Starting problem finally solved. 1966 P1800S

[paul staines]

Well it's taken 13 years of ownership
And poor starting / rough running.
Called in a tuning expert. Wish I had
Done it sooner. Wrong plugs. 6hs now
Fitted ( I had 6s ). Wrong jets for the
Cam I have fitted along with exhaust mod
And head skim. Ignition timing / curve
on the 123 ignition system not set to
optimum performance. And to top it all
The chokes were not operating correctly.
The Carburettors have been balanced
and the car starts / runs great. Big thank you to Andy AG mobile tuning. Yorkshire.
Regards Paul

[Rustinmotion]

Originally Posted by paul staines

Well it's taken 13 years of ownership
And poor starting / rough running.
Called in a tuning expert. Wish I had
Done it sooner. Wrong plugs. 6hs now
Fitted ( I had 6s ). Wrong jets for the
Cam I have fitted along with exhaust mod
And head skim. Ignition timing / curve
on the 123 ignition system not set to
optimum performance. And to top it all
The chokes were not operating correctly.
The Carburettors have been balanced
and the car starts / runs great. Big thank you to Andy AG mobile tuning. Yorkshire.
Regards Paul

How did he check the ignition curve and the wrong jets? Genuinely interested

[paul staines]

He came equipped with a gas analyser
And some other gadget that he held on the Carburettors ( not sure what it measured )Also armed with some sort of strobe light for the timing. He specialises
In tuning old cars and seemed to have a bit of an ear for it as well as the technical knowledge.
Best money I have spent.

[Rustinmotion]

Originally Posted by paul staines

He came equipped with a gas analyser
And some other gadget that he held on the Carburettors ( not sure what it measured )Also armed with some sort of strobe light for the timing. He specialises
In tuning old cars and seemed to have a bit of an ear for it as well as the technical knowledge.
Best money I have spent.

Nice to know there are still old school mechanics out there

[paul staines]

These folk are out there but seem to be getting more difficult to find. He did say the engine seemed noisy considering it's had a full rebuild.
All became clear to him when I told him that I had replaced the fibre timing gear with steel cut.Car running on semi synthetic at the moment. He also noted that the new fuel hose I fitted was not ethanol rated. He replaced it and removed the non return valve I had fitted as it was not needed. He did fit a fuel filter and replaced all my rubbish clips with stainless fasteners. Not bad service that !

[mike gilbert]

I'm more interested in how he diagnosed the wrong jets and identified the right ones. I have a B20 enlarged to 2127cc with a K cam and was advised to go with KD needles. Cabs are balanced and idle mixture is 0.4%. It idles lovely but hesitates on acceleration. I'm sure its fuel related and not ignition. I suspect I need different needles but cannot find anyone in my neck of the woods who can confirm if i'm right and what needles I need to go with.

[Rustinmotion]

Originally Posted by mike gilbert

I'm more interested in how he diagnosed the wrong jets and identified the right ones. I have a B20 enlarged to 2127cc with a K cam and was advised to go with KD needles. Cabs are balanced and idle mixture is 0.4%. It idles lovely but hesitates on acceleration. I'm sure its fuel related and not ignition. I suspect I need different needles but cannot find anyone in my neck of the woods who can confirm if i'm right and what needles I need to go with.

Mike
Northampton Motorsport is close to you they have everything needed to set them up on the dyno, they do a lot of historic racing prep so are good with SU

[Derek UK]

Hesitation can be caused by too thick damper oil. Some like ATF but the original SU supplied oil was about 20 sae, like 3in 1 sewing machine oil. Might also be running a bit weak. Try an extra flat down on the adjuster screw or maybe 2 flats. KD's often recommended but need a good free flowing filters. KN are a bit leaner across the range.

[Puntah]

Originally Posted by mike gilbert

I'm more interested in how he diagnosed the wrong jets and identified the right ones. I have a B20 enlarged to 2127cc with a K cam and was advised to go with KD needles. Cabs are balanced and idle mixture is 0.4%. It idles lovely but hesitates on acceleration. I'm sure its fuel related and not ignition. I suspect I need different needles but cannot find anyone in my neck of the woods who can confirm if i'm right and what needles I need to go with.

Mike, I'd try RN needles with the K cam, also if it is SU's you are running, I'd 'lozenge' the butterflies and match all the inlet ports.

Regards,

Gordon