turbo my engine

a few things. i bought a tourbo for my 78 kz750b and come to find out they make no hp parts for this bike. I mean it took me 6 months just to find a set of os pistons for the bike. So i know the compression is 8-5-1 which is pretty low so i figured a turbo would be a great idea. only questions i have are #1 is the bottom end going to hold up and #2 am i going to have to do anything to the carbs besides jet them. I havent seen a turbo on a kz 750 so this should be interesting

Pictures of bike and turbo kit please. Need lots more details and then can try and advise. LORCAN is a member here who is the 750 turbo go to guy. But you need to post as many details as possible on bike and turbo you purchased.

Good Luck
Dave

What kind of boost numbers are you wanting to run? I'm not very familiar with the twins. But you may be able to run small <5-6psi and be ok. The pistons are going to feel the most heat, literally. The cast pistons can develop some extremely hot spots and that can cause some major issues. Most turbo applications for the older bikes use a draw-through carb setup rather than a blow-through as you kinda suggested. There's all kinds of other factors but those are the two biggest concerns I have.

Later, Doug

i dont have any pics at the moment im in the hospital been here for a month now and have another month to go so i cant get any pics but the turbo i purchased from ebay its a cxracing gt15 t15 part#1033206001396 I cant wait to get out of here so i can put the motor back together and finish this thing.

No hot rod parts for the 750 twin? Parts are available to take it to 885cc, and aftermarket cams are available. I have all of that plus a set of 10:1 pistons for standard bore, and of course, two into one exhaust.

It just takes more imagination and research to build a 750 twin

I'm currently going through this myself with my 650-4. There is a lot of work that goes into turbocharging one of these bikes, probably more than you might realize.

To answer your initial questions;

#1- I'm not sure how much the twins can handle power wise, but I'm sure it won't be much until stock pistons are melting or rods are bending.
#2- The current carbs run off of vacuum, so if you were going to turbocharge the factory carbs you will need to do a good bit of modifications to make them run under pressure. It would be much easier to move to a single draw through carb.

oh yeah so where do i find that stuff ive been look for about 8 months and finally just gave up. figured ide go .020 over and just re grind my valves and resurface everything slap a turbo and hope it all holds togethe.r

any idea where i might find two of those?

oldscut385 wrote: oh yeah so where do i find that stuff ive been look for about 8 months and finally just gave up. figured ide go .020 over and just re grind my valves and resurface everything slap a turbo and hope it all holds togethe.r

I couldn't tell you where to source parts for the the twin motors unfortunately. As much as you will have invested in this you might want to look into a 657/750-4 bike. I'll say a stock bottom end, turbocharged, 750 twin will make just as much power as a stock or slightly modified 4 cylinder bike.

oldscut385 wrote: oh yeah so where do i find that stuff ive been look for about 8 months and finally just gave up. figured ide go .020 over and just re grind my valves and resurface everything slap a turbo and hope it all holds togethe.r

The Kawasaki Twins Owners Forum of course !
Look in the 750 twin engine section, it was a sticky there. I think Megacycle still regrinds 750 twin cams.
The two into one exhaust I have is no longer in production, but there's another one that will work (I'm well into my Margarita painkillers right now and can't remember much).
The 10:1 pistons I have are custom Venolia pistons. The big bore kit is two Yamaha Wiseco big bore kits with a pair of Yamaha Big bear liners, read about it at the link above. I went to the largest over bore size, 885cc vs 865cc for the standard size. I think Wrench Monkees has gone over 900 cc.

You're just in the wrong forum for 750 twin stuff

I talked to a fellow that races WERA with a 750 twin, 90 rwhp but it took him 15 years of development to get there. And yes, he told me how he did it

Think your right that these Wreckmakers did a 970cc and that it couldnt really be bigger due to the space in the crankhouse.... and if i heard correct the piston was specially made in Germany
ALso read that it ran with to Mikuni RS carbs, had a CRAZY torq but not much top-end due to standard cams....
Also heard that the kickstarter aksel bended when they tried to kickstart it the first time

Would say the crank is the 'dangerous' part on this bike