I’ve just fitted a Hi-comp head to a MK1 Ruby, following a de-coke and fitting new exh.v/v’s.
She starts OK and runs but the engine sounds a bit “lumpy”
How do I go about tuning it? Where do I start? Adv or Retard the Dizzy? Weaken or enrich the mixture? Where do I start and what is the correct sequence to take?
I’d be grateful for any advice or where to find the data.

Hi Dave,

I fitted a 9E1, sports head to the Ulster last year and had to retard the ignition slightly as I was suffering from a "pounding-engine", try doing the same and see if if smooths out. I am think of changing back to a late ruby head as the 9E one is very harsh.

Are you coming up to the Scottish Rally this summer? It would be great to see you!

Cheers

Ruairidh

I fitted a '37 head to my 1931 box some years ago. The car goes well and I did nothing but retime.THe carb needs no attention. Fitting a larger main jet,In my experience ,will make no difference . AS both the all Ruby models had the same jet sizes.. Plug gap .25 thou. points.12 thou and valve clearences 8 thou( up from 4 and 6).In my case I opened up the plug threads to 18mm so it looked "right " and fitted champion D16 plugs If 14mm us L86c champion.It did not really increase the top speed. but improved the stamina in 2nd gear and the general feeling of Get up and Go! As you have an extra gear I ,m sure you will notice the difference.As the compression is raised the sound of the engine will be different,espesially if the bottom end has been in service for some time.

Ruairidh has the 9E head given much of a performance boost? Any problems with it?

Regards

Rob

Hi Rob!

It gives more pull but doesn't add much to the top speed. The exhaust note is much crisper, but engine is harsh.

How's the special?

Have fun,

R

Hi, Thanks for the replies, I’ve tried retarding the dizzy and it has improved the roughness slightly, but the engine still sounds lumpy. Is this harshness to be expected with a Hi Comp head married to a 2-bearing engine? Should I return to the standard head?
Hi Ruairidh, I’d like to think that I will be attending the SA7 rally but reality is that it’s too far for a return trip from Penrith within a day, but you never know.

Dave,

the rally is over 4 days with free camping and a free bar! Come and join us, you know you want to!!!!



Ruairidh

Dave ---- If the Cornwall lads and lasses can attend from Penwith, then Penrith is just round the corner....

St Piran, (Birthday boy today)