Thinking about it
|
| posted on 11/3/09 at 08:36 PM |
|
|
Camshaft advice please
With a combination of conflicting information in the manual and a little bit of haste I think I may have bought the wrong profile camshaft.
The engine is a 1600CVH XR3 Type.
It was intended to be a standard replacement.
On the camshaft I have now fitted the exhast valve will open 6 dgrees earlier but still close at the same time and the inlet valve will open at the
same time but close 2 degrees earlier.
Can anyone explaine what differences this will make?
|
|
|
|
|
will121
|
| posted on 11/3/09 at 08:59 PM |
|
|
what make cam is it? some usefull info on the kent cams web site
linky
|
|
|
britishtrident
|
| posted on 11/3/09 at 09:06 PM |
|
|
The most important number is the number of degrees of over lap when the inlet and exhaust are both open over TDC at the end of the exhaust stroke
start of induction stroke.
ie overlap = inlet openning BTDC + exhaust closing ATDC
The bigger the number the higher up the rev band peak torque and peak power are delivered.
|
|
|
snapper
|
| posted on 11/3/09 at 09:15 PM |
|
|
looks to me like 8 degs extra overlap
not to much then probably something like a 285 cam.
I currently have a 285 on my Pinto and it is quite mild at low revs
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
|
|
|
daviep
|
| posted on 11/3/09 at 09:25 PM |
|
|
Only looks like 2 degrees extra overlap to me.
Davie
|
|
|
mark chandler
|
| posted on 11/3/09 at 11:17 PM |
|
|
Sounds to me like an XR3 cam, not an XR3i cam, they closed them up slightly as injection is more efficient. Should give slightly more power, certainly
not a worry anyway.
As the lobes are slightly more advanced you will pick up mid range, when you dial in are the lobe peaks equally spaced when at TDC ?
If evenly spaced the the cam is central, advance by 5-7 degrees from this and you get 5% - 10% more mid range but loss a little top end from central,
retard by a few degrees from central and you lose 5% - 10% mid range from central and grow maybe 5% top end.
So for normal spirited driving advance, for drag strip when wheel spin is an issue run retarded.
Its all to do with pumping loses apparantly.
Regards Mark
|
|
|
