Dunemaster wrote:

So I'm a mechanical engineering student that has made a buggy with a kz750 F LTD engine and I'm thinking about making big changes to the engine to attempt to make more power. I am planning on replacing my carburetors for fuel injection and add a turbo while I am at it. Id be aiming for a max hp of ~120. I'll be using a genuine Garrett gt1241 turbo for the conversion and I'm modifying the throttle bodies of a 2005 Yamaha r6. I have a spare engine which I plan to use the head of because of its mechanical tachometer which I should be able to use as a cam position sensor. Apologies that parts of my post may overlap with other posts I've seen on the site. here comes my list of questions so far:
Any and all input is appreciated! thanks for your help in advance.

I'm working on a turbo kz750 as well and can fill in some blanks. Kawasakik1e is working on a turbo project as well.

I have realized I am essentially recreating the GPZ750 turbo engine so what are the differences between the engine internals? I know they have more aggressive cams but what else? are there any compatible parts I should look into buying?

Does the GPZ turbo have a stronger transmission to deal with the extra torque the turbo gives? If so, how can I improve my chances of not blowing mine to pieces?

You are definitely going to need heavy clutch springs and better clutch disks (APE is what I used). You'll want a hydraulic conversion if you do this. There are lockup clutch options as well.
Also do the viton clutch rubbers, for sure. 
I am not sure where the undercut gears, HD head studs, MLS headgasket become necessary. I'm working my way up to 150hp, so I'll find out. I'm running two kz650 254 duration intake cams with slotted gears to reduce cam overlap to about half of stock, ie about 20deg now.

I know the GPZ turbo has lower compression than the stock kz750, should I lower it to be on the safe side? I know in the automotive world some opt to just double up head gaskets to lower compression. 

Probably. There are somethings you can do to maintain the higher compression with boost. E85 fueling or water/meth. I put in a 16g aluminum gasket instead of the stock base gasket considering my end goals. stock composite head gasket still.

because of extra heat from the turbo and reduced air flow because the engine is blocked by the rider I want to install a large oil cooler to help the engine stay cool. If I install a significantly large oil cooler I'm worried about how restrictive the oiling system will be with both the turbo and large oil cooler.

I blocked off the galley in the oil pan and installed an automotive style oil thermostat between the main galley and the rear oil pan port that allows for quick warmup but also good cooling when needed. There was a couple psi drop with this system if I remember correctly. 

oes anyone know if anyone has had problems with the oil pump being too weak? Has anyone installed a scavenging pump on their bike to combat a restrictive oiling system?

You should be concerned with how un-restricted the oil system will be with a turbo. stock oil pressure on the NA engines is around 8psi hot idle. most turbos want 10psi minimum. I modified my oil pump to about double the flow.
I used an external electric facet pump to handle the scavenging. I also designed an adapter plate to use a stock oil pump as a scavenge pump driven by the secondary shaft. 

switching to an EFI system will I need to upgrade my generator?

Ive run my EFI system on single and three phase kz650/750 generators without issue, but i am using a non-return PWM fuel pump which greatly reduces idle power consumption. LED lighting also helps.

mechanical tachometer which I should be able to use as a cam position sensor.

I designed an MJF nylon 3dprinted cam sensor bung for the kz650/750 cam covers. I have a couple extras, if you'd like to buy one. 
I also designed a laser cut and bent metal crank position sensor bracket that reuses the stock pickup. 

Are there any other performance modifications I should look into?

Dont be scared to port the head a bit. clean up the casting line roughness, taper out the intake runners to match the TBs (as possible). Improving head flow makes turbo power easier.

Is there anything else I should know before getting sucked too far down the rabbit hole? I'm aware there is quite a lot of work to be done fyi

Figure out your control system. If you're using ITBs, youll want to use tps based tuning with map adjustment for boost. Or switch to a single TB manifold with map tuning. Map with ITBs might work with something like this  efi.ttrignition.com/quadramap.html , but i havent been able to contact this vendor or try the idea.


 

This member (RIP) did a carb/turbo conversion :

www.kzrider.com/forum/11-projects/423436...-turbo-kz650?start=0

Lots of good info there plus he was trying to get a DIY scavenge oil pump working, not sure if it working or not because he got sick

I am not a turbo expert by any means but have collected some information over the years. I was going to put a Eaton supercharger on one of my builds (sort of similar) so I have investigated putting power adders on Z1 and 650/750 engines in the past.

Dunemaster post=910298 userid=65727As for my reason to why I am using the KZ750 shaft I have a conventional drivetrain, no chains that is.
 

First off, please post many many photos of your buggy. We'd love to see the details.

Second, you should absolutely do an EFI and turbo conversion on your KZ engine.  Why not?  Even if you blow it up, the process of getting it built and tuned and running will have provided you with a huge amount of knowledge and experience.  And you already have the engine in the buggy right?  Just do it.

Oh.  If you do want a later KZ650/750 oil pan with the oil cooler taps, I have one sitting around I'd be happy to send to you.

Dunemaster post=910298 userid=65727 

• I know Suzuki was able to make a high performance motor with the '86 GSX-R 1100 that was oil cooled. They had a high performance oiling system but it makes me reason that if I get enough volumetric flow of oil in combination with a large enough oil cooler I should be fine with cooling.

That's not necessarily true. The SACS GSXR engines were designed from the ground up with oil cooling in mind. They had internal oil sprayers to cool the underside of the pistons, and sprayers in the head to cool the combustion chambers. That type of targeted oil cooling does not exist in the KZ engine. Even the oil cooler itself was an afterthought, added much later in the engines evolution.  Even if you keep the oil very cool, it's not necessarily going to carry heat away from the top of the cylinder (piston crown and combustion chamber) fast enough to keep the engine cool.

en.wikipedia.org/wiki/Suzuki_Advanced_Cooling_System

The SACS system uses high volumes of engine oil aimed at strategic points of the engine, like the top of the combustion chamber, which are not typically well served by air cooling alone. In order to provide enough oil for both cooling and lubrication, the system uses a double-chamber oil pump, using the high-pressure side for lubrication of the parts (crankshaft, connecting rods, valvetrain), while the low-pressure, high-volume side provides oil to the cooling and filtering circuit. The oil removes heat from hot engine parts through direct contact, is pumped away and subsequently routed through the oil filter, followed by routing through an oil cooler before being returned to the main sump.

 

That was an enormous pain in the rear, WOW! But in the end, it is done and my problem is technically fixed.
to start, the clutch dampers were turbo shrunk, like raisins next to a grape. Attaching vids of difference before and after install.

the awful noise I was hearing went away after I cycled oil through the engine for a good 10 minutes, something just wasn’t lubricated and happy. My clutch also now VISIBLY separates, so if the plates are stuck at this point, I’ll just send it on the center stand and hope for the best.
now onto my final problem, SURGING IDLE!
who knows what it is, but I’m gonna hit the carbs with a clean as much as I can as the previous owner stripped every single bolt on the carb rack. Impact hammer didn’t work so I’m not gonna try to damage it further for now.
also going to take this opportunity to check how my carb boots are looking, because this is where I suspect my issue lies, since I had a kz650 that had the same bad boots.
anyways, thank you for the help! Even if it didn’t specifically fix my issue (it was me being impatient) I learned a lot about the clutch mechanism, and built some better modification skills and my tool variety(I will never do this again)     

Those dampers are in the secondary shaft.  Partzilla lists them as still available.  Another huge improvement can be gained by changing the rubber dampers in the clutch.  A guy on the KZ750 Turbo site sells them, or at least he used to.

After being out of stock for a couple of weeks I'm glad to announce I've got a fresh batch of Viton dampers ready to ship.

The cost is still $45 US for a set of six. Shipping costs can be found in earlier posts.

So if you're interested contact me at turbosteve84 "at" verizon.net. I'm in the US.

Thanks,
Steve

Injected wrote:

It did not work like that as far as vintage Japanese bikes, nothing like the car world special build houses. No Kawasaki 650 was ever done up like that from a dealership.
 

The only exception to that I can think of is the Z1R-TC, where an independent company added the turbo kit and paint, but it was then sold through Kawasaki dealers.

Grateful to be on the forum.  I'm currently reviving a 1979 KZ1000A3A MKII. Previous owner seized a piston due to oil starvation. (More on that later)  Prior Kawasaki riding history:
My first motorcycle was a 1976 KZ400D3. 18 years old in the Marine Corps - purchased new in Arlington Texas. 2 days later rode to my duty station in Camp Pendleton, CA. Six months later, traded in for new KZ1000A1. That one got stolen - replaced by Insurance.  That one was totaled when I ran off a curve in San Diego County back country.  Insurance was not renewed for some reason....  Shop owner let me revive it (New frame required). From my experience, was hired part time as a parts sales man. When I got out of the Marines in 1979, I went to work as a full time Parts Manager at the shop. Later partnered with the Sales manager to buy salvage wrecks which we restored and sold.  He was the body/paint guy - I was the wrench.  Various motorcycles owned/raced/restored over the years include:
1976 KH400 triple - raced AFM
1980 KZ550A - raced AFM
1981 KZ750E - took cross country with my girlfriend (now wife of 39 years)
1983 GPZ550 - street ride & raced AFM (Last race April 1984 - too busy with new job) 
1986 ZG1000 Concours - rode for 80K miles+  Several long trips.  In 1986, I rode the Concours, wife rode the GPZ550 from Oceanside CA to World's Fair in Vancouver BC and returned.
1979 KZ1000B LTD - rebuild/sold
1982 Yamaha 650 Seca Turbo - rebuild/sold
1978 KZ650C (x2 - basket cases) Restored both - sold
Had 3 KZ1000P's that I rented to officers wanting to practice for Motor School. Since sold all three.
2003 BMW R1150RT - sold after 9 years
2014 BMW R1200RT - current primary ride
1971 Norton 750 Commando - Resto-mod. Originally picked up in 1989 as a basket case. Current 'tinker' attraction
1979 KZ1000A3A MKII  Present project, .  Picked up from PO in pieces.  Currently have the engine apart. Identified 2 issues for oil starvation:
1.  Apparently he kicked up a plastic bag while riding along the freeway in So Cal. When I took the countershaft sprocket off, there was a wad of plastic behind it that had forced the seal into the engine. It was dangling there with a huge gap for oil to mist out to the chain, case, rear wheel etc.
2. Split the cases. Previous mechanic(?) installed a too-long bolt in the right lower engine mounting position.  The bolt was apparently over-torqued and subsequently forced the oil -passage plug inward. The plug now covers 2/3rds of the oil access port for the Pump to Filter pathway.  Trying to come up with a workable solution (maybe drill out the plug then install a threaded plug? - May have to enlarge the engine mounting hole for access, then install a bushing to return to correct size). 

Enough for now!  Looking forward to sharing, learning and growing in the hobby.  

Bob F.
 

You might want to look into the colors of the Bosch EV1 injectors. My daily driver is a Ranger with one of those 2.3s.
Just installed some 24lb. following my secondmodified upper intake. Here is a list off the top of my head of what Ford used.
      lbs./color /application.
   12lb./ forgot the color/ / 300 6cyl (55 psi )
   14lb./ grey / 2.3 '89-'94 Ranger
   15lb./ red-maroon / 2.3-2.5 '95 and up Ranger
   19lb./ orange / V8 and V6
   24lb./ blue / 460
   35lb. / brown / 2.3 turbo (Thunderbird )


.

This is the kind of thing I've found in a few places. Just that '83-'85 flow better but without explaining why and without including '82. This is just a post from another thread here:

"The turbo and N/A head's are the same other then the turbo head has a temp. senser. Turbo cam's are stock KZ650 cam's. 83-84 GPz head is the best 750 head flow wise."

I mentioned previously in this thread my recent bikes have been 175HP or so. First step for this KZ is to get it running but eventually I'll want to get more power out of it. Have some extra money to spend now so looking at collecting parts. Figure they'll just get harder to find as time goes by.
 

Back to the frame mods...

There is no bottom front engine mount bolt on the early Z1 motor so you need to weld in a front lower cross tube to gain back some rigidity. The KZ650 frame is pretty rigid stock, if you look at a GPZ750 Turbo frame it is very similar (maybe the tubing has a bigger wall?) The Turbo made about 110HP stock so I am not too worried about any flexing.





You can see how the oil pan will sit low in the frame.

I also checked the chain line, I swapped the sprocket to 530 so it would match the 650 rear sprocket. No issues with chain line.



I made sure the sprocket cover and the shifter shaft cleared the frame





Ground down both center lower motor mount lugs as they are not going to be used, but I did not cut them off.





This is how close the lugs need to be.





I think in the end I used 2 of those .040" aluminum shims on both sides so I have .080" to the frame at those spots with the motor mount bolts tightened.

Here are the motor mount and weld plates (not finished here) The thick lug is for the lower rear and there is a 1/8" plate to convert the B drum brake frame to a C disk brake frame.



For the upper rear bolt on mount plates I increased the thickness to 3/8" 1018 steel.









1/4" thick weld plate.



3/16" thick bolt on plate.



3/16" thick weld tab.