DA85 on pipe! Results please.

[ejohn18]

I have 2 85's sounds like it might not be enough prop for my extra but it my be the ticket for my H9 Sukohi on a pitts.

[ejohn18]

well my prop is a 24X12 not 10 type O we will see what it does this weekend.

Eddy

[pe reivers]

Even with 24x12 prop, your rpm might be quite high.
Below are my test results on an 80cc engine, with header probably a little too long for that prop.
(Sagging of an engine when the muffler gets hot is indicative of a too short header.)

Prop 24x10x3 Mejzlik.
Exhaust Header 14”, outer dia 28mm.
TD 75KK, shortened, 6390, 7.7hp (muffler first chamber volume reduced to 400cc) - no sagging
TD75K, 6460, 8.0 hp - no sagging
TD75, 6420, 7.8 hp (has longer internal header) - no sagging
MVVS 3204, 6350, 7.6 hp - no sagging
Scrapbox 4-chamber canster, 6950 rpm (sagging to 6750), 9.9 hp (14” header too short?)
MTW T3 tuned pipe 7000 slowly rising to 7100, 11.0 hp - no sagging

[Royster]

Thanks Gene

Mine is on a can not a pipe and thought of trying a 28x10 2 blade as well but was told by DA that I would lose power compared to a 27x10 which is what I currently have.

[sprice50]

	Quote: Originally Posted by Royster
	Thanks Gene Mine is on a can not a pipe and thought of trying a 28x10 2 blade as well but was told by DA that I would lose power compared to a 27x10 which is what I currently have.

Yes, you should run a 27x10 on can. Night and day compared to a piped setup for power, but perfect for light 85cc planes.

[sprice50]

	Quote: Originally Posted by sprice50
	Guys, Can someone with a broken in KS1090 setup perform static rpm test on a 27x10 and 26x12 Mej? I don't have these props and would like to compare to the MTW RE3 results.

	Quote: Originally Posted by RustyTumbles
	If on a pipe the 27x10 would be to small. They say that the 27x10 and 28x10 have the same static load but the 27x10 would unload alot more in the air which would increase noise due to the increase in RPM. I'm running a 27x10 with a KS95 canister and it seems about right. While the prop unloads in the air it is not excessively noisey. I think the motor will turn a 28x10 at around the same figures as the 27x10 on the ground but I think the in flight performance will suffer.

Hey guys,

The reason I was pushing for a test with a 26x12 or 27x10 is so that we have a direct comparison with the RE3 in Reza's thread as he only has numbers for these props.

However, now that Nick is running his RE3 setup hopefully he will try and tach it on a 28x10mej soon. Nick ask someone at the field if you can borrow one, even for just a test run!

Nick, I too am going to try 12" pitch props next year. Likely a 27x12 Xoar to start and then a 28x12 if need be as I want to see how quiet I can get it without going to 25x12 3 blade mej. I am not going to bother tuning the pipe length as I can handle a little power loss

[avi8freak]

Here are pics of my 85 at the start of my 4th gallon! I ran 2 gallons of lawnboy 32:1 and just switched to amsoil 100:1. I hadn't had ANY problems until I had a deadstick after about 9 mins of flight on Friday. I decided to check into it by pulling my cowl and everything off. What do you guys think could have caused this???

There is a pretty big crack in the crankcase and the cylinder head bolts on the header side are about 3-4 threads loose....

I will call DA tomorrow and get it ready for shipping tonight.
Attached Thumbnails

[Henna_Ojisan]

I'd wager the loose head bolts caused the case to crack - good thing you got it down and inspected it... About every other time out to the field I'll pull the cowl and do a cursory inspection for just that reason...

DA turned mine around pretty quick last time I sent it in...

[sprice50]

	Quote: Originally Posted by avi8freak
	Here are pics of my 85 at the start of my 4th gallon! I ran 2 gallons of lawnboy 32:1 and just switched to amsoil 100:1. I hadn't had ANY problems until I had a deadstick after about 9 mins of flight on Friday. I decided to check into it by pulling my cowl and everything off. What do you guys think could have caused this??? There is a pretty big crack in the crankcase and the cylinder head bolts on the header side are about 3-4 threads loose.... I will call DA tomorrow and get it ready for shipping tonight. Attached Thumbnails

What caused the deadstick? Was it sagging at all i.e. potentially running lean? If not then if the bolts were coming loose that would likely have done it.

At least you know DA will take care of you!

[sprice50]

My Xoar 27x12 arrived. I will report back on testing when things warm up.... in a couple months.

avi8freak - did you get your 85 back from DA?

[ejohn18]

Going to the field tomorrow and wil get some tests with the 85 on a 24x12 mej 3blade I have a 85 with TB muffler and one with a ks1090.
numbers and video tommorow!!!!!! 75 deg wow only in Texas


Eddy

[avi8freak]

	Quote: Originally Posted by sprice50
	My Xoar 27x12 arrived. I will report back on testing when things warm up.... in a couple months. avi8freak - did you get your 85 back from DA?

Jeff called me on Tues. evening and said they were replacing the crankcase and bearings. Said he would get it shipped out on Wed. I am expecting it the first of next week. He believed the cylinder head bolts coming loose just stressed the case too much...He did say "We have NEVER seen this before, but we will take care of it."