Cam Profiling

[Mike GTT]

New poster! (less than 10 posts)

Did i see on here a while back, somebody was measuring all sorts of different cam profiles?? :crap:

Doing a project in uni and could do with some info.... :scared:

cheers

[Big Jim]

New poster! (less than 10 posts)


New poster! (less than 10 posts)

Did i see on here a while back, somebody was measuring all sorts of different cam profiles?? :crap:

Doing a project in uni and could do with some info.... :scared:

cheers

What info you after?

[Mike GTT]

New poster! (less than 10 posts)

basicaally it's an engine build project(on my GT Turbo). i wouldn't mind the lift profiles of the piper 285 cam... i can't measure it, as i haven't bought it yet.... i've tried gettin in touch with piper, but no such luck as of yet.

just need the lift info so i can plot it on an excel graph, and calculate valve velocities etc...

i've got the standard cam out of the engine so it woun't be a problem measuring it.

[Big Jim]

New poster! (less than 10 posts)


New poster! (less than 10 posts)

basicaally it's an engine build project(on my GT Turbo). i wouldn't mind the lift profiles of the piper 285 cam... i can't measure it, as i haven't bought it yet.... i've tried gettin in touch with piper, but no such luck as of yet.

just need the lift info so i can plot it on an excel graph, and calculate valve velocities etc...

i've got the standard cam out of the engine so it woun't be a problem measuring it.

leave it with me, I'll see what I can do :)

[Scoff]

hi mike. you need to have a chat with andrew cooke, he spent a lot of time plotting the lobes of most of the common GTT camshafts, inc the few variations of bp285. On the old site there were the excel files andy created, maybe he'd upload them again if you asked him. Chris

[Mike GTT]

New poster! (less than 10 posts)

cheers mate.

i've got the info off the website which is basic for my needs.

I'm gonna be measuring the standard cam and measure degrees vs lift and plot it that way, but as i said, no cam...... which sort of throws up a little problem lol from the data i want to compare the two, in terms of emissions, peformance and application.

thanks again fella :D:agree:

[Andrew Cooke]

New poster! (less than 10 posts)

basicaally it's an engine build project(on my GT Turbo). i wouldn't mind the lift profiles of the piper 285 cam... i can't measure it, as i haven't bought it yet.... i've tried gettin in touch with piper, but no such luck as of yet.

just need the lift info so i can plot it on an excel graph, and calculate valve velocities etc...

i've got the standard cam out of the engine so it woun't be a problem measuring it.

the question is which Piper 285?

You're going to need some pretty accurate kit to get velocities, and the measurements I made aren't accurate enough, you can do a bit of filtering to get close, but Piper are you best chance - if they'd share their data. Of all the cams measured the Piper ones have the steepest ramps.

[Mike GTT]

New poster! (less than 10 posts)

cheers scoff will do...

if i have the wonga i'd do it all myself,but with the credit crunch and all.... lol :D

[Scoff]

andy has 360° plots, angle vs lift of most any of the common cams you can imagine, including the standards. hopefully he'll upload them again :)

[Andrew Cooke]

New poster! (less than 10 posts)

cheers mate.

i've got the info off the website which is basic for my needs.

I'm gonna be measuring the standard cam and measure degrees vs lift and plot it that way, but as i said, no cam...... which sort of throws up a little problem lol from the data i want to compare the two, in terms of emissions, peformance and application.

thanks again fella :D:agree:

I found the best way for me to do that was use a block with a follower and pushrod fitted to measure cam lift. When I first started measuring I used a built up engine, but not only was it a pain to keep building the engine for every cam, but it also meant the valve clearance and rocker geometry became critical.

[Mike GTT]

New poster! (less than 10 posts)

the first part of the assignment is just presenting the strip down and what i'm hoping to acheive. so at this stage i'm just gathering as much knowledge as possible. everything i need to measure the cam's are at my disposal, so i'll see what i can afford after christmas in terms of buying the cam, and maybe post up my data once i'm done.

at the mo i'm working on the head, hopefully should have a head design drawn up in cad before crimbo and put it into WAVE to calculate power and torque then make the changes to my head, or ideally make my own on the CNC machine....if i can get the funding that is(dreaming:p)

any data at this stage would be awesome tho if you've got it laying about?? makes it easier to see what i'll need to find out..

[Andrew Cooke]

this should get you started, not the nicest curves I think the lobes may have been worn.

http://www.rtoc.org/files/index.php?path=Technical%20Files/Andrew%20Cooke%27s%20stuff/

[Mike GTT]

is that the lobe being measured after the pitch cirlce?

that's a fair bit of of lift :p

[Scoff]

is that the lobe being measured after the pitch cirlce?

that's a fair bit of of lift :p

it'll be lift over and above the base circle. it needs multiplying by 1.5 then -0.2mm/0.25mm (valve lash) to get to approximate valve lift.

[Mike GTT]

Thats awesome stuff.

Is there any data on here for exhaust cam profiles?? or am i actually have to get off my ar*e and do some work here??? lol

Cheers again guys! got some cool graphs here :agree:

[Andrew Cooke]

Thats awesome stuff.

Is there any data on here for exhaust cam profiles?? or am i actually have to get off my ar*e and do some work here??? lol

Cheers again guys! got some cool graphs here :agree:

both lobes are the same, you just need to dial in your chosen LSA.

[Andrew Cooke]

Post your graphs when you're done, and I'll have a quick scan that they're what I'd expect.

Those numbers include the effect of the follower, they aren't measured straight off the lobe.