jimcork1

My Feedback: (4)

Just FYI I am flying the ccrc 50 and after a new ignition I have had no issues. I went to 22x8 prop and now have rpm at 6800 which is almost vertical take off for 17.5# bird. I have had none of the engine issues exclusive of replacement of ignition and my 50 was one of the 1st engines sold in US.

antiquefer

I have just maidened the HL Gee Bee y with the crrc 26. I amazed how this little engine started and ran right out of the box.Flawless. I put 1 tank (14) oz through it on the plane, on the bench. Another tank through it in the air. 17/6 prop and a little rich. HOWEVER, after landing and shutdown there is noticable side to side play in the prop shaft. What part numbers do I need to get BOCA bearings? Why would the original ones be worn so soon? I used lawnboy @ 25:1. No sustained full thrittle.......................................ant iquefer.

Planeclothes

My Feedback: (1)

Well this seems to be way beyond too soon, with only 2 tanks of gas? How bad is it? To be honest I did not check mine until recently, so I can't tell how long this side to side play had been there.

jedijody

My Feedback: (1)

About this "play in the crankshaft bearings" issue a number of you guys seem to be experiencing, if these are new engines or within 1 year of purchase, I would really like to see a couple of these engines before they are torn down to see if there is a common problem with them that could be taken care of before they get to the end user. I would repair them under warranty whether you purchased them from VVRC or not. All you pay is the shipping to get it to me.

Carlos G

Hi All,

I have been thinking of buying one of the CRRC 26 and from most of the posts here is sounds like a good deal.

As far as the end play some of you are feeling it maybe that the pocket the front bearing is set in was machined a bit too big. As the engine warms up, the aluminum expands to a greater diameter than the steel bearing race. The bearing race then starts to vibrate ever so slightly causing the bearing pocket to wear and grow larger. It sort of feeds on itself until failure of the engine or crank.

When Plainclothes took apart his engine he said the front bearing was easy to pull out while the back was still tight. I bet if he looked at the bearing pocket it was polished.

It takes about .0015" to .0020" interference fit between the aluminum housing and the bearing race to keep this from happening. The problem might be repaired by knurling the bearing pocket, heating the case , chilling a new bearing, and quickly pressing the bearing into the case. The best way though would be to replace the case with the correct fit between the case and bearing.

It sounds like the front bearing pocket of the crankcase maybe slightly too big while the back pocket is slightly too small.

I was the engine guy at Walker Sachs-Dolmar and I had a run of crankcases that this happened to. We scrapped the run.

Jedi, I hope this helps.

Best Regards

Carlos G.

jedijody

My Feedback: (1)

Hi Carlos,

This is a newly developing issue with this engine that has not ever been a problem in the past 2 years. My post was an appeal to the modelers experiencing what they feel is exssesive crankshaft play to send their engines in for inspection under the factory warranty.

I am, as you put it, "the engine guy" in the US for the CRRC Pro factory and I would like to determine if there is in fact a problem just like or similar to the one you described with the Sachs-Dolmer engines.

As many of the posters in this forum will attest, I am well qualified to make this determination, effect repairs as necessary, and make recommendations to the CRRC Pro factory to improve the performance, reliability, and durability of the CRRC Pro engine line.

jstanton

My Feedback: (14)

Jody,

I am a little confused about what type of battery to use on the ignition. I see here in this thread that some use a 4.8 while others are using a 6v. My manuel has 6v crossed out and 4.8v written in. I have looked at the manuel on your web site and it says 6v. What size battery do you recommend and what mah rating? I have a 4.8v 2000mah nimh I can use, but if 6v is what you recommend I'll order a 6v 2500mah battery

jedijody

My Feedback: (1)

Jim,

Use your 4.8v 1200MaH or more battery, the manual should and used to read 4.8-6v. That is the new version of the manual, and they still have some translation glitches. Below is from the factory website and is the correct info.


Parameter:
Type : 2 cycle piston valve type gasoline engine for airplane only
Displacement (cc) : 26cc
Bore x Stroke (mm): 34mm*28.6mm
Dry Weight (g) : 1150g (Ignition ,Muffler and stand-offs included)
Carburetor : Walbro(Diaphragm butterfly valve type)
Maximum Output : 2.4ps / 9000rmp
Speed rang : 1600-8000rpm
Ignition : Auto advanced Ignition, 4.8-6 V
Gasoline-Version : Pre-mixed Fuel, 25-40 (Gasoline):1
Lubrication Oil : 2 cycle engine oil
Propeller : 16x8 16x10 17x8 17x10 (Two leafs prop)
Cooling System : Air Cooled

edwal07

Hi Jody,
After reading the past few posts I went back and checked all three of my 26's and have no play in any of them, the old "Swamp Monster" has over 50 flights on her and still nice and tight. Carlos could be right and something changed on the machining table or in the cast its self, could even be a different aluminum alloy mixture with different thermal qualities, an endless list, but traceable. Knurling as a last resort, I have used a Caterpiller brand of bearing setter to seat races which I thought "may" possibly turn in the housing or just to get a reassurance that it would "not" turn later on. Always works great and can be removed with heat like red loctite. I call it bearing locker!
Just another note, I got my shipping notification on the parts for the 50cc, just wanted to say thanks, I am still amazed it happened, red loctite on the threads will be mandantory on reassembly. Thanks again to you and to Tom! Quality and 1st class customer service!!!!!! I will keep you up to date on the mod we were talking about on the washer and hub, will know once I get into it!
Ed

jstanton

My Feedback: (14)

Jody,

Thanks for the quick reply. I guess you can use either a 4.8 or 6v battey. I'll start with the 4.8 battery and than if I have trouble I'll give the 6v battery a try. I was worried a fully charged 6v battery might damage the ignition sine they are over 7v when fully charged.

edwal07

Hi Jim,
I use 4.8 2500's on all 4 of my CRRC Pros and have had nothing but good flying! I have not had any problem using that setup. 6v batteries will be way over the maximum allowed for the module at full charge sometimes as high as 7.2-7.3v, not advisable. I have noticed that once the voltage drops to 3.9v you will get a high speed miss, below that it will start but then shut off. I ran a series of tests watching the voltage on the pack (4.8v 2000mah Nimh) and running the engine to see just what happened as the voltage decreased. I did not see any change or problems until it dropped below 4v. The reason for this as a friend at my club had a 50cc and just wouldn't run correctly, missing, starting and shutting down during his ground break-in. It turned out his battery pack was faulty, it would be at 5.2v but after a few moments running it was down to 4v and below. Changing the battery pack was the answer. Another friend had a high speed miss after a few minutes flying (sounded like a DA, dah da, dah da, etc) again faulty battery pack! The DahHan batteries Valley View is selling is the only packs I use and have excellent service out of them, I have 14 planes just for the record.
Hope this helps,
Ed
"The Stand Man"

Carlos G

Hi Jody,

Sorry, I meant no offense regarding your skills and/or ability to deal with the problem. I was only trying to illustrate what happened to me as an engine builder. There are so many ways things can go wrong in production its a wonder anything get made at all, :-) . From the retailer's standpoint, he is on the frontline of the whole product chain. He is the one who has to deal with customers for good or for ill.

From the post here in this thread, Valley View and you have been doing a great job supporting the CRRC engine line. Keep up the good work!

Best Regards,

Carlos G.

jimcork1

My Feedback: (4)

Info. Locktite makes a sealer for bearings. It is red and if I remember it is labeled bearing mount. The specific purpose is to help seat bearings with .001 to .003" clearance. I used it on a break down basis to get production equipment running. One 6" ID bearing with way over .003" clearance ran for a year (almost 8000 hrs at full load of 15 tons) until our next scheduled outage before having to change it.

I realize of course on warranty etc, you would want the case to be mfg' to spec for proper fit. But in those situations where you have too much clearance, no warranty and are considering scrapping an engine you might consider the locktite.

jedijody

My Feedback: (1)

Hi Carlos,

Don't worry I did not take any personal offense to your post. I apologize, I can come off a little cheeky sometimes without meaning to. Your post was good information and was already considered as a possible cause of the problem. My goal is to maintain the good reputation of the CRRC engines and to help whoever asks for it to the best of my abilities.

For what it's worth, I routinely use bearing lock in all repairs involving replacement of press fit bearings or crankshafts, it's cheap insurance and hurts nothing. I would never though use a case that has evidence of a bearing spinning or that does not have a press fit with parts at room temperature.

jstanton

My Feedback: (14)

Ed,

Thanks for the great information. I'll be ordering me a 4.8v 2500mah battery for my igniton.

jimcork1

My Feedback: (4)

This is what I use on my CCRC gas burner. the 4.8 V 2500 nimh.

skip1320

Have you guy,s ever noticed the striking simalarity the cylinder has to zenoah g26,thats why these engines make power,good luck.

OK2Fly

I think this engine is actually just a clone of the Zenoah 26...

jstanton

My Feedback: (14)

That would be really great in The CRRC pro26 in a Zenoah clone. I have mine mounted to a CMP 76" Corsair. Here are a few pics

jstanton

My Feedback: (14)

Sorry forgot to attach the pics.

OK2Fly

nice

cpsdd56

Does anyone know what the normal exhaust temp should be on a GF26

CAT POwer

My Feedback: (61)

Hi, what fueline size should be used with CRRC26.
Thanks
Manfred

davidj

I just got my engine back today. Thanks Jody, hope to see you at the Expo. I'm using the smaller gas fuel line. I think there are only 2 sizes.

najee

Getting my 26cc today and i am quite new to gas engines...had a real bad trip wif my G20 so looking to try a china engine..
will it have problems running a APC16X10 prop? i have a few of it and no other apart from 14x10s...
Do gas runs better wif wood props or APCs are good enough?
Anything to loolout for ?

ThANX guys..

Forgot to say that mine is the CRRC Pro 26I SP