IronCross

Thanks, I always assumbed it got pushed up the pusrod tubes and lubed the top end that way...

It is beginning to apprear to me that the hookup between the vent and ithe intake pipe is necessary for a decent idle... I think restricting the flow is the wrong direction to go.. I think enlarging the bore closer to the old specs might be a better direction... This is more intuition then science though..

gkamysz

My Feedback: (19)

I have an FS-91 SII with the head off on the bench right now. With the little nipple installed there is enough pressure while turning it over to blow the lifters out of the case. You can turn it over only so quickly by hand and it's more than enough to show that the small nipple is a restriction.

It's hard to say what really happens with the fuel mix. You are essentially recirculating exhaust gas from the crankcase. This means that the throttle would have to be slightly more open at idle, than an engine without the system because this inert gas replaces the some fresh air fuel mix. The amount of this gas will vary depending on the orifice size, tubing length, manifold vacuum, and probably several other things.

You can't choke an engine with the system because the crankcase air fills the intake manifold and there isn't much pressure differential to draw fuel. If you look at the manual that comes with the OS FS-II engine it doesn't mention anything about choking during starting. It doesn't even suggest hand starting. For the same reason it will be hard to drawn fresh fuel air mix through the carb while hand propping. And that now occurs to me as strange because the Magnum includes a choke.

I always lube the rocker assembly after checking/adjusting valve clearances. A drop of motor oil on each contact point. Since this area is pretty well sealed up this lube won't be washed away. It amazes me that OS ships their engines with so little of a lightweight lube inside.

IronCross

Considering that Magnum chose to reduce the bore in there new carburators perhaps they are metering the flow that way whereas OS is doing the same thing with a smaller ID nipple on the crankcase...
All I know for sure is there is a lot more going on here then I originally assumed when I tried to run with the intake nipple blocked off and the crankcase vent running out the bottom of the plane...[]

gkamysz

My Feedback: (19)

I did run an FS-91 SII with the manifold plugged and the crankcase vented. It seemed to tune OK, but I wasn't paying particularly close attention and it was a while ago.

I forgot to mention the OS FL-70 has a strange setup running the crank case vent to a second fitting on the muffler. It also used a fitting with a small hole in the system. I don't have it anymore so I can't tell you where it was.

yallaair

I have just broken in two ASP 91 FS with the new vent system. The engines has been consuming abt. 1 gallon each. Been using 15/15 synth oil. Compression is very good. In the initial running, there was some metal shavings [X(] coming though the silicone tube to the suction tube. This happened to both engines. I stopped them, dismatled cranckcase and camshaft end covers and viped clean inside. After this cleaning, there has been no problem with metal sediments. I was a little conserned about this metal going into the engine... I have taken off the cyl head and inspected the liner. No excessive wear..

However, performance is not so good. I manage following readings:
MAS 14x6 9500RPM
APC 13x8 9600RPM
Volk 14x16 9200RPM

Anbient temp about -5 degr. C.

This is average 700 RPM BELOW the older version. We have tested them side by side with same fuel, same plug, same prop, with and without one headshim removed. Compression is the same on both engines.

Why make a weaker engine???[&:]

P.S. I have just started to break in one ASP 180 FS with the same vent system. I will consider to block the nipple to the inlet pipe, and vent direct to atmosphere...

asmund

SC 91 fs (old version): Mas 14-6, 10300 rpm and Volk 14-6, 10200 rpm. [sm=lol.gif][sm=lol.gif]

yallaair

This is what's killing me!!! Two engines that seems identical with a eeeehhh... [:@][:@] H**l of difference in power.....

A third ASP 91 FS (new version) was capable of producing 9900RPM on APC 13x8 under the same condition as the other engines....

WHAT CAN BE THE REASON FOR THIS DIFFERENCE??? IS IT THE VENT SYSTEM???

gkamysz

My Feedback: (19)

I don't believe the vent is the reason for the reduced power output. It would be easy enough to test. The obvious reasons for reduced power would be reduced compression, smaller carb, and/or different cam timing. Why they would reduce the power output intentionally, I don't understand.

IronCross

Must be the smaller carb... Something to do with the draw on the vent maybe ?... I figured I would get one of the "new" ones ready to test this weekend .. Was tightening everything up includient the 4 nipples and the crankcase one broke off when I pulled the tubing off it to tighten it.. Bummmer.. These are sure thin walled... Looks like it was overtightened when installed... Got the broken part out of the block easy enough... Now need a new one... Just from looks all 4 appear to be the same size and I have a couple extra's for the fuel inlet.. Guess I will look at some part numbers and see if they are indeed all 4 the same... Ain't one thing it's another...

yallaair

In theory, I guess some of the difference in power can be explained by the extra inert gas from the crankcase, going quickly in and out into the inlet pipe and then into the combustion process. Extra inert gas in the combustion chamber is "no good". Also the pulsation from the crankcase into the pipe after the carb will probable disturb the mixing of the fuel/air in the carb. Maybe even blow some of the fuel/air mix trough the carb and into the atmosphere.

Think this must be tested and maybe we can get this confirmed.

NM2K

My Feedback: (14)

Of course, we do not know the reasoning behind the reduced flow carbs.

Perhaps they are focusing more on the 3D crowds needs and have smoothed out the cam profile too in conjunction with the reduced flow carbs? This would also be good for the scale crowd's needs. Fuel economy should increase significantly, if this is true.


Ed Cregger

IronCross

I fired up my first one with PCV on it... First impressions are very good... I have run two 13 oz tanks through it now... Got the idle down to a dependable 2400 and the top end running around 8k... Still a tad rich on the bottom and way rich on the top... Now that the idle is set to a usable range I will take it to the field and do the rest of the breakin in the air... My impression is that this smaller bore carb draws much better... The sweet spot for the idle seemsed much easier to find and the idle itself a lot steadier at this point then my others have been... I haven't peaked out the top end yet.. Like to get a couple more tanks through it and work it up gradualy as per the instructions... Got a feeling I am going to like this new setup even if it is a couple hundred rpm off the older one.. This is just a good sport engine for me... If I want balls to the wall I will get a YS

Phil Heller

My Feedback: (9)

"Much ado about nothing!"

Phil

Patxipt

When i broke-in my ASP FS30AR, for the first 5 tanks of fuel, with the mixture set to very rich, the oil coming out of the crankcase breather was very dark due to metal shavings (the engine is very tight from factory), and eventually started to come clean. I don't dare to think what "good" would this make to the engine if vented to the inlet manifold...
I would advise to break-in the new engines - at least the first fuel tanks - with the breather vented to the atmosphere. One doesn't need full power for the first runs on the bench, right?

NM2K

My Feedback: (14)

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So that the yahoos out there that insist upon running 20% or higher nitro won't break the crankshafts.


Ed Cregger

yallaair

Ed, you may very be right about this!

When I get the chance, I'll check the carb diam. and compare the new and tne old version...

This just underlines what's said before, you'll get what you pay fore! Buy ASP.SC or Magnum, you don't get the same power and durability as the Saito and YS engines!

B.E.

IronCross

As stated in previous posts the carb intake diameter is slightly smaller on the new Mags.. The rpm aprrears to be about 300 off the old ones also... Really nice running sport engines though..

As for getting what you pay for get serious... My Mag .91's will perfrom at least as well as any OS .91's at the field... Seems OS also lost about 300 rpm with there new crankcase vent... As for Saito .91 no one at the field has one to compare to.. I know my Magt. 70 will turn at least as well as my Saito .72's... Ys is a whole different ballgame...

As for wearing out any 4 stroke I have yet to do that... I do have about a dozen 4 stroke engines so use gets spread out... I have older Mag .91's that have many gallons of fuel through them and they still running like new...

Sounds like if Automakers were to take there biggest peice of junk and jack the price way up on it you guys would think it was great...

yallaair

There is a reason why SAITO is more expensive than ASP engines. I have one Saito 80 from the early 90's. About 20-30 gallons though is now. I has handled a lot of dirt, pinewood, seawater and "penetrated" one AUDI A6 , and still running perfect!

I have recently bought 3 ASP engines and they are to be severly tested. But from the look of them, you can see that this is "inexpensive casting". From the reformance record, it seems that they are underpowered compare to Saito and ENYA engines. When is comes to using Curtis Youngblood 30% Nitro 23% synth, the RPM will increase by 300 RPM compared to 15/15.

You get what you pay for, I don't think SAITO or enya or YS are "overpriced"!

IronCross

The only 4 stroke I have had trouble with were my Saito .72's... Bad plastic back plates, bed orings on the intake manifold etc... Ended up wireing down the intake manifold to hold it in place.. Looks real cool, expensive Saito held together with wire... I went through all the backplate upgrades etc and it did no good.. Accidently (finally) discovered what the problem was... My .72'w were shipped with an undersized (od) intake manifold which were loose enough to keep loseing the top oring seal... I had a replacement intake pipe (spare) I put on for grins one time when I was replacing the oring... Fit real snug compared to the original... No problem since.. Just goes to show high prices do not guarentee quality...

asmund

You`re just out of luck The looks is just cosmetic, they usually perform great. My 30 fs, 91 fs and 180 fs produce just as much power as any other brand. Actually my 91 (old one) outpowers OS 91 by a fair bit and is close to Saito 100 on 14-6 prop. I think yours will develop more power as they are used more. I have read several threads on how long it takes the Magnums to reach its full potential. You need to get home and fly more[sm=lol.gif][sm=lol.gif][sm=shades_smile.gif]

NM2K

My Feedback: (14)

An excellent point. Higher price does not guarantee higher quality.

Saito engines are good and I have a fair amount of them. Ditto OS, Enya, Sanye and a few others.

Sanye engines are fine, as long as you don't expect them to perform outside of their design/performance envelope. Just like any other engine that is made.


Ed Cregger

Sport_Pilot

That is only a finish, some like some don't. It may be done that way to save money, I don't know. Earlier ASPS had a smoother finish similar to OS and TT, I thought this looked better. Fox used to use a real cheap finish. No texture in the molds to maintain, no blasting, etching, or cleaning of the injection molded parts. Just throw them in a drum and let the tumble in an abrasive polish for a time. Made for a highly polished finish, but you could see slight swirls where the aluminum would ever so slightly change density, and it highlighted very small surface voids of which every casting has a few. With a finished surface the edge of the voids would smooth a bit and would hardly be noticed.

yallaair

"they usually perform great"

How many do I have to buy before i get ONE that is "great"?? If I spend some extra kroner (bucks) on a Saito, Enya, YS, or O.S heli engines, I'll consider that's a good investment. Then I don't have to test a bunch of engines to get one good. I have tested 3 ASPs 91 FS (new type) with the same prop, fuel, plug and atmospheric condition ( read: side by side test ) and the RPM reading is from 9200 to 9900 on APC 13X8!! [:@]And a Saito has better berformance than a average ASP!

IronCross

And a YS has better performanced then a Saito... What is your point... They cost three times as much as a Mag also... If you prefer to pay 3 times as much for a couple hudred rpm go for it... I find all six of my .91 Mags to be nice rinnung dependable sport engines.... If I wand beg buck performance I go to YS....

asmund

He he , not always. You know what happened to my YS 110, and I had the 91 Fx when it was new, not a very great engine at all, I had to dump the stock carb and remote needle to make it airworthy.

There`s no guarantee for success, no matter what brand

Oh I forgot, I always tell them on my order to ship one of the good ones, don`t you do that?? Magnums that is.
[sm=lol.gif][sm=lol.gif][sm=lol.gif]