The Dodge Dart Dyno Day...

Propane, Butane, LPG, GPL, C3H8, C4H10
storm
Posts: 796
Joined: Wed Jan 10, 2007 10:10 pm
Location: NSW, Australia

Re: The Dodge Dart Dyno Day...

Post by storm »

For my Holden V8 I purchased one of these. When I get the LPG system finished I can dial in an ignition curve using a laptop with the distributor still in the engine (they are at the back of Holdens similar to Chevs so it's a pain to do it over and over again in a small engine bay). If I were you I'd be looking for an equivalent item for your 318.
Fuel flow requirements calculations
Engine air flow requirement calculation: CFM = Cubic Inches x RPM x Volumetric Efficiency (VE) ÷ 3456

Steptoe
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Re: The Dodge Dart Dyno Day...

Post by Steptoe »

I really dont see the need...
A rubber band around the counterweights
establish the idle advance
Then establish the power advance, simply advance the intial up
u now have the total (intial+ cent) at a given rpms
Unless u are dialing in with a knock sensor all up... intial+cent+VA should not exeed 40 /42 degrees
Other than dropping a rubber band on the weights and turning the dizzie no issues so far right?
Now remove the dizzie, adjust the cent degs and the VA unit to meet the above specs, drop back in , set the intial so intial+ VA =idle on non Egr engines
The only thing now is changing springs so ... with LPG have fast curve off the bottom , but slow enough to hold the counter weights in at , at least idle rpms + 200.
Thjne diizy has been out once, and u will need to do that with the unit above...
And a few springs changed, requiring removing the cap an rotor, which really is no biggie

Also keep in mind once it has been set up.... thats it dont have touch again untill the shaft bushes have worn out and need to replace the unit anyway.
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storm
Posts: 796
Joined: Wed Jan 10, 2007 10:10 pm
Location: NSW, Australia

Re: The Dodge Dart Dyno Day...

Post by storm »

Steptoe wrote:I really dont see the need...
A rubber band around the counterweights
I thought I'd heard it all but this idea takes the cake. Rubber bands deteriorate with heat, cold, usage, etc etc etc. When they break, without notice, you're gonna have a problem. Not to mention all the little bits ending up through the inner workings of the distributor. I have a completely new distributor and I set it up with a readily avaiable laptop without having to climb over the engine to see anything. In getting prices on refurbishing my old one and using the new one taking into account the back and forth of setting the timing up for LPG I am actually saving money already. You don't see the need? I most certainly see many needs.
Steptoe wrote:Also keep in mind once it has been set up.... thats it dont have touch again untill the shaft bushes have worn out and need to replace the unit anyway.
Keep in mind after the rubber band starts to deteriorate your settings are gone.

In my readings of your posts in this section of the forum I find you seem to have a thing about timing and how to set it up. Yes it is important (which is why I don't get the rubber band idea as it is a recipe for disaster) but I can't help but think it is your be all and end all.
Fuel flow requirements calculations
Engine air flow requirement calculation: CFM = Cubic Inches x RPM x Volumetric Efficiency (VE) ÷ 3456

kikkegek
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Location: Netherlands, The Hague

Re: The Dodge Dart Dyno Day...

Post by kikkegek »

very cool Herman,

are the numbers of the AFr on the dyno gasoline numbers?
storage/project: 1974 GMC 25HUNDRED Suburban - fresh rebuild 350 small block - TH350-NP203 - 4.10 gears - IMPCO425 mixer
driver/project: 1977 GMC C15 Suburban - 454 big block - 4L80E- LPG VSI - 3.08 gears
sold: 1986 Chevrolet Suburban K20 Silverado

Steptoe
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Joined: Fri Feb 02, 2007 8:32 pm
Location: JAFA , New Zealand

Re: The Dodge Dart Dyno Day...

Post by Steptoe »

I thought I'd heard it all but this idea takes the cake. Rubber bands deteriorate with heat, cold, usage, etc etc etc.
Well in that case u really having heard much, using a rubber band to lock out the counter weights in a dizzy has been around for at least 70 odd years and a common practice dialing dizzy curves in.
"deteriorate"
How long would it take u to dial in a dizzy, certainly not long enough for ANY deterioration of the rubber band....
To establish the idle advance spec required and total all done in 1/2 to couple hours if dont have a dyno....
but I can't help but think it is your be all and end all.
Well maybe u tell us how to dial in a dizzy curve then....the simplest and most accurate way?
Establish best idle advance, best total... best advance within the curve rpms its self to shape the curve
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storm
Posts: 796
Joined: Wed Jan 10, 2007 10:10 pm
Location: NSW, Australia

Re: The Dodge Dart Dyno Day...

Post by storm »

Steptoe wrote:
I thought I'd heard it all but this idea takes the cake. Rubber bands deteriorate with heat, cold, usage, etc etc etc.
Well in that case u really having heard much, using a rubber band to lock out the counter weights in a dizzy has been around for at least 70 odd years and a common practice dialing dizzy curves in.
Did you mention dialing in? The way you wrote that post indicated that the rubber band was to be left there to stop the counterweights from going full advance. In that regard it is nothing but a patch up job.
Steptoe wrote:"deteriorate"
How long would it take u to dial in a dizzy, certainly not long enough for ANY deterioration of the rubber band....
To establish the idle advance spec required and total all done in 1/2 to couple hours if dont have a dyno....
Problem is you never said anything about simple dialing in, you said a rubber band around the counterweights etc. without ever saying anything about removing them. You are giving advice on a forum that many people read and that advice when not complete, i.e. remove rubber band AFTER you have finished setting your distributor up because if you don't you could cause yourself problems in the future, may helping people to actually cause a problem with their engines.
Steptoe wrote:Well maybe u tell us how to dial in a dizzy curve then....the simplest and most accurate way?
Establish best idle advance, best total... best advance within the curve rpms its self to shape the curve
Maybe I'll just start ignoring you if you are going to get all defensive. You post the process (for a chev) quite often in this forum and I can practically do it blindfolded because you post it so often. Do you really think that you need to tell everyone in nearly every single thread how to set up a dizzy?

Do you also think you need to tell people what parts in their cars are like? Mopar distributors are not like GM distributors regardless of what you think and because of this it is not a 1 process fits all scenario. You tell me how long it would take you to pull apart a Chrysler 318 distributor in the car after the customer has just driven it to your workshop? How long then to "dial it in" with rubber bands? put it all back together, test it, then pull it apart to give it some more fine tuning, then put it back together, test it and finally when you are happy with the results pull it apart one more time to remove those rubber bands? Remember this is done with an engine at operating temp. It is obvious you have done Chevs many times and I bow down to your knowledge in that regard but there have been a few times you post things that are just not correct and when I see them I will correct you so that people reading these posts do not leave things, such as rubber bands, in their distributors and expect everything to be fine in the long run.
Fuel flow requirements calculations
Engine air flow requirement calculation: CFM = Cubic Inches x RPM x Volumetric Efficiency (VE) ÷ 3456

Steptoe
Posts: 1504
Joined: Fri Feb 02, 2007 8:32 pm
Location: JAFA , New Zealand

Re: The Dodge Dart Dyno Day...

Post by Steptoe »

Fair comment...
I tend to make the assumption that anyone who undertakes the process to get to have to dial their engine, have a certain degree of basic engineer concept, an even greater degree of common sense.
The should have enough to understand the rubberbands stop the counter weights from moving... which means there is only 1 advance... the intial...and turning the dizzy with 1 constant makes establishing different dial in points such as total, intial , and idle at a given rpm easy.
Then they remove the dizzy , dial in the parameters, file counter weights what ever, one would be real thick to put the rubber band on...
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franz
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Re: The Dodge Dart Dyno Day...

Post by franz »

Boys, Boys, Boys, calm down! Even in the research lab we might play with temporary methods to establish baseline settings, or to determine if an idea is practical before we make permanent mods. I agree that a rubber band might help to isolate a total advance issue and that it is indeed a temporary measure.

We have to experiment before we can make something. Not all of us are blessed with a full CAD or Autodesk system.

Franz

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