Ke30 Rotorolla

[LXY-642]

love your car mate.

 

got a question for ya to. so you gotta mix in some 2 stroke oil in your fuel for a rotary? i thought you could just run straight pump?

[kangaroosa]

love your car mate.

 

got a question for ya to. so you gotta mix in some 2 stroke oil in your fuel for a rotary? i thought you could just run straight pump?

 

Standard Rotaries run an Oil Metering Pump (OMP) that you'll find on the front of the block with a linkage to the standard carby. There is oil lines from the OMP to the intake manifold, and more oil is injected into the combustion process as the accelerator/linkage is moved.

So it just injects dirty sump oil into the combustion process to lubricate the seals. Sometimes they fail.....some people don't like the idea of injecting dirty oil......some people hate topping up the oil every now and then...etc

The main reason is that alot of people swap to webers, and they require some thought and modification to setup the linkage.

 

So the alternative is to remove the OMP, and run a 100:1 mix of 2 stroke when you fill up for track days or 200:1 for the street. I normally just throw in a cap or so of oil. Your gauranteed of good lubrication, and no premature failure due to an OMP not working and the seals not getting the required lubrication.

 

So I guess thats where some of the Myths come from that Rotaries burn oil and need to be topped up every week. Yes they use oil, but it serves a purpose and its normal.

Edited November 11, 2010 by kangaroosa

[LXY-642]

sweet as man, thanks for the info. always good to learn more about rotaries.

[13BT_KE20]

nice work with the car, its looking awesome and saounds like its coming together nicely.

 

I recently replaced almost the complete brake system in a car and was shocked at how BAD they were on the first drive.

Very much how you described yours, I rebleed my lines and gave them a good bedding in and they have been AWESOME since.

So maybe give them a bleed and a few more ks.

 

I run 200:1 pre-mix in my rotors, and any two stroke oil seems to be fine. Sometimes a little smoky at idle but no stress cos i know its just the pre-mix and its only very light. Most of the shitboxes driving around most worst.

[Taz_Rx]

I removed my OMP on the last re-build too.

 

Advantages:

I've now never used any sump oil, my oil level NEVER changes now. For this reason I buy more expensive sump oil as its not just just being burn. I used to just run $25 for 4lt oil.

2 Stroke oil mixes with fuel and burns much better than sump oil.

You have to piece of mind of know - If you're engine is getting fuel, its also deffinately getting oil. Don't have to worry about an OMP failure.

 

I run Yamalube outboard 2 stroke BTW.

[kangaroosa]

I bled the brakes last night and went for a 15min drive to bed the brakes in again (remove the rust more so). They felt better, but not 100%.

 

I then unbloted the brake pedal and wound out the fitting on the threaded rod to make the pedal sit higher and give it more throw before it bottoms

out before the push rod does.

Just sitting at idle the pedal seemed to feel alot better. Like it had more travel and wasnt bottoming out. I'm yet to drive it again...but i want to half the difference and lower it a bit from where it is. As heel and toeing is dangerous because my foot tends to slip off the pedal reaching for the accelerator :(

 

As for premix, I've been running a Stihl 2 Stroke oil. Its fairly cheap (well my first bottle was as we do alot of work for them). I have been recommended Motul 800 by my engine builder, but it seems a bit pricey considering many others use other brands and don't have an issue.

I also just realised i have been under oiling my engines. I normally chuck in 40-50mls on every fill up including half tank fillups. For some reason i did the maths wrong and the online calculator is telling me it should be 225mls for a 45ltr fill up. Agree?

Seems like alot of oil.

My previous engines have all still had the OMP connected, but the linkage was removed so it was effectively getting idle mixes through the rev range. So the premix would have helped to compensate for that.

Edited November 12, 2010 by kangaroosa

[SLO-030]

Lookin' good mate. Sounds good!

 

I agree, 225ml into a 45lt fill up works out at 200:1

 

40-50ml into a 45lt fill up works out from 1125:1 to 900:1 :o

[kangaroosa]

Lookin' good mate. Sounds good!

 

I agree, 225ml into a 45lt fill up works out at 200:1

 

40-50ml into a 45lt fill up works out from 1125:1 to 900:1 :o

 

Thanks. Seems like alot of oil compared to how much would be injected from the sump by the OMP over a tank full. Now I understand why blokes are bitching about the price of oil and how much they go through :P

 

Took the car for a spin after i made my last post. The brakes are still not right. There is not enough bite. I noticed that the rear wheels were waaay hotter than the fronts. Makes me wonder if the rears are glazed or if the pistons are seized up again. I'm bloody over these skyline brakes. It seems all I do is rebuild them every few months because they have rusted up and seized.

[ninja-philbo]

dude sex i love this car

[Taz_Rx]

I run 100:1 with the Yamalube so 40ml per 40 litres.

 

Maybe its worth spending the $80 odd for one of those Wilwood bias valves!? :hmm: At least that way you'll have some way of controlling the bias if the rear are working a bit too hard.....

 

http://cgi.ebay.com.au/Wilwood-Brake-Proportioning-Valve-260-8419-New-/270650389574?pt=AU_Car_Parts_Accessories&hash=item3f04053446

[kangaroosa]

I run 100:1 with the Yamalube so 40ml per 40 litres.

 

Maybe its worth spending the $80 odd for one of those Wilwood bias valves!? :hmm: At least that way you'll have some way of controlling the bias if the rear are working a bit too hard.....

 

http://cgi.ebay.com.au/Wilwood-Brake-Proportioning-Valve-260-8419-New-/270650389574?pt=AU_Car_Parts_Accessories&hash=item3f04053446

 

Thats the way i worked it out intially, but after doing the maths again and using an online calculator I realised my figures were wrong.

1L = 1000ml

200:1 Ratio

1000 div 200 = 5mls of oil per litre of fuel

So 45ltrs X 5 = 225mls per 45ltrs of petrol

 

So 100:1 = 450mls per 45ltrs of fuel. Thats waay too much in my opinion. No way would an OMP inject 0.5lt of fuel over a tank of fuel.

 

My engine was smoking from what I assume was all the oil sitting in the bottom of the tank. I used to put in 40mls at a time. I can't imagine chucking in a few hundred on each fillup and not having it smoke.

 

 

As for the brakes....they have worked perfectly in the past. So good they felt like they would put me through the windscreen. Both times they have given me grief was after the car had sat for an extended period and the rear calipers (handbrake mechanism) had rusted up and locked. Last time they were locked on that much, the inside wheel would lock up when cornering when it unweighted.

Having said that, I have to do something so i'll look into the bias controller. No good will ever come of it if I have the ability to lock off the rear brakes though :P

[Taz_Rx]

No good will ever come of it if I have the ability to lock off the rear brakes though :P

 

I was going to mention that ability but yeah!! :lol:

 

It does seem like a lot of oil, and yes its probably more than the OMP would inject over a tank. Saying that though 2 stroke is a different type of oil and it mixes with fuel different. At the end of the day I'd rather over-lubricate my motor even if it does mean I spend and extra $1 every time I fill up. My engine builder told me to run 100:1. He's been racing rotaries for 30 odd years so I'm happyto trust him. :yes:

[_FNQ_rolla_]

I never knew about the “OMP” on the rotary engines, and as for one of those Wilwood bias valves …….

 

“You know you want to”! :nervous:

[rolla13bt]

I always run mine at 200:1 so 100ml to every 20 liters and i use stihl 2 stroke which is made by castrol and is designed for high reving two strokes. it burns realy clean and my car doesn't smoke at all and it's about $40 for 4 liters. i used to run castrol r30 which is a castor based oil which smells nice but seems to carbon everything up and it's about 20 per liter so doesn't last long.

[kangaroosa]

I always run mine at 200:1 so 100ml to every 20 liters and i use stihl 2 stroke which is made by castrol and is designed for high reving two strokes. it burns realy clean and my car doesn't smoke at all and it's about $40 for 4 liters. i used to run castrol r30 which is a castor based oil which smells nice but seems to carbon everything up and it's about 20 per liter so doesn't last long.

 

Thanks for clarifying that up. Sounds like we use the same oil. Time to go top up the oil I think.

 

Do you remember some bloke chatting to you in the bottle shop drive through in G'Town about 18 months ago? That was me anyway. I was there for Dans wedding. I think i meantioned my car as we were chatting about your beast. You have the best sounding/angriest rotor ever buddy.

 

If its not already nominated, i'm adding you to the list for Car of the Year.

Edited November 16, 2010 by kangaroosa