THE NEW MT 57CC ENGINE

[sinergy]

Ya nothing wrong with either way really.. some like to be able to tweak it a bit. Don't really go bad that often unless you check for spark and don't properly ground the plug.. will blow one everytime

[rcign]

And now the REST of the story...I have a test pilot because there is no time for me to fly...The test pilot flies UAVs and can fly anything with wings...He flies our 240 mph USRA Bearcat...There WILL be a video...
The numbers I got with the first engine were not what I wanted. Might be the altitude, 7000 feet..The test engine and pilot are in Phoenix at 1000 feet...It was the one that started all the controversy about the prototype engines in the first place...I have another engine coming from Tomy this week..He's sending it unassembled....There is no problem with the machining, it's very good..There is no problem with the bearings, they're Japanese...The carb is a genuine Walbro, no problem there..Reeds look good..I don't like the use of standoffs, but that's just my opinion...The ignitions come with different caps according to the plug used..For some reason Richie's engine uses the RCJ7Y/NGK BPMR6A spark plug so the cap was too big for the smaller hex on the BPMR6F plug....
The RC EXL ignition has been tested by Bill and also by Pe Reivers in the Netherlands...All the numbers are on my website...He found no problems at all..
There is NO reason to put a spark plug in a RC EXL ignition when checking the timing..It will NOT blow anything, I do it all the time...The spark is strong enough to jump inside the cap to the metal shield...
An ignition WITHOUT a shielded wire and cap WILL blow the sensor if not grounded with a plug in the cap...The spark has to go somewhere, the closest ground is the black wire at the sensor and that's where it blows...
Only ignition problem I have seen was the fault of the customer...He didn't want to make a big hole in the firewall to put the plug cap through...Took the cap apart..Split the silicone insert inside the cap...Spark now jumps through the split in the cap before it gets to the end of the spark plug..
Did it on 2 different ignitions...No problem frixing it, I have new caps....

[closetguy]

Hey! who said tune pipes don't make a difference.i was getting 6800 on the pipe before i change the timing from 14*to 29* BTDC. now i am getting 6840 after moving the timing,on a 23-8 mejzlik.
now i removed the tune pipe and installed the stock pitts muffler and i got 6750.
i need to get a good plug in it still getting a small mid to high end miss in it.

[jrjohn]

	Quote: Originally Posted by closetguy
	Hey! who said tune pipes don't make a difference.i was getting 6800 on the pipe before i change the timing from 14*to 29* BTDC. now i am getting 6840 after moving the timing,on a 23-8 mejzlik. now i removed the tune pipe and installed the stock pitts muffler and i got 6750. i need to get a good plug in it still getting a small mid to high end miss in it.

are you adjusting the mixture after these changes? If not, you could be missing something

[joe barrington]

	Quote: Originally Posted by closetguy
	Hey! who said tune pipes don't make a difference.i was getting 6800 on the pipe before i change the timing from 14*to 29* BTDC. now i am getting 6840 after moving the timing,on a 23-8 mejzlik. now i removed the tune pipe and installed the stock pitts muffler and i got 6750. i need to get a good plug in it still getting a small mid to high end miss in it.

U need a BPMR6A and it will need to be the resistor type.As for drilling and tapping for a change of ignition timing,weve found no issues in the UK as set by the factory.All you have now done is VOIDED any warranty you may of had

Also you wont be able to just put a tuned pipe onto a header and off you go for max performance.You will need to match the length of header to the internal baffle,to the prop size your gonna use.Each time you change prop size,the length will also have to change.There is a formula that can be used to work all this out,but unless you get it right you may as well not bother with a tuned pipe and just use a cannister

[Al Lewis]

	Quote:
	U need a BPMR6A and it will need to be the resistor type.As for drilling and tapping for a change of ignition timing,weve found no issues in the UK as set by the factory.All you have now done is VOIDED any warranty you may of had

Why would this void his warranty?? Did he buy this engine in the U.K?

[joe barrington]

	Quote: Originally Posted by Al Lewis
	Why would this void his warranty?? Did he buy this engine in the U.K?

I would guess not,but i suppose you must of heard of warranties in the States,as im sure you guys aint far behind the UK on customer services.

If you sold a Ford to a guy,who then bought it back,complaing it didnt work properly.He the showed you that he'd drilled some holes in the side of the engine and changed the timing.Would you then repair his car free of charge or even better.Give him a new one.
I think not

If you would.Let me no what youve got up for sale,LOL

[Al Lewis]

No what I would say is that call would be up to the guy who sold him the engine and not you. If Larry is mod-ing his engines because of a problem with timing it's unlikely he wouldn't warranty this one.

[mistydee0]

Dan,
Not to worry you did not void the warranty, you did not do anything to compromise the running of the engine. If you called me I would have told you to do the same thing. I do not agree with the lenght of your header to the pipe. I really think 12" is to long. Soarich said he calculated that the header should be in the 6" range to be effective. I would talk to PE on that one. Dan, get a good reliable idle setting on the needles with good transition and fly the engine and get some time on it then continew to tune.

Larry LS PRO ENGINES



AIRBORN RANGER

[closetguy]

yes i retuned the carb after changing to the pitts,had to make it a little richer.when a company tells you that it should be set at 28-30 degrees thats what i do, just to get rid of that maybe the problem of low RPM.as far as drilling and taping the new holes for the timing sensor there was no other way to fix it.the slots in the hall sensor could not be made long enough to get it to the correct 28*BTDC.the only other way to do it is to move the magnet in the prop hub,SO TAKE YOUR PICK of one or the other! the pipe and header came off a 58gx2, i know you have to match header length for pipe and prop.what i was trying to do was get rid of the idea that the pipe and header are holding down the RPM's. now i can eliminate the timing and the header and pipe of being the problem.
also i was getting 7400 RPM's on the 58gx with a 24-8 beila prop on this same header and pipe after tunning it for good midrange,not peak RPM's. i try to find a happy spot between the two.

Joe, thanks for the spark plug number.

[soarrich]

	Quote: Originally Posted by mistydee0
	Soarrich said he calculated that the header should be in the 6" range to be effective.

I think it was 8", but this is with one of the pipes I have. I was aiming for max hp at about 70~7100 rpm, I think with the pipe set-up properly this would need a 24x8~10. From my testing I've found that prop designations and rpm are not a fixed relationship, so now I'm thinking that rpm readings are BS, I've gotten 8000 rpm with a 22x8, and also 6660rpm with a 22x8. The two things that count are thrust and flying. I've gotten 33 pounds of thrust without setting up the pipe, from what I've read a DA50 is good for 26~7 pounds of thrust, a Brillelli 366GT makes 33 pounds of thrust, so the MT57 is in good company.

From what I've found you can count on 1Hp for every 10cc from these engines set-up for our flying with stock mufflers. Yes you can get more but there's always a trade-off somewhere. There's no substitute for cubes.

This where I got the info, look under tips #6.
http://www.dmac.org.uk/

[closetguy]

WOW! 6" long header now that is short! i am going to start to fly it when the weather gets rite.then i will start to play around with the header length,but i would be willing to bet that i can't get it up to say 7300 just by a shorter pipe?but who knows i just started to mess around with the tuned pipe and header thing on my last plane.
Thanks Larry, on the warranty.