Rallye and XSi cam specs

[sandy309]

I've measured the inlet side of the cams, exhaust to follow. The 1.3 Rallye, 1.6 Rallye and 1.6 XSi all use the same cam, stamped "J" on the flywheel end. The 1.4 XSi uses a different cam, stamped "Z" on the flywheel end.
Headline specs:
"J" cam:
Peak lift 10.6mm
Duration at 0.1mm lift 270 degrees
Duration at 1.0mm lift 235 degrees

"Z" cam:
Peaklift 10.3mm
Duration at 0.1mm 270 degrees
Duration at 1.0mm 234 degrees

Here are the lift curves:
http://www.goodhand.co.uk/sandy/files/TU8vCams.JPG

They are almost identical, peak velocity is about the same, but at the "J" cam has a slightly more aggressive opening slope, opening acceleration and marginally more lift, that's about it.

[rajjinator]

good info! much of a gain to be had on say a 1.4 xsi then with the rallye cam?

[sandy309]

Nominal I would think, probably a slight change of induction note more than anything!

[Louis]

I was always under the impression the 1.4cam was meatier but clearly not. good work sandy, imformative and helpful as always.

I wouldnt say you'd notice any diff in the cams looking at the graph tbh. not worth the effort...

[Gareth.Eyre]

If the standard Rallye "J" cam has 10.6mm peak lift then doesn't that mean that it has more lift than the newmans PH4?? As on their site it says the PH4 has 10.3mm of lift.

http://www.newman-cams.com/pdf/peugeot.pdf

I'm probably reading it wrong but just thought I'd ask.

[sandy309]

The Newman PH4 actually lifts the valve 11.5mm peak, the specs they publish on the site doesn't seem to correlate in an obvious way with the actual profiles I've received. I don't know why that is and I'm not complaining, because the profiles I've had from them so far have been closer to what I wanted than the actual spec. I've plotted the curve for the PH4, I do it for every cam I use to help me develop the rest, but I don't know that my various cam suppliers would be too chuffed if I published their profiles publicly! If they weren't concerned, I'd imagine the curves would be available already, I wish they were.
Cams from different manufacturers are quite different and what some of the manufacturers make for the specialist engine builders are quite different in many to what's publicly available. But clever cam design/choice isn't much use without knowing what else is needed anyway.

[sje00]

Sandy, sorry to grab the thread, but do you have the Bhp/torque graph and AFR graph for a standard S2

[sandy309]

I don't, sorry!

[sje00]

any chance you know where i could get them??

[loudandproud205]

i havnt searched but by any chance do you have the info in standard vts cams? as from rolling road results i have every one seems to think its cammed but in all honestey i have no idea

[sandy309]

I was going to measure the J4 cams next, when I get time!!

[loudandproud205]

thanks sandy if you could let me know when you do and which i need to measure to try find out the cams fitted to my car would be very greatfull

[will_1988]

The Newman PH4 actually lifts the valve 11.5mm peak, the specs they publish on the site doesn't seem to correlate in an obvious way with the actual profiles I've received.

really?!?! would that not be false advertising or something along them lines?!

[sandy309]

I'm not sure about the legal implications, but there's no apparently accepted standard for measuring cam profiles. It's been common practice for years for profiles to be described according to where they fit in the range, rather than the actual duration etc.
I measure the lift curve at the valve, with the advised clearance (0.2mm for these), which is as close as possible to what actually occurs in use. With rockers, the exact lift profile at the valve isn't as consistent as with bucket followers and at speed, the valve movement will vary according to the flex and rebound of the valvetrain too.

I'm not sure about the legal implications, but there's no apparently accepted standard for measuring cam profiles. It's been common practice for years for profiles to be described according to where they fit in the range, rather than the actual duration etc, much like recent BMW 316s having 1.9 litre engines I guess!
I measure the lift curve at the valve, with the advised clearance (0.2mm for these), which is as close as possible to what actually occurs in use. With rockers, the exact lift profile at the valve isn't as consistent as with bucket followers and at speed, the valve movement will vary according to the flex and rebound of the valvetrain too.

[freddy6868]

hi just a quick question if not a stupid one but did you measure the cam with a DTI plunger while the cam was still in the engine?

[sandy309]

Sorry I missed that question... as I mentioned before, I measure the lift at the valve with digital DTI to 0.0005" accuracy, degree by degree of cam rotation. It's laborious, but gives me a wealth of information about the profiles.

[simon182]

Sandy, Have you ever measured a Piper300 rally Rallye cam? the advertised lift is 10.16mm - how accurate is this figure?

[rajjinator]

Sandy, Have you ever measured a Piper300 rally Rallye cam? the advertised lift is 10.16mm - how accurate is this figure?

why not just measure the lift with a DTI?

[simon182]

why not just measure the lift with a DTI?

because ive not had chance yet! :P And i wondered if anyone had done it on my Cam before! - it could save me some time!

Piper are useless at replying to emails too!

[rajjinator]

because ive not had chance yet! :P And i wondered if anyone had done it on my Cam before! - it could save me some time!

Piper are useless at replying to emails too!

lol.. wont take long to measure!

[simon182]

lol.. wont take long to measure!

Depends on how many points you measure!

:P

[simon182]

Right then:

S1 J cam measured!
Direct from the cam, Was doing this to compare to my 300 Duration Piper jobbie....
(which is actually for the quiksilver/early VTR not a rallye! - self inflicted for not checking before I bought it - see the for sale section)

http://i6.photobucket.com/albums/y213/he_pauses_shaving/S1cam.jpg


Does anyone know the cam to rocker ratio?? 1.4 rings a bell...

OK,
now im confused,

Ive measured a max lift of 6.7mm (ignoring base circle) giving a Valve lift of 9.38mm (ratio 1.4:1)

but Sandy gets a peak valve lift of 10.6mm....

Pipers lairiest cam gives an advertisd lift of 10.42... (including ratio)

So whose right... me or sandy?

:S

[sandy309]

I always measure at the valve, which takes the full effect of the rocker shape and ratio into account; as long as the gauge is firm and zero'd correctly, it can't be wrong. What can vary, although not greatly, is wear on the cam and/or rocker pad.

[simon182]

Does that not make it really hard to measure?

i.e. getting the DTI directly in line with the direction of travel of the valve?

I guess there just different ways of measuring the same thing - so long as I use the same method for measuring when comparing cam profiles all will be ok.

[sandy309]

Yes exactly. I use the same method every time and measure/check every cam I use to ensure consistency etc. Aligning the DTI isn't hard or super critical and obviously check you have full travel over the profile.

[pugmadnath]

What is the difference in performance gain between a longer duration and higher lift?

For example, what advantage would a 300 degree duration camshaft have over the standard one, if it produced the same lift as standard?