12 replies to this topic

[T10NY]

Hey Folks looking for some help with what timing figures I should be going for and at what RPM, I also have a couple of secondary issues below as well.

 

So I have re-set the static timing on my car and have it running ok at idle at 1200rpm with around 6 degrees of advance however when I bring up the rev's its sluggish I am getting a fair amount of backfire.

 

I have also found some oil in chambers 2&3 and carbon in 1&4.

 

Engine spec is:

Stage 4 smart performance head with double valve springs, wasted race valves, bronze guides, 1:5:1 roller tip rockers.
Omega flat top pistons, cross drilled crank.
Hiff44 carb Minispares inlet manifold, Maniflow stage 2 manifold,
Aldon yellow dizzy(non vac).

VMM 66 Cam (276)

 

I am just not sure I can drive it yet with the lumpy nature of the higher rev's any ideas would be great,

 

I am going to do a compression test on Sat so will get some figures from there what sort of number should I be looking for as a Benchmark.

The car was running really well before winter and I had it off the road and changed the fluids etc and made some repairs to the wiring loom and floors.

 

So I am not sure the fuel mix has changed so it must be the timing. (I also need to put some fresh fuel in that might help)

 

Any thoughts would be appreciated

 

If anyone knows or recognises the car I am looking for some details on the engine build apparently it was tuned last by slark and may have been built by them as well. I don't have a huge amount of paperwork car was located in Newcastle.

 

Thanks

 

Tony

[nicklouse]

and the cam is a?

 

advance sounds low.

[KernowCooper]

If your VMM66 is the same as a Kent 276 which I run in my 1330 then the timing is retarded as Nick pointed out above, I run 10degs at 1000rpm and I'd be putting in fresh fuel and then retesting

[mk1leg]

also what needle are you using.......

[T10NY]

Thanks Guys,

 

Ill try more advance and fresh fuel, as far as I know its a Slark Custom needle.

 

Tony

[T10NY]

So I have the car running at last, I changed the fuel out and re-set the timing again. Its running 15 degrees of advance at 1300rpm this is about as low as I can get it to idle.

 

I took the car out for a run but found that under load or above the 4000rpm the engine is sluggish and is restricted, is this a sign that I need to retard the timing slightly.

 

I am running a no Vac advance Dizzy however I noticed that what I think is the Vac advance inlet on the Carb 's cover is missing would this cause the above?

[nicklouse]

Yes as it will be leaning the mixture off.

[T10NY]

picture attached.

 

[Leonrjohnson]

The big pipe connection that you show in the pic (that is open and has a slight kink) is for the crankcase breather, so if you aren't using it, you need to blank it off, as it sucks air and runs LEAN. Also the vacuum advance hose connection port on the carb needs to be blanked off. It is showing in the pic as having something on it, but needs to be blanked off. It is the port on the base of the carb close to the unused stud for the air filter that isnt being used.

picture attached.

 

[T10NY]

Hey guys so the vac advance on the carb being missing was indeed one of the problems. I have got te running ok, it's running 12 deg advance at 1300 rpm and idling ok at 1050 rpm. However it's really sluggish and lacks power. Should I continue to advance it to see if that helps any? How far should I go? I have also replaced the plugs as the old ones were a bit worn.

[Dusky]

I think an engine should run as much advance as possible without pinking. In theory that should give max performance. Please correct me if I'm wrong though.

[KernowCooper]

A aldon yellow set at 10 deg at idle and the  inbuilt mechanical advance of 22degs should be enough to allow it to rev freely, I would check its not drawing air from the inlet/carb gaskets and is the distributor advance is free to move, check it advances as the revs go up with your timing light

[T10NY]

Ok thanks, I'll check the above, I am not sure what's going but my thermostat just packed in as well.... One thing after another.