riot3d

Just finished breaking in the non cdi 185 DZ on an engine stand, & all I can say is "WOW". This thing is an animal, with scary power, especially on transition from mid to top end.

On my last two tanks, I put on a 20x10.5 PN prop - the same one I normally use on my 175. With 30% heli fuel, the 175 gets about 7,100 with header & pipe, the 185 get close to 7,800 without any restriction. However, the 185 power delivery is smoother than the 175. Since the 175 with the 20" prop already have more than enough reserve power, I have the feeling the 20.5x10 PN is probably more suitable for the 185. Hopefully, I will have time next week to fly with the new engine.

More to follow.

Adrian

apereira

Hi Adrian,

There is a new APC prop which is in test right now, the 20.5x10 is not enough prop, you know the beast will unleash in about 10 flights, believe me, 20.5x 10 is nothing......... the power on the 185 is ridiculous, but I have to note, is on the CDI version that I have noted it.

Best regards

Alejandro

Ryan Smith

My Feedback: (25)

Pictures boys, don't tease. Some of us have to live vicariously, you know.

riot3d

Just take a look at a 140 DZ, it looks the same ...

apereira

Ryan,

The only difference you will see is the reference hose on the fuel pump is not used anymore so it is not connected. I will post a picture of mine in the Acuracy later.

Regards

Alejandro

serious power

' the 175 gets about 7,100 with header & pipe, the 185 get close to 7,800 without any restriction '

Hi,
That RPM increase represents a power increase from 3.2Kw to 4.2 Kw - that is something else altogether.

Brian

apereira

Here is a picture of it, it has Bryan's valve cover on it.

Regards

Anthony-RCU

My Feedback: (2)

The sound meter is going to be a big challenge!

apereira

It is right now with the current props, with the new one it will be ok.

tuny

Its no problem with sound limits. I used 185 in the worlds and every time it was well under the limit

apereira

True!, I forgot about that little detail...

Dave Harmon

Did the pump wear problems ever get fixed?
Some guys were putting inserts into the valve face.....the pump piston was wearing out quickly too.....this was on the fuel pumps...the rest of the engine was great.
This was on the 170 and later versions.
I have 25 cases of CP 30% that I need to use but I had so much trouble that I had perhaps 8 flights over 2 years...I had to give up using these engines until more development had taken place.
The most experienced YS tuners (not me!) had worked on it and given advice...I have a nice airplane and everything else just rotting away for almost 4 years now.
Has the pump been fixed??

Dave
NSRCA 586
AMA 5053

apereira

Dave,

Yes, the pump was fixed on the 175 and on, there is a stainless steel sleeve now on the valves holes.

Best regards

Alejandro P.

Dave Harmon

Hi Al....thanks for the quick answer.
How about the pump piston? Was that ever fixed??
My first pump and it's replacement pump was wore out quickly because of the piston just eating it up....the bore got so big that I am sure the internal pressure was much lower than it should have been.
Lots of black, aluminum filled oil inside the pump bore. I used only CP 30%....no low oil fuel.

Dave

apereira

Dave,

I am going to check on that, as I am not sure and want to give only accurate information, I had a problem with a pump yesterday as I did not flushed the pump about two years ago and have to do that, I will let you know if there are changes.

Regards

Alejandro

Dave Harmon

Thank you and I will certainly be interested in what you can find out.

Dave

apereira

Dave,

Here is a picture (the best I could do at the moment) of the pistons, the one on top is on the 175 pump, 170 on thebottom, it has a taper on top and the lubrication groves are bigger , I guess with better lubrication it should last longer.
The pump internally pretty much remains the same.

I hope this helps and is what you wanted to see.

Regards

Alejandro

Dave Harmon

Alejandro......

Thanks a lot for your efforts to answer the pump piston question.
I had hoped that YS had installed a cylinder liner of harder material than aluminum.
I am somewhat surprised that it lasts as long as it does with a steel piston.
This might be a good reason to avoid low oil content fuel and perhaps add a small amount of castor.

My airplane has limited space in the engine area even for the 170.
Also, I hope the 185 has the same mounting hole spacing.?
Is the 185 larger externally than the 170?

Dave

apereira

Hi Dave,

The fact the piston and liner are aluminum/chrome is no surprise as it is the most used combination for piston engines, from RC to full scale aircraft piston engines, but backwards, where the piston is steel; An aluminum body is easier to manufacture and it is lighter, but I do think the grooves in the piston might be all that was needed to solve the situation you had, how many flights did you have on that pump? 600+?

I fully agree with you about the oil, I still run 23% oil and never had problems, but no Castor, castor in this pumps is a killer if you let the engine sit for a while, my engine was in a bag for over a year, and the old fuel stained the piston, now that I took the pump apart to take a picture for you is when I realized if I want to store this engines, it is better to take the pump apart completely, clean it and lube with a light oil. Personally a have been using 3 in 1 since I was a kid and started on Rc with great results. What do you think?

The 185 is identical to the 170 and it's predecessors, exact same dimensions and physical appearance, the only way to tell which is the 185 is on the pump, the reference pressure hose it is not used anymore, look at the picture I previously attached, apart from that, like with previous models it is a bolt on replacement.

Best regards

Alejandro

Dave Harmon

Less than 50 flights....and I flew the second pump perhaps 5 times because this second pump fixed the first problem but brought a second problem with it that I could not fix in spite of replacing everything there was to replace.

For the past 8 years or so I have been using Castrol synthetic motor oil for after run and storage oil. I have several engines stored in plastic bags after using a considerable amount of oil....they are still perfect after several years,
Previously, I had been using air conditioning or compressor oil which is similar and works well also but the Castrol is much easier to get at Walmart or any auto parts house.
This is not a petroleum product....I use the thinnest weight...cant remember exactly right now....but it is very similar to the oil we use in fuel.
When I get home after every session I put a considerable amount in the intake then spin the engine.....right side up.
This oil has worked better than any other oil I have tried except castor which of course as you mentioned above...will cause other problems.
Because it is synthetic there is no problem starting the engine next time out......or 2 years later.
Try it.....but use more than a few drops....I probably use an ounce after every session...it is odorless so it does not stink up the shop!
Thanks again Al.....

Dave

apereira

Yes, I know that oil, actually have it at home as it is the one I use for my cars, Castrol Edge.

But the pump not lasting 50 flights is very strange, never had that issue, but I always run my engines rich, never lean, and only use CoolPower, Cosmo is better but can't get it, I got 100 RPM more o Cosmo without touching the settings on the engine, but, still, CoolPower to me is the best you can get on the US. What did you use for fuel?

Regards

Alejandro

Dave Harmon

I have always used CP 30% Heli ....
I'll bet I burned up 2 cases on the test stand...
Cosmo would be good too but I have never seen or heard of anyone using it in the USA.

Regards

Dave

apereira

I got two gallons of Cosmo at the '11 Nats , but never had the chance to find out who brought it.

Oh well....

rm

My Feedback: (27)

Anyone know the weight of the 185's new ignition?

Another question: If u were to covert from the cdi version to glow, what's all involved modifyng the motor? I may need to cut some weight after making some fuse fixes.

apereira

The weight of the CDI with spiral wrap on the ignition cable is 108gr.

The conversion only needs replacing the spark plug with a Glow plug, YS prefferably, the backplate you can leave the way it is stowing the hall sensor wire, as probably there's about 6gr of weight on the cable.

Regards

Alejandro P.