was making sure the Srad 750 block fit the 600 cases and they did. I've been burned before on a ZX10/11 project when the 11 block didnt fit the !0 cases after being told they would. In order to use 750 pistons I got some from an 00-03 K model 750 and they fit the 600 rods no problem. Side by side the 750 piston pin is slightly taller...maybe 1/4 mm but the 600 piston dome is actually taller so they will be the height at TDC. Ive done several big bore projects before but was amazed at how much bigger the 750 pistons are next to the 600. Still deciding on a 3 or 4 layer head gasket just to be safe. Can someone tell me if SRAD 750 cams are that much more aggressive than the 600 ? I might as well sort that out while I have everything apart.
Have you not considerd a rod upgrade? By all means i dont know everything but an extra 150cc is going to put alot of stress on those rods, if your planning on using the 600 head id suggest stronger springs and hard weld cam, the last thing you want after doing a build like this is valve bounce
Got everything bolted back together and she fired right up. Cant ride it because of 14 inches of snow. I ended up using the 600 intake and 750 exhaust cam combo with the stock carbs and BMC race. Sounds damn good but there is a small coolant leak between the head and block between # 3 and #4 cylinder. I used a new 74mm Cometic head gasket to try and lower the compression a little but I'll either have to go with a stock head gasket or try and re-torque the cometic a little higher...maybe 36-40 ft. lbs.
Today I got the coolant leak fixed and even though its in the low 30's I couldnt resist testing it out. On my street there is a 2 block stretch that is snow free but thats all I needed to know that this thing has some balls now. Cracking the throttle open in 1st from low rpm results in the tire spinning on the damp pavement until it hooks up and wheelies you down the block.It reminds me a little of my old R1 the way it comes up at will. I see that the 600 is geared a little shorter than the 750 so I might changed the rear sprocket to make it more sane and less squidly.
Today I got the coolant leak fixed and even though its in the low 30's I couldnt resist testing it out. On my street there is a 2 block stretch that is snow free but thats all I needed to know that this thing has some balls now. Cracking the throttle open in 1st from low rpm results in the tire spinning on the damp pavement until it hooks up and wheelies you down the block.It reminds me a little of my old R1 the way it comes up at will. I see that the 600 is geared a little shorter than the 750 so I might changed the rear sprocket to make it more sane and less squidly.
Motorcycle: 2012 Suzuki GSXR 750 (L2), 2011 BMW X5 M
Posts: 32
Re: SRAD 725 Project
Nice, I had a 97 600 and grenaded the engine at mosport. Did an engine swap from a wrecked 98 750 for about $1600 about 12 years ago.
Nice thing was I was paying 600 insurance rates for essentially a 750 lol. Was a real sleeper too, cause the badges were still 600 so other riders were real confused when I pulled away from them so strong.
Didn't upgrade the swing arm either so it wasn't a dead giveaway. Hahahahaha.
Hello i have 98 gsxr 600 with duplix yoshirmura headers carbs done by ccm im new to the forum but im real intrested in this 725 good job i have found 2001 750 pistons i havnt bought yet because they want 132.00 for them and i still got to match 750 cyclinder my 600 your concern not matching is what im worried about what year 750 cylinder work on 600 and does the 750 camshaft have to be certain year i plan on using the duplex headers and the can is also yoshimura but ccm did some tunning to it im going to use 600 carb that he built for me just making sure having right cylinder and camshaft is my main concern and you seem to solve it.I also like to know what grimlins im going to run into.I havnt even done my profile yet so i could ask you for any help would be appreciated
I emailed dood that does the 750 crank, rods, pistons and barrels into the 600 cases using the head, he said its a straight swap but you have some can work, dial em in a I think? so you would need an adjustable sprocket.
I think you also have a few cam options as well forget which cams he used if he even mentioned it but he said with carb work he got 125 hp at the wheel, I think he said with a lightened and balanced crank you could eek out a little more?
I want to do it, that would set the SRAD up very respectable as he says he no longer has to down shift when passing.. :-)
Arh the 725 mod,yes i remember doing one of those , ended up with a great engine.
Heres what ended up with;
1999 750 barrels/pistons(balanced)/crank(lightened)
1998 600 head (i ported and skimmed)
1999 750 head gasket(thin)
Race 600 cams with Adj. cam sprockets( A MUST imo)
1998 600 carbs
K&N + AKRO full system
Gearing 15 front and 46 rear
Arh the 725 mod,yes i remember doing one of those , ended up with a great engine.
Heres what ended up with;
1999 750 barrels/pistons(balanced)/crank(lightened)
1998 600 head (i ported and skimmed)
1999 750 head gasket(thin)
Race 600 cams with Adj. cam sprockets( A MUST imo)
1998 600 carbs
K&N + AKRO full system
Gearing 15 front and 46 rear
Linear Mode
