MOT fail due to cams??
- Thread starter cavaddict
- Start date
lol you should watch it he expanse cams and why with sound effects in vid 2
corsaZ22se
Senior Member
with your cams the spec data sheet should show max lift at tdc. this is the figure you need to set the cam timing.
you will also need a dial gauge to find true tdc by measuring the top of the piston through the spark plug hole.
a pointer and a ruler on the crank pulley can also be used, longer the better for the pointer.
once bottom end is set to true tdc then adjust cams so you get the max lift at tdc by measuring the position of the valve with the dial gauge while turning the cam shaft with what ever type of vernier pulley you are using lose.
some cams are made so far out that you may need to move the cam chain around the sprocket to get correct timing.
I had a lot of trouble with cams in my x20xev, piper cams were a whole tooth out on inlet and half a tooth on exhaust, newman cams were 3 teeth out on exhaust and 2.5 on inlet!
kent cams were the best at half a tooth on both. its running 286 degree cams and passes mot just with a friendly mot station. yours should breeze mot once set up correctly and you have it mapped for the cams, sound will change to once its mapped, my Vectra had a really deep boomy note after fitting shrick cams and fueling was miles out running a map that was done on Dbilas cams.
think there a guide to setting cams on kent web site or PEC site?
you will also need a dial gauge to find true tdc by measuring the top of the piston through the spark plug hole.
a pointer and a ruler on the crank pulley can also be used, longer the better for the pointer.
once bottom end is set to true tdc then adjust cams so you get the max lift at tdc by measuring the position of the valve with the dial gauge while turning the cam shaft with what ever type of vernier pulley you are using lose.
some cams are made so far out that you may need to move the cam chain around the sprocket to get correct timing.
I had a lot of trouble with cams in my x20xev, piper cams were a whole tooth out on inlet and half a tooth on exhaust, newman cams were 3 teeth out on exhaust and 2.5 on inlet!
kent cams were the best at half a tooth on both. its running 286 degree cams and passes mot just with a friendly mot station. yours should breeze mot once set up correctly and you have it mapped for the cams, sound will change to once its mapped, my Vectra had a really deep boomy note after fitting shrick cams and fueling was miles out running a map that was done on Dbilas cams.
think there a guide to setting cams on kent web site or PEC site?
vocky
Staff
Last edited by a moderator:
dewismotorsport
Senior Member
I have no idea tbh I'll have to ask him, they are just re profiled GM ones by the look of it
Piper cams are original cams that are reprofiled
dewismotorsport
Senior Member
Piper cams are original cams that are reprofiled
Makes sense then, tbh I have literally took them out the bubble wrap to check for any damage and then put them straight back in the box and carried on unwrapping everything else, will give them a measure when I'm back in work
cavaddict
Senior Member
This is what i find weird. As far as i can tell these are not re-profiled cams and are made for this engine, so why on earth didnt they put the sprocket locaton slot in the right place!!??
Anyways that aside, have dug my old dial gauge out and will have a go at printing a degree wheel out later as i'm changing the rear brakes today.
Anyways that aside, have dug my old dial gauge out and will have a go at printing a degree wheel out later as i'm changing the rear brakes today.
cavaddict
Senior Member
Well i've googled, yahooed & read the instructions that came with my cams about a trillion times now and it still makes absolutely no sense to me!! What i find weird is Comp Cams state that at TDC you find max lift of No.1 lobe on No.1 piston.....surely this will bend the valve?
corsaZ22se
Senior Member
corsaZ22se
Senior Member
they are using the other way of setting timing which is less accurate, they measure lift at degree's before tdc and bdc.
line, valve timing @ .050. 5- btd 35 abd written in proper English would translate to .050" of valve lift 5* BTDC 35* ABDC.
so the valve will be open .050" 5 degree's before top dead centre and still be open .050" 35 degree's after bottom dead centre. (intake cam)
as you have to move the bottom end of the engine during this process this is where you loose accuracy and is not the preferred method of timing an engine although it does still work all be it taking much longer to get spot on.
line, valve timing @ .050. 5- btd 35 abd written in proper English would translate to .050" of valve lift 5* BTDC 35* ABDC.
so the valve will be open .050" 5 degree's before top dead centre and still be open .050" 35 degree's after bottom dead centre. (intake cam)
as you have to move the bottom end of the engine during this process this is where you loose accuracy and is not the preferred method of timing an engine although it does still work all be it taking much longer to get spot on.
oh how i wish it was that simple new rules and cameras in the testing bays dont help
