RE: 2.5cc diesel day
 

Jack,

that model Taipan 2.5cc was my first of that size in 1959 and my second diesel.

I still bear the scars of starting it in the days before we knew about ignition improver.

Why the enormous propeller though? It's just punishing the poor thing.

Ray

RE: 2.5cc diesel day
 

Ray, I forgot the prop size so I checked a photo taken that day. 10/5 is what I had in the prop box at the time. Only smaller props were 6 inch in diameter. Getting old and alow ao went with the 10 inch prop. Would have used less pitch if I had one. My first 2.5 cc diesel was the Super Tigre G-30 late 1950's. Jack

RE: 2.5cc diesel day
 

Here are photographs of the venturi/ NVA holder and venturi insert from the RIRE MVVS 2.5D

Insert bore diameter is 4.5 mm at narrowest point. Six peripheral fuel inlet jets exit just below waist.

Overall (exterior) diameter of insert is 9.95 mm (10 mm nominal).

Insert machining and fit is first class.

I could only get the engine to run on suction with my finger blocking off 9/10's of the intake aperture.

RE: 2.5cc diesel day
 

Derek,

if you look at pics of 2.5cc diesel racing engines around the internet you'll ofter see that they have been fitted with a Cox TD 049 or 09 venturi assemblies.

An 049 would suit yours very well. It would just require a Delrin or Alloy plug with an internal 1/4" x 32 (glow plug) thread.

You need to scrape around a bit to get the bits but they're out there.

Below is a pic of my K&B 2.5cc diesel with such a TD 049 assembly fitted.

http://images.rcuniverse.com/forum/u...40/Mj24723.jpg


Otherwise Zenalook on ebay has these nice throttles for TD engines which would also fit the above mentioned plug.

http://www.ebay.ca/itm/Cox-049-050-0...item56476c987e

What is the diameter of the current hole in the backplate, 10mm? I can do you one if you like but they're so simple almost anyone can do them.

I'm ready to do your comp screw, just need it to cool down a bit. We're on bushfire alert today!

http://images.rcuniverse.com/forum/u...40/Lj23523.jpg

Ray

RE: 2.5cc diesel day
 

Hi Ray

Stay safe out there ...

What is happening down south is not good.

Oddly, we are having a cooler (and so far dryer) Summer than usual. Some bushfires up here, but so far no catastrophes.

Take your time on the Russki Elfin.

***

Doing up an insert should be OK, I have access to a lathe though I am zero skilled and have a machinist mate assist. I am freshening a Pee-Wee and have bought off Cox International, so I will look into the Tee Dee carb. That set up is preferred by nearly all.

***

I suspect fuel blockage. It should run on suction on 4.5 mm bore without me restricting the intake. I will clean the jets in the insert with carb cleaner and blow dry.

Backplate intake orifice is 9 mm diameter nominal. NVA holder is 10 mm diameter nominal.

Just for s@*ts & giggles here it is with the ENYA R/C air bleed carb I took off my Ultra 11 CXD when it received its new ENYA R/C TN carb. Awaiting a home the air bleed carb slots perfectly into the backpate intake. Purists may scowl but I may fire it up like this, just to see how it runs.

Bore diameter on the R/C ENYA air bleed carb rotor is 4 mm but the spaybar jet stub must also be taken into account.

RE: 2.5cc diesel day
 

At the Mannering Park engine running soviet on Wednesday afternoons, we've noticed a pattern emerging from the testing of 2.5cc glow and diesel engines on suction.

Interestingly air density seems to be more important that the different glow or diesel fuel.

They can cope with a maximum unrestricted hole diameter of around 4.5 to 5.0 mm in the cool weather.

In high summer they won't even run with maximum hole size.

I'm not surprised that 4.5mm won't work in a Queensland summer.


Bushfires: We're pretty safe really, we live in a small community on a coastal lake on a peninsular with thick bush behind.

We're vulnerable to the hot westerly wind though.

While the house is always in danger, we can safely drive about a kilometer east to the old RAAF seaplane base.

In 2002 we were evacuated and our homes were saved by the timely arrival of an "Elvis" Air-crane helicopter which put out the whole fire front with a couple of ~3000 Litre dumps right on sunset.

I'm a bit nervous about the models and engines though.

Ray

RE: 2.5cc diesel day
 

Fiery,

Sorry but none of my adopted venturis would slip into your 10mm holder.

Ray's solution sounds best, or giggle yourself silly and run it with the Enya carb.

Greg

RE: 2.5cc diesel day
 

Thanks Greg.

Will try the Tee Dee path as Ray suggests. Seems the best solution.

In the meantime, I will have a go with the ENYA R/C Carb.

Mark from Cardiff, Wales runs his on suction ... up to 6 mm bore!

"hi derek i have no rossi abc piston and liners in stock having a new batch of 50 in april/ may. i use 6mm on suction and i have in stock 6mm/5mm/4.5mm/ also mvvs 2.5 abc piston and liners in stock regards mark."

I have lived in the UK. I always thought the air over their more dense compared to here.

RE: 2.5cc diesel day
 

Yep, the UK is about the same Latitude as Alaska I believe.

As opposed to:

http://images.rcuniverse.com/forum/u...40/Yw66620.jpg


From this morning's Newcastle Herald.

RE: 2.5cc diesel day
 

Ray we had a wildfire here in the US California . last year many homes lost all you need is a careless camper or lightning strike and sadly a water-tanker plane and its crew lost
think a KC 130 4 engine turboprop martin

RE: 2.5cc diesel day
 

Martin,

your fire-bombers are far more spectacular than ours. It always strikes me as very unusual to see a Californian fire being bombed by a Boeing 727.

Aussie fire bombers are almost always agricultural aircraft or helicopters. The latter can refill their water tanks by hovering over and dropping a long flexible tube into a dam, or small creek.

In urban areas they can use private swimming pools and I suspect that there's a law allowing it.

Anyway we got a cool change overnight but the hot weather is back with a vengeance later in the week.

Ray

RE: 2.5cc diesel day
 

Derek,

6mm is very big regardless. I wonder if they're running crankcase pressure as well? Mark was using Greg's old RIRE MVVS

and I thought he may have won Diesel Goodyear racing at the UK Nats with it (or most of it).

Talking of Enya Carbys, I should have a spare Enya CX11 glow carby somewhere. Since my CX is now a speed motor I won't need it anymore.

Ray

RE: 2.5cc diesel day
 

Taipan 2.5 cc TBR.

Series 68 (aka Mk. 10).

It does not have the circlip retention for the gudgeon pin.

RE: 2.5cc diesel day
 

A bright Autumn morning at the local flying field.

Running in a late production MVVS for an acquaintance who was experiencing difficulty, and my tight re-built Mk. 10 Taipan.