Now first I know this may not be very relevant in the world of the modifying FB/EK's. But here goes anyhow.
Got my 3.3 running fairly well with the after-market ECU. The computer controls the ignition advance as well as fuel, so I can modify my timing as I see fit with the clicking of a mouse. Much has been learnt about air to fuel ratios, accel enrichments, air density, peak cylinder pressure, combustion chamber turbulence and many other amazing things I've never thought of before while in carby/dizzy land. It seems the more I learn the more I realize there is a lot to learn. I know there's a philosophical saying somewhere about being free from choice is a true freedom......
And now the question: Does anyone know what a good advance curve looks like for the 3.3 (low compression). My curve starts at 900 rpm, climbs steep to about 2000, where it's about 25 degrees, then flattens out to the all-in point just over 4000 rpm at about 30 degrees.
The vacuum starts at about 7"of mercury and is all in by 10 inches at another 10 degrees.
Giving me 40 total degrees at 4000 rpm with closed throttle.
This is including the 6 degrees at idle.
Does that land in the "normal" park?
Stock cam, btw.
Basically I put a lot of time and money into rebuilding this motor, so really I'm giving you wiser heads go to give my virtual dizzy a sanity check do as I can keep my pistons in one piece.
Thanks.
Ignition curve
Re: Ignition curve
Hi Richard - you're years ahead of most of us..... I just wonder if it might be worthwhile visiting a Commodore sight (if one exists) - those chaps should have some info for you - at least something you can use as a metre(yard)stick - and hopefully some figures which might give you base levels (safe) to set up.
I have an "optronic" (Lumenition) system fitted to mine - it has been almost faultless for thirty years (with one exception of a faulty connectory - Tenterfield nats) - but it still incorporates all inputs from the distributor mechanical and vacuum parameters....
And, of course - that old Stromberg "squirter"...
Your ECU controlled combustion system should afford you marvellous fuel economy - and I note you run low compressions...
Even though you have more than an extra litre of capacity - you should be able to parallel figures equivalent to that of a grey in good condition.....
Looking forward to your further investigation and enlightenment....
frats,
Rosco
I have an "optronic" (Lumenition) system fitted to mine - it has been almost faultless for thirty years (with one exception of a faulty connectory - Tenterfield nats) - but it still incorporates all inputs from the distributor mechanical and vacuum parameters....
And, of course - that old Stromberg "squirter"...
Your ECU controlled combustion system should afford you marvellous fuel economy - and I note you run low compressions...
Even though you have more than an extra litre of capacity - you should be able to parallel figures equivalent to that of a grey in good condition.....
Looking forward to your further investigation and enlightenment....
frats,
Rosco
You're more than welcome to pop over some time and see this in action. See how the fuel and spark map can be viewed and adjusted while the engine is running. Close to getting a permit from VicRoads so as to get all I need to finalize engineers report, get a roadworthy and finally rego!
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Re: Ignition curve
Richard,
any "popping" over would require a lear jet at present...... we are slowly making our way south back to (and I hesitate to type this..) Melbourne...... at present, we have come leaps and bounds from our most northerly point (Endeavour Falls some 37 km north of Cooktown)... as far as Cairns... and I, for one - will dig my heels into the ground as deeply as I can before leaving here.... sadly, which will happen on Sunday..... this Sunday....
Hope to be in a position to be awestruck at your creation - but, sadly this won't happen until you have probably driven it around for awhile ......
I do hope you keep it clean for me to see..... you will most likely have washed it a number of times by the time I get to place my beady little eyes on it...
thanks for the invitation, Richard.... sadly, I can't fulfill it just yet.....
frats,
Rosco
any "popping" over would require a lear jet at present...... we are slowly making our way south back to (and I hesitate to type this..) Melbourne...... at present, we have come leaps and bounds from our most northerly point (Endeavour Falls some 37 km north of Cooktown)... as far as Cairns... and I, for one - will dig my heels into the ground as deeply as I can before leaving here.... sadly, which will happen on Sunday..... this Sunday....
Hope to be in a position to be awestruck at your creation - but, sadly this won't happen until you have probably driven it around for awhile ......
I do hope you keep it clean for me to see..... you will most likely have washed it a number of times by the time I get to place my beady little eyes on it...
thanks for the invitation, Richard.... sadly, I can't fulfill it just yet.....
frats,
Rosco
Great to see you are enjoying the nomad lifestyle Ross (I deliberately omitted "grey"). And enjoying the spectacle this land has to offer. I too look forward to a (still fairly distant) future where my alarm clock is no longer my master. As for the computer controlled motor, yes, I've already been having lots of fun tuning the motor while running, adjusting the fuel mixture at various rev ranges while watching the signal from the oxygen sensor to determine stoich points. One thing with the fuel is being able to set the points in the fuel map where the manifold pressure is ultra low (eg downhill coasting) to be almost switching the injectors off altogether. Some time soon I'll do a proper dyno tune to get her spot on. For now though, the focus is on getting her certified, roadworthied and registered.
Re: Ignition curve
Yes, Richard - it is indeed a lifestyle of splendour when the only time you actually set an alarm is because you want to - not because you need to....
As for the grey bit - well, nearly qualified.... I'd be happier if they all went grey and stopped abandoning the host.....
As for your curve - I can probably make one comment which might just throw a little light on coasting for you.
I don't know if there is any relevance, but we have a 4.5 litre V8 twin tubo diesel in the 200... I have a "scanguage2" fitted to it and monitior fuel consumption amongst other things...
When coasting - specifically - using the engine for braking - there is absolutely no fuel usage... not one drop - it is all run on compression.
I would therefore expect, that it would be likewise advantageous to set your decelerate map to the same.
Of course, the spark would be wound way out in advance.... as there is absolutely no risk of any pre-ignition.. if there is no injection.
I can recall, it was fun in my youth to roll down a long hill with the ignition off....... the fuel build up in the exhaust system would load up considerably.... then, when you went past someone's house who you were having trouble with - you'd just turn on the ignition again......
I did this many times - until eventually I had to replace the muffler..... and decided the grief I was causing was not worth the expense.....
My further suggestion, would be to have the engine dynoe'd at some time... they should give you a pretty exact figure at many different speeds and loads...
But - be warned - a petrol engine will harm itself if "perfect" combustion is achieved.... I believe you will find that even the best engine tuners set their paramaters to "just" the rich side of perfect......
And, on a continuous heavy load, it would certainly be beneficial to the longevity of the engine not to configure your settings to "optimum"...
my thoughts..
frats,
Rosco
As for the grey bit - well, nearly qualified.... I'd be happier if they all went grey and stopped abandoning the host.....
As for your curve - I can probably make one comment which might just throw a little light on coasting for you.
I don't know if there is any relevance, but we have a 4.5 litre V8 twin tubo diesel in the 200... I have a "scanguage2" fitted to it and monitior fuel consumption amongst other things...
When coasting - specifically - using the engine for braking - there is absolutely no fuel usage... not one drop - it is all run on compression.
I would therefore expect, that it would be likewise advantageous to set your decelerate map to the same.
Of course, the spark would be wound way out in advance.... as there is absolutely no risk of any pre-ignition.. if there is no injection.
I can recall, it was fun in my youth to roll down a long hill with the ignition off....... the fuel build up in the exhaust system would load up considerably.... then, when you went past someone's house who you were having trouble with - you'd just turn on the ignition again......
I did this many times - until eventually I had to replace the muffler..... and decided the grief I was causing was not worth the expense.....
My further suggestion, would be to have the engine dynoe'd at some time... they should give you a pretty exact figure at many different speeds and loads...
But - be warned - a petrol engine will harm itself if "perfect" combustion is achieved.... I believe you will find that even the best engine tuners set their paramaters to "just" the rich side of perfect......
And, on a continuous heavy load, it would certainly be beneficial to the longevity of the engine not to configure your settings to "optimum"...
my thoughts..
frats,
Rosco
Re: Ignition curve
rosco wrote:
I can recall, it was fun in my youth to roll down a long hill with the ignition off....... the fuel build up in the exhaust system would load up considerably.... then, when you went past someone's house who you were having trouble with - you'd just turn on the ignition again......
I did this many times - until eventually I had to replace the muffler..... and decided the grief I was causing was not worth the expense.....
I haven't done that for AGES!!!!!!
FB Holden Fernando Yellow/Arctic Beige flash
Stock as a rock
75 series Landcruiser 350 Chev
Not so stock
Stock as a rock
75 series Landcruiser 350 Chev
Not so stock
Re: Ignition curve
Richard,
because it's your thread, and you are digressing - I don't feel so bad having introduced this tributary .....
But - you mentioned locking the column..... in fact, it was here in Oz - when two elderly ladies did this to conserve fuel because they feared running out before reaching the next town - and crashed - killing both of them......... it was after that, that a cognitive decision had to be made by the driver to press a button, depress the ignition switch before the steering would in fact - lock......and all such new vehicles in Oz had to conform to the new AS xxyyzz.... I can't recall when this was - but know it was before 1972.... I definitely know the LJ torana had this feature.....
Yes, can appreciate that locking it at 60 mph might just have been a concern.... no matter how hard he might have pulled on the wheel... it would have continued to follow the steered coure......
Just as a bye the by.... we tried something similar when the new 26L pneumatic brake unit arrived on our locomotives.... we used to "bridge the valve" with the handle in an unofficial "bridge" position on both No. 4 and A7EL units which closed all ports and passages in the brake control handle - allowing an instantaneous further application....after a momentary release...
The 26L did not have such a position - because it was a "maintaining" brake unit - so, in my early days - decided to close the main feed and control button valve..... I found out very quickly that I could no longer apply the brakes... and, thus ended my ever trying to simulate a "bridging" application with that unit....
You ask, what happened....? we didn't "crash" or run off the rails.... well, when the brakes finally applied in "emergency" - we went a lot further with the passenger train past Melton than the guard expected us to... we had to "set back" about three train lengths to let passengers entrain..... we didn't ever get asked "what the heck at Melton?".... but the passengers waiting on the platform had looks of shock on their faces when they realised they might just not be catching "this" train.... until we slinked back in like a mangy dog with its tail between its legs........
Yes, never, never - depress the ignition switch to "lock" if you want to try the "back-fire" trick on a vehicle..... just to "off" will do it.....
I don't believe injector ECU vehicles will ever afford this opportunity, anyhow....
Sorry - how on heck did we ever get to this.....? from an "ignition curve" thread......?
frats,
Rosco
ps Mini - don't ever try it...... it completely isolates the brake valve... both in AND out...... emergency (the big hole) still works, though......
because it's your thread, and you are digressing - I don't feel so bad having introduced this tributary .....
But - you mentioned locking the column..... in fact, it was here in Oz - when two elderly ladies did this to conserve fuel because they feared running out before reaching the next town - and crashed - killing both of them......... it was after that, that a cognitive decision had to be made by the driver to press a button, depress the ignition switch before the steering would in fact - lock......and all such new vehicles in Oz had to conform to the new AS xxyyzz.... I can't recall when this was - but know it was before 1972.... I definitely know the LJ torana had this feature.....
Yes, can appreciate that locking it at 60 mph might just have been a concern.... no matter how hard he might have pulled on the wheel... it would have continued to follow the steered coure......
Just as a bye the by.... we tried something similar when the new 26L pneumatic brake unit arrived on our locomotives.... we used to "bridge the valve" with the handle in an unofficial "bridge" position on both No. 4 and A7EL units which closed all ports and passages in the brake control handle - allowing an instantaneous further application....after a momentary release...
The 26L did not have such a position - because it was a "maintaining" brake unit - so, in my early days - decided to close the main feed and control button valve..... I found out very quickly that I could no longer apply the brakes... and, thus ended my ever trying to simulate a "bridging" application with that unit....
You ask, what happened....? we didn't "crash" or run off the rails.... well, when the brakes finally applied in "emergency" - we went a lot further with the passenger train past Melton than the guard expected us to... we had to "set back" about three train lengths to let passengers entrain..... we didn't ever get asked "what the heck at Melton?".... but the passengers waiting on the platform had looks of shock on their faces when they realised they might just not be catching "this" train.... until we slinked back in like a mangy dog with its tail between its legs........
Yes, never, never - depress the ignition switch to "lock" if you want to try the "back-fire" trick on a vehicle..... just to "off" will do it.....
I don't believe injector ECU vehicles will ever afford this opportunity, anyhow....
Sorry - how on heck did we ever get to this.....? from an "ignition curve" thread......?
frats,
Rosco
ps Mini - don't ever try it...... it completely isolates the brake valve... both in AND out...... emergency (the big hole) still works, though......