P1 Cam Specs

XBCoupeJota

XBCoupeJota

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Race Central - Sydney
I've searched the forum for specs on the P1 cams but can't find any open and close figures, does anyone have these as I would like to model the profile to check out some cam combinations.

Cheers Crispin
 
Hey Lothar,

always do but unfortunately JLO's site doesn't have the info either:


Anyone know the missing info on open and close figures for the P1's?
 

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Hi Crispin - Don't know the open/close figures - the factory spec is for 100 degree lobe centres - best to check what you get after setting up at that with running clearances if you want truly accurate info, then work out what you'd like to do. if you look at my old racer - you'll see adjustment can be made in minutes of cam timing - if red's got his dyno going - i'd do all the work off lobe centres - much quicker - HTH - Phil
 
Hey Phil,

thanks for that, no problem to setup the cams as I always use ML as the basis. I wanted the open and close figures for some software modelling first and am too lazy to fit them on my engine and figure out what the open and close figures are. I will probably have to get into the garage over Easter and figure it out. Your racer is still at Red's as I've been flat out with the Spaceframe and work keeps sending me off to all sorts of places disrupting my race prep time.

Hope all is well
Cheers Crispin
 
XBCoupeJota said:
Hey Lothar,

always do but unfortunately JLO's site doesn't have the info either:


Anyone know the missing info on open and close figures for the P1's?
Click to expand...

ups - sorry...  :-[

Checked my files and they match with Phil's info, at least for the inlet (100? loop center). For exit though it shows 80?, both having a lift of 11,22mm Hope that'll help you any further.
 
crispin,

these values are from my files
i believe they are from doug home with chris pritt's cams
i haven't had a set in hand to verify

P1 measured spec
Inlet 11.02 lift
0.006 106/125, 411 dur, overlap 210
0.050 36/55 271, overlap 72
Exhaust 11.07 lift
0.006 127/104 411
0.050 55/36 271

what kind of sim are you using?

cheers,
scott
 
Hi Lothar - Uk uses 100 degrees ( where some european mostly) use 80 degrees - we split (for example) 100 degrees after where you split 80 degrees before - out of a 180 degree cycle - has caused me a few headaches in the past!1 - Regards - Phil
 
If you have the cams in hand rather than in a motor, go see a cam grinder - I believe there are a couple in Q'land...
Most if not all these days have a "cam doctor" style measuring rig.
Very quick (and usually cheap) printout of all the cam specs incl things like hydraulic intensity if you need it.
 
One of the partners in a ChCh outfit went back to Q'land a few years back, he was a keen motorcyclist and I'd built a motor for him while he was here. I'll ask next week where he's working as he was a pretty good guy.
You're not asking them to work on the cams - just run them over their measuring rig which basically consists of a dial gauge linked to a computer.
 
I know what you are talking about, I have bought a Valve Pro unit from Audie Tech but not seen it yet as it is still being shipped

 
Chaps

Scotts helpful figures may answer the timing question, but I dont understand the 'discrepancy' in quoted lobe centre figures - some saying 100 100, some saying 100 80. My printout of all Laverda cam figures gives 100 80 for P1's.
Phil - I dont quite follow your UK/European explanation. Do you suggest make the exhaust 90?

I'm looking to get my P1's checked in the near future, so want to get it right.

Regards, Andre
 
Hi Andre - Just a different way of saying the same thing - EG - 100 degrees after TDC is also 80 degrees before BDC. I don't like the amount of lift on the exhaust P1 - can't see the point of overlifting the smaller valve and don't like masses of overlap on a motor that has such good torque characteristics. can see the relevance on a long fast track or drag racing, but I use a 4/C exhaust cam to keep low down grunt. I do get easily confused by the "befores & afters" in cam speak, so always take the simple way out of sticking a masking tape pointer on my disc so that I know where I want Max Lift or other figures. - Regards - Phil
 
jotacorsa said:
crispin,

these values are from my files

what kind of sim are you using?

cheers,
scott
Click to expand...

Hi Scott,

thanks for the details, have to agree with Phil the durations on these cams are suited to a land speed record attempt not for our style of racing down under. I've been modeling the cams in Dyno SIM and have come up with some promising results. Might look at some custom grinds in the next couple of months based on revisions to the F1 cam profile which have much shorter durations than the 4C, 7C or P1.

Cheers Crispin
 
Checked with my local firm of cam grinders - Kelford camtech in ChCh NZ - re the guy who went back to Oz.
apparently he's bought into a Sydney firm - not a lot of help, sorry.
On the subject of Q'land cam grinders there were comments made I couldn't repeat here...
Looks like you were quite right Red...kelford do cams for a number of control classes in Oz and hence soon realise who is honest in the business as cams are sent back for checking when motors are stripped.

Crispin - if you come up with a spec you'd like to try, I can recommend Kelford's work. They do very durable hard overlays.
They've also got an enormous profile library - and your dollar makes it attractive too.
 
Not sure if there is any sense in it, but I do know that Doug Home (btw - anyone know what he's doing today? still riding his Lavi?) did several cam profiles he said based on calculations etc. As said - not sure what knowledge was involved with him, had a lengthy chat with him years ago and got lost at some point with all these duration numbers and BDC and TDC and so on. But maybe worth checkin?
 
Doug is racing pushbikes these days,one of his cams is in Chris Pritts SFC triple I think but thats now owned by another club member.I will ask tonight at the NSW Club meeting.BTW Doug's bike is for sale.I just remembered Chris,s SFC was bought by another club member who swapped it for a SS bevel that another forum member owned so over to ??
 
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