Cams, followers, wrist pins. Engine men please read...

Message

hawksd1 · #11 Post by **hawksd1** » Thu Jan 25, 2007 10:20 pm

QUOTE (Wayne Schofield @ Jan 25 2007, 03:33 AM) <{POST_SNAPBACK}>

We're not short of 'R', we just need to all work on the 'D'!!!

Hee-Hee!!

Let's face it, if these things were only reliable they'd be pretty unbeatable.

I bet no-one gets tired of the performance or handling but they must get tired of fixing them!

When we've got the reliability sorted, maybe we can do something with the looks......?

u gotta be kidding I dont know about you but mine is beautiful....lol

wayneschofield · #12 Post by **wayneschofield** » Fri Jan 26, 2007 6:04 pm

Mine looks worse to than my wife did!

Mind you, she did cost less money.....

A little tech-spec of the new cams everybody......

Inlet stock:- 298 deg .385" lift

Inlet new:- 304 deg .405" lift

Exhaust stock:- 288 deg .355 lift

Exhaust new:- 300 deg .375 lift

Obviously, these numbers will only give a partial indication as the area under the lift envelope could be considerably more if the acceleration rates are much higher. Two cams with the exact same lift and duration can be totally different in use.

wayneschofield · #13 Post by **wayneschofield** » Fri Jan 26, 2007 7:17 pm

Multiple drillings as normal for vernier adjustment, absolutely chaps.

cannondale27 · #14 Post by **cannondale27** » Fri Jan 26, 2007 7:51 pm

Cool that is a big plus.

(quote)Obviously, these numbers will only give a partial indication as the area under the lift envelope could be considerably more if the acceleration rates are much higher. Two cams with the exact same lift and duration can be totally different in use.(quote)

Why would they be different except for valve float or duration which you dont show?

wayneschofield · #15 Post by **wayneschofield** » Sun Jan 28, 2007 4:15 am

A cam with higher off the seat valve acceleration and more of a radius to the flanks could have the same lift and off the seat duration but have much more area under the lift envelope than one with lower initial acceleration and flatter lobe flanks.

This is why you often see durations listed as 'deg at 050" lift', because that eliminates the variation in off the seat acceleration and gives a more comparable set of numbers.

I'll see if I can dig up some lift envelope graphs to show you what I mean....

Sandstorm · #16 Post by **Sandstorm** » Sun Jan 28, 2007 4:48 am

I don't understand a thing your saying!!!

All I do know is if they work better and will last I'm in!!

ozarkdaler · #17 Post by **ozarkdaler** » Sun Jan 28, 2007 4:53 am

LMAO I don't either.

J. Delaney · #18 Post by **J. Delaney** » Sun Jan 28, 2007 5:20 am

Cam lobe profiles. you can have 2 profiles: one shaped like a mountain peak, the other shaped like a plateau. The plateau shaped cam will keep the valve open further for a longer period of time.

cannondale27 · #19 Post by **cannondale27** » Sun Jan 28, 2007 11:52 am

I like thinking of a cam as a deformed triangle.Change one side and others change with it.Not totally true but close.On that if acceleration of the cams is different between two cams of .050 lift.Duration ,base circle or the falloff also changed.

wayneschofield · #20 Post by **wayneschofield** » Thu Feb 01, 2007 7:44 pm

I'll try to dig up some old development graphs and stuff, if I can find it, it might make things easier to understand.

What I 'think' as I 'write' and what you 'read' from my 'writings' could very well be different. Minor terminology differences can cause confusion, me being a 'Limey' and all....