Joined: Jun 2022 Posts: 17 Threads: 5
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Location: UK
Car type: Austin Ruby
I am trying to start a Ruby after some engine work; the starter is turning over easy and there is spark and fuel at least to the carb but no ignition.
I set the tappets on the bench buit wonder if something is wrong and the fuel is not being sucked through.
What is the best way to set the tappets, do I need to start at TDC or can I dive in anywhere as long as I stick to the rule of 9?
Not sure what else it could be but open to suggestions.
Joined: Aug 2017 Posts: 926 Threads: 22
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Location: Near Cambridge, UK
Car type: 1928 tourer (mag type), short chassis Gould Ulster
Even if your valve tappet clearances are not perfect this should not prevent the engine from starting. If you can feel four compressions when turning on the handle it should start if other things are right. Are you sure the float chamber fuel level is correct, and have you made sure the choke is closing fully. If you are getting four good sparks, did your work involve distributor or dynamo removal, and if so is the ignition timing correct and have you got the plugleads on the right plugs? More information would help remote diagnosis.
Joined: Mar 2015 Posts: 5,442 Threads: 231
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Location: Scotchland
What work have you done to the engine since it last ran?
Joined: Jun 2022 Posts: 17 Threads: 5
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Location: UK
Car type: Austin Ruby
Engine out and stripped down to replace piston rings, flywheel removed etc and rebuilt. Crankshaft and camshaft not touched.
All ancilleries removed and cleaned etc.
Timing is only set by eye at present using TDC as guide (1" before).
Have not checked actual compression but can feel it.
Carb stripped and cleaned and there is fuel in bowl.
Stupid question but could I have set the tappets 180 deg out?
Joined: Aug 2017 Posts: 1,337 Threads: 34
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Location: Cheshire
Car type: Race Ulster, 1926 Special, 1927 Chummy, 1930 Box
06-07-2024, 02:38 PM
(This post was last modified: 06-07-2024, 02:39 PM by Alan.)
If you haven’t disturbed the camshaft and crank, I can’t see there being a problem with cam timing. If you start with valve 1 fully open set tappet clearance on valve8, then follow the rule of 9. Not much to go wrong. Have you got the ignition timing set 180deg out? A very quick way to tell is to swap over leads 2 and3. If it was wrong it should start and run on 2 cylinders. However sometimes it’s just the rings aren’t bedded in yet and it may need a tow start first time. I used to replace rings quite often on the race car- sometimes it needed a tow start sometimes not but it would always start on the handle after that.
Alan Fairless
Joined: Aug 2017 Posts: 612 Threads: 19
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Location: Hampshire UK
Hi
Have you got the correct TDC ?
Assuming you are timing on Cylinder 1, you want near TDC on compression, not exhaust. Look for both valves being closed with the tappet cover off, or put your finger on the plug hole to feel for pressure. A third method I use is a short length of garden hose fitted with a hollow conical rubber tip - if you apply this to the plug hole and try blowing down you can soon tell if the valves are closed.
Then check that the rotor arm is facing the contact for No 1 plug lead.
Joined: Mar 2015 Posts: 5,442 Threads: 231
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Location: Scotchland
Would it be helpful to talk you through the timing process?
Joined: Jun 2022 Posts: 17 Threads: 5
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Location: UK
Car type: Austin Ruby
I have gone through the tappet clearances and apart from one they all seemed ok, am using 6 and 8 thou.
Only no4 cyliunder seems to be getting any petrol.
Am using the 1/4 mark on flywheel as TDC and setting distributor accordingly.
Will look again at that in line with comments regarding both valves closed on No1 at proper TDC.
Thanks for all the support and offer from Ruairidh I may take you up.......
Joined: Dec 2017 Posts: 1,160 Threads: 68
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Location: Nottinghamshire. Robin Hood County
Car type: Austin Ruby Mk1 1935
Hello,Have you removed then refitted the manifold whilst doing your piston job. If yo have check for leaks as this will give you a weak mixture. Also see if the engine starts and runs on ‘Easy Start’. If it does then it’s a furl problem.
John Mason.
Would you believe it "Her who must be obeyed" refers to my Ruby as the toy.
Joined: Jun 2022 Posts: 17 Threads: 5
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Location: UK
Car type: Austin Ruby
Ok
Have doubled checked TDC on compression stroke and re adjusted distributor with flat on cap pointing between 1 and 2 piston and gap of 12 thou. Double checked spark and it seems healthy enough.
It seems only No4 plug is getting slightly wet and checking with plugs out is the only chamber exhibiting traces of fuel which is now pointing me toward a fuel issue as John has just mentioned.
Battery now back on charge so will strip down carb again and see if I can find an issue, I have already done this by taking out all jets etc and blowing compressed air through the body to clear any blockages but can try again. Float appears to be ok with no splits or damage.
Will also see if I can beg or borrow a compression gauge to double check if it is ok......
