Timing a Cam in

[frostmotorsport]

ok, for a friend on here...

Start by installing cams, cambelt etc.

Find Crank TDC (using a pin in the #1 sparkplug hole method) - turn crank one direction till it hits stopper in sparkplug hole, turn other way till it hits stopper, divide the difference to find actual crank TDC. mark this on cambelt cover or something. reset your degreewheel (on crank pulley) so it now points to true TDC.

now, you need to find the CentreLine (CL) of your first cam. Using a dial indicator on a solid base, so it is measuring the #1 cam lobe, turn one direction to, say 0.500 lift, record what it reads on your degree wheel - now turn the other direction to the same lift (0.500 say) record the reading on the degree wheel - divide the difference and you have the CL of the cam. This should be around what your lobe CL is for the cam, but may be a few degrees out.

Now this is where you use the camwheel to adjust the cam forward or backward to set the cam on it's correct CL.

Rinse and repeat for the other camshaft....

here is a useless and pokey drawing I did to illustrate....



enjoy!

[palmer77]

I can see your a born artiste Mr Frost !!

[frostmotorsport]

one tries ones best!!

it's a hard concept to explain to a non-engine engineer, so sometimes even the simplest diagram helps!!

[GT-R_Dan]

What are the torque specs needed for a cam swap?

[frostmotorsport]

you mean the torque settings for the cam bearing caps?? the manual says 9.0 - 11.8 NM - or 6.7 - 8.7 ft/lb.

seems like pretty low torque settings to me, but thats what the book says!!

[GT-R_Dan]

Thanks! My manual is in Japanese which doesn't do me much good.

[Default]

Aren't there 3 steps with torquing them up... that might be the first/lowest one.

[frostmotorsport]

for the main cam cap bolts, the manual says....

9.0-11.8 NM, 0.92-1.2 kg-m, 6.7-8.7ft-lb

this includes the studs on the front caps.....

not sure if they mean "start at 9.0 and torque up to 11.8" or not.. doesn't say.

[Vipes R32 GTR]

that is right 1 step the 3 step your talking about is the head bolts 9.0-11.8nm is just for the cams

[Darbo]

not alot of torque is it

[frostmotorsport]

no it's not - but then I think the factory setting for a clutch pressure plate for Evo 1-3 is something silly like 25ft-lb!! which is not much past finger tight tbh!! but that's what the book says!

my OS clutch plate is done up to 40ft-lb or something a bit more sensible.....

I would say with cam bearings (any bearing in fact) - STICK to factory settings otherwise you could cause bigger (more expensive) issues!!