Author Topic: interesting carb on the bay  (Read 5725 times)

Offline steamer

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interesting carb on the bay
« on: November 22, 2023, 10:08:34 PM »
A sliding plate Mactep carb....fairly large....anyone have any experience with this one?

"Mister M'Andrew, don't you think steam spoils romance at sea?"
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Offline Admiral_dk

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Re: interesting carb on the bay
« Reply #1 on: November 23, 2023, 06:57:04 AM »
I have some engines that I havent found time to restore yet, that uses them.

So I can only say that they can be damaged into many shapes when chrashed (not me) :facepalm:

Are you thinking 917 ?

Per         :cheers:

Offline steamer

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Re: interesting carb on the bay
« Reply #2 on: November 23, 2023, 11:41:10 AM »
I was ....
"Mister M'Andrew, don't you think steam spoils romance at sea?"
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Offline steamer

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Re: interesting carb on the bay
« Reply #3 on: November 23, 2023, 03:05:53 PM »
I'll tear it down when it gets here and understand how it works...
"Mister M'Andrew, don't you think steam spoils romance at sea?"
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Offline steamer

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Re: interesting carb on the bay
« Reply #4 on: November 28, 2023, 12:53:09 AM »
The carb arrived today....It's very well made!     Mike the plastic is injection molded, not 3D printed and the throttle slide is ground steel.    I'll get into it and tear it down and we can jaw about it.


Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline dieselpilot

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Re: interesting carb on the bay
« Reply #5 on: November 29, 2023, 02:05:50 PM »
You won't get many hits on that carb in particular. You'll find plenty if you look for Webra Dynamix which it's a copy of. Your carb has a "remote adjustable" needle. The lever on the main needle adjusts the mixture with a servo.

https://www.rcgroups.com/forums/showpost.php?p=33740527&postcount=12

Offline steamer

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Re: interesting carb on the bay
« Reply #6 on: November 29, 2023, 02:50:26 PM »
T
You won't get many hits on that carb in particular. You'll find plenty if you look for Webra Dynamix which it's a copy of. Your carb has a "remote adjustable" needle. The lever on the main needle adjusts the mixture with a servo.

https://www.rcgroups.com/forums/showpost.php?p=33740527&postcount=12


Thanks diesel...   I've now read some.of that....interesting albeit very complicated!...

But that's why I got.it...to find out...

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline jcge

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Re: interesting carb on the bay
« Reply #7 on: November 29, 2023, 09:33:17 PM »

Online petertha

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Re: interesting carb on the bay
« Reply #8 on: November 30, 2023, 04:07:24 AM »
Echo what dieselpilot says. I ran them on 0.60 size 2-stroke RC pattern models for a few Webra seasons back in the day. They worked but did require some adjustment learning, not quite as plug-n-play as the typical Japanese carbs. I do remember them being fussier about fuel pressure boost (typically pressure nipple off the tuned pipe or crankcase, sometimes with/without restriction or check valve). But typical aerobatic flying conditions make more demands on carbs vs stationary engines - range of high speed, low speed, transition, varying attitudes & G's resulting in wider fuel pressure swings. Once I went to YS timed diaphragm regulator, I never looked back.

good source for Japan engine parts
https://www.rcjapan.net/

Perry (now Conley) USA
https://www.perrypumps.com/
« Last Edit: December 01, 2023, 12:19:28 AM by petertha »

Offline steamer

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Re: interesting carb on the bay
« Reply #9 on: November 30, 2023, 03:53:38 PM »
Thanks Peter and Chris     wanted to understand the ins and outs to see if it's even possible


Dave
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Offline Vixen

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Re: interesting carb on the bay
« Reply #10 on: November 30, 2023, 04:29:57 PM »
Hello Dave,

The heart of this carb will be the needle taper and jet. If you are thinking about the 917; You will need to be able to measure the needle taper precisely and then reproduce it numerous times. The rest is just precision engineering.

Mike
It is the journey that matters, not the destination

Sometimes, it can be a long and winding road

Offline steamer

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Re: interesting carb on the bay
« Reply #11 on: November 30, 2023, 04:42:35 PM »
Hello Dave,

The heart of this carb will be the needle taper and jet. If you are thinking about the 917; You will need to be able to measure the needle taper precisely and then reproduce it numerous times. The rest is just precision engineering.

Mike

Yup ...well I'll need to replicate it at least twice!.       Right now it's all exploratory.     It would be easier to hide 2 carburetors if they looked like part of the Bosch slide valve fuel injection system, so at the very least, I had to at least look at what's available, and what would be entailed to build one...or should I say 2.

Like I've said, I'm thinking 2 carbs, one on each bank of 6.    That said I'm trying to disguise it all a bit  (10 dummy injection stacks and 2 real carbs  for this instance)
I am not considering building 12,  or even 4.  carbs   I think this engine is challenging enough to just get running let alone to that level of complexity.

I may build a non prototypical manifold plenum just to get the engine running and debuged ....then craft something a bit more realistic

One must obey the 11th commandment.....
"Thou shalt not kid thyself!"



   
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline Admiral_dk

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Re: interesting carb on the bay
« Reply #12 on: November 30, 2023, 09:31:15 PM »
Amen  :praise2:

 

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