GPZ Oil Fitting

Is it possible to drill the GPZ oil cooler fitting out for a 3/8 NPt pipe thread?  A second question, what risk is there in using one of the after market fittings that doesn't have the bypass? .It would seem to me that the bypass insures some oil flow at startup in case of oil cooler drain back.

Can you be more specific (with pics if possible) of what you are wanting to do and is it a 550, 750 or 1100 ?

I fave a 1000J motor in my race car and having overheating problems.  I took out a 9x9 fan forced air fin and tube cooler with AN-8(.4375 dia)  hose to it.  Was set up in a very poor position.for cooling.  I have changed to a Setrab Series 6-19 row(plate type) in better air flow.  But, concerned about oil flow as the GPZ fitting has 1/4NPT pipe going to it which has a .368 ID where the GPZ oil fitting has ID of .460  so .106"sq vs .166"sq .  Since the motor is behind me out of the air stream with several large cooling fans not all well placed oil cooling is critical, I have been pegging my temperature gauge at 250F and easy running for a mile or so doesn't cool it down much.  Using 3/8 NPt and a -10 hose(.5625 dia) would greatly decrease the pressure loss in the oil cooling side. I don't have any pictures of the new arrangement. The old arrangement had the cooler in the side pod (door ish)horizontal with a cooling fan, new arrangement the cooler is in the top of the side pod where the air duct is.  Pictures attached.  There is European guy on Ebay who can make an oil fitting with -8AN outlets and Web Bike has them also, but neither has the bypass Kawasaki  put there for some probably good reason.

I bought the car I believe undeveloped after the Kawa motor was installed many years ago, the previous motor was the old Suzuki water buffalo 750 triple  2 stroke.  So I get to figure out all the problems, oil cooling is the top of the list..


 

I see an air and oil cooling problem in the cooling air flow guiding enviroment.

 

When you talk about a bypass I am assuming you are referring to the passage between the two sides of the oil switch housing ? If so this isn't a "bypass" the stock "J" doesn't have a cooler so this is the main oil gallery. If this passage is open on your set up then the cooler will be doing next to nothing which may be a large part of your problem. When fitting a cooler to a "J" this passage needs to be blanked or removed. On my build I am using the below fitting which replaces the stock oil switch housing and has no bypass passage so the full flow runs through the cooler. This fitting has 18x1.5mm fittings so you can use AN8 or even AN10 fittings

 

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.

1/4NPT pipe going to it which has a .368 ID

Are you sure???? It's CALLED 1/4 because the ID is 1/4"... give or take a couple thou

The normal pipe you can buy is called schedule 40.  1/4" Sched.40 has a .540 OD and a wall .088 so that gives an ID of .364".  If I recall correctly Schedule 80 or heavy wall pipe is much closer to its nominal ID.  I believe the history is that back when pipe was first being made the heavy wall pipe was the norm,  They kept the OD of the pipe the same for joining purposes. The only places I've heard of using sched 80 pipe was in building sprinkler systems(got changed many years ago) and high pressure steam boilers.  If 3/8 pipe could be used it has an ID of.493" ,which would be large enough for the flow, but the bypass in the GPZ fitting would probably negate that also.  I am curious as to what was different in the GPZ motor so that the oil cooler worked.

Can you post a pic of the fitting you are currently using. If the below is the GPZ "take off" you are using then I have included pics of the adaptors I made to use AN8 fittings with a GPZ cooler (has the same hose fittings as the take off)



 

I think it's a size application. You can get fittings with all sizes of ID'd. In my case I got 1/4 NPT 1/2" ID thread to barbed fittings instead of 3/8 to keep oil flow. I then used copper elbows and fittings to my oil cooler. Not pretty but it works. 
Steve
 

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

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.