Wasted power!

[Rctintin]

you may open up the hole and the engine cut once up and down comes the heli in a shower of bits.

If this were true, your engine would not 'cut' but a reduction in back pressure would just loose you some power.

Look at control line racing planes - 2stroke, 30K rpm and no exhaust at all. Now they are fast!!

[Tim Procter]

you may open up the hole and the engine cut once up and down comes the heli in a shower of bits.

The very reason we learn to "Auto"

[trillian]

Not to contradict your statment, but flowing is much more important than polishing.

On an inlet, you need a smooth flow, but with roughish finnish. This improves fuel and air mixture as turbalence (eddies) are created along the path of the flow helping to mix the fuel and air up.

'Matching and polishing' was a very standard service done on motocross bikes and gocarts back when they needed tweaking to get a competitive edge.

[Steve]

If you're using a Hatori pipe with the separate header and anti-vibration mountings, then it might well be worth giving it a go. If it doesn't work then you should be able to just get a new header without having to replace the whole exhaust.

I'm interested in the results, but I'm a coward, so will wait with interest to see what your published results here are Tim.

[Tim Procter]

I'm interested in the results, but I'm a coward,

Having met you Steve I think not a coward but quite sensible..

In other words let some other bugger try it first at their expense.

[Rctintin]

Tim, do you run OS or YS?

If its YS, I am only to happy to mod mine and send to you to test it as I dont have a 700 yet, or your flying skills!

[shuglu]

The Kasama header already offers this choice. Opinions seem to be divided over whether the Kasama header offers increased power over the entire RPM range or increased torque at top end while sacrificing mid range recovery.

[Tim Procter]

Tim, do you run OS or YS?

If its YS, I am only to happy to mod mine and send to you to test it as I dont have a 700 yet, or your flying skills!

OS91-HZ with CY MP6 on all three helis Rob.

[Steve]

I didn't know Kasama did headers for Hatori pipes. Are these sold on there own or as a part of a complete Kasama muffler?

Anyone got a link to these products?

[heliward0]

The Kasama header already offers this choice. Opinions seem to be divided over whether the Kasama header offers increased power over the entire RPM range or increased torque at top end while sacrificing mid range recovery.

beat me to it buddy!!!!
fast-lad sell em and real raptors BUT they where a bit scarse a few weeks back

[Steve]

Tim, do you run OS or YS?

If its YS, I am only to happy to mod mine and send to you to test it as I dont have a 700 yet, or your flying skills!

I've got a YS, but I wouldn't be able to tell the difference unless it hit me like a juggernaut at full chat!

[shuglu]

Available on their own.

Fast Lad Performance

Fast Lad Performance

[Kwickkwack]

Great thread Rob
Must admit in my early two stroke days, different tuners had slightly different ideas, but there is no doubt that a finely tuned motor was always better than a stock engine. The only downside of more power is usually at the expense of engine life.

[Downdraft]

Rob your thread reminds of when I built my Rex 600, I was too mean to buy the NSP and purchased the motor and pipe seperately only to find that I had no gasket for mating the two. I popped along to my local model shop and purchased a packet of Quick UK gaskets designed for 50 size engines only to find when mating the pair togeather that the alloy gasket was in execess of 1mm too large all the way round the manifold, I like you say made the choice of using a dremel to remove the material not wanted and it's always worked fine.

[Butuz]

I was just going to post to be careful with the dremel because depending on the engine it may actually require a certain level of back pressure in order to function at it's best - but I see someone has already posted that so will leave it at that!

Freeeeeeeer flow is not always best for a normally aspirated engine.

Butuz