OPS .65 bench run.. finally!
 

[link=http://www.youtube.com/watch?v=6As9jreMlDA]OPS 65 Youtube run[/link]

It's loud. The carb works great.

MJD

RE: OPS .65 bench run.. finally!
 

wow!! i can watch that over and over. thx for posting it.

RE: OPS .65 bench run.. finally!
 

MUSIC to my ears![8D]

RE: OPS .65 bench run.. finally!
 

I'm not able to watch, haven't spent enough money and time on upgrades plus the phone line here is 30,000 feet of wire from the nearest station......

So, does it look like a good engine?

RE: OPS .65 bench run.. finally!
 

i recently acquired a OPS .67 speed. i could just own these engines for the music and fun of bench running them.

RE: OPS .65 bench run.. finally!
 

Ooh, that .67's got about 10% more top end apparently. I can make these into .67's with just the P/L set. "Just" the $165 P/L set..:)

I made a G-10 tubular spacer for between the header and pipe, about 1/8" long (I happened to have a piece of tubing lying around). I now understand that even that is not close to capable of surviving in there.. :).. it got chewed up and spat into the pipe on the run prior, partially closed it up and drove the engine super rich, and then puked out the back of the pipe all in about the time it took to type this. No harm done, I reset the needle and fired it right back up.

There's more to be had but I am pretty sure the load is light enough now. I first ran it on the prop at 90% diameter and it was having trouble getting on the pipe. At 85% it gained about 2000 rpm.

Pipe length is at about 11.5" right now.

So do you think this will fly a Demon?

MJD

RE: OPS .65 bench run.. finally!
 

I don't really know yet in terms of peak power. It seems to run beautifully now, I have not even dialed in the low end yet, it is still pretty rich. It had more rpm as you could hear when I was pinching the line, I saw 21 and change on the tach and was still not quite at peak rpm near as I could tell. I don't know if I shold be excited yet - this is a carbed versus venturi engine, running 7.5% nitro, early runs on the clipped prop. It seems like 22 in the air on the flight prop should be no prob, but I thought there might be a bit more though I am not sure how much to expect. These numbers equate to 205-ish pitch speed.

The sound level is astonishing.. I pulled the ear muffs off experimentally standing about 2m to the side and back a bit - it was painful [:-]. Should sound wild in the air.

The Jett needle is nice and broad - you can see me screwing it in like a faucet early on.

A few more runs should tell the story. I'm not clipping the prop any more, I can tell you that! 8.125" x 0.85 = [X(].. ?!

MJD

RE: OPS .65 bench run.. finally!
 

Hopefully it ends up running like a bull for hundreds of flights. Nice to know that you can keep the engine going with fresh parts without beating the bushes looking for stuff.
Are you ready to finger start it yet?

RE: OPS .65 bench run.. finally!
 

I wonder if we will finally see a structural failure of a Screamin Demon. :D

RE: OPS .65 bench run.. finally!
 

mjd

good healthy sounds, thats some good rpms, a few more runs, and i would then look at your deck height if its not popping plugs i am curious as to the shape of the combustion bowl, is it single or double dish, and is this engine bushing or needle bearing on big end of the rod? but over all real clean sound, now i gotta run my ops .80 fan engine... unless it does a shaft run it should last for ages, 24k is the upper limit for the bushing rod on the big ops motors

RE: OPS .65 bench run.. finally!
 

It's a bushing rod. Is what gets called the "rpm" rod a needle bearing rod?

Last time I tried to run it - I had a few starts and aborted runs with the clipped Zinger wood club - I used a rubber chicken stick after it had warmed a bit. No sweat. When this gets tamed and we know each other well I'd do it once just to piss off the safety gods - if I'm allowed to back flip off compression.

From the numbers I am seeing here, I could be in the right range to stay within operating limits in the air with the full prop. But I think it qualifies as running it hard.

Hey Mike - I am not going bone stock here.. the CF spar count may go up by about 2, and I have 1/16" full sheeting plus Ceconite (Stits fabric) over top in mind. The one I have downstairs ready for color paint is stock but Stits covered, and I swear it would be tough to break that thing in the air with anything much less than this, short of an MB 40 anyways. I set up the mount and t-nuts for standard .46 spacing, but I just started thinking stupidly about the merits of fitting a pattern .60 and a 10-9 prop to it.. [sm=50_50.gif] Build and abuse more.. the only answer.

MJD

RE: OPS .65 bench run.. finally!
 

I'll get pics of the head buttons for you LF, and I'll put a straight edge against the bottom as well to see what sort of squish action is going on. What, we're modding combustion chambers now..? :)

Tomorrow morning though. I'm tired and it's time to crash. I reek a bit of castor oil but my wife was grumpy this evening so who cares.

MJD

RE: OPS .65 bench run.. finally!
 

the "RPM" rods were made by richardson precison machine, which i believe is now defunct, they were bushing based as well, but could be had in either 7000 series alloy or titanium, the needle bearing rods came a little bit later, and ops actually makes them, the ops dealer called niagara hobbies or sumthin has the needle bearing rods, and also a combo with a new crankshaft with different pin diameter for the rod. the button heads are offered in the low nitro or high nitro config, with the high nitro having the double dished area, most of the rossi and ops and the like have a flat squish band , so setting deck hight is pretty much the same, but the dish area is how they make the compression lower to hold the higher nitro mix, OPs ducted fan users usually tried to keep ground rpms under 24k for ducted fans:D

RE: OPS .65 bench run.. finally!
 

Ouch - $172.05 for the rod and crank. For only about $350 I could turn this into a needle-bearing rod .67. I think I'll do with it as is for now..

MJD

RE: OPS .65 bench run.. finally!
 

yup, run it on 10-:D25 percent nitro and have more fun than most people ever have in their bedrooms:eek:;)

RE: OPS .65 bench run.. finally!
 

Congratulations MJD. I havent bench run the Rossi yet, but Ill surely do it after watching your video.
Ed

RE: OPS .65 bench run.. finally!
 

It has a nasty ripping sound as it leans out and stages, like tearing fine fabric at high speed. The kind of sound that makes you cackle with evil delight actually. I've certainly never encountered a louder glow engine, though I am sure an open pipe AMA pylon or D speed model would bury it.

I still say I pity the guy who's gonna hand launch the delta this is bolted to. He'll need a bib for the exhaust and self-contained breathing apparatus, esp. if I ever bump the nitromethane.. [>:]. RVman's Picco .45 RE nearly burned my eyes out every time he tuned it on only 15% nitro. Mind you that might have had something to do with the cumulus cloud of exhaust billowing out of the pipe before it got leaned out each time.. [sm=stupid.gif]

RE: OPS .65 bench run.. finally!
 

:D

RE: OPS .65 bench run.. finally!
 

LOVED THE VID Mike

Cant wait to hear it howl on the deamon Video and break 200mph.!!

RE: OPS .65 bench run.. finally!
 

Yeah, that run got me going a bit. I am ready to assemble and bond the center section now, having finished the laminated motor mount plate to my (perhaps temporary) satisfaction and drilled it etc. There was much fiddling about thinking about how to arrange things but it's making sense now. I have what appears to be a working rectangular 11 ounce bladder tank now, and it fits nicely so I think I can keep the profile pretty low, probably level with the top of the cylinder head cowl.

I am humming and hawing about run this afternoon. It was hailing half an hour ago but that seems to have let up.

MJD

RE: OPS .65 bench run.. finally!
 

Glad you got some fuel capacity, My 8oz on my OS 46 vxdf last 3 minutes.

Current average wind speed here in Rancho Cordova Ca ..... 45 mph! Green leaves flying past my windows. I cant believe we still have power.:D

RE: OPS .65 bench run.. finally!
 

Set rich this thing sucks fuel like a shop vac. In-flight consumption should be about 4 oz/min.

MJD

RE: OPS .65 bench run.. finally!
 

Less then three minutes may be all you need/want. :)

RE: OPS .65 bench run.. finally!
 

It's enough time to take care of business and it's enough time for something to either shake loose or explode.:D

RE: OPS .65 bench run.. finally!
 

Hey, that only resembles some of my work. [8D]