timing for red motors

[dave a]

my 186 motor seems to run very warm. i was wondering what the recomended advance is. my son set it up at around 6-8 degrees advance i've always set it up by ear.

[Trev]

i've always set it up by ear.

Me too

[rosco]

If it were absolutely stock - AND you were running on leaded fuel - I suggest using the timing mark verbatim.....

I believe with most of us with red/blue motors - it's now used as an initial guide..... tweaking it to suit is now mandatory....

I don't know if this is of any help - and I'll try to keep it short (struggle)...

I set mine statically using a power timing light - ignition on, leads connected and hand pull over the engine until the flash co-incides with the marks (TDC #1, compression stroke).

Nip up the distributor and start the engine.
I then move the distributor fore and aft of this settting until it runs smoothly then creep up slowly on advanced until there is ever the slightest change in "note".

Road testing/adjusting is now needed to complete my settings. I find a pretty steepish hill that top gear can be held.
At about 20 mph, I push the throttle to the floor..... I aim at getting a very occasional "knock or ping" - once every 3 - 5 seconds - and only one......
If it rattles its head off - too advanced.
No rattle at all - retarded.
Takes a few goes at getting - but this procedure has worked for me for all the time I have been tuning my own engines....
Once you are very comfortable with your final setting - you can mark the harmonic balancer (try a yellow/white crayon until you find the spot - then mark it with something more permanent.... I don't like the idea of nicking it with a small chisel - paint/whatever can be removed) ... so that you can easily re-set the timing..... it should always now "ping" as above at this setting...... with the same fuel and under the same load.....

This is the way the old chaps taught me to set ignition timings - has proved to be both the most efficient setting with almost maximum performance....

If you change fuels with differing octane ratings using a high compression motor - there is always the chance that you may need to adjust the above.....
What I suggest is that - if you use a premium unleaded stick with it.. if you fill up with standard ULP with the ignition set for premium - there is a fairly high chance that you'll run too advanced for the lower octane rating... and it will "ping" under heavy load.

You might care to take a good look at all ignition components prior to tweaking this final setting.
Vacuum advance, point faces and openings, inside of distributor cap and rotor button, braided earthing lead from action plate to body, coil leads..... they can all cause fluctiations in timing.

The mechanical advance weights should be free to move without any binding. The vacuum advance should pull in smoothly and hold position when tested with a length of tubing with diifering amounts of vacuum applied to it.

Sorry folk, think I've over-done it again.....

frats,
Rosco

[Devilrod]

Don't think you've over done it Rosco. Very thorough. The only other thing to consider is your mixture setting it can have an effect too. Only problem is a can't remember if it's too lean or too rich that makes it run a little hotter.

[rosco]

Thanks DR,

Too lean causes the chamber to overburn - too much oxygen....
Too rich just wastes fuel and makes more emission....there is too much fuel in the mixture to get perfect combustion.

The mixture screw only impacts on ignition timing - (typo..... read as air/fuel mixture ) at throttle idle position and just above (there are three discharge ports in the throttle body just above the throttle butterfly - these are the only ones which the mixuture screw impacts upon).... the main metering jet and power jets are "fixed" sizes - these control "correct" fuel/air mixture above this setting. If the engine capacity were to be significantly increased, it may be appropriate to increase the jet size (jet sizes can be marked in different conventions..... some quote 1,000ths of an inch - others in "drill" size.

With .000" - the hole gets bigger as the number increases.
With "drill" sizes (i.e. No. 70 drill) - the hole gets smaller as the drill size increases).

I don't believe there would be a great need to increase the metering jets for the purpose of even an .060" increase in bore..... Technicians at GMH spent hundreds, if not thousands of hours developing and determining appropriate settings for different sized engines... if you take a comparitive peek at different sized red motors - there's not an awful lot of difference between 149 HC and 179 carburettor jet sizes..... in particular - the main metering system.... so, a relative increase in a 186 engine to a 192 - probably doesn't support an increase in jet size...... my thoughts.....

My mixture procedure is to thoroughly warm up the engine to "operating" temperature.
Level ground - and fuel bowl level checked to specs.

Carburettor air horn screws and all pipes/fittings secure - air cleaner on.

If you have re-built the carburettor, set the mixture screw at one turn out from closed (be careful not to turn this screw in too firmly - it is brass and a "score" circle can be made on it) - with fingers only, gently turn it in until it stops..... NO SCREWDRIVER! .... the slot is for convenience when tuning on engine.....

On level ground (in a garage where it is quiet is helpful), start engine and allow to settle for a minute or two.

Slowly turn in the mixture screw until it "hunts"... ummmm..... runs rough and "just" makes it over... (this is why it is important to have the air cleaner on - it can "pop" up through the carby if you go too far... not always, but potentially).

Slowly turn out the screw until it runs smoothly and then continue until it starts to "roll" .... splutters and shakes
Screw it back in until it just runs smoothly again (pause a few seconds after altering - it will take a few rpm's for the rich fuel to burn out ...... this is the safe setting... if anything - just leaning (exuse pun) on the rich side of good.....

If the carby is in good condition, there shouldn't be an awful lot of alteration in the setting of the screw from lean to rich.... an intake system with problematic leaks/worn components may show up by being able to turn this screw a number of turns between parameters.....

If you have a vacuum gauge and a tachometer - you can get closer to the mark..... but, when tuning by "ear"... this is how I set mine.... rightly or wrongly...

Many years ago ( I still have it), I purchased a "colortune 500" tune up kit.... basically, a spark plug with a window around the electrode. The purpose was to actually "see" the colour of the chamber burn....... tuning by this method suggested that the mixture setting be turned "rich" until the flame was yellow in colour.... then turning in the mixture screw until the flame "just" turned blue.... hence colour-tune......

Vacuum gauges and tachometers have put paid to this primitive method..... but it was "period" - and I refuse to create shelf space by ditching it......

All of the above are my understandings and thoughts, not necessarily correct......

there, that was shorter.... (not by much)


frats,
Rosco

[dave a]

thanks for all your advise,it really helped. i used to drive around the block with a half inch spanner in my hand.stoping to adjust until i was happy. i need to go back to my old ways.sorry son use the force luke

[rosco]

Dave,
we are fast coming to an age where vehicles cannot be meddled with..... even changing a spark plug gap can in some cases cause the engine management light to come on...

But - in the "dinosaur" age.... where I come from - procedures such as these were what we young chaps used to thrive on.... an awful lot of b/s... and a lot of chest beating.... but we learned, made mistakes and paid for them......

End of the day, if we broke down somewhere (and it was usually by something we had done earlier).... we had a fairly solid knowledge foundation to get out of it without having to walk (no mobile phones then, folk) miles to the nearest phone and call the RACV (or even worse.. Dad!)....

I believe with our genre of vehicle - the methods used of old are the most appropriate.... go tinker and LEARN... but NOT with the modern multi-valve, ECU controlled MPV, SUV or HSV "yellow marked only" no-user-serviceable parts within - machines now dominating our driveways......

A large part of owning/operating one of these beloved old relics - is to learn how they work.... and even more importantly learn how to work on them...... pure bliss...(says when bonnet is up on a cold, wet, dark night and it refuses to co-operate... oh, what you youngin's have missed)....

frats,
Rosco

[Harv]

"A large part of owning/operating one of these beloved old relics - is to learn how they work.... and even more importantly learn how to work on them...... pure bliss...(says when bonnet is up on a cold, wet, dark night and it refuses to co-operate)"

Couldn't have said it better Rosco .

Cheers,
Harv.

[Plasman4]

I'm about to install electronic ignition

[Errol62]

Grey motor I take it sir?

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[Blacky]

Grey motor I take it sir?

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'tis a thread about red motors, so guessing red ?

Welcome to the forum Plasman, what is your question mate ????

[Errol62]

Ah yes, it’s that good ale to blame.

I’ve used the Bosch blue motor dissy and coil on a couple of engines. Simple bolt up, no issues, great performance. Injected black motors also have the same dissy but you can’t use the carby black motor esp version unless you run some form of computer to manage spark advance. You can buy Chinese knock offs on eBay but I’m wary of them. Commodore ones aren’t dear but have possibly done a few miles by now. It is the only way to go now days with points and condensers being harder to get. I used to change them as a set every five minutes back in the day.


FB ute fixer upper, EK van on rotisserie