Cam Degreeing

[Belle427]

Ive had a go at timing my MC1 cam this week following the method below, i have a figure of 110 degrees to dial it in at
My first attempt with timing set straight up came up with a figure of 109 degrees at the crank, going by the below guide I would expect to see a figure closer to 118 degrees here.
This figure seems quite a way out to me, I have the Cloyes set with 3 keyways which are straight up, +4 and -4.
Ive not had chance to call V8 today and wanted to have another go on the weekend and wondered has anyone done a similar cam job or dialled in an MC1?
I realise I may have to tinker with the keyways but would be interested to hear from anyone who has done one or another cam.
http://www.v8developments.co.uk/technical/camshaft...

[Belle427]

Steve_D said:

How did you establish true TDC?

Steve

Using the dead stop method as above.

[Belle427]

Sardonicus said:

If indeed that figure is correct see above comment ^ then that cam as been ground correctly the only reason you need the vernier or multi slot timing sets is to allow for any machine error/offset when the cam is ground relative to the keyway if you are after 110 but found 109 then fit it that figure will soon recede to 110/111 once the timing chain stretches

According to that V8D method my 110 at the crank is actually 104.5 at the cam or am I missing something?

Edited by Belle427 on Saturday 20th January 07:04

[Belle427]

I’ve just had another play and using the 4 degree retard key I’m now at 116 degrees at the crank, which would equate to 108 at the cam which makes more sense.
All timed using the method above.

[Belle427]

On their example they obtained a reading of 106 degrees, at step 5 they explain that the crank has moved 6 degrees so the cam has moved 3, so the actual cam timing measured is 103 degrees. (6 too far advanced)
Probably better for me to call them Monday as its not that obvious to me.

[Belle427]

Steve_D said:

Ignore the bit about the cam turning at a different speed as it is not relevant.
You are just trying to set the maximum lift of the cam to coincide with 110 degrees of crank position.

You don't have a vernier cam wheel so fine adjustment is not possible.
Your gear set only has 3 fixed positions (some have 6) so your first result of 109 was pretty good and you have no options to get it better.

Steve

Ok thanks. Makes more sense to me.

[Belle427]

DangerousDerek said:

I assume you will be checking piston valve clearance.
I had to retard my cam a little on one build to get to safe clearances

I wouldn’t expect this cam to cause too many issues but I will check.

[Belle427]

I spent a day triple checking everything this week and the final figure I had was 108 Degrees, slightly advanced but I don't think its enough to worry about.
I wont be able to do any better unless I install a Vernier set but i would expect this to go towards 110 when the chain etc beds in.

[Belle427]

It’s one of those jobs that your not quite sure when to stop as it’s pretty important to get it somewhere near.

[Belle427]

Some cams are ground with 4 degrees of advance built in which makes sense.
I’ve read that even the cloyes true roller chain I’m using will still stretch a certain amount.