Russian Diesels - OTM Striz - renovation and new handmade conrods

getback wrote:You should bee Happy and Proud of your achievement , excellent job on the con. rod replacements . The engines sound really good !!  

getback wrote:You should bee Happy and Proud of your achievement , excellent job on the con. rod replacements . The engines sound really good !!  

rsv1cox wrote:
Got a chuckle out of the first few seconds of your first video.  Sounds like one of those "hit and miss" engines.

Nice job creating those connecting rods, little things can yield big results.  

Ken Cook wrote:       I own the OTM COLIBRI .049 diesel. I love the looks of the engine but it doesn't run. I'm pretty close to giving it the sledge hammer treatment. I've had many issues with the Russian school project engines. The OTM got my attention when I discovered that the liner was hardened. I actually have a freeflight plane ready to go for this engine but despite all kinds of tries, it won't run. I get a occasional pop but that's about all the excitement one gets. I had a new contra piston made for it. The stock one was so loose it was going up and down in the cylinder. The crankshafts are somewhat long and thin in diameter on this engine so one needs to use caution. It needs to run however in order to break.

KariFS wrote:Good work on the rods! I’m impressed What material did you use?

I have a 1.5cc Webra with a loose rod, might be an interesting excercise to try to make a new one.

KariFS wrote:Good work on the rods! I’m impressed What material did you use?

I have a 1.5cc Webra with a loose rod, might be an interesting exercise to try to make a new one.

fps60 wrote:
czarobest
Fuel: 34% Kerosene, 33% Ether, 6% Motul 710, 25% Castor Oil and 1% Mannol diesel additive

Very interesting fuel mix. How did you figure it out?

gkamysz wrote:Witam,
You can get some high viscosity 2T oils. In Motul something like 800 or Kart 2T has viscosity similar to castor oil. Usually these are marketed as premix only racing oils, not for injection, but check the spec sheets. Also consider racing castor if you're spending the money on synthetic. Maxima Castor 927 runs extremely clean. Though engine grade castor oils are disappearing pretty quick.

If you are using Mannol 9955 you have to check the data sheets to see what it's made of. 2-EHN is what replaces amyl nitrate, and 9955 contains only 10-37.5% I don't know if anyone found a product similar to Amsoil ACB (100% booster) in the EU.

Greg

fps60 wrote:Thanks, I see, I'm interested because,

first, I'm a devoted fan of compression-ignition engines now intensively using PAW and, to a less extent, Enya diesels, and

second, following recommendations of one experienced vintage combat flyer from the UK, some time ago I'd switched to synthetic fuel and, I should say, I'm quite happy with results.

I've also chosen to go with Motul 710 2T that I use as 100% lubricant for engines which have passed full run-in cycle and run perfectly free. I've found out that castor oil replacement with Motul significantly improves engine performance without any notable adverse effects, especially in cold weather. The only precaution you should keep in mind concerns those engines which have already run long with castor oil. Such an engine needs either cleaning or running on fuel with sufficient content of synthetic oil at a moderately high r.p.m. (so that to warm it up but to avoid overheat and leaning) until it stops spitting black.

And to run in a new diesel engine, I use fuel with Castor 927 either without cetane improver or with its content not above 1%.

I use IPN (isopropylnitrate) as a cetane booster additive at a level within 1% up to 2% (1.8% in most cases). It works great but I'm also going to play with Mannol 9955, it looks attractive in terms of cost and availability.

Ether content is within 30% up to 35% depending on weather and engine type.

fps60 wrote:My choice of Motul 710 2T was not incidental. They told me they were using Exol Optima Racing 2 Stroke. We have no such oil on the market over here. Therefore, I had to select a substitute with similar specification and the Motul appeared to be the closest having almost exactly the same characteristics.

fps60 wrote:According to Tony Eifflaender (PAW), you may use any high-quality synthetic oil provided that it's suitable for 2-stroke engines. My good old PAW 249 GT has run around 3 hours on Motul only without any degradation. Provided that it never runs below 15k r.p.m., I can conclude that the Motul has successfully passed the test.