JB Atoms

THE BLACKBIRD
Offline
Forum Master

23 Oct 2017 10:24 - 23 Oct 2017 10:26 #46 by THE BLACKBIRD

Replied by THE BLACKBIRD on topic JB Atoms

It is a brilliant thread, to see how a professional works, thank you Tony
My measurements go in half a brick lengths

Last edit: 23 Oct 2017 10:26 by THE BLACKBIRD.

Please Log in or Create an account to join the conversation.

Klipkopwildlife
Topic Author
Offline
Administrator
I'm supposed to be retired!

23 Oct 2017 12:16 #47 by Klipkopwildlife

Replied by Klipkopwildlife on topic JB Atoms

To say I didn't like the supplied conrod would be an understatement!

While the piston/cylinder fit is still tight (very tight) on both engines the big end fit with the original crankshaft and conrod is very sloppy = badly worn.

This is the arrangement that holds the gudgeon (wrist) pin in.

Do it now, you may never get another chance

Thanks: Eric, Quorneng, THE BLACKBIRD, boz, Squirrelnet

Please Log in or Create an account to join the conversation.

Quorneng
Offline
Forum Master

23 Oct 2017 12:40 #48 by Quorneng

Replied by Quorneng on topic JB Atoms

Klippy
I presume the gudgeon pin retainer is screwed into the piston?

Please Log in or Create an account to join the conversation.

one tenor
Offline
Forum Veteran
johnpcalex@gmail.com

23 Oct 2017 14:35 #49 by one tenor

Replied by one tenor on topic JB Atoms

Can't make a lot of difference can it Klip? As screwed insert comes in from the other side / front

Anything will fly given enough power

Please Log in or Create an account to join the conversation.

one tenor
Offline
Forum Veteran
johnpcalex@gmail.com

23 Oct 2017 15:02 #50 by one tenor

Replied by one tenor on topic JB Atoms

I agree about the conrod Klip Not enough meat round the crankpin and too thin in the shank. I would leave it blocky with just enough taper or relief to clear piston skirt The sloppy fit is likely down to the metal stretching in the big end eye I think. Next thing would have been fracture.

Anything will fly given enough power

Please Log in or Create an account to join the conversation.

one tenor
Offline
Forum Veteran
johnpcalex@gmail.com

23 Oct 2017 15:11 #51 by one tenor

Replied by one tenor on topic JB Atoms

one tenor wrote: Can't make a lot of difference can it Klip? As screwed insert comes in from the other side / front

I mean the induction hole in the shaft

Anything will fly given enough power

Please Log in or Create an account to join the conversation.

one tenor
Offline
Forum Veteran
johnpcalex@gmail.com

24 Oct 2017 00:54 - 24 Oct 2017 01:12 #52 by one tenor

Replied by one tenor on topic JB Atoms

one tenor wrote: I agree about the conrod Klip Not enough meat round the crankpin and too thin in the shank. I would leave it blocky with just enough taper or relief to clear piston skirt The sloppy fit is likely down to the metal stretching in the big end eye I think. Next thing would have been fracture.

I meant to ask you would you replace the other Con Rod for me as well please? An ounce of prevention etc :evil:

Thanks John O/T P.S. I thought of lapping the piston and cylinder by hand with drop of dilute metal polish. What do you think?

Anything will fly given enough power

Last edit: 24 Oct 2017 01:12 by one tenor.

Please Log in or Create an account to join the conversation.

Klipkopwildlife
Topic Author
Offline
Administrator
I'm supposed to be retired!

24 Oct 2017 18:08 #53 by Klipkopwildlife

Replied by Klipkopwildlife on topic JB Atoms

Re the piston/cylinder fit, they used to run together so I'm thinking it's just residue that the cleaning process can't get off. I don't want to go anywhere near it with any kind of metal remover. I'm busy making a needle valve assembly at the moment I'll make another conrod when I'm done and have tested the engine.

Do it now, you may never get another chance

Thanks: THE BLACKBIRD, boz

Please Log in or Create an account to join the conversation.

Klipkopwildlife
Topic Author
Offline
Administrator
I'm supposed to be retired!

24 Oct 2017 18:10 #54 by Klipkopwildlife

Replied by Klipkopwildlife on topic JB Atoms

Quorneng wrote: Klippy
I presume the gudgeon pin retainer is screwed into the piston?

Yes, and on the complete engine I can't get it out to make a replacement conrod!

Do it now, you may never get another chance

Thanks: Quorneng, THE BLACKBIRD, boz

Please Log in or Create an account to join the conversation.

Klipkopwildlife
Topic Author
Offline
Administrator
I'm supposed to be retired!

24 Oct 2017 18:13 #55 by Klipkopwildlife

Replied by Klipkopwildlife on topic JB Atoms

one tenor wrote:
one tenor wrote: Can't make a lot of difference can it Klip? As screwed insert comes in from the other side / front
I mean the induction hole in the shaft

The hole is now only half as long as it is on the complete engine, I would guess the crankcase volume is only 75% or less of what it was.

Do it now, you may never get another chance

Thanks: THE BLACKBIRD, boz

Please Log in or Create an account to join the conversation.

one tenor
Offline
Forum Veteran
johnpcalex@gmail.com

25 Oct 2017 16:45 #56 by one tenor

Replied by one tenor on topic JB Atoms

Gotcha

Anything will fly given enough power

Please Log in or Create an account to join the conversation.

one tenor
Offline
Forum Veteran
johnpcalex@gmail.com

27 Oct 2017 00:59 #57 by one tenor

Replied by one tenor on topic JB Atoms

one tenor wrote:
Klipkopwildlife wrote:
Quorneng wrote: Klippy
I presume the gudgeon pin retainer is screwed into the piston?
Yes, and on the complete engine I can't get it out to make a replacement conrod!

No worries I'll shift it . The other was a swine too...

Anything will fly given enough power

Please Log in or Create an account to join the conversation.

Klipkopwildlife
Topic Author
Offline
Administrator
I'm supposed to be retired!

28 Oct 2017 08:36 #58 by Klipkopwildlife

Replied by Klipkopwildlife on topic JB Atoms

Well this is embarrassing! About 5 days ago I sat at one of my work centres and measured the original needle valve assembly. Then I drew it, selected a piece of 1.5mm Piano wire for the needle and went to my workshop to cut material. An hour later I could not find the valve or the wire! I'm still looking! In the mean time I have started trying to make a new valve, and learning all about drilling very small holes!

Do it now, you may never get another chance

Thanks: THE BLACKBIRD, boz

Please Log in or Create an account to join the conversation.

Mike Rolls
Offline
Elite Member

28 Oct 2017 08:57 #59 by Mike Rolls

Replied by Mike Rolls on topic JB Atoms

I know the feeling. I once had a 12" white plastic rule go missing in the workshop for months! Then I found it just like that - when, of course, I had got a replacement.
Mike

The older I get, the better I was!

Thanks: boz

Please Log in or Create an account to join the conversation.

one tenor
Offline
Forum Veteran
johnpcalex@gmail.com

28 Oct 2017 13:28 #60 by one tenor

Replied by one tenor on topic JB Atoms

It's always in the last place you look isn't it/? I "LOST" 2 steel rules for a long time .Looked every where. Eventually turned up Stood on edge under the turned over edge of the steel tool box held in place by the other tools in the box.Meantime like you I had bought new Grrrrrrrr!

Anything will fly given enough power

Thanks: boz

Please Log in or Create an account to join the conversation.

Time to create page: 0.269 seconds

Login Form

JB Atoms

Attachments: