7 replies to this topic

[Down under Luke]

I was hoping that someone might be able to help me please with my timing as i can't seem to find anything on here or the internet. I have set idle at 5 degrees BTDC as per the Haynes manual but, i am struggling with the advance. I don't seem to be able to set it with the same window in the bell housing that i used to set idle and i do not seem to have any marks on the pully or marking teeth anywhere. I am looking for around 28-30 degrees. I do love the expectation on the user to hold a mirror, a strobe while holding and turning the dizzy and potentially having to rev the carb. LOL

 

Can someone possibly shed light on this as i am keen to get the best out of the engine? Carbs are fully rebuilt, i am running am electric ignition set up and all other clearances have been checked and set. 

 

Thank you in advance. 

[nicklouse]

options. make a holder for the mirror and adjust strobe to see what timing is then adjust dizzy and check again. get another body to help out. make your own marks on the crank pulley and add a pointer on the timing chain cover.

 

I have always found it a two person job if you are going to swing the dizzy at the same time anyway.

[smurfomatic]

For timing I use an old wing mirror, plastic case so it can be wedged in place to show the timing marks. Still tricky to adjust the dizzy and/or rev the engine though!

[unburntfuelinthemorning]

If you have a top dead centre marking then you can use a timing light with an advance feature such as this one. 

 

Turn the dial on the timing light so it flashes on the top dead centre marking and read the amount of advance off of the timing light itself.

[Down under Luke]

If you have a top dead centre marking then you can use a timing light with an advance feature such as this one. 

 

Turn the dial on the timing light so it flashes on the top dead centre marking and read the amount of advance off of the timing light itself.

Thank you for this, i have my light but failed to remember that it has an advance feature so will go one and use that. While here, where would one set the RPMs when looking for max advance or at least, setting up 28-30 degrees? I should be able to just pull the choke cable to this amount and go from there...One less hand needed.

[unburntfuelinthemorning]

Rev it up until the ignition stops advancing, it should be all in somewhere between 3000 to 4000 rev/min.  You'll struggle to get that high by pulling the choke unless you mess around with the fast idle screw, also you'll be on full choke so running well rich.  As nicklouse says it's much easier with two people, failing that you'll have to improvise.

[Spider]

The original Cooper S Distributor isn't 'all in' until you get to 7000 (Crankshaft) RPM.

 

I have a figure of setting it to 4⁰ BTDC at 600 RPM. That seems more sane to me, but I'll also point out that all the old published figures these days are out the window, as the fuels they were for are no longer available. Our Modern Fuels, for better or worse, burn quite differently.

 

I'd suggest making sure you have a load of good fuel on board, pick an average temperature day, get the car, including the oil up to running temp, so a run of at least 10 miles, preferably 20. Then find a hill and run up it at wide open throttle, listening for the engine to Ping (Pink, Knock), particularly around the 3000 RPM Mark (peak Torque). If it does, knock the timing back a little (say 2⁰) and try again. If it doesn't then advance the timing by say 2⁰ and try again. Keep at this until you hear it Pinging, then back the timing off by 2⁰. Go home, put your strobe on, note the engine speed (I'd suggest checking at 1000 RPM) and measure off the timing. Make a note in the Haynes for next time.

[Down under Luke]

Thanks for all of this. Interesting thing though, i set the base timing (5 degrees and 9000RPM) when the engine was up to temp, seemed to run nicely but, once left to get cold i went to start her back up and wow, tough to get going. Took a good few times and plenty of choke and even when she did start the revs sounded so low it was crazy. Spluttering and coughing until a few minutes had passed and some heat was rising and then seemed to get running ok. Just seems odd and everything is by the book...plugs, clearances etc. Any advice is much appreciated. Thank you