18 replies to this topic

[ohsuchislife]

wonder if anyone can give some pointers ...

my engine is running lumpy at idle .. KC 266 CSI ignition ... the timing mark moves around the 10 mark using a strobe ... this has a new cam thinking the old one was worn out because it did it then ... so new cam new carbs new dizzy and still no real smooth idle ... tried different dizzys and still no joy .. cam is timed in at 106 spot on but still the mark moves around slightly around the timing mark when on the light .... any ideas ,...

 

could it be the coil

[dklawson]

I am unfamiliar with the CSI ignitions.   When I Googled them I found products that look like complete distributors with electronics inside.  Is that what you have?

[ohsuchislife]

yeah that's the one ... taken it off and put a standard 52d back on ... but still the same ... I want to get some sort of idle before I start using it ... the timing mark still bouncing around the 10 degrees mark

[Guess-Works.com]

What sort of rpm are you trying to idle at ? it may be too low which is why you're struggling...

[ohsuchislife]

trying to get 1000 rpm ... I think its ignition tried everything else ... run it at 1000 ish but when you shine the timing light on the 10 mark its moving around slightly not constant .... I bought a straight cut gearbox from you John the other day what a piece of art thanks

simon

[Guess-Works.com]

Thank you very much sir... tenner's in the post ;)

 

well at least you're not trying to get it to idle at 600rpm.... I don't think 1000 is unreasonable, in fact possibly still a bit high

 

Strobes will wobble about a bit but what I think you're seeing is small variations on timing as the rpm goes up and down...

 

My only suggestion would be to get it idling comfortably at what ever RPM, and then getting it onto a rolling road where it can be properly setup, and then the correct/nearest curve on the dizzy selected for the engine.

[ohsuchislife]

I think your right sir ..... thanks again for the lovely gearbox .. just wanted to look at it ... lol

your an artist sir

[Dan]

Is this with the vacuum disconnected?

[ohsuchislife]

yes mate .... just found out I have put the old cam thrust bearing in so the cam is moving for and aft .... hope that may be the cause because the dizzy drive will move as well ... does that sound right

[KernowCooper]

Is the timing chain and sprockets worn and do you run a tensioner ? could be your issue

[ohsuchislife]

timing  chain etc is all brand new ... duplex chain so I don't run a tensioner ... I think it the cam movement is my problem ... going to change the cam thrust ... then check the cam timing then give that a go ... will keep you all updated

[carbon]

I'm running 1293 with KC266 cam.

 

For what it's worth I don't think you will get anything like smooth idle with 10 degrees advance on this cam at 1000rpm, in my experience it needs quite a lot of advance to idle smoothly.

 

I'm using about 12 degrees static advance, with a very weak primary spring which is likely giving me another 5 to 8 degrees advance at about 800rpm idle. Using points, not electronic.

[ohsuchislife]

thanks mate ... I have a CSI dizzy with 16 curve adjustment .... changing the cam thrust plate tomorrow as mine is worn ... running a 1293 with 266 as well

[carbon]

CSi may have 16 curves but I don't think any of them are close to what I am using.

 

Should have said, I am also using 10 degrees mech advance to avoid over-advance at high rpm.

[Earwax]

sorry to op,, but from Carbon's comments

 

so you are basically running 18 degree static and 28 at what...... how did you come up with this solution... i have seen some hi static timing used in bathtubed heads?

it is interesting because i have a kent clone 266 and it seems to prefer higher static but i have been scratching my head at readings....(1310) i may go back and put a stop on the mechanical and see how it goes advanced.  Cheers