40-70CC high rpm
03-15-2011, 09:14 AM
#1
40-70CC high rpm
I have a dominator 1500 now and will be getting another soon. I have a Moki 2.10 that will be modded. the other plane i will build for a gas engine. I am looking for a gas engine that can turn high rpm on small props in the 16x14 - 18x18 range. looking for an engine less than 4.5 lbs
03-17-2011, 11:38 AM
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RE: 40-70CC high rpm
Moki 2.1, 16-15 prop, 10,000 rpm...Fast enough ?
Raced in a hangar 9 sundowner last year in our USRA racing series....Fastest Sundowner on the planet..
Raced in a hangar 9 sundowner last year in our USRA racing series....Fastest Sundowner on the planet..
03-17-2011, 02:00 PM
#4
RE: 40-70CC high rpm
I talked with longrifles and i know what i can do to the MOKI he turns a 16x16 at 9,400 so both seem close. I am looking for a gas engine also so i will not have to run 50% nitro and get 5 flights per gallon.
I am thinking of the DA 60-85 or a 70cc twin.
I am thinking of the DA 60-85 or a 70cc twin.
03-17-2011, 07:34 PM
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RE: 40-70CC high rpm
All Unlimited class racers turn way over 200 mph...a DA 150 will do that @ 10,000 rpm with a 26 pitch prop....Our new ZDZ 210 race twin turns the same prop as the Black Flame at least 800 rpm faster and is way lighter...250 mph is not out of the realm of possibility, a hopped up Aerrow 200 turned 246 mph a few years ago in a NA 50, modified AT6....
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03-17-2011, 09:39 PM
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RE: 40-70CC high rpm
If you are lookig to get the engine to turn high RPM's, then you may need to look at piston port or rotary valve induction motors. Reed valve induction are not great over 8000 rpm. Modified reeds may help a little, but there are others on this forum who will have more experience in this regard. ZDZ have a rotary valve induction, and may be your best bet. Zenoah's are used a lot in racing, but I can't see thet they would match the ZDZ's in the power department, unless modified
03-17-2011, 11:08 PM
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RE: 40-70CC high rpm
Don't tell the DA racers their reeds are not too good over 8000, they're turning 10,000...Quite well 
I have a GT 80 with a special CNC case using a DA 100 reed, it turns close to 12,000..On 25% nitro....With a 19-18 special carbon prop....
No carb, just a BIG venturi....
I have a GT 80 with a special CNC case using a DA 100 reed, it turns close to 12,000..On 25% nitro....With a 19-18 special carbon prop....
No carb, just a BIG venturi....
03-18-2011, 09:04 AM
#10
RE: 40-70CC high rpm
i looked at the GT 80 but seemed a bit heavy. trying to not go much over 4.5 lbs. the box did say could go up to a 4.3ci engine. i looked back in the race rules for this plane and min weight was 13 lbs. The box is stating 18-19lbs. i will look today at the ZDZ 60-85 today. i would think i could get to 130 with the moki. i know there are some MOKI 3.6 twins out there also but then i would be down to 4 flights a gallon.
03-18-2011, 09:50 AM
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RE: 40-70CC high rpm
I'd try looking at the BME 58 if weight is an issue.
The problem with reeds typically isn't in floating, it comes from heat. They all float after a certain RPM point. The better fiber versions are limited to a max of about 90C. After that they permanently warp.
The problem with reeds typically isn't in floating, it comes from heat. They all float after a certain RPM point. The better fiber versions are limited to a max of about 90C. After that they permanently warp.
03-18-2011, 11:08 AM
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RE: 40-70CC high rpm
Our rules for racing are 81cc or less...No other engine we have tested works as well as the GT 80 for this application..my custom CNC case reed valve ignition GT 80 weighs 5 lbs 12 oz without mufflers..
We have a new ZDZ 80 twin ready for testing this weekend, it might work well, it's a rotary valve with a custom larger venturi and no carb...We inject fuel directly into the transfer ports using a small fuel pump and computer control...
We have a new ZDZ 80 twin ready for testing this weekend, it might work well, it's a rotary valve with a custom larger venturi and no carb...We inject fuel directly into the transfer ports using a small fuel pump and computer control...
03-20-2011, 01:14 PM
#14
RE: 40-70CC high rpm
ORIGINAL: Antique
Our rules for racing are 81cc or less...No other engine we have tested works as well as the GT 80 for this application..my custom CNC case reed valve ignition GT 80 weighs 5 lbs 12 oz without mufflers..
We have a new ZDZ 80 twin ready for testing this weekend, it might work well, it's a rotary valve with a custom larger venturi and no carb...We inject fuel directly into the transfer ports using a small fuel pump and computer control...
Our rules for racing are 81cc or less...No other engine we have tested works as well as the GT 80 for this application..my custom CNC case reed valve ignition GT 80 weighs 5 lbs 12 oz without mufflers..
We have a new ZDZ 80 twin ready for testing this weekend, it might work well, it's a rotary valve with a custom larger venturi and no carb...We inject fuel directly into the transfer ports using a small fuel pump and computer control...
