maxtenet

Hey guys,

Check out this Japanese web site and the novel approach to diesel conversions to rear intake. They are for sale but I can't read Japanese!




http://www.50products.com/english/diesel/remodel.htm



Max

AMB

Max it is available in english they had a conversion that had to be loaded. I do not know if this a commercial enterprise or AJ has
a japanese clone. they all look great and quite a variety ,NOTE as soon as I pulled up the site the english conversion download appeared martin

DesignMan

Verrry interrrrestink! The ones that have been converted to rear rotor will run left hand, won't they?

I wonder why he did that.

AMB

AJ or Randy any thoughts on this?? (the rear conversions at the least new cranks and crankcase fronts maybe 2 pc pinned crank to run the intake would not be much of a load maybe extended crank pin to turn valve disc?? martin
the thottled cox is pretty cool looks line only original part is cylinder assembly

Hobbsy

My Feedback: (102)

It looks like he used a drum style rotor for the rear intake, it would not allow reverse running. Had he used reed valves it would run either direction as you suggest.

Tom @ Buzzard Bluff

dieseldan wrote:
< the thottled cox is pretty cool looks line only original part is cylinder assembly>

Looks like a bone stock Queen Bee from here. Only give-away is the altered head with contra-piston adjustment device in place of the glow contact.

hobbsy wrote:
< It looks like he used a drum style rotor for the rear intake, it would not allow reverse running.>

Wouldn't that depend entirely at what point he cut the induction window? Is my ignorance showing?

Hobbsy

My Feedback: (102)

In reality the drum timing is the same as the front induction, just on the other end of the engine and would only work well in one direction, it would require a different drum to run reversed just like reverse direction requires a different crankshaft. A good question is not a sign of ignorance but one of a desire for more knowledge. A good thing.

DesignMan

I was assuming that he just used the standard crankshaft as a rear rotor. It would cause the engine to run counter-clockwise viewed from the rear, thus, from the new "front", it runs clockwise, or what we regularly call "left hand" rotation.

Of course if he made a new "rotor" he could set the timing wherever he wants.

gcb

I remember somewhere in my memory archives that a "regular" drum rotor can be turned 90° to run reversed. Seems to me it would work as long as the cover is rotatable (screw positions). Same works for front rotor if the front housing is screw mounted instead of integral.
This, of course, does not apply to engines where the power has been tapped off the back. I would assume that on the FP-10, TT-15, and other rear intakes that the regular crank has been replaced by a timing drum similar to the old SuperTigre G31, 32, and 33 rear drum diesels from the late 1950's.
Opinions?
In any case, those are some great looking engines.

George

Tom @ Buzzard Bluff

Well Duh! I did it again---I made an assumption. Looks like I'd learn at some point. I was thinking of a disc rotor, not even noting that he was still using the crankshft.

Design Man wrote:
<I was assuming that he just used the standard crankshaft as a rear rotor. It would cause the engine to run counter-clockwise viewed from the rear, thus, from the new "front", it runs clockwise, or what we regularly call "left hand" rotation.>

Sho' nuff. Had I observed rather than merely looking I would have seen it. [&o]

gcb wrote:
<I remember somewhere in my memory archives that a "regular" drum rotor can be turned 90° to run reversed. Seems to me it would work as long as the cover is rotatable (screw positions). Same works for front rotor if the front housing is screw mounted instead of integral.>

Once again I open mouth to better insert foot. If the induction port was moved to the bottom in the case of the physically reversed engines would that maintain CCW rotation when observed from the new 'front'?
As someone observed on another board my 'Lysdexia' may be showing. Tom

gcb

You wouldn't really want to turn it 180°. If you look at a normal front intake engine with the crank pin at bottom, turn it in the normal direction and note where in the rotation the crankshaft bypass opens and closes. Now picture where that would be if rotated the other direction. The setting would be closer to 90° in the clockwise direction (from front).

George

Hobbsy

My Feedback: (102)

Interesting to note that on the LA .40 and a couple of others he cut the front off of the stock crankcase, turned it around and made a new "front", for the other end, now the exhaust is on the other side of the engine.

DesignMan

I tried flipping the tank 180deg on my RR1 once, figuring it would reverse the rotation. It didn't!

I still have a couple of those engines, maybe I'll try the 90 deg thing and see what happens. Or be sensible, measure the timing and figure it out on paper. Naaaaah![:'(]

Tim Wiltse-RCU

Larry,


Well funny you ask. I was working on my little drum rotor project engine over the weekend and I was messing with the messed up RR-1 tank that I have(don't ask what happened to it). I thought turning it 180 would make it run reverse as well but after looking at it nope. It looks like 90 should do it I just wonder if having the drum opening off center would have any effect on the balance of fuel going up the cylinder.

LAter,

Tim

RRyan

Most rotory engines use a crank timing of about 45 degrees, thus the 90 degree change will reverse the rotation of the engine perfectly.

Most drum valve rear rotors use a tang off the drum that engages the crank pin. Very little load there. I built a rear rotory Cox .051 and simply filed away part of the rod to gain enough pin to engage the disc rotor. Of course you probably wouldn't want to do that on a high performance engine, but you could drill the crank pin out with a carbide drill bit and use a pin to drive the valve. Lots of way to do it simply.

The engines using the case backwards either run reversed or they made new cranks. My guess is they run reversed otherwise the convenience of the setup would be lost. I'd like to see how they linked to the drive shaft since it carries all the engine torque. Then on the other hand, they may have made solid cranks and new drum valves. On the one piece cases the timing would have to be changed with the valve since the case can't be moved. They are probably ball bearing as well by the looks of the bearing housings. Very clever, wish I'd have thought of it!

DesignMan

Yes, but I don't see any advantage over keeping the original setup. All you seem to be adding is weight and extra bearing drag. Unless crankshaft breakage was an issue??[]

maxtenet

Hard to say, but with a drum valve one can get much more radical timing without worrying about the crank breaking. The drum can be made very light! Also, its much easier to turn up a new drum on the lathe for experiments!

Max

Tim Wiltse-RCU

I guess it's something different.

Later,
Tim

RRyan

Larry,

Beside the reasons already stated think about the work save in the case. That is the single most complex part of the engine to make and really there isn't that much added weight if the drum is new and thin walled. The additional weight is in the bearings and a little in the bearing housing. Besides that, these are really just done for the sake of doing it, were they to be produced I'm sure they'd be done quite differently.

Dan Vincent

Some other examples of rear drum rotary valve engines are the original Supertigre G-30, G-21 & G-32 engines.

Another neat trick was when the Czech FIT 1.5cc RDRV engine was created using a Russian 1.5cc OTM "Stryx" engine as the basic building block. FIT made them in BB and PB versions.

gcb

Dan,
The only thing I don't like about the ST .09 diesel is the weak looking mounts. For that reason, I have not had mine in a plane since the 1050's. It is an excellent runner, and perhaps not as fragile as I perceive it to be, but because of the lack of parts, I don't want to chance breaking it.

George

Dan Vincent

Hi George,

Good to hear from you....it's been a while.

Yeah, the G-31 is a neat engine. Very unique look. It came with a choice of BB or PB front end. Early versions had a brass plug at the end of the drum while later versions had a rubber snap-on cover.

The Supertigre G-33 1.5 is another nice engine. It is front rotor with one-piece case...mine started on the first flip.

Motorboy

"STRYX"???? [X(] I can read the text at engine at your picture. There are texted "СТ�*ИЖ"
pronounced as STRIZH.

Jens Eirik

Dan Vincent

Jens,

Thanks for the correction.

Yeah, it's a loose translation. Check Clanford's book, he calls it a Stryx too. I think it means "Stork" in English. Some of the Russian words get changed to make them sound better in English.

The point was FIT used the OTM engine to make their rear drum engine.

Motorboy

No it is wrong, "Stork" at russian will be "АИСТ" (Aist).
"СТ�*ИЖ" (Strizh) means "Tower swallow".

I learned russian because i am married with wife from east europe. We are speaking russian every day when we are home.

Jens Eirik