OMG it arrived - Profi speed .049
 

Look what just showed up in the mail. Excuse me for a few minutes while I deal with my excitement somewhere private.. :p

Problem with my job is the post office box is right out the front window. So now I am totally distracted and will accomplish nothing for the next hour/day.

Now I can get to work on the fuselage design for the mini F3 speed model. Big Q was if I could tilt the pipe up a degree or so, and actual pipe dimensions - side view same as the proto speed version.

http://www.rcuniverse.com/forum/atta...mentid=2089306http://www.rcuniverse.com/forum/atta...mentid=2089305

I like the needle..!

Yeah I got a chuckle out of that. A design feature dedicated to AMA speed I guess. If it was a Canadian edition it would be Robertson head.

Haven't weighed it yet - later - but the pipe is featherweight like the two-piece tend to be with the machined OD.

Maybe I'll get off my butt and CAD out a degree wheel.. I'm curious on the specs. 10% nitro, lots of castor and a real small cut down two blade CF prop.. let's hear it for ear damage! I'll try to get it on the stand in the next few days, but I gotta get some turbo plugs first, don't use them at present. Gotta get some single blade 1/2A props now too.

Make sure to treat it / tune it as you would if it was a diesel.

pipe looks long for rpm

Shaaaweeet engine!
When you get a moment with a caliper post the pipe dimensions?
I have some carbon sleeves on the ready. Email them tell them they forgot the pipe and send two spares :rolleyes:

Here are my outside guesses.


http://www.rcuniverse.com/forum/atta...mentid=2089322

The G&Z .061 would pre-stage at 30,000 and hit 40 just like you threw a switch. The APC 4.2 x 4 was what I used with it. Those pipes are joined at the apex by threads formed in the sheetmetal. They can accidentally unscrew themselves. Look for evidence of brazing filler with your's or else keep your eye on it...:cool:

Here is my CS .061 bought new old stock owner didn't have the pipe shown with a 4.2 x 4

http://www.rcuniverse.com/forum/atta...mentid=2089327

It's shorter than a Profi F2A pipe. The diminutive size makes it look long.

PS - I will measure up the pipe and post the dims. I'll do a ten point or so diameter map. Stinger outlet is tiny.

CP - how much ether and kerosene should I use? KIDDING.. I know exactly what you mean.

Even the MDS .15 on the thinner/less peaky pipe does that, it would jump hard from 19-20k to 28k with a quick pinch.

Hey experienced peaky pipe with snotty engine guys - do these observations sound sensible to you? (from MDS .15 running)

1. I figured it was underpropped when I had to bring the needle in after a prop swap - and the engine would stage on the previous prop and I could keep it on the rich side. Still staged to the same rpm range.

2. I figured it was not overpropped when I was able to stage it and needle on the rich side after staging.

3. With the AMA speed nitro head button and one shim, it would sputter down and die after a few seconds when I pulled plug heat using 2.5% nitro fuel. Conclusion: undercompressed (brilliant, Holmes)

4. With 10% fuel it would just barely change when plug heat was pulled, but if too rich would still cough and try to die if I didn't pinch it up again and needle it in. Conclusion: still undercompressed, pull a shim or leave it for now.

You can get CS with a carb? Didn't know that. How high is the timing?

Yes to observation #1 and #2. The prop load and fuel requirement go hand and hand. The qualifier is that you noticed a return to healthy running after you leaned it for the lighter load.

#3..undercompressed symptoms go hand in hand with not enough nitro. Always be quick to swap plugs or inspect them with an eye glass when in this mode.

#4 Not sure. Your suspicion sounds right. Always keep track of where the deck height is. You know about squishing and measuring 1/16" solder. Lay it in line with the wrist pin and squish it flat.

You can be led astray by maintenance issues, so always stay on top of the tightness of screws, the quality of the pipe seal, head button or liner-to-case chatter, NVA orientation, plumbing, engine feel....what did I miss...?
Should get the checklist tattoo'd to my wrist.
Black streaks emanating from any place are always evil mojo.
A hot run will loosen up everything...and anything that is loose can cause a hot run.
These engines will scorch wood mounts, so it's good to lay down aluminum sheet to delay that process.
At 40,000 there are high frequency vibrations that I wonder if an upper liner support / brace could dampen...?
You can grip the liner with pliers and see an RPM increase.

The oil had a bit of color first couple of runs, then cleaned up. It wasn't black, no blackness seeping from anywhere. The front bearing is definitely not suffering from a lack of oil flow.

This is the same rod that I thought I had spun the big end bushing. I figured out I had not thinned the big end evenly to match the crankpin, and believe got a rub on the backplate kicking up aluminum swarf which got in the big end and bound it up. So I opened up the oil holes to 3/64", gently opened up the clearance, and thinned the journal down to spec all round.. it was fat on one side hence the scrape, missed that. I couldn't feel it flipping it over.

Yes it does Mike

Here is a comparison pic to the stock CS Sport RC .061
The race carb comes with a fine thread NV and its the locking type - large bore as this one runs off of crank case pressure.

I do have the specs on the CL:

Exhaust - 182 deg.
Transfer - 130 "
Intake - 178 "

Stroke is 10 mm
CS .061 (1.0 cm³)

http://www.rcuniverse.com/forum/atta...mentid=2089383

I have a couple of Norvel .074's w/turbo heads. The best prices I've found on turbo plugs (OS) were on FeeBay.

Mike I see Alberto rates your engine up to 45,000 rpm - look forward to your tach readings when able. Geez the sound is going to be beyond most propped electrics.
Did it come with a short list of recommended prop sizes?

Should be able to do some of the tricks in this vid :cool:


https://www.youtube.com/watch?v=lMJ4Ol4e7vw

RC Guy where did you source the adapter? What was the noted rpm gain?

One was made by Mr. Valentine and purchased through FeeBay and the other was purchased from the NV Engines website. The performance is about the same as with a stock glow insert, but turbo plugs are actually available. I've never tached one with a turbo head, but I can't tell the difference flying them.

Note the CS .061 Pipe in comparison to the Profi should be close full size pic.
Mike - Alberto is sending me two of the new pipes so good to go you can disregard measurement request.
Finally I get to play with the CS :)

http://www.rcuniverse.com/forum/atta...mentid=2089484

I think it's interesting to read Dub Jett's thoughts about rod to crank pin fit. He advocates a loose fit, figuring that the pin maintains contact with only the "push" side of the rod's hole. The unloaded part of the hole that is void maintains a supply of oil according to Dub's reasoning.
In automotive engine work, the mechanics of the old days would assemble the rod to it's journal on the crank, hold the rod horizontal, let go of the rod and judge how well the rod dropped down to hanging vertical. Once they cleared the "pre fit" hurdle, they would turn the engine over with the oil pan off and inspect all of the rotating parts for the proper amount of oil drippage. It doesn't sound like a very fun job, but that's what apprentices are for. The Model A engine manual called for new rings, bearings and valve work every 10,000 miles. Ahhh, the good old days.

While searching for engine break in recommendations I ran into this active site - http://hobbyist.us/


Raptorz GZ049/061 Instruction ENGINE

BREAK IN
Each engine has been tested with FAI fuel in factory for rpm check. However your first 10 minutes break in should be completed on the test bench and subsequent break in can be in the model. During the break in, the engine must be kept with rich carb, avoid to decrease it too much. During last time of break in your engine should be operated at similar rpm to that intended during use but on a lighter load and at a slightly richer fuel setting. If you intend to operate your engine on high nitro fuel you should start the break in process on low nitro (5% fuel) gradually increasing the nitro content.

GLOW PLUG
Use standard glow plug for FAI fuel and Nelson glow plug for high nitro fuels. When nitro methane is added tothe fuel, the head must be raised to cope with compression. Shims are included at 0.10 to 0.20 mm thickness.

RPMThe GZ 049/061N
Free Flight or Combat engine can be operated at 30,000 rpm, and the GZ 049S/061S Speed engine is at 36,000 – 40,000 rpm.
These figures are only a guide; the actual rpm obtained will vary depending on the fuel and propeller used.

MAINTENANCE
Always keep your engine clean. Do not let dust or dirt get into it. Always lubricate your engine with a good engine lay up oil after use. If you use high nitro/synthetic oil fuel, flush out your engine to remove fuel residue before beginning the oiling procedure.

INSTALLATION
It is most important that the engine is mounted rigidly and on a true flat surface. We recommend that you use a good metal engine mount or metal plate.

TUNED PIPEGZ 049S/061S requires tuned pipes.
The pipe length determines rpm of engine. If you reduce either the air screw pitch or its diameter, the engine increases its revolutions and you have to reduce the length of the down pipe, on the contrary if there is a decrease in the revolutions you have to lengthen the down pipe.Never connect the pipe at the maximum efficiency at ground because the engine on flight increases its revolution in order to have the maximum efficiency on flight; it is necessary for you to have a shorter pipe.

LIMITED WARRANTY
Your GZ049/061 engine has been produced using the best materials available. However, because of the highstresses imposed by extremely high rpm operation, we cannot offer a guarantee against material wear ordamage resulting from use. Anyhow we guarantee the parts defective before your usage for a year.

CONTACT US
Please visit our web site http://www.hobbyist.us for the latest technical information. Please write us byemail: [email protected] in case you have any questions.

I'm surprised to read that they run them. They will just barely run without the pipe, I think this is all they would be doing is making sure that the rod doesn't snap if the piston is too tight.

The engine came with 3 shims - lucky for me I can just throttle down to ease the break in tonight I feathered filed in a 4.5 x 4 after about a half hour of removing and retrying till it fit as close as my efforts allowed. Surprising the difference from the previous 4.2 x 4 - engine prop / spinner and mount 103g I will stick with 10% tune with the 4.2 and fly with the 4.5 there is not enough spinner for any other APC size props.


http://www.rcuniverse.com/forum/atta...mentid=2089790

Yes, when I got my CS .049, it would barely turn over. That is the reason the gentleman sold it to me. He could not get it to run at all because it was so tight. I had to lap it a fair bit to get the fit right. I ran it up back then and it seemed ok, but had no tach at the time. Maybe I should run it up with the pipe again for grins and giggles. I started making a magnesium pan for a sidewinder 1/2A speed plane way back in the 1980's or 90's, but had no place to fly, so it is on hold. I think the rules have changed to use 10% fuel instead of the 80% we used then. Good move IMHO.

RPM is a good substitute for nitromethane, and easier on engines (well, small ones anyways).

Would the CS turn over with some heat on the head? Until advised by someone that knows better (there are many..) I warm up the heads to loosen them up on first runs. Did that on the two open exhaust Profis, seemed to do the trick, plan to do so on this guy too.

For first runs I think I would use the pipe, under prop it, oily fuel and and keep the mixture comfortably fat.

Stinger exit diameter on this is about 0.128". Holy mini F2A engine. Maybe this weekend I'll get it on the stand.

We used to break them in with no pipe so it would not get too hot. I think that nowadays the plan is to break them in at the operating temps, but well on the rich side. That CS was nasty tight. Not even heat would do much there. It is good now, just a manufacturing "defect" The CS is more of a kit motor that you have to fit yourself. I am sure the Profi is much closer to being right. The pipes on the F2A stuff sometimes have adjustable outlet sizes that screw in. I think 4.__ mm is about average for them. Quite small really, as the F2D is more like 6mm, which is down from the older 8mm.