GPZ Oil Fitting

Injected wrote:

MJinCO wrote:

The fitting you show is the one I am looking at.  A previous owner installed the GPZ oil fitting to the J motor and probably never looked at it as I hadn't.  It just always had cooling problems.  These old cars always have had a tendency to just get ignored in the corner of the garage .  I agree the bypass would decrease the system pressure going to the cooler, I didn't know the bypass was there until I read an older post on the board. I think to be safe I need to get that same fitting and fit it with -10 hose as the -8 hoses are smaller than the port in the crankcase.I just measured it at .603 dia. So the fitting itself can cause a significant restriction.  This is not an inexpensive solution but much less than a motor.  Thanks for the help.

 

The main oil gallery is big but there is considerable restriction going into the both ends at the rear outer studs, that builds oil pressure for the top end. Most people are running -8 hoses, I have not heard of many running -10. Just looking at the picture of the car body it seems you could use some addition ram air by using some hood scoops.

 

I think also if the current "by-pass" is still in play the current cooler set up will be doing very little

Wookie- Ihave the standard GPZ fittings,but a PO modified it by cutting off the thread flanges and tapped it for 1/4NPT , that is why I inquired about tapping to 3/8NPT.  I have ordered one of the other fittings and some adapters 18-1.5 to 1/2NPt so that I can go to 10AN hose. I hope I don't have any drain back and have to crank the motor over build oil pressure before firing it up.

Injected- Yes air flow an issue and  small air scoops under construction. I also took the fan off the old cooler and mounted it in the side pod as the cooler extends below that inlet duct.  The inlet duct is no where close to the modern standards of using NACA ducts, but at this point I really don't want to modify the body unless abslolutely necessary.

My ultimate fall back position is to modify the oil drain plug to get oil out then either to an electric pump(haven't found yet) or a gilmer belt driven pump off the drive shaft to the cooler and then just dumping back into the case, maybe where the case vent is.  That one is complicated and very expensive.  This type of thing has been done with both alternators(clean up engine bay and help weight distribution) and oil pumps for differential coolers. 

The below company supplies AN10 fittings to go straight into the new take off (ID 12.5mm) - I have inverted my cooler to have the hose fittings on the top to minimise "drain back" down to just the hose.  I think the new set-up without the by-bass and your fan cooling of the rad should do the trick 



 

Wookie58 wrote:

Steve do the separate fittings you have posted work with a "J" motor ? (which is what the OP has)

I don't think so. There was a post where the PO had blocked off the passage going to the head and couldn't figure out why he kept blowing the oil filter cover. Turned out it was modified so the oil would come out the fitting go through the cooler then back in the test plug on the side of the engine then up to the head. That's one way to do it. 
I think this is the one you have?
 
Here's another but I don't think it has a oil pressure switch in it. 
 
Either way it would work and the blocking off can work on both models. One is discrete and the other is exposed. 
Steve
 

The later GPZ has the pressure switch in the bottom of the motor

I believe the US fittings are NPT (National Pipe Thread) not sure about the EU and UK fittings. Do the AN fittings have NPT threads? 
Steve

SWest wrote:

I believe the US fittings are NPT (National Pipe Thread) not sure about the EU and UK fittings. Do the AN fittings have NPT threads? 

Steve

The supplier I posted does both 

Wookie58 wrote:

SWest wrote:

I believe the US fittings are NPT (National Pipe Thread) not sure about the EU and UK fittings. Do the AN fittings have NPT threads? 

Steve

The supplier I posted does both 

What are the other kind called? 

SWest wrote:

Wookie58 wrote:

SWest wrote:

I believe the US fittings are NPT (National Pipe Thread) not sure about the EU and UK fittings. Do the AN fittings have NPT threads? 

Steve

The supplier I posted does both 

What are the other kind called? 

Found it M18x1.5 

MJinCO wrote:

My ultimate fall back position is to modify the oil drain plug to get oil out then either to an electric pump(haven't found yet) or a gilmer belt driven pump off the drive shaft to the cooler and then just dumping back into the case, maybe where the case vent is.  That one is complicated and very expensive.  

If you really want to optimize and maximize oil cooling effectiveness, this is the route I would go.  You can flow a lot more oil through the cooler this way, and you can have much better control over the oil temperature.  When using the stock oil cooler takeoff, no matter how large the fitting and lines you use are, the volume oil flowing through the cooler is going to be limited by the oil flow restriction of the camshaft bearing clearance, which is likely much much less than you could flow with an independent pump and an unrestricted return path.

Here is another thing to consider.  These engines were designed to be air cooled.  Keeping the oil cool is certainly a good idea, but I doubt it's going to be able to keep the cylinder head and cylinder block sufficiently cool without proving substantial air flow for air cooling.  

The oil coolers that were fit to the air-cooled GPz bikes were very small, and in my opinion were mostly ornamental, more for looks that functional.  If you compare the oil cooler on the air cooled GPz models to the oil cooler on the 1986 GSXR-750 and later Suzuki SACS air/oil cooled bikes, the Suzuki cooler is probably 5 to 10 times larger.  The Suzuki engine was released after Kawasaki had already come out with the all-new GPz900R Ninja water cooled motors.  The GSXR-750 was considered a substantial jump in street bike performance while still being air cooled, and it didn't switch to water cooling until the early 90s.

Here are some details about the SACS system:

The SACS (Suzuki Advanced Cooling System) motor would have oil squirters to cool the underside of the pistons, as well as a secondary oil circulatory system to cool the cylinder head, ports and combustion chambers. The oil pump had both a normal high-pressure rotor, for the main and cam bearings, and a low-pressure/high-volume rotor that circulated oil through the cooling passages. 

www.rideapart.com/features/246108/the-hi...oil-cooled-machines/
en.wikipedia.org/wiki/Suzuki_Advanced_Cooling_System

The KZ1000 engine doesn't have any of that.  The oil does not flow near the combustion chambers, and it does not flow near the cylinder walls or piston crowns.  The engine you have is an evolution of a design released in 1973.  Even though oil coolers were fitted to all the race bikes, it was not designed to be "oil cooled".  And while the KZ engine is my favorite engine of all time, it doesn't seem like a great choice for a race car application.  I'd probably be inclined to find a Suzuki Bandit 1200 SACS engine (1996–2007?) and swap that in.    Or if you want to keep it Kawasaki, the water cooled GPz/ZX/ZRX 900/1000/1100/1200 engines were produced from 1984 to around 2005 or so and were used in many models and should be relatively easy to find.

Most of the aftermarket oil cooler adapter blocks for Z1 engines come with 1/4NPT female threads. Tap drill is .437" ID, this seems to be the common size of hole thru those blocks. The limiting factor is the thru hole ID in the fittings used.

I know its not J motor specific but here is mine with -8 AN fitting installed.


 

Injected wrote:

Most of the aftermarket oil cooler adapter blocks for Z1 engines come with 1/4NPT female threads. Tap drill is .437" ID, this seems to be the common size of hole thru those blocks. The limiting factor is the thru hole ID in the fittings used.

I know its not J motor specific but here is mine with -8 AN fitting installed.



 

I believe the OP has ordered the same German made take off that I have, this comes with M18x1.5 threaded holes which will take AN8 or AN10 fittings directly (I am using AN8) The AN10 fittings I posted are 12.5mm ID so slightly bigger than the holes on the casing