Re: pistons

[jonathan coates <alfa@domain.elided>]

In message , Greg Hermann <bearbvd@domain.elided> writes
Snipped loads of good stuff
>
>The place where there is GREAT room for improvement in performance and
>durability is in more accurate machining of liners (like with them
>installed in a block with a torque plate installed and warm water
>circulating in the water jacket--and in use of sophisticated coatings to
>both reduce wear and friction and to reduce heat transfer into the pistons.
>(Among other benefits are tighter allowable piston to sleeve clearances,
>and still lower leakdown rates. Most Alfa motors have attrociously high
>leakdown rates!!
>
Is this for real?
People actually put them in the block to do a re-bore like in a mini?
This is a new one on me, and I thought I'd heard all the ideas about
engines, from the Alfaesque to the downright sidevalve. Where would you
attach the torque plate, and how do you keep the steam around the liner,
or do you just have HOT water?
Reducing the heat transfer into the pistons pushed me into "this is a
wind-up" mode so bear with me here guys and gals, I thought that the
heat transfer was from the pistons, via the liners to the coolant.


>The other problem you will get into with compression ratios above 10 on
>forged pistons in an Alfa is extremely rapid wear of the top ring groove.
>The right coating can help this, as can a true synthetic oil.
>
Wonder why the ring groove would wear? Anybody know?

>Close attention to the design of your ring pack is also VERY important.
>Personally, I would not take a gift of Deves rings for any engine! My own
>preference is for a ductile chrome top ring, Total seal second, and a
>chrome plated iron, H section, oil ring with a coil spring expander.
>
>I am also partial to hard surface conversions on the sleeves.
Such as chrome, or what?

After reading this post, as I rarely do before spouting, I can see that
it looks like a Gregflame. This is not the case, as I have found some
new ideas which is, IMHO always a good thing. I also found several
questions implicit within the original post, because of my ignorance.


- -- 
jonathan coates
I would like to know more (Life Philosophy)

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