Story.The Life and times of the WP Racing Service.

Jeremy Wilkey

Owner, MX-Tech

Jan 28, 2000

1,453

0

• Apr 30, 2002

• Thread starter
• #26

SVI,
We can get low to middle 200 ferieheht with out too much trouble..

Regards,
Jer

 

MX-727

LIFETIME SPONSOR

Aug 4, 2000

1,810

13

• Apr 30, 2002

• #27

I'm seeing the same thing Marcus is seeing. When Blade's posts are expanded, they are just smiley's, and not the pictures, but the colon and paran. When his posts are compressed, I can read the first line and see that something is actually contained in the post.

 

marcusgunby

LIFETIME SPONSOR

Jan 9, 2000

6,450

2

• Apr 30, 2002

• #28

mx 727 i too now can see he has more in the reply than i could initially see- i wonder why his replies arnt working?

 

H

Heat

Member

Jan 8, 2002

21

0

• Apr 30, 2002

• #29

He made a post in the flame forum a mod or admin didn`t like , I guess they are trying to change his attitude. I know the guy , it won`t work.

 

W

Wakisashi

Mod Ban

Apr 29, 2002

120

0

• May 6, 2002

• #30

Interesting problem , could it be something to do with the outside OD of the body not being concentric with the ID? If it is a casting that isn`t quite concentric the thicker side of the body would grow thicker than the thinner side from the higher temps causing a binding problem in extreme situations , just a thought.

 

Jeremy Wilkey

Owner, MX-Tech

Jan 28, 2000

1,453

0

• May 7, 2002

• Thread starter
• #31

Wakisashi,
Thats exactly what i However could a casting density issue casuse this?
Regards,
Jer

 

W

Wakisashi

Mod Ban

Apr 29, 2002

120

0

• May 7, 2002

• #32

To explain my post a little better , what I mean to say is for example a 1" thick part will expand more than a 1/2" thick part at the same temp. So the thicker part of the body would expand more than the thinner part which could put things in a bind.

I would guess to say ,YES, that a casting density that isn`t consistant through the whole body might do that also.

 

M

Mark Hammond

Member

Apr 6, 2000

87

0

• May 7, 2002

• #33

Hi Guys
I have never experienced this problem in the UK probably due to the fact that it dosen't get so hot here, however we are talking about mass produced cast bodies here and I would think that it is possible to get some discrepencies in the casting and machining process which would cause some shocks to bind up

 

S

shaggy829

~SPONSOR~

May 28, 2001

130

0

• May 7, 2002

• #34

the manufacturer must know that there is a small percentage of bodies that will experience disformation due to heat and cheap casting .
but with there works stuff they won't even consider risking the problems that com with cast metals and only use billet .when was the last time anyone saw a true works piece lock up and i know they see temps well over 200 :think:

 

marcusgunby

LIFETIME SPONSOR

Jan 9, 2000

6,450

2

• May 7, 2002

• #35

mark ive seen one 98 kx 250 do this-i serviced it and after it was a bit better as i guess i bleed it better and the oil was fresh but after 20minutes it would get real sticky.

 

W

WhiPit

Member

Mar 16, 2000

236

0

• May 9, 2002

• #36

wasn't this thread originally about MX-TECH's amature support program?
:think:

 

EricGorr

Super Power AssClown

Aug 24, 2000

708

1

• May 10, 2002

• #37

Regarding the production tolerances that Mark was eluding to, I've used my Sunnen honing machine to true-up the inside bores of shock bodies. In 1999 I saw a frequent problem on KX250 shock bodies, with tolerance variations of 40 microns. The shock bodies are finish honed at the manufacturers, but when the cutting stones get worn the bore shapes like an hour glass, making the seal bushing bind in the middle of the stroke. I've heard a theory that the manufacturers design that shape into the shock body in order to account for the typical wear pattern which resembles an onion shape iin the middle of the stroke.
I remeber Gary Semics first making notice of it in 1999 while riding a new KX250. I honed the shock and it made a difference especially when the shock got hottter.

 

John Curea

LIFETIME SPONSOR

Feb 29, 2000

177

0

• May 11, 2002

• #38

Eric

Do you heat the body prior to honing to simulate actual operating conditions.

Take Care, John

 

EricGorr

Super Power AssClown

Aug 24, 2000

708

1

• May 12, 2002

• #39

Hi John,
the honing method you're refering to is "Hot-Tensioned Honing". A popular honing method used on NASCAR engines. The torque plates are about the same size as the heads, with water jackets to allow an outside heated fluid like oil to simulate the same stressed @ temperture loads. Kwikway in Iowa makes a complete hot-block honing rig that includes a separate fluid heat/pump.

My method of honing shock bodies is simple. I use a popular Sunnen horizontal (MB1660) honing machine with blind bore diamond tooling on #P-28 mandrels. Most automotive hop up shops use these honing machines to fit connecting rod pins to pistons. I use diamond tooling because it cuts so straight and round, which is all you really want to do with a shock body. The problem is the bore gets too oversize for stock piston rings. Maybe Jeremy should make oversize rings for his pistons :think:

As far as a hot-tensioned rig for a shock body, the heat jacket should probably stress the body under a compression load, with some sort of adjusters attached to the clevis.
As far as I know, nobody has ever written a tech paper on hot-tensioned honing for shock bodies, but there are lots of magazine articles on how to use it for V-8 engine block honing.