Author Topic: IMD Pistons  (Read 487 times)

Offline paulmbsa

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IMD Pistons
« on: 26.12. 2019 19:50 »
has anyone fitted these and used them in Anger please


Online muskrat

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Re: IMD Pistons
« Reply #1 on: 26.12. 2019 21:26 »
G'day Paul.
I have not used that brand yet. They look like cast so I wouldn't race them.
Look at reply 11 on this page.
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
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Offline Steve.Carter

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Re: IMD Pistons
« Reply #2 on: 26.12. 2019 21:33 »
An engine in my Ariel Huntmaster is just about clocking up 100,000 miles over  the last 6 years or so. I had problems early on with the pistons used by SRM for its rebuild but after they were replaced by IMD pistons all was great.  After they had done ar around  50,000 miles things started to get smokey and she needed topping up between oil changes. A re-grind and with the next size up IMD pistons takes me to where I am today. She still isn't noticeably smoking but she does use a little oil.   
My main worry now is 100,000 miles without even looking at the sludge traps!  Hmm, maybe it's time *smile*


Offline BSA_54A10

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Re: IMD Pistons
« Reply #3 on: 27.12. 2019 02:18 »
It all depends upon how often you change the oil and weather you have an external supplimentry filter fitted.
I have seen engines with well over those miles with less than 10% of the sludge trap full.
Bike Beesa

Offline edboy

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Re: IMD Pistons
« Reply #4 on: 27.12. 2019 21:22 »
i agree with the above. fit a cartridge oil filter , multigrade oil and forget the sludge trap. i ve used imd pistons and rings no problems. i use my bike daily but  get 3,ooo miles per year. steve where are you going with that milage ?

Offline Steve.Carter

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Re: IMD Pistons
« Reply #5 on: 28.12. 2019 21:14 »
 I'm an insulation contractor Ed, surveying boiler houses and used to go everywhere on my modern BMW. Stupid thing started to let me down so began riding my Huntmaster more and more. She didn't let me down and really wasn't that much slower either. Over the last 6 years riding her she always got me to my job save for one flat tyre.  I've a small morgo screw on oil filer and do run multigrade. 
I do a fair few Ariel rallys through the year also.

Online Colsbeeza

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Re: IMD Pistons
« Reply #6 on: 29.12. 2019 01:41 »
Hi Paul,
The IMD pistons rings are coated steel, not the original conventional cast iron, so recommend you get advice from your machinist on honing the bores to suit.
The bedding-in of Cast iron rings in bores honed to a coarse grit ( about 150 grit) is responsible for a fair bit of the sludge buildup in the sludge trap, and contributes to excessive wear of the motor generally. Frequent oil changes help considerably.
Modern motorcycles can do 60,000 miles or more between rebores but our old bikes used to get up to 25-30,000 miles before wear or lost lubrication due to blocked sludge trap required a tear-down and rebuild.
My machinist honed my bores to a 500 grit size, then "plateaued" off the tops of the honing ridges.
Everyone (almost) also recommend a Return-side oil filter and multigrade oils with high Zinc content for maximum life for our Brit bikes.
You can also read up on "Dry" Running-in. Seems very popular on this Forum for cast iron rings. Probably not best for modern rings however.
I will duck now to avoid the stones.
1961 Golden Flash