Port timing

[Stoneman]

On the transfer ports in the cylinder the angles are a bit off on the side closest to the exhaust ports...You Lose about 30% of your mixture being sucked right out of the exhaust port.

You ultimately want the entire charge being directed to the intake side of the combustion chamber.

Yes that’s true. Very good write up and instructions on Jaguars web site if you need the info

 

[Street Ryderz]

Thanks SR

I’m more talking peek power around the 10,000

I was given the idea of squaring the transfers with JB weld not actually increasing the area
This I learnt should give me a faster in take charge but not really understanding what that means. I’m thinking it’s less charge being lost during compression or back pressure into the case on the up stroke?

I’m thinking of raising the exhaust duration to around 160-165
I believe that can make good use of the power, I have to work out the measurements yet
TBH I’m still confirming what I’m thinking

I believe the version 6 cdi is good upto 10,000 rpm and couldn’t be tested past that, so could probably be happy reaching higher
He has a bit of a right up on his web page about it

Sorry for all the edits

If your peak power is at 10,000 rpm then the peak rpm will be higher yet.As I said that can be controlled by the pipe tunning.Look at this dyno graph you can see when the pipe hit's, the peak power and the extra rpm after peak power that falls off the pipe.I run 170 degrees duration for exhaust with no issues and no loss of torque so 165 should be fine.As far as the transfers go it's the wall closest to the exhaust port that needs it's angle corrected to aim the flow rearward to the intake it can be done without the jb weld by cutting into the upper corner and blending it back to the window,Again saying that 30 percent of the intake charge is lost to this casting error is only true for a stock or untuned pipe since on a tuned pipe the return wave puts what was pulled out back in.the second pic is how I fix the casting flaw in the transfers.

 

[Stoneman]

It looks pretty tricky the way I’m looking at it



From what I can tell the angle is relatively pointing towards the intake?

 

[Street Ryderz]

It looks pretty tricky the way I’m looking at it

View attachment 79856 View attachment 79857

From what I can tell the angle is relatively pointing towards the intake?

What I do is put it under the faucet and run water through from the base and watch to see how it exits the port,The way yours is right now is close but if you do the water flow test you'll see that at that edge it will hook around. Then after water testing I spray it all with wd40 (water displacer) and oil the cylinder wall.

 

[Stoneman]

Mate that’s an awesome idea

THANK YOU!

 

[Stoneman]

What I do is put it under the faucet and run water through from the base and watch to see how it exits the port,The way yours is right now is close but if you do the water flow test you'll see that at that edge it will hook around. Then after water testing I spray it all with wd40 (water displacer) and oil the cylinder wall.

Spot on!

One done and look at the difference

 

[6blueoval9]

Where the stream of water from the faucet is being sent down into the transfer will change how the stream flows out of the port..closer to the exhaust side the more it shoots towards the intake due to that lip.

I would imagine the stream of water needing to be large enough to cover end to end of the port to really see how it flows.

Flow of water in center of port...has an awesome flow on intake side even hugging the cylinder but the flow from closest to the exhaust port is shooting over half the width of the piston.

Stream favoring exhaust side...appears to be sufficient when pressure is high enough to redirect flow over the lip.

The only way I'd know how to get that flow is filling that gap between the port and that lip and angle that exit towards the intake side... You want the same angle on the exhaust side as the intake side...it's almost like a Y between the 2.

 

[Stoneman]

I’m not trying to be a smart arse but I’m not a dummy

I could see the difference moving it around.

If you look at my photo properly I have attempted to direct it the same way

 

[6blueoval9]

I know..I'm just making sure people understand when checking, the position of water flow changes things....someone might put it towards exhaust side and think flow is just fine.

 

[Stoneman]

if you want a true Indication you need coloured smoke that will fill the transfer to show true direction with suction I would think would work best rather than just blowing/pushing alone

The water just shows the direction the angle is flowing and believe that will the best indication with the average bloke

I don’t have access to a F1 workshop unfortunately.

My wife said no your bike motors are enough!