The TRX900 Project kicks off

[dandywarhol]

Lookin good coxxxxxxxxxxxy - when you going to learn to focus the camera?

[coxylaad]

Its an iphone Al, it does what it does!

anyways, who said the trx900 oil tank wont fit?





the top needed dressing a little, and I am going to have to pull the filler cap/dipstick round a bit, but its going to go.

Fuel tank next.

[Killerwhale]

Its an iphone Al, it does what it does!

anyways, who said the trx900 oil tank wont fit?


the top needed dressing a little, and I am going to have to pull the filler cap/dipstick round a bit, but its going to go.

Fuel tank next.

So little TLC and you could kick it in there!? Good un!

[lenny]

Did you know that the tdm air injection system can be easily modified to provide crankcase vacuum which gives a slight power increase and lowers bearing temperatures? Something I learnt from my 600 supersport racing days (although not legal, shhh dont tell anyone). The ideal breather solution.

[Strix]

Respect for the straight on, no nonsense approach.

Looks mighty interesting!

[coxylaad]

Did you know that the tdm air injection system can be easily modified to provide crankcase vacuum which gives a slight power increase and lowers bearing temperatures? Something I learnt from my 600 supersport racing days (although not legal, shhh dont tell anyone). The ideal breather solution.

Sounds interesting - got any pics/info on that?


I will keep posting snaps as I go, I still plan to get it on the road april/may time fingers crossed.

[Killerwhale]

Did you know that the tdm air injection system can be easily modified to provide crankcase vacuum which gives a slight power increase and lowers bearing temperatures? Something I learnt from my 600 supersport racing days (although not legal, shhh dont tell anyone). The ideal breather solution.

Sounds interesting - got any pics/info on that?


I will keep posting snaps as I go, I still plan to get it on the road april/may time fingers crossed.

Blimey i want to ride mine home but winter struck here

[lenny]

Too easy. Just connect the breather to the reed valves in the cam cover, bypassing the solenoid valve.
How it works--- the tdm head has an opening in the exhaust port near the exhaust valve that connects via a tunnel in the head to reed valves in the cam cover. When the exhaust valve closes a vacuum is formed behind the exhaust valve. Normally this vacuum opens the reed valves and air is drawn from the airbox through the solenoid valve (controlled by the ecu, only open at idle) into the exhaust port. By connecting the breather directly to the cam cover a level of vacuum is applied to the crankcase/oil tank. All serious race engines use crankcase vacuum usually provided by large scavenge pumps that will pump air as well as oil. The top fuel drag bike guys usually use an electric air pump and crankcase vacuum is worth around 1/10 second a run. Ever wondered why the oil level rises after you warm your engine. Its because the oil becomes full of tiny air bubbles (not because the oil becomes hot and expands) Oil full of air bubbles does a bad job of removing heat as it passes through a bearing. By applying vacuum to the crankcase/oil tank much of the air is pulled out of the oil. It also helps the rings seal by increasing the pressure differential across them. By the way , I am using crankcase vacuum in my trx using a different method--- easy to do also. Ive mentioned it before but no one seemed interested.

[Killerwhale]

Too easy. Just connect the breather to the reed valves in the cam cover, bypassing the solenoid valve.
How it works--- the tdm head has an opening in the exhaust port near the exhaust valve that connects via a tunnel in the head to reed valves in the cam cover. When the exhaust valve closes a vacuum is formed behind the exhaust valve. Normally this vacuum opens the reed valves and air is drawn from the airbox through the solenoid valve (controlled by the ecu, only open at idle) into the exhaust port. By connecting the breather directly to the cam cover a level of vacuum is applied to the crankcase/oil tank. All serious race engines use crankcase vacuum usually provided by large scavenge pumps that will pump air as well as oil. The top fuel drag bike guys usually use an electric air pump and crankcase vacuum is worth around 1/10 second a run. Ever wondered why the oil level rises after you warm your engine. Its because the oil becomes full of tiny air bubbles (not because the oil becomes hot and expands) Oil full of air bubbles does a bad job of removing heat as it passes through a bearing. By applying vacuum to the crankcase/oil tank much of the air is pulled out of the oil. It also helps the rings seal by increasing the pressure differential across them. By the way , I am using crankcase vacuum in my trx using a different method--- easy to do also. Ive mentioned it before but no one seemed interested.

I´m interested as i´m going to do something about the blow thru...

[coxylaad]

that is very simple and very clever!

Will definitely be doing that, as I am in a bit of competition with a big bore 850 with kent cams and flat slides that my father in law has!

[andyaber]

Too easy. Just connect the breather to the reed valves in the cam cover, bypassing the solenoid valve.
How it works--- the tdm head has an opening in the exhaust port near the exhaust valve that connects via a tunnel in the head to reed valves in the cam cover. When the exhaust valve closes a vacuum is formed behind the exhaust valve. Normally this vacuum opens the reed valves and air is drawn from the airbox through the solenoid valve (controlled by the ecu, only open at idle) into the exhaust port. By connecting the breather directly to the cam cover a level of vacuum is applied to the crankcase/oil tank. All serious race engines use crankcase vacuum usually provided by large scavenge pumps that will pump air as well as oil. The top fuel drag bike guys usually use an electric air pump and crankcase vacuum is worth around 1/10 second a run. Ever wondered why the oil level rises after you warm your engine. Its because the oil becomes full of tiny air bubbles (not because the oil becomes hot and expands) Oil full of air bubbles does a bad job of removing heat as it passes through a bearing. By applying vacuum to the crankcase/oil tank much of the air is pulled out of the oil. It also helps the rings seal by increasing the pressure differential across them. By the way , I am using crankcase vacuum in my trx using a different method--- easy to do also. Ive mentioned it before but no one seemed interested.

HI Lenny

So how are you doing it now?

Cheers, Andy.

[lenny]

I welded a piece of 12mm tube into the exhaust pipe just to the rear of the footpeg. The pipe is angled away from the exhaust flow so it provides an extractor effect. This is connected by a length of silicon hose to a car brake booster valve (a fast acting one way valve.You will find one on your car in the hose from the inlet manifold to the power brake booster)You can get one from the car wreckers for free or buy a new one for very little money.The valve is connected to the breather hose by another piece of 12mm i.d. hose that plugs into the cut down original breather hose..
How it works----as the two pistons move down the bore, air in the crankcase is forced out the breather through the one way valve into the exhaust pipe. When the pistons rise the one way valve closes and a slight vacuum is formed in the crankcase. Once this first cycle is complete the crankcase is operating under a pulsating low level vacuum that helps remove trapped air in the oil and reduces pumping losses.. Any blowby will reduce the vacuum to the point when the one way valve will open and re establish the vacuum. A little thought will show that this will only work on a single, parallel twin or odd fire twin (motors that "pump" the crankcases). Another good breather solution, works for me.

[fung]

hi fellas.
i've been in touch with a bloke named Rex Bunn www.bunn.co.nz
http://bunnbreather.bigblog.com.au , who seems to know a lot about this subject and he is looking into a setup for the TRX.
he is of the opinion PCVs dont cope with the requirements well enough and has designed his own pvc valves which can be split and serviced.
i have some pages of research' and if you want to have a read PM me your email and i will flick you a copy.
cheers
fung

[lenny]

A pcv valve is a slow acting device, it opens when the motor starts and closes when the motor stops. and NOT suitable. Thats why I said to use a brake booster valve. Reed valves are even better.

[dandywarhol]

I think you've been loking at too mant Norton air cooled Rotary injun pics lenny, that's the way they "pulled" air through the engine casings - that's a really simple idea - I like it