Camshaft timing

[BigSteve]

Does anyone know how many degrees of timing each tooth on the Intake cam timing gear, and scissor gear are?

I saw somewhere mention of it being 7.5 degrees, so was wondering if it were possible to retard the intake cam 7.5 via shifting the gear 1 tooth and advance the exhaust 7.5 via the scissor gear to tighten the overlap (or other way around) to shift the power band up and down.

Next important question, does anyone know the factory piston to valve clearance at TDC?

Cheers.

[gloverman]

I beleive it is possible to get adjustable sissor gears along with adjustable cam gears. This would make it easier to get good gains. Cheers

[BigSteve]

Ah that'd be nice, for adjustable cam gear you need to lose the rotors/caps I think.

I have not seen any available, I'll keep looking around.

Even if this were possible I think 15 degrees total might be pushing it.

[ash]

Originally Posted by BigSteve

Does anyone know how many degrees of timing each tooth on the Intake cam timing gear, and scissor gear are?

I saw somewhere mention of it being 7.5 degrees, so was wondering if it were possible to retard the intake cam 7.5 via shifting the gear 1 tooth and advance the exhaust 7.5 via the scissor gear to tighten the overlap (or other way around) to shift the power band up and down.

Next important question, does anyone know the factory piston to valve clearance at TDC?

Cheers.

count the number of teeth on the pulley, and divide by 360
that gives a ball park on whateach tooth will adjust cam timing by..

i should be looking at PV clearance this weekend.
i ordered some weak springs to play with this

[BigSteve]

Cant find adjustable cam gears anywhere, I spoke to kelford and they said they were trying to get some made but never managed to.

[gloverman]

I just talked to one of my suppliers who makes them up. Hopefully he will find some time in his busy schedule to send me some photos soon.

[samsdad]

Steve there's a good reason for this and it is coz quite simply there isn't the room in the heads to fit adjustable cam gears where they'd hold together and remain adjustable (or hold together for that matter hence why nobody has done it yet, plus without the scissor gear they'd rattle like hell which is why you bought it in in the first place). Were each cam driven by the timing belt then this wouldn't be an issue. Also in the course of reassembling everything going a tooth either side on the scissor gears is not an option. Without the high lift cams the 1U isn't "interference" but with it is so that's the difference of almost 1mm lift. You'll be happy with the results but. Aint driven it yet but it sounds totally evil

[XR8tt]

Keep in mind the cams spin 1/2 crank speed when working out cam timing...

[BigSteve]

Yeah I can work out the timing XR8, was just wondering if it were possible. Wasn't sure on the valve to piston clearances etc but samsdad cleared that up.

I guess best option is just to match the other mods to the power range of the cams rather than adjust the cam seperation.

Looking forward to hearing her up and running!

[BigSteve]

Just heard from Kevin (kelfords) this morning via email, He mentioned they've bought the gear they needed to make the adjustable gears so they're going to get started on that soon.

Bit of good news there for those looking for adjustable cam gears.