The V8 Owners Forum -

Hi there,

Just thought I'd fit up a Viper Hurricane cam and Coyles timing set to an engine that I'm building up at the moment.

It's the first time that I've used a timing sprocket with more than 1 keyway (to adjust the timing slightly).
I have two main questions, the card that came with the cam specifies the lobe centre to be 111deg ATDC.
I've got the Degree wheel setup on the crankshaft and and a solid lifter dropped in above Cyl. one inlet lobe. When my timing wheel (setup properly) reads 111deg ATDC (rotating in the correct direction) presumably the lifter should be at maximum lift (and in the middle of it's 2 degree dwell period? So at 110 Deg ATDC the cam has opened fully and at 112Deg it is just on it's way down. Please let me know if this is correct.

Also using the Coyles timing chain set I can only get within 1-2 degrees of the target 111 Degrees. Am I missing something or should I not expect any better?

All the best,
James

You will never get it bang on using that sprocket so what you have is the best you will get. The only way to get it 100% is to use a vernier cam sprocket. If what you have has the option to leave it very slightly advanced then use that as within a few miles the cam will retard due to chain stretch even if you are using a pre stretched chain.

Superbly fast answer, thanks so much.

Yes that makes sense, I may try to get hold of a vernier set then. Did I get it right about he timing up method?

All the best,
James

assuming you have found the centerline properly then yes it all sounds good. If you want I can send you a PDF on cam timing to the address you have logged on here. Let me know.

That would be very good of you indeed.

Many thanks again,

James

(Email addess - y@rdley.org.uk)

mail sent

Total Star,

Many thanks again,

James