What are the advantages and disadvantages on using a tuned pipe on an OS 65 LA??
This engine is a dog with a 12x7(9120rpm) so i want to increase it's power with THIS prop.
Thank you.
Kostas
Greece

Hello,
Advantage are abvoiously much more power and quicker throttle response. Disadvantages are the cost and the size.
If you wanna try a tuned pipe then get the "flatdisk" type as they are tuning much broader and easier for sport applications.

These people have the flatdisk , they call it purple pipe, and header you need.

http://www.justengines.unseen.org/pipesjen.htm

Excellent!
Thank you.
Do you own any of these and what increase on power you saw?

I have one on my Irvine 53 and it works great. Fast throttle response and very good peak rpm[sm=thumbup.gif].

Irvine 53 on a pipe turns a APC 13x6 @11500-12000. I have never tried the stock muffler but I guess the rpm would drop down below 10000rpm.

Kostas, as an intermediate (& cheap) trick, remove the muffler baffle, & additionally, drill out the exhaust nipple with the next-size-larger drill. That is -- try drill bits up its arse until you get a close fit, then drill one size larger.

You will have to re-tune it, but it will gain a bit more power. It could be as much as 200-300 RPM if you are lucky. Your engine should also pick up a bit with a few more hr of run-time.

Too much trouble for a not standard conclusion???

I'm not sure what you mean, but it is a common tuning trick & is very easy. The extra power is free.

Well maybe you're correct!
Also have you seen the OS hano tuned pipe?
Ofcourse it is very expensive!
But my engine will gain true power with it!

I do exacly that to all my 2 strokes. it`s a great way to wake up an engine.thats why I get 13300 rpm on the 12.25 prop on my asp xls 52. Normally this engine and prop will give 12800 rpm. I have also done this on my os 91 fx, but did not tach it before modifying it so I don`t now how many rpm`s I gained, but the engines power in flight was greatly improved. go ahead and do it kostas

that is get rid of the baffle and drill out the exhaust outlet. free power

APC 13x6 12000 with an Irvine 53?[X(] Are you sure you did not mean a 12x6? Yes a pipe is good for a lot, but this much?[&:]

Can i ask you sth else?
I haven't used any tuned pipe in the past,so is it easy to set-up and gain the lovely +++rpm's?

STG,
The numbers are correct and I am gonna put a APC14x6 on it soon.

Drilling out the muffler is no option where I fly as the noise would be much higher.

Kostas1
(previous statement from you)
With my LITTLE experience though and with 3 OS engines noe i am very very pleased!
I will keep buying OS engine until i find one that is a piece of crap!
You know what i mean!

This past statement made by you pretty much sums it up, and you want to talk tuned pipes. Others have mentioned the basic ways to get more power and you appear to be lost. I guess you found your match. I hanno pipe on a LA .65. This just proves you have no clue what's going on.[sm=drowning.gif][sm=drowning.gif]

Kostas,
The Hanno is twice as expensive as the purple pipe I suggested and is specially made for the OS61 Hanno engine. Nothing wrong with that Hanno pipe but the other pipe I suggested will do the job for your engine.

If you buy the purple pipe then just bolt it on and go out and fly dont cut anything. You could use anything in the range of 12x7-14x7. Good luck

Thank you.
I mentioned hano tuned pipe because i just saw it!
And thank's again for your help.
You know,
many people here on RCU are critisising people who place threads for info!
Look the above of your post![&o]

I'm just curious why you think that a pipe would be quieter than removing the muffler baffle & drilling the outlet pipe, or have I misenterpreted what you are saying?

-------------------


I used muffled tuned pipes when flying pattern. They were much quieter than the stock mufflers. Did I miss something?

It seems that I missed something -- I'm surprised that the pipe would be quieter than a stock muffler. The pipes that I used years ago would blow your ears out.

britbrat,
Dont get me wrong because the idea of removing the baffle is often good for better breathing and more power. The pipes I have suggested are modern flatdisk "fourchamber" pipes, "Hatori look a like" but much cheaper. They have one expansion chamber and three silencer chambers. Thats why they are more guiet than any other "bolt on" muffler and give your engine the supercharging effect you desire. The modern OS mufflers has one expansion chamber and only one silencer chamber.

That's nice to know -- I haven't been near a pipe for years -- my ears are almost gone & I don't want to lose what's left.

Just before you run off thinking you've done the best thing by buying the Just Engines cheapo Hatori copy pipes instead of the original... there is a difference.
I bought the 1.40 pipe... it looks very similat to the original Hatori... infact some people can't tell it apart. I can tell you one thing... it's doesn't perform anywhere near as well.
It costs half the price of the original... The problem is that the original performs 250% better. It isn't just a RPM thing, it's about throttling and a smooth flat response/power line and finesse! The copy is far more on and off... sure you can play with the lenth for the season... but it's to avail... it isn't a class act.
Not that 99% of JE market cares... one presumes they just want on/off power!

Now this is a real "challenge".
So the pipes of Justengines are copies of Hatori tuned pipes?
And another question.
When we use a tuned pipe instead of the original muffler,did the temperature of the engine increases?

Kostas,


I wrote to you that your engine should spin at 11,000 RPM with this prop, as did this same engine, in the MAN 03/05 issue multi engine test, on 10% nitro.
The performance of your engine is particularly substandard.

A tuned-pipe should not be installed to treat a malady of an engine, but to increase the performance of an engine, which is in good condition and is producing its maximum performance as it is.

If your engine was getting 11,000 RPM, a properly set muffled pipe would bring it to 12,200-12,500 RPM.

You should contact BAX in the OS support forum, as your engine is currently producing only about half as much horsepower as it should.