Switch_639

I have to decide between MT70 twin or 55 DLE... any advantages of twin engines over single cylinders? which engine would be the better choice?...

jedijody

My Feedback: (1)

That depends on several factors that you do not mention. The MT70 is notably more power, a little less expensive, runs very smooth but takes a little more effort to set up, so far though a very good engine. The DLE55 is almost idiot proof and proven, if noise is an issue where you fly that will rule out the 70 unless you can make your own headers, bolt on after market exhaust is readily available for the 55.

Switch_639

are twin engines more reliable? I did see yes it looks like effort... looks like a split carb and two sets of needles with two fuel intake valves... but I do like the idea... and its $40 diff between the 2 here in SA... so if I am willing to spend more time on it, would I be more happy with it than single cylinder?

arobatx

I haven't heard anything about the MT70 having dual carbs....all the pictures and comments I've seen reflect a single carb, reed induction, offered in a narrow version, with the small 1/4-32 plugs, or standard version with the CM6 plugs. Where did you get the twin carb thought?

jedijody

My Feedback: (1)

You are not listening and are ignoring/not providingsome of the more important criteria for choosing an engine, these two engines run and are physicaly very different from each other. The intended airframe, its size and weight, intended flight parameters, your flying style, flying site noise restrictions, desired exhaust type,what you expectthe engine to provide, and your level of experience are all factors that should be heavily weighted in the decision making process.

No one can tell you which one is the better choice for you with out some of this input.

the Wasp

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plus, the Twin has more "cool" factor [8D]

Flyfast1

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How true that is!

Has anyone heard of any inline twin offerings in the works for us warbird guys? An inline twin in the 70cc range would work well in a lot of narrow cowled planes, e.g., P51, Spitfire, ME109, etc.

-Ed B.

Tired Old Man

My Feedback: (1)

Those are not really practical due to the low quantities that would be sold. It would make a few people happy but a manufacturer quite unhappy. Inline twin development is expensive to do right. You would not want an inline twin that went through a fast and incomplete R&D process.

Tired Old Man

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Jody,

The OP appears to be looking at the 70 due to a lower price and nothing else. It's quite possible he does not know his requiremnts aside from what he can spend.

jedijody

My Feedback: (1)

You could be right Pat, that's why I pointed some of them out. I want to help him if I can but not much to go on. What I also wanted to prevent was the usually confusing 20 different opinions based on ones experience with only one or the other engine, not both.

Tired Old Man

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Good call once again. Still want to hear about the clubhouse debacle.

Switch_639

ok guys, sorry for not too much detail... I have been flying for over 2years... been flying mostly speedy planes, had a mini showtime 4D as 3D... this will be my first GAS 3D plane... but I really want twin, so give me do's and dont's and advantages and negatives of the MT70 please... I know the 55 DLE is nice, everyone uses it around here, but I want something else for that exact matter...

jedijody

My Feedback: (1)

Very well then, first you will need to choose between the slant plug version or the CM-6 version. The slant plug cylinders need 9-3/4" minimum to completelyfit inside the cowl, theCM-6 version requires 10-3/4". The CM-6 version has a bit more power but it's not dramatic,when you get your new MT70 the carb will not be installed, take this opportunity to flush the engine out with fresh fuel and oil mix, just fill the engine cavities up and slosh it around and dump it out, do this several times both in the cylinders and in the crankcase, then let it sit outside overnight to let the gas evaporate. Check all the screws to make sure they are tight and the heads are down all the way making contact with the flange they are supposed to be holding down. Mount the carb with the needles angled forward and test fit the mufflers with the down tubes to the outside and rear. Now get a look at your biggest challenge, throttle linkage, Ican post a picture of what I did but it may not work for your application so you will need to figure that out for yourself. When you have gotten this far come back for lesson number two.

Switch_639

it will be the CM6 version... I checked... I do not as yet have the kit or engine... it will be Goldwing Sbach 50cc... doing thorough research before I rush into anything... I want to know exactly what I am letting myself into... 10-3/4" is this the measurement from the one plug's tip to the other plugs tip? could you post that pic in advance of throttle linkage? thanks

mbinkley

This my MT 70 carb set up. Hope it helps

Switch_639

what is that black cover thing on the carb? does it come with the engine? and the engine mount for firewall? does it also come with engine?

arobatx

That is 3W's solution for the carb reference pressure. Instead of allowing turbulent air to directly hit the open hole in the carb plate, some brass tubing was soldered into place, and tygon run from the brass to the fitting on the 3W velocity stack, where the pressure remains much more constant.

Tired Old Man

My Feedback: (1)

I find the intake reference location interesting. The carb tuning will change as the engine heats up due to the hot exhaust pipe's influence in inlet air temps. It will work, but accurate carb tuning for both ends of the operational temperature range would be interesting.

The 3w intake plenum is typically oriented in line with the crankcase. They also have a secondary tube provision that can be used to connect to the diaphragm cover to route diaphragm pressure sensing to the carb's intake tract.

Switch_639

is this necessarily needed?

jedijody

My Feedback: (1)

No.

arobatx

I used to proactively do these little reference pressure modifications, when many didn't likely require it. I now tune em and test fly em first and only modify the reference pressure if indeed required.

Tired Old Man

My Feedback: (1)

I agree.

av8tor1977

My Feedback: (6)

Those are nice looking mufflers. Do you have dimensions on the bolt pattern, and inlet? How much are they? I might want a set for my latest BME 50cc (homebuilt) twin.

Yeah, I wouldn't want to be drawing hot, exhaust heated air into my engine(s) either...

AV8TOR

jedijody

My Feedback: (1)

Won't fit, they have G26 specs.

av8tor1977

My Feedback: (6)

Ok, thanks anyway.

AV8TOR