1.0ltr Cams V 1.3ltr. Why ? The answer lies here !

[malcolmt]

This is not a definitive guide, more a laymans outline of some basics

These specs are taken from open source.

CG10

Inlet 196deg - 5.59mm lift - timing 16 / 0/ 0/ 16
Exhaust 196deg - 5.59mm lift

CG13
Stock

Inlet 222deg - 7.46mm lift - timing 42 / 0 / 0 / 42
Exhaust 222deg - 7.46mm lift

As you can see the 1.3inlet gives approximately .....

26DEG more DURATION. (VALVE OPEN LONGER = More fuel air mix = good)

1.17mm Greater valve opening (Opens 7.46mm instead of 5.59mm = More fuel air mix = good)

Same principal applies to the exhaust except More exhaust gasses get out More quickly.

Kind regards

Malcolm

 

[frank]

all the more reason to get your finger out and fit yours then malc :grinning:
and here,s a plot of the openings (the 2 dotted lines)

 

[malcolmt]

Thanks for adding that graph, it adds a visual dimension to what i am saying.
As stated above this is a laymans guide only, so any information folk want to add to make this "mysterious" subject easier to understand, please feel free to add.

Kind regards

Malcolm

Oh, Frank, Piccy's to come.............

 

[Maccy]

Interesting info

 

[r-reg-sr]

i love it
now makes better sence to me

 

[COZ!!!!]

thanks for that. good to see solid information on the subject.(Y)

 

[MrMigs08]

Is it possible to open the inlets on the 1.0ltr engine longer?

Just some madness but not saying its doable,

Great information indeed!

 

[frank]

Is it possible to open the inlets on the 1.0ltr engine longer?

Just some madness but not saying its doable,

Great information indeed!

my original 1.0 engine went well with the piper cams in (especially the inlet cam) and they were "advertised" 272 deg duration
so the inlet valve was closing about 60 deg after bottom dead center