camshafts??

[jonnyshaw49]

hi just stripped down 2 blocks i had lying around and removed the camshafts, i have 2 camshafts that look very similar, both have 270 stamped in the centre, but all the other numbers are different, and also 1 is painted red in the end section of the shaft near where the vernier bolts on.could anyone tell me off these numbers if they are standard or uprated?? at the end where i mentioned painted red there are 2 lugs on one side and 1 lug on the opposite side these are noticably different sizes on each shaft, the numbers are

cam 1 from vernier end 3/ f?20 270 13

cam 2 from vernier end 12/ f021 270 11


opposite side


cam1 from vernier end 5\ p m 13

cam2 from vernier end 6\ fish sign m 11

anyone any ideas???


thanks

[Andrew Cooke]

probably standard.

Best thing to do is measure the lobe lift, zero your vernier across the narrow part of the lobe then measure the tall part. You're looking for something in the 5.1 to 5.6mm range for standard. Post what you find.

Andy

[HULK]

This is very interesting. I have a piper cam fitted but unsure if it's a 260, 270 or 285. How can I find out??

[Penfold aka The Dealer]

This is very interesting. I have a piper cam fitted but unsure if it's a 260, 270 or 285. How can I find out??

Should be stamped on the end of the camshaft..

[Markey Mark (BD)]

On the end of the camshaft (flywheel end) they normally have the number stamped on there of what it may be.
If its standard its normally has 2 letters only, something like C U i think, i may be wrong but i've always found this.

[jonnyshaw49]

these 2 camshafts hav e nothing stamped on the ends, on the edge of the round parts of the cam they look like they have been grinded slighly by hand as it isnt perfect all the way around like a machine would, im not sure on how to mesasure them, can i not just measure the size of the lobe?? thanks

[Sparkie]

this is one the most common errors made.

if it hasnt got anything on the end of the cam it will be standard. the 270 you describe is moulded into the main shaft - its doesnt mean anything.

the next error will be your uprated red painted valve springs, which are actually standard.....

[Andrew Cooke]

this should explain it.

you need to measure lobe lift, it's not complex maths, so as long as you have a vernier it's a 30 second job

[rs250nut]

the next error will be your uprated red painted valve springs, which are actually standard..... [/quote]

Higher poundage springs have five coils where as o.e have 6

[jonnyshaw49]

The springs are black and have 1 less coil the red I'm on about is the end part of the shaft near vernier is red I will measure the size when I get chance thanks

[Wallace]

this should explain it.

you need to measure lobe lift, it's not complex maths, so as long as you have a vernier it's a 30 second job

I've been seaching on the site to find the cam tolerances (standard cam!) but am struggling to find the info..........

Can anyone point me in the right direction?

Thank you

[Sparkie]

tolerances as in what? - lift?

how about this?

https://www.rtoc.org/cam/?cam=std+GTT...vance=0&vc=0.0

rocker 1:1 and 0 tappet gap mean you are measuring the cam.
so the cam peak is 5.1mm over the base circle.

[Wallace]

Tolerances as in, from the diagram, taking the measurements of your cam and seeing where it's worn.....

So i suppose what i actually mean is what are the dimentions of the standard cam as per the drawing measurements???

Cheers Sparkie

[Wallace]

probably standard.

Best thing to do is measure the lobe lift, zero your vernier across the narrow part of the lobe then measure the tall part. You're looking for something in the 5.1 to 5.6mm range for standard. Post what you find.

Andy

Just read through properly