Are we aloud to doing anything to the pistons???
Best to do it quietly......
I think "no" is the answer you're looking for...there's a bit somewhere in the regs which states that it is forbidden to mill/machine/grind/polish anything not expressly permitted.
Derek's got the general idea, however, I would suggest that you read the rules, you may be surprised at the things that are covered that you'd assumed there would be no problem tweaking.
;D 8)
If it says you can you can. If it don't say you can you cannot.
Steve
Hmm ok well does anyone no where i cn get a copy of the regs??? :-\
Yes....here.
http://www.2cvracing.org.uk/technical/25-gettingstarted
And you have entered a car in the 24 hour race how many times????????? :o
I have the rules somewhere but not with me at uni! Have lots of new ideas though i want to try and dont know if i can for racing. Also looking into developing a new cam shaft for racing as my second year project. ;D
<developing a new cam shaft for racing>
Why?
Because i actually feel that there could be better. I think now after long chats etc with people who build and design engine that the cam has the wrong profile. I believe this is part of the reason that we are pulling valve heads off.
Would you not be better off designing a valve that won't break in the circumstances?
(tempting fate a bit...)....I haven't dropped a valve yet; one engine has done 2 seasons (minus the last race at Mallory) and 3 24 hour races (2 at Snetterton and 1 at Spa) with regular oil changes and occasional valve spring changes. It's had one head off for the scrutineers and one off to retrieve bits of broken cable tie; undisturbed apart from that.
I suppose the answer is to get Norry to build your engines.......
Why do we consistantly feel the need to beat ourselves up over the camshaft? For every person who says the profile is wrong, there is an equally vocal person who says it isn't.
Didn't bully compare the profile of the standard to club cam?
How to scare people away from racing when money may be tight if we tell them that we will change an expensive part of the engine, again
Great idea as a uni study / project, but leave it at that
Cheers
Trevor
And we should now have valves that don't break thanks to g&s.
Yeah i think its going to be a great project hence going for it.
I looked a bully's comparisons and looking at the race cam it looks like it closes far to harshly. It should idealy slow down just before it closes.
What valves are we going for now then paul???
I have received them today via trevor one piece stainless valves made especially for the club by G&S valves in Godalming,theu are made to our regs and require no modification.
They make 5mm stem 41mm head valves that rev to over 11000rpm so the club's 8mm and 8.5mm stem ones should be nigh on indestructable(we hope).
Will we need to change the valve guides and springs??
Dont know if there is a wieght difference with new ones??
Also will stainless work ok with the current valve guides?
more questions for your uni project then?
The regs don 't say you can use different valve guide material marc so according to our rules you can't change it anyway even if you wanted to.
I wasnt saying i wanted to Paul. Just wondered if the 2 materials will work together???
In answer to the question of valve weight, here is what I have found:
Standard Road valve from ECAS = Exh 65g, Inlet 65g
Race valves from ECAS = Exh 55g, Inlet 60g
2CVRC 1 piece valves = Exh 55g, Inlet 55g
All valves brand new, never been used
Trevor
(Sad, I know!!!!) ;D
very very sad :'( :'( :'( :( :'(
The new valves are indeed very nicely made - as would be expected from a top UK manufacturer, they are in fact manufactured from 2 types of steel & are in reality 2 piece valves in the manner that would normally be expected, the use of a 'billet' cam will in fact obviate their use since there will no longer be 'float' except when an engine is vastly over-revved.
Quote from: Paul Robertson on November 22, 2008, 12:53:33
I have received them today via trevor one piece stainless valves made especially for the club by G&S valves in Godalming,theu are made to our regs and require no modification.
They make 5mm stem 41mm head valves that rev to over 11000rpm so the club's 8mm and 8.5mm stem ones should be nigh on indestructable(we hope).
Quote from: Roy Eastwood on March 05, 2009, 12:54:46
the use of a 'billet' cam will in fact obviate their use since there will no longer be 'float' except when an engine is vastly over-revved.
Hows that then?
If Kent grind your new billet to their (Our?) Race profile surely the characterisics, and flaws, will be the same? or can you get some other shop to do the grind as long as its to the club cam spec.
Sean
The regs state the cam can only come from the club's approved supplier, namely Kent Cams. Any one else doing anything to a cam would be in breach of the regs and in SERIOUS trouble if / when caught
Quote from: Trevor Williams on March 23, 2009, 12:56:36
Any one else doing anything to a cam would be in breach of the regs and in SERIOUS trouble if / when caught
Ok- Knew that ;D
And whats the advantage of a billet cam, presuming there is an advantage or else why go to the trouble / expense ???
Sean