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Webster IC Engine build log.
raynerd:
OK, well this is from the pollymodel website:
Would any of these be any good, I get the option of the ID/bore being 3/4 but with either a 1" or 15/16 OD and also the cross section changes as well.
I don`t understand that, how can you have a 3/4" ID yet a 1" OD, does that mean the piston ring is 1/4" thick?? In which case neither of these 3/4" o-rings will fit my 7/8" bore :scratch: :scratch:
Chris
NickG:
Nice 1. I'd still be tempted to make the piston from cast iron with no rings. Infact for my first i.c. I'm definitely going to try a graphite piston before anything else. It seems to cope well with the heat on the flame gulper, the only question is whether it will cope with the extra force on it by the internal combustion. Over on HMEM a guy has used it in a 7/8" bore i.c though so pretty confident. The advantages would be great - low friction, good seal, no lubricant, no rings, easy to machine, light weight, no need to lap!
http://www.homemodelenginemachinist.com/index.php?topic=12591.0
Nick
ps no, it'd be 1/8" or 3/32" cross - section Chris!! :poke:
You need the 11/16" x 7/8" and make the groove deeper / wider.
raynerd:
:palm: Nick, I still don`t get it! How can the inside diameter be 3/4" and the outside be 1" - that leaves a 1/4" which is the thickness of the ring or is cross section not the ring diameter!?!
raynerd:
Blackgates have just replied - but it looks like the same range:
www.raynerd.co.uk/wp-content/upLoads/orings-blackgates.xls
I`m totally confused :coffee: :scratch: :coffee: :scratch:
Bogstandard:
A 3/4" ID ring having a 1/8" cross section.
So double the cross section (one on either side of the ID bore as it sits in it's groove), and that will give you 1" OD.
See C-o-C
I hope this explains things OK
Bogs
BTW, I told you what you need here
http://madmodder.net/index.php?topic=4232.msg46696#msg46696
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