RE: Echo 2400T Short blocks
 

Hi BME, I would like to make one of the twin conversions. I sent you a PM.

RE: Echo 2400T Short blocks
 

I see the 23.6 Kioritz is used is several different machines

Shortblock for the -

Blower is sb1016
Hedge clipper is SB1034
Shred n vac is SB1027
etc.....

What are the differences in these shortblocks I wonder?

RE: Echo 2400T Short blocks
 

Hi jrjr,

I have two of the SB1034 engines. They have the left hand threads on both ends of the crankshaft.

George

RE: Echo 2400T Short blocks
 

There are several others too...
I think the blower was right handed threads ..

There are no more of this deal available I take it?

RE: Echo 2400T Short blocks
 

There were 24 of them originally. When I mentioned it on here August 19, 06, they were all gone from the shelf by the end of the next week August 26, 06. A local guy bought one and put it on the famous auction site where it went for $26. I don't think he made up his auction charge with that one after he had to pay sales tax and haul it 10 miles to his house?

RE: Echo 2400T Short blocks
 

I bought two of them also, started working on the second one last weekend. Just got finished with the prop hub. Called C-H earllier and ordered a couple of the flat pulse sensors so I can mount the ignition sensor on the rear of this one.

RE: Echo 2400T Short blocks
 

flipflop: When you do the inside taper for the prop adapter..what degree angle do you set the compound for. Is it around 16 degrees? Does your taper fit tight enough to lock-up good or do you also cut a key slot to prevent slipage? I got a tap for the metric threads but have to get another. The threads was too loose. Thanks Capt,n

RE: Echo 2400T Short blocks
 

Capt,n if you set your compound up for the same taper he has your taper will most likely be off. There are many different ways compounds are layed out as far as the vernier scale goes. Best way is to trace the taper with an indicator.

RE: Echo 2400T Short blocks
 

Loose threads??? Did you use a lubricant (such as WD-40)? Did you use the right size drill? Did you break the chip every two turns? (If using a normal tap) The numbers on the compound are just used for getting ballpark settings. The easiest way to get it exaxtly right would be to mount the crank in your chuck, the dial-indicate the taper while making your compound adjustments. Using a keyway on a taper that deep in the hub? Not needed, the taper handles all the torque loads. I would imagine that would be extremely difficult machining even for the CNC boys. Cut a taper in a test piece, paint the taper with Dykem Blue, slide it on the taper and give it a turn while pushing it against the taper. You'll be able to see when you get it right.

Too much trouble? Stay with engines where the prop hub just buts up against the flywheel.

RE: Echo 2400T Short blocks
 

flipflop: I used tap magic on the threads. I had a idea this may happen...when I tried the left hand nut( a Echo part) as a test fit, I noted the tap seemed to large of dia. Nut would not go 1/2 turn on it. Anyway...I am going to try another tap. Did you mike the major dia of the threads on crank? I could compare that to threads on my engine? What style of boring bar did you use on cutting inside taper? Thanks Capt,n Update....I just measured the dia of tap= .320....threads on crank .311 ....????? [X(]

RE: Echo 2400T Short blocks
 

Capt,n an 8X1mm thread takes a 7mm tap drill and an 8x1.25mm thread takes a 6.8mm tap drill. The keyway in the shaft is really an assembly line deal. Meaning it takes the guess work out of assembling the engine. Timing accuracy is built in for the line workers. The key is just soft steel or it is cast into the flywheel.


7mm = 0.275590 inches
6.8mm = 0.267716 inches

RE: Echo 2400T Short blocks
 

Is 17/64 close enough? .2656 Capt,n

RE: Echo 2400T Short blocks
 

Capt,n sent you an email with a PDF on tap and drill information from Triumph Drill Co. FWIW a 7mm tap drill converts to an I letter drill which is .2720 and a 6.8mm tap drill converts to an H letter drill which is .2660. Good information on tapping and issues with the same. Hope this helps.

RE: Echo 2400T Short blocks
 

tim220225: Thanks for sending me the tap and drill data. I may print some of it out. How is the temps there? Its going to be in the single digets here in Mich. BBbbrrr...Thats COLD. Take Care Capt,n;)

RE: Echo 2400T Short blocks
 

No problem Capt,n. Supposed to be about normal here which is 50's to low 60's. I do remember those days well being from Chicago originally. I need to get to the field before the game Sunday. Been out of town on business and I need a flying fix. Also need to work on finishing my Carden Edge so I can get some machining done on my 23.6 Echo. Amongst others..

RE: Echo 2400T Short blocks
 

tim220225: I am now thinking of cutting off threads and tapping crank for right hand threads. If I had a backplate, could I bolt the engine to it and drill and tap on lathe? Lacking a backplate do you think it could be done on a drill press. Using the center allready in crank for alignment? Like drill with a small pilot drill first past threads, then cut of threads. The small pilot hole would still be there for center alighnment? What do you think? Capt,n

RE: Echo 2400T Short blocks
 

Tim,

Can you send me a copy of that tap and drill data as well?

Thanks

RE: Echo 2400T Short blocks
 

When drilling a hole in the center of a shaft, to maintain concentricity, you need to turn the shaft and not the drill.

To have the shaft stationary and turn the drill bit, the bit will most always lead off.

RE: Echo 2400T Short blocks
 

w8ye: Thanks for the reply about concentrcity. Can you tell me how to forward or send a pdf file to foamcut. Thanks, Capt,n

RE: Echo 2400T Short blocks
 

Capt,n I plan on doing the 23.6 engines I have that way. Take the engine apart and chuck the crank. In my case I am using collets and also a steady rest for support. Just cover and tape up the rod to keep it from flopping around and getting chips in it. You need to drill the center hole on the crank deeper and drill, bore or ream to correct size for tapping. Then part and face off the threaded end. You are drilling steel so your spindle speed will be slow. Use lots of cutting oil and take it slow and you can do it. D&B engines makes his 61cc twin using the same process on the stock Echo cranks. Depending on how deep the case hardening is may determine the quality of drill bit to use. If you have cobalt bits use them. Also use short ones if you can as they are more rigid and use a bottoming tap for final tapping so you get to the bottom of the hole. Just don't force things or you will break a tap.

RE: Echo 2400T Short blocks
 

tim220225: I will wait untill you get your Echo done. I got many more engines to play with! Best Regards Capt,n

RE: Echo 2400T Short blocks
 

disregard :D

RE: Echo 2400T Short blocks
 

You can do it Captin John... Just take it slow. I believe that 99% of the mistakes that knowledgeable people make when working on engines or machining (or many other things for that matter), is getting in a hurry or impatient.

AV8TOR

RE: Echo 2400T Short blocks
 

I agree with Av8tor Capt,n but I understand your position too.

RE: Echo 2400T Short blocks
 

foamcut: This will get you to site and one of they reference pdf. Just shorten address and view rest of site. This may be different than what was sent to Capt.


http://www.triumphtwistdrill.com/cat...ch_section.pdf

Tim....: pdf file shows some percentages for amount of thread contact in the mied 70's. For this application and it you have ability to size the hole as you desire, would you go with smaller ID to gain on the % of surface contact on the threads?