2.25P timing

[isuzutoo-eh]

G'day all,
I tried timing my engine last night. First of all, there isn't the timing marks that any of my manuals/bible show. Being an early engine, there is no marking on the pulley crank. There is only one set of marks visible on the flywheel, which is the E|P mark that the manual shows on A1-56 for fitting the cam shaft. Although mine looks more like L|P.
Where is this mark in relation to TDC? Can I use this mark to set timing?
The pointer only has the one point and requires a mirror to see.
I turned it over watching the valves open and close and the marking is in about the right spot for TDC I think.


I have heard that to tune the 6 cylinder, you can use a vacuum gauge, find when it pulls maximum vacuum then retard slightly. Is there a method like that that can be used for 2.25Ps that doesn't rely on non-existant marks?


I have rotated the dizzy till it has enough power to drive up my driveway but it blows a lot of smoke, and rotating for minimal exhaust makes it lose revs till its barely ticking over on one cylinder.

Finally, im not conviced the sound the engine is making is it missing, it isn't tappets though. I don't know how to explain the sound, might try recording it later.



Won't be getting to All British Day under its own steam, if at all

[JDNSW]

I have not struck an engine without timing marks either on the flywheel or the crankshaft pulley, but I can see how you could get one - e.g. old engine but with new flywheel, for example.

You can establish TDC No1 by removing all spark plugs and turn it until you can feel the No.1 piston come up with a suitable feeler (e.g. a piece of wire) in the plug hole. Once set on TDC you can mark either the front pulley or the flywheel, and measure degrees calculated from the diameter of the pulley or flywheel. Once the ignition timing is set, advance it until the engine pings under load and then retard it slightly until this stops. Can take a while to do, as the engine must be hot to get the best result, and it will have to be iterated, burning your fingers adjusting it each time!

John

[Bunjeel]

[You can establish TDC No1 by removing all spark plugs and turn it until you can feel the No.1 piston come up with a suitable feeler (e.g. a piece of wire) in the plug hole. Once set on TDC you can mark either the front pulley or the flywheel, and measure degrees calculated from the diameter of the pulley or flywheel. Once the ignition timing is set, advance it until the engine pings under load and then retard it slightly until this stops. Can take a while to do, as the engine must be hot to get the best result, and it will have to be iterated, burning your fingers adjusting it each time!

John[/QUOTE]


Just to clarify: the piston needs to be at the top on the compression stroke, not the exhaust stroke - so both valves should be closed with tappet clearance when the piston is at its highest - sometimes there's a notch on the dizzy to indicate this position. Another tip: make sure the vacuum is running off the manifold and not off any 'no-vacuum at idle' carby port while adjusting the timing by this method - and wear waterproof gloves - that way you won't get zapped by the HT either!

cheers

[Blknight.aus]

do it the easy way...

remove the rocker cover

observe the #4 valve set.
turn the engine by the crank handle untill the exhaust valve is closing and the inlet valve starts to open

that puts you into the correct ballpark for the timing of the firing on #1.

that will get you to running if all things are near enough to correct (no vac leaks, no carby problems, no major dizzy problems) the final timing I usually set by ear to suit the engine.

to get your final tune get it warmed up and idling smoothly then advance untill it pings, back it of a couple of degrees and take it for a good run then labour it up a hill if it pings back the timing off a couple of degrees and go again.