Timing in an MG Metro cam

[linearaudio]

As a wonderful, wonderful person has dropped an MG Metro cam in my lap, just as I was putting new rings/mains in Molly, I have another possibly controversial question.....
According to the Bible all standard A series cams up to A+ tend to work better advanced 4 degrees. Is there any evidence that the MG Metro cam works better either way. At very least I am going to check it to spec. And yes, I will re-check my exhaust valve to deck clearances before finishing re-assembly!

[Simon P]

I believe it's recommended to advance an a series cam by approximately 4 degree's and understand this is due to slack in the timming gear,

I was given timing instuctions and a dial gauge when i bought a kent 266 kit recently,
If it's any help i could dig it out an post it here...

[linearaudio]

I believe it's recommended to advance an a series cam by approximately 4 degree's and understand this is due to slack in the timming gear,

I was given timing instuctions and a dial gauge when i bought a kent 266 kit recently,
If it's any help i could dig it out an post it here...

Thanks very much for the thoughtful offer, I'm fine DTI'ing cams (when I am calm and cool, around 7AM usually!), just wanted opinions on the actual figure. So thats one for +4 degrees!

What says the Scots Sage??

[bmcecosse]

Dot to dot is fine! This 'timing in' of cams is fine for a racing engine - for a road car it's nonsense. Only repeated trials on a RR will tell you the best timing for any cam. Your engine may get 1 extra bhp at the very top if set 4 advanced - and lose plenty lower down. Equally - if set say 4 degrees retarded - it may give great low torque and lose a small amount at the very top end! So - just assume that MG actually did some trials/tests when developing this cam - and ground it up so it would work well in most engines when set dot to dot!

[linearaudio]

OK- thats sorted then

[bmcecosse]

Well - that's my view........ But as you well know - 6 others will say something else! But I firmly believe dot to dot is fine. I did mess about for ages timing in a 544 on a MIni engine a couple of years back - the amount the key for the sprocket has to be moved to advance it 4 degrees is TINY! The engine didn't run well at all - very peaky etc. I pulled out the timing gears and fitted a normal key - dot to dot - it ran much much better. Still peaky -as expected with a 544 - but much more driveable. You won't be disappointed with an MG cam. It should have the same lift as the standard cam - but do indeed check !

[PSL184]

I think you would struggle tremendously to time it accurately 4 degrees either way ! and I'm with Roy on the merits (or not) of doing so....

[Peetee]

The general consesus of opinion is that the MG Metro cam is properly sorted and leagues ahead of other stock BMC cams. I would conclude therefore that a standard setup would be best.

[linearaudio]

The general consesus of opinion is that the MG Metro cam is properly sorted and leagues ahead of other stock BMC cams. I would conclude therefore that a standard setup would be best.

Thats what I had in mind, only someone's statement that the 4 degrees is to remove backlash that made me query it. I will check the timing to spec anyway out of curiosity to see how close or not it is.

If BMC/ BL managed to get the timing right on production, then Triumph could have learnt something from them with their offset fixing hole-to-chainwheel-tooth relationship, takes a bit of thought and turning the chainwheel over to get the timing right on a Spitfire!