oil mods

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hawkwind
Posts: 294
Joined: Fri Dec 17, 2010 3:50 pm

oil mods

Post by hawkwind »

Due to some problems encounted at wot & high rpm im planning on doing some mods and need help in deciding what and how to do them.

First the problems at around a 1/4 mile beforre the 3 mile marker I loose oil pressure typically im at wot and over 8k rpm in top gear, I set up a warning light to activate at or below 30psig. Seems the oil migrates to the head and wants to stay there so drain back is a problem any idea what causes this ? secondly im getting a lot of blow by (blown alky ) and the temp of the engine is not getting hot enough ,maybe this is pressurising the return passages ? causing the first problem.when I slow down and decrease my rpm's the pressure returns again .

some solutions
1. plumb in a 10 or 12 an external oil return line from the head to the sump ( where is the best place to return it to above the sump or below the oil line ?
2. Install a windage tray and crank scrapper. sadly no such beast exists for my motor how does one go about making one ??? design, material etc.
3 install a crankcase vacuum pump ( i have an electric pump and can place an exhaust venturi in as well) again where is the best place to draw the pressurised blowby gasses from the existing breather, or the rocker covers ???
4. preheating the oil to above 100 deg C and returning it to the sump before I race ?
5. experimenting with not running a radiator or running without any coolant at all remember im using a lot of methanol for fuel and planning to use some 30% nitro next time out any ideas ?

any one else experence these problems and any solutions :)

cheers
Gary # 282
Vehicle......................A new creation.
Designed by................Troglodyte.
Engineered/ built by......Rustic.
Financed by.................Nickles & Dimes.
Rider......................... Tardus Vetus Inflatio
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JonB
Posts: 268
Joined: Wed Oct 06, 2010 6:35 pm
Location: Brisbane

Re: oil mods

Post by JonB »

Getting the blowby under control would be the first task IMHO.
If you have a fair bit of blowby and your breather is from the rocker cover it's going to be difficult to get oil back down.

Running a bypass style thermostat will help get temperatures up quickly and then stabilized.
I first run across them trying to keep a Cleveland in a XD cool, they circulate water through the motor constantly and bleed in a little cool water only when up to temp rather than taking full slugs of cool water in like a conventional thermostat.
I got one for my bike from a guy called Watt-man, he mainly does Kawasaki kits but has a 1" universal kit http://shop.watt-man.com/Thermo-Bobs_c4.htm

Cheers
jon
DLRA#1115
Underhouse Engineering
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ROSS BROWN
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Re: oil mods

Post by ROSS BROWN »

Gary..
I take it your still runnuning the Kawasaki gpz 900r engine
As you know that family of engines went 900r, 1000rx, zzr1100, and zzr1200.
all similar bottom ends.
Have done some massive modifications to ths 1000rx and the zzr100.
The oil migrating to the cylinder head and staying there was there biggest issue as the only drain back was down past the timing chain cavity and through the insufficient drain holes behind the ignition .I have put the oil feed both above and below the level , as the engine has 2 sumps and twin pumps I found the most effective place to run the drain line was to were the balance shaft was, that feeds directly to the main sump which has the engine feed oil pump( the more critical one to be kept fed )
In the top of your cylinder head is 5 screw out core plugs , and they are in there tight.. :shock: removing these items will give you access to the water jackets. fill this area with engine oil and do not put the plugs back in (this will let the oil expand with heat) so now your engine will take approximatley 6 litres of oil instead of 4 .(this oil will not drain down to the sump when the engine is stopped , it is captive in the jackets..
NEXT :remove the water pump and radiator then throw them in the bin, plug the water pump hole, remove the water housings from the rear of the cylinder head and the front of the block and replace with 20mm frost plugs..
Number 2 of the twin pumps feeds the oil cooler , with methanol your cooling will be sufficient.
Kawasaki's fix to the drain proplem in the later models was the fitting of the 2 reed valves in the rocker cover , this stopped the vacum issue in the cylinder head ,thus helping the oil to return to the sump ...
this worked well enough on a street engine but not well enough for a race engine.
In saying this .. if you have not got a breather in the rocker cover ...you need one....

I employed this system to a covered in speedway bike for 5 race seasons ... and had absolutley no issues with overheating.

Hope this is of some help ..
Ross..
IT IS ALL A RACE AGAINST TIME.
TIME WAITS FOR NO ONE.

HOW FAST CAN YOU GO ?

S/UF 925
hawkwind
Posts: 294
Joined: Fri Dec 17, 2010 3:50 pm

Re: oil mods

Post by hawkwind »

Thanks Ross, yes a very big help ...you have confirmed what i suspected about the oil return problem ....by the way its an rx1000 so I would be interested in hearing about your other massive mods :) I have already done the oil mods for # 3 big end. the water jacket mod is a new one :shock: oil cooling hahaha again thanks for the advise:)
gary

ps your not wrong about the head water jacket plugs being in tight ,wonder what the lock tight stuff they use is ?
Vehicle......................A new creation.
Designed by................Troglodyte.
Engineered/ built by......Rustic.
Financed by.................Nickles & Dimes.
Rider......................... Tardus Vetus Inflatio
momec3
Posts: 780
Joined: Tue Mar 01, 2011 10:36 pm
Location: Cedar Grove Qld

Re: oil mods

Post by momec3 »

A little point you touch on which I see mostly ignored at the salt is oil temp. Forget coolant temp, its critical to get oil temp to at least plus 70c before the thing leaves the line.

Fit an oil temp gauge if you don't have one

Most racers rely on coolant temp which comes up quickly but the thing won't make the best power till the oils at temp and stabilised. Cars/Bikes no different.

Chris
Chris
Stayt`ie
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Re: oil mods

Post by Stayt`ie »

momec3 wrote:A little point you touch on which I see mostly ignored at the salt is oil temp. Forget coolant temp, its critical to get oil temp to at least plus 70c before the thing leaves the line.


Chris
what Chris said,, :wink: ,
First Australian to ride a motorcycle over 200mph at Bonneville,,,
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JasonBishop
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Location: Jamaica Plain

Re: oil mods

Post by JasonBishop »

GlowShifts Blue Digital Celsius Oil Temperature Gauge have integrated a digital LED displays with a tinted lens and twisted sleek incredibly thin design of gauge.
penny
Posts: 335
Joined: Mon Feb 26, 2007 8:30 pm
Location: adelaide

Re: oil mods

Post by penny »

Dont look at the price but these are the good vac pumps

http://www.starvacuumpumps.com/
a friend runs electric oil and electric vac pump on his bike
glengowrie annexe of the Institute of Backyard Studies
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