EFCO 39cc project   
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
    Search This Thread  
 
Printable Version


TurboHeader Muffler
Seller:  RC Specialties
Details:   $69.95   |  3/4/2010   |  Classified Ad
We will rotate YOUR AD in this spot if you select "Forum Featured" when placing or editing your ad!

All Forums >> Glow Engines, Gas Engines, Fuel & Mfg Support Forums >> Engine Conversions >> EFCO 39cc project
Page: [1]

Login
Message << Older Topic   Newer Topic >>
EFCO 39cc project - 9/20/2009 3:44 AM   
Scota4570


 

Posts: 182
Score: 100
Joined: 1/8/2009
Last Login: 3/21/2010
From: Salinas, CA, USA
Status: offline 		This post morphed into my EFCO 39cc project. It started as a question about scored pistons and jugs. Enjoy.

About half the saws I have aquired have scored cylinders and pistons. The one a stripped down today could have made a decent engine, a Homelite 42cc. To bad it is ruined. It is very low time, the top of the piston was hardly covered by carbon. You could still read the laser marked parts numbers on the top of the piston after cursory cleaning. The area around the exhaust port and less so the intake port were real badly galled. I tried smoothing it up with 400 grit paper but even the ring is damaged. The compression is poor. It is almost like somebody put dirt in the spark plug hole. The owner said his laborer told him it just stopped running.

So, is kind of thing usually from running gas without oil?

< Message edited by Scota4570 -- 9/30/2009 2:01 AM >

Hide Signatures
       Post #: 1

RE: EFCO 39cc project - 9/20/2009 4:16 AM   
Nosedragger


 

Posts: 308
Score: 110
Joined: 6/19/2006
Last Login: 3/21/2010
From: hartford, CT, USA
Status: online 		yup, see this everday.

Hide Signatures

(in reply to Scota4570)
       Post #: 2

RE: EFCO 39cc project - 9/20/2009 4:23 AM   
w8ye



Posts: 27246
Score: 143
Joined: 12/11/2001
Last Login: 3/21/2010
From: Taylortown, OH, USA
Status: online 		I've seen guys sabotage equipment so they didn't have to work too.

_____________________________

Attended the CutFinger Institute of DirtNap University for years but never did graduate....
Recipient, Mangledhand award August 2008
Club Saito Member #7
Original AMA #31261

Hide Signatures

(in reply to Nosedragger)
       Post #: 3

RE: EFCO 39cc project - 9/20/2009 5:31 AM   
Ralphbf



Posts: 1428
Score: 100
Joined: 3/15/2004
Last Login: 3/21/2010
From: Woodland, CA, USA
Status: offline 		From what I understand most oil is repelled by heat.

The exhaust is the hottest part of the cylinder, so it's the least lubricated.

That's why it's important to use the best oil and at the best ratio, to me that means 32 to 1.
50 to 1 was created to handle smog, not for engines to run longer.

The they put Carbs. on that can't be adjusted correctly so that makes them run even leaner.

It's a wonder chainsaws last as well as they do.

And yes, especially with piston damage around the intake makes me think no oil in the gas.


_____________________________

Ralph

Hide Signatures

(in reply to Scota4570)
       Post #: 4

RE: EFCO 39cc project - 9/20/2009 10:27 AM   
pe reivers



Posts: 3997
Score: 111
Joined: 1/23/2002
Last Login: 3/21/2010
From: Arcen, , NETHERLANDS
Status: offline 		Many saws etc are returned for warranty, because the operator just put gas in it.
Oil? What's that? Engines run on gas don't they?


_____________________________

Pe, Dealer for MVVS, MTW, Xoar and Mejzlik
Ignorance a blessing? , there is sanctuary in analysis.

Hide Signatures

(in reply to Ralphbf)
       Post #: 5

RE: EFCO 39cc project - 9/20/2009 7:31 PM   
Scota4570


 

Posts: 182
Score: 100
Joined: 1/8/2009
Last Login: 3/21/2010
From: Salinas, CA, USA
Status: offline 		Just for yucks I attacked the jug with a hacksaw and belt sander. I got the short block assembly down to 2# 4-oz.. With the carb, muffler, hub and mount rails that should be less than 3#. It looks nice too. Can one of these scored engines be saved economically?

Hide Signatures

(in reply to pe reivers)
       Post #: 6

RE: EFCO 39cc project - 9/20/2009 8:19 PM   
w8ye



Posts: 27246
Score: 143
Joined: 12/11/2001
Last Login: 3/21/2010
From: Taylortown, OH, USA
Status: online
quote:

ORIGINAL: Scota4570

About half the saws I haveaquired have scored cylinders and pistons. The one a stripped downtoday could have made a decent engine, a Homelite 42cc. To bad it isruined. It is very low time, the top of the piston was hardly coveredby carbon. You could still read the laser marked parts numbers on thetop of the piston after cursory cleaning. The area around the exhaustport and less so the intake port were real badly galled. I triedsmoothing it up with 400 grit paper but even the ring is damaged. Thecompression is poor. It is almost like somebody put dirt in the sparkplug hole. The owner said his laborer told him it just stopped running.

So, is kind of thing usually from running gas without oil?


We are not worried about the piston/ring anymore. They are toast!

But look in the cylinder by the ports and examine the scratches. If there are deep gouges that you can feel with your finger nail the cylinder may be toast also?

But if your finger nail doesn't feel any roughness, a new piston and ring may save it


< Message edited by w8ye -- 9/22/2009 11:24 PM >

_____________________________

Attended the CutFinger Institute of DirtNap University for years but never did graduate....
Recipient, Mangledhand award August 2008
Club Saito Member #7
Original AMA #31261

Hide Signatures

(in reply to Scota4570)
       Post #: 7

RE: EFCO 39cc project - 9/20/2009 9:00 PM   
Scota4570


 

Posts: 182
Score: 100
Joined: 1/8/2009
Last Login: 3/21/2010
From: Salinas, CA, USA
Status: offline 		I'll put the Homelite it in the toy box for now. Thanks for the information.



Hide Signatures

(in reply to w8ye)
       Post #: 8

RE: EFCO 39cc project - 9/21/2009 2:55 AM   
Ralphbf



Posts: 1428
Score: 100
Joined: 3/15/2004
Last Login: 3/21/2010
From: Woodland, CA, USA
Status: offline 		I'd like to see a picture.

Can you post one?

_____________________________

Ralph

Hide Signatures

(in reply to Scota4570)
       Post #: 9

RE: EFCO 39cc project - 9/22/2009 8:39 PM   
Flypaper 2



Posts: 4490
Score: 100
Joined: 3/29/2002
Last Login: 3/21/2010
From: Kingston, ON, CANADA
Status: offline 		When I ran a small motor shop, a customer brought in a lawnmower that was smoking like a fogging machine and wanted to know if I'd fix it. Did a minor check and took the air filter cartridge off and there was no filter in it. I asked him where it was and he told me he took it out because it kept plugging up. True story.

_____________________________

Gord
Dreamed I was a muffler. Woke up exhausted.

Hide Signatures

(in reply to Ralphbf)
       Post #: 10

RE: EFCO 39cc project - 9/29/2009 3:57 AM   
Scota4570


 

Posts: 182
Score: 100
Joined: 1/8/2009
Last Login: 3/21/2010
From: Salinas, CA, USA
Status: offline 		Some pics were asked for, here you go. On the left is the 42cc homelite. I pared down the extra bits for fun. Check out how trashed the piston is. Yikes! Never leave straight gas in the same area as illeterate laborers.

On the right is an EFCO 39cc. That one looks like a winner. It is ready for a beam mount, no mods. I only removed a little bit of extranious cooling fins. It has two rings and huge compression with very slow leak down. The inside is as pretty as new shiny penny. The hub came out straight first time, with in 0.002" wobble a the prop end, good enough for me!. Nottice the knurling? I did that with a regular old knurling tool. I set up the cross feed at 4 TPI and ran the edge of one wheel of the the knurling tool out from the center in back gear. One pass and done! I had been broaching radial grooves with the taper cross feed manually, a huge pain. This was about 10 second in back gear to do an equivelent job. The prop was about 1/8" of kilter a the tips. I fixed that with a file. Here is a tip, my new favorite cutting lube for aluminum is a shot of castor oil in mineral spirits. It makes the cuts really clean an smooth.

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to Ralphbf)
       Post #: 11

RE: EFCO 39cc project - 9/29/2009 11:05 AM   
pe reivers



Posts: 3997
Score: 111
Joined: 1/23/2002
Last Login: 3/21/2010
From: Arcen, , NETHERLANDS
Status: offline 		The efco sure is a nice engine. I like the soft carb mount!


_____________________________

Pe, Dealer for MVVS, MTW, Xoar and Mejzlik
Ignorance a blessing? , there is sanctuary in analysis.

Hide Signatures

(in reply to Scota4570)
       Post #: 12

RE: EFCO 39cc project - 9/29/2009 4:01 PM   
Scota4570


 

Posts: 182
Score: 100
Joined: 1/8/2009
Last Login: 3/21/2010
From: Salinas, CA, USA
Status: offline 		I like the soft carb mount!................

Me either, I am going to try making a split ring out of aluminum that will make a flange on the jug projection. From then on it is the same as any other.

Hide Signatures

(in reply to pe reivers)
       Post #: 13

RE: EFCO 39cc project - 9/29/2009 6:04 PM   
lewdfinger


 

Posts: 165
Score: 100
Joined: 4/23/2002
Last Login: 11/18/2009
From: CalgaryAlberta, CANADA
Status: offline 		Nice work Scota. Good tip on the knurling. 

_____________________________

Do I know what rhetorical means?

Hide Signatures

(in reply to Scota4570)
       Post #: 14

RE: EFCO 39cc project - 9/29/2009 6:08 PM   
pe reivers



Posts: 3997
Score: 111
Joined: 1/23/2002
Last Login: 3/21/2010
From: Arcen, , NETHERLANDS
Status: offline 		The soft mount is an advantage. It allows you to mount the carb to the airframe, and iso-mount the engine. With the carb separated from the vibrating engine, you will see a lot less wear and tear on the carb. The "lack" of vibration in the carb will also let it meter fuel better!
IMHO, it is worth the effort to keep carb and engine separated as much as possible.


_____________________________

Pe, Dealer for MVVS, MTW, Xoar and Mejzlik
Ignorance a blessing? , there is sanctuary in analysis.

Hide Signatures

(in reply to Scota4570)
       Post #: 15

RE: EFCO 39cc project - 9/30/2009 1:55 AM   
Scota4570


 

Posts: 182
Score: 100
Joined: 1/8/2009
Last Login: 3/21/2010
From: Salinas, CA, USA
Status: offline 		Huh, I'll kepp the soft mout idea in mind. Before I read that I made the carb manifold and split ring. The intake maniforld is bolted to the split ring. The split ring is afew thousands lower than the flat face of the boss on the jug. That permits a good seal. I guess the good news is that by using the split ring I did not mess up the jug. I could go ahead and use the rubber boot if it looks like and advantage.

Here is a tip for making two holes meet in the middle, like for the pulse pressure tap the carb uses. Look at the thing real carefully and make use the planned route does not come out the side. Start each side of the hole in the normal way. Put a slightly smaller bit in the drill press vice and secure it such that the bit in the chuck line up with it. Drill the hole a little alternatly from both sides using the bit shank in the drill table vice to align the work. They will meet up in the middle.

Attachments
Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to pe reivers)
       Post #: 16

RE: Scored piston/jug cause? - 9/30/2009 2:02 AM   
av8tor1977



Posts: 3423
Score: 100
Joined: 5/3/2003
Last Login: 3/21/2010
From: ASH FORK, AZ, USA
Status: offline 		The carb should be isolated from the engine heat. You should incorporate a spacer that does not conduct heat or you will have hot start problems, or worse.

AV8TOR

_____________________________

If it's not scary, it's NOWHERE NEAR powerful enough!!

Hide Signatures

(in reply to Scota4570)
       Post #: 17

RE: Scored piston/jug cause? - 9/30/2009 2:08 AM   
Scota4570


 

Posts: 182
Score: 100
Joined: 1/8/2009
Last Login: 3/21/2010
From: Salinas, CA, USA
Status: offline 		I'll incorporate a phenolytic spacer. Just have not made it yet.

Hide Signatures

(in reply to av8tor1977)
       Post #: 18

RE: Scored piston/jug cause? - 10/4/2009 9:31 PM   
Scota4570


 

Posts: 182
Score: 100
Joined: 1/8/2009
Last Login: 3/21/2010
From: Salinas, CA, USA
Status: offline 		Progress is made on the EFCO. The ignition arrives next week.

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to Scota4570)
       Post #: 19

RE: EFCO 39cc project - 10/5/2009 1:40 AM   
w8ye



Posts: 27246
Score: 143
Joined: 12/11/2001
Last Login: 3/21/2010
From: Taylortown, OH, USA
Status: online 		Looking good


_____________________________

Attended the CutFinger Institute of DirtNap University for years but never did graduate....
Recipient, Mangledhand award August 2008
Club Saito Member #7
Original AMA #31261

Hide Signatures

(in reply to Scota4570)
       Post #: 20

RE: EFCO 39cc project - 10/11/2009 6:55 PM   
Scota4570


 

Posts: 182
Score: 100
Joined: 1/8/2009
Last Login: 3/21/2010
From: Salinas, CA, USA
Status: offline 		It runs! props, 20 x 8 6400, 18 x 8 7200rpm, 15 x 6 9200, it idles down to 1600. I have not messed with the timeng yet, it is 28 deg BTDC. The muffler is too heavy for real use. It is odd, to me that I pick up 100 rpm with the guts installed. The hub turned out nice and straight, it runs real smooth.

I had a thought for locating the magnent on the hub. Next time I will tape it in place to get the location before I drill the hole. Then I will fuss with it until the sensor is located in the middle of the ajustment range at 28 DBTDC. Once I know the exact location I will then mark it and drill.

Later that day.....

I set the plug to 0.020" gap and installed a Menz 21 x 8. The wider plug gap made it run a little smoother. I also packed the muffler full of chor boy scrub pad to keep the neighbores happy. 6100 and got the idle down to 1300. It is fun to watch it run so slow.

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


< Message edited by Scota4570 -- 10/11/2009 10:32 PM >

Hide Signatures

(in reply to Scota4570)
       Post #: 21

Page:   [1]
All Forums >> Glow Engines, Gas Engines, Fuel & Mfg Support Forums >> Engine Conversions >> EFCO 39cc project
Page: [1]





Jump to:


 
Google 



Search | Marketplace | Event Calendar | Local Clubs | Magazine | Product Ratings | New Products | Discussion Forums

Photo Gallery | Instructor Search | Field|Track|Marina Search

Advertisers | Hobby Vendor Resources | Rate Manufacturers | Sign In/Sign Up

SITE MAP!   : :   FORUM RULES

© 2001 - 2007 24-7 RC, LLC, all rights reserved.

Charities we support that also need your help
Yorkie Rescue | Humane Society | ASPCA | Crohn's-Colitis America


0.992RCU1