Saito 82a Questions

[Lyle]

Hi

I have a Saito 82a in my Sundowner 50.

Here are some questions

...Smoke system...
The nipple were the smoke flued enters the exhaust is at least 1.3cm from the exhaust manifold.
Is that too close?

...Dual Exhaust...
I got a T-piece and added some exhaust deflectors to it will this change the tuning.

[RCModelReviews]

Where did you get the exhaust system?

Do you have pictures?

It's a bit hard to say without seeing.

[Lyle]

Yes, i do have pics.
But they are to big to post. I just tried.
Could I send them to you via E-mail or somthing else.

[Lyle]

Here the exhaust..

[Lyle]

The nipple for smoke...

[RCModelReviews]

To be totally honest, I don't see how that's going to function as a smoke system.

Whose design is it.

Normally a smoke system requires that the smoke fluid runs through a metal tube that is inside the muffler so as to pre-heat the liquid. The liquid then sprays out into the muffler where it's heated by the exhaust gases and turned into smoke.

It's hard to tell from the pictures but it looks as if this is just a T-connection on the end of a silicone exhaust extension. I have my doubts that this will do anything but spray out a stream of liquid smoke fluid with very little smoke going on. That's because there's no pre-heat of the fluid and the liquid won't stay in touch with the exhaust gases for long enough to be converted into vapor. Also, because of the diameter of the fluid tube -- you won't get a nice spray of small droplets so vaporization will be very minimal.

[Lyle]

There is a preheat that runs around the head of the engine. Just tested it now{works great} and it took a while to find the door cause of the smoke.

One last thing. The Dual exhaust is exacty what you said.

Will it effet the tuning and smoke?

Also when i turn the smoke on it bogs down the engine a touch??? why???

[RCModelReviews]

That's a crazy smoke system you have there, I don't think I've seen anything like it before and I must admit that I'm surprised it works.

4-strokes tend not to have tuned exhausts but they are still sensitive to excessive backpressure -- which may be what you're getting when you add the smoke.

When the smoke fluid turns into a vapor, it increases dramatically in volume so that means the pressure in the exhaust pipe increases. That increased pressure makes it harder for the engine to push out the exhaust gasses so you will end up with a drop in power due to contamination of the fresh air/fuel charge with exhaust gasses and a reduction in the amount of fresh air/fuel that can be drawn into the engine due to the remaining pressure when the exhaust valve closes.

[Lyle]

Thank you bruce. So will the Dual exhaust have and diference to the performance???

[RCModelReviews]

I shouldn't think it would make too much difference -- but I'm not a fan of those silicone exhaust extensions -- they can cause other issues because they're so flexible. I've seen engines that kept overheating and stopping in mid-air because the propwash and slipstream airflow was bending the silicone tube until it collapsed, thus restricting the flow of exhaust gases.