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Engine basics => Engine set up tips => Topic started by: Robin_Holden on October 11, 2008, 12:30:21 PM

Title: Diesel 40 for Stunt ?
Post by: Robin_Holden on October 11, 2008, 12:30:21 PM
Greetings all ..... There's an Irvine 40 Diesel R/C on you-know-where ! E-Bay that is !
It's located in the U.K and is NIB as they say.

Now , when I was a lad all we could afford were diesels. I remember fondly a Frog 150 , terrific little engine.

My question is : Is it worth swapping the R / C Carb' on this piece of  British engineering for a venturi and suitable NVA ?

Anyone had any experience with 'bigger' diesels for stunt please ?

Much obliged for any contributions ,

Robin [ ex-pat Brit in the Charente full of ex-pat Brits ]
Title: Re: Diesel 40 for Stunt ?
Post by: Ralph Wenzel (d) on October 11, 2008, 04:32:05 PM
If you can get the Irvine for a reasonable price (doubtful), I'd say go for it. In the larger sizes, I have only P.A.W.'s, which are uniformly good. There was a glowing (pardon) review of the P.A.W .40 in Stunt News about 10 years ago. For a better recommendation, you might contact Tony Eifflander of P.A.W. who designed a pretty PA ship called Freebird, designed for the P.A.W. .49 or .60. BTW, diesel's love to be mounted sidewinder, so you might take that into consideration.

Ralph
Title: Re: Diesel 40 for Stunt ?
Post by: BillLee on October 12, 2008, 05:44:59 AM
... BTW, diesel's love to be mounted sidewinder...

Ralph

Why?

Bill Lee
Title: Re: Diesel 40 for Stunt ?
Post by: Ralph Wenzel (d) on October 12, 2008, 06:00:14 AM
Hi Bill,
I really can't explain it. I asked Eric Clutton, aka Dr. Diesel, that exact question, and that was his response. Since then, all my diesel-powered planes have been sidewinders, with no problems whatsoever.

I will venture a guess - - For starting, I really don't have to worry much about either flooding the crankcase (upright) or about hydraulic lock in the cylinder. I can certainly remember some of the inverted-engine catastrophes I saw in FAI T/R. As far as running characteristics, I honestly can't see any difference.

I obviously should have given my response more thought, rather than just parroting another's statement . . .

Ralph
Title: Re: Diesel 40 for Stunt ?
Post by: dennis lipsett on October 12, 2008, 11:03:07 AM
If you can get the Irvine for a reasonable price (doubtful), I'd say go for it. In the larger sizes, I have only P.A.W.'s, which are uniformly good. There was a glowing (pardon) review of the P.A.W .40 in Stunt News about 10 years ago. For a better recommendation, you might contact Tony Eifflander of P.A.W. who designed a pretty PA ship called Freebird, designed for the P.A.W. .49 or .60. BTW, diesel's love to be mounted sidewinder, so you might take that into consideration.

Ralph

I think that it went for about $160.00. Definitely the economy is lowering the prices on everything. Now to converting the Irvine 40 diesel for stunt. It's doable and will make a pretty potent engine with pretty good performance to be had on 12 and 13 sized props. I converted one and ran it but sadly never got it into a plane to fly. I did however run one on a Sundancer R/C for a few years with  nothing but fond memories of absolutely trouble free flying. Being somewhat of a packrat I ended up with a few of them and only ran 2. one tip, if you run them regularly. Use a starter as it will let you keep your compression setting. The Irvine did have a reputation of dropping the contra piston  after awhile from constant adjustments. I dont believe that I moved mine in all the years that I ran it on the Sundancer with the same prop/fuel combination. Ron Irvine adaped the Davis type head for his 40/20 diesels with the contra piston in the head.
The rarest Irvine is the 20 diesel, an absolutely beautiful runner with good power and perfect throttle response.They only made them for a few years.
Dennis
Title: Re: Diesel 40 for Stunt ?
Post by: Jim Thomerson on October 12, 2008, 03:06:20 PM
I flew the Tower 40 with an RJL head for several hundred flights.  I eventually went through 4 crankshafts.  I was running a Harry Higly heavy hub and think that may have caused the problem.  The Tower crank has a grinding relief around the shaft right in front of the counterweight/crankpin wheel, and that is where the shafts broke.  However, I flew one for maybe a thousand flights glow with the same heavy hub and no breakage.  I did the business of using a starter and leaving the settings alone.  I've flown the same head a couple of flights on a Magnum Pro 40, without heavy hub, and it ran very well after I took the muffler off.  I used muffler pressure with no problem on the Tower. 

I would expect a diesel 40 to turn a 12 x 6 around 9,000 RPM.

I did have a problem with the RJL head.  The shelf under the O-ring came off in flight.  Gene Hempel made me another contrapiston with a thicker shelf and no more problems there.   
Title: Re: Diesel 40 for Stunt ?
Post by: Manuel Cortes on October 18, 2008, 09:46:12 AM
Hi all.

Diesels like sidewinder position because the speed on their transfers cause that when they are mounted vertical and you perform a hard corner (in the sense that the engine heat is outside the flight line) some drops of fuel (diesel fuel is more heavy and oily than glow and its spraying is not as claean) arrive to the combustion chamber, causing a misfire, and even stopping the engine, the sidewinder position makes that dissapear and that engines run happier.....and saves some tip weight  #^

Hope that helps.

Regards from Spain.

Manuel
Title: Re: Diesel 40 for Stunt ?
Post by: Jim Thomerson on October 18, 2008, 12:20:25 PM
I have flown ST G20-15 diesels, CS Oliver, and Taipan 2.5 mounted upright and they ran fine.  I think the ST diesels run better upright than side-mounted.  I've never flown a PAW, so I don't know what is true of them. 
Title: Re: Diesel 40 for Stunt ?
Post by: rustler on October 18, 2008, 02:42:13 PM
I have found diesels to be perfectly satsfactory in upright, inverted, and sidewinder, mode. But that is from the days before I really knew what we were looking for! Haven't tried any lately.
Title: Re: Diesel 40 for Stunt ?
Post by: Pinecone on October 19, 2008, 09:20:20 PM
There is an article in the latest Fly R/C about a diesel conversion (Davis Diesel) on an OS 46 for 3D flying.  The article was pretty positive.

Davis makes conversion heads for the OS 10, 15, 25, 40, 46; ST 40/45/51 (4 bolt head); and a slew of others.

http://www.davisdieseldevelopment.com/price_list.php
Title: Re: Diesel 40 for Stunt ?
Post by: dennis lipsett on October 20, 2008, 06:46:00 AM
As to the position of the engine it really dosn't matter at all. But suprisingly enough most of mine were mounted inverted and I think that they ran the best in that position. I know that they idled better. There was no accumulation of fuel in the bottom of the crankcase to surge when you hit the throttle.
Dennis