Ready to run distributor thoughts?
- Thread starter Duster 72
- Start date
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Rat Bastid
Dunamis Metron
Make SURE you can adjust the advance curve on it. Some of those chicom distributors come with an advance you can’t adjust. To me, that is junk.
A hard pass. With any of stuff like that, I look for parts sold separately. You will need caps, rotors, pick ups, and control boxes. If all the components aren't sold separately it is literally a throw away!
Professor Fate
Push the button, Max...
I've had two cars that came with "ready-to-run" distributors on them.
They weren't Speedmasters or MSDs, but they had the "red cap" on them...
Never could get either one to run right, I finally put factory stuff back on them, and voila- ran perfect.
I know some people say they have run these with good results, but to me, cheap ignitions are just asking for issues, even if they work fine initially. Think about parts availability down the road- if you'll even be able to get replacement rotors and caps, let alone pick up modules. Just finding diagnostic specs can be an issue.
They weren't Speedmasters or MSDs, but they had the "red cap" on them...
Never could get either one to run right, I finally put factory stuff back on them, and voila- ran perfect.
I know some people say they have run these with good results, but to me, cheap ignitions are just asking for issues, even if they work fine initially. Think about parts availability down the road- if you'll even be able to get replacement rotors and caps, let alone pick up modules. Just finding diagnostic specs can be an issue.
Professor Fate
Push the button, Max...
Ya treed me!
Agree. Watch that Skip White type stuff. He probably isn't the only company putting his label on them
Mystery distributor
Really the most important thing is to have the correct distributor curve for the setup.
A potential of a bizzillion volts of blue lightning will always lose to a spark at the right time to build maximum pressure through the crank angles of maximum leverage.
The factory curve is a lot closer than most hot rodders think.
The other thing most hot rod drag racers miss is that electronic switching is a lot slower than they realize when compared to engine spinning over 4000 rpm.
Mystery distributor
Really the most important thing is to have the correct distributor curve for the setup.
A potential of a bizzillion volts of blue lightning will always lose to a spark at the right time to build maximum pressure through the crank angles of maximum leverage.
The factory curve is a lot closer than most hot rodders think.
The other thing most hot rod drag racers miss is that electronic switching is a lot slower than they realize when compared to engine spinning over 4000 rpm.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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agreed.
Parts, curve and parts!
68383GTS
Well-Known Member
I have a ready to run Summit brand distribitor on my 383 Super Bee and on a 318 both work great. 4 years and no problems..
These are ready to run, and you can set the timing right on before it starts too.
Simple is good, one wire.
Simple is good, one wire.
And Halifaxhops has all the parts you need!
What’s the attraction, it’s gimmick or reason to buy? Ready to run? Looks like it’s ready to run wire, run a crimper, run a drill, etc.
I’d give a suggestion on what would be a better option but others here already have that covered.
I’d give a suggestion on what would be a better option but others here already have that covered.
Unless you stay close to the factory Mopar distributors, OR the big cap GM HEI replacements, you're going to box yourself in with hard to find replacement parts. The way I always think before I buy something is, "Where would I find replacements parts broke down on a Sunday afternoon drive?"
Rat Bastid
Dunamis Metron
He’s talking about the slew rate of cheap electronics. If I got that wrong Mattax, correct me.
That is what I thought he meant. If so it will have no measurable affect for two reasons:
- most people set their timing with a timing light. The timing light is picking up the spark after it has been generated, so that any delay in producing the spark is already factored in. What ya see is what ya get...
- current flows at 186,000 miles per second. Any delay over the short distance the current has to travel through the ign cct would be immeasurable.
- most people set their timing with a timing light. The timing light is picking up the spark after it has been generated, so that any delay in producing the spark is already factored in. What ya see is what ya get...
- current flows at 186,000 miles per second. Any delay over the short distance the current has to travel through the ign cct would be immeasurable.
Dave999
Well-Known Member
the only time ive seen electronic switching issues are when
1) connecting the trigger up backwards, yes the igntion works but the timing drifts with rpm looks like slow switching. see digram below, If you trigger off the point under the axis you have what looks like slow switching that varies so much with RPM you can't work out whats going on.
2) certain MSDs seem to have a step where they retard at the point where they switch from multi spark to single spark. the multispark is supposed to be a feature, im suspsicious its just in place so they can run the Inductor/capcitor vibrator at a frequnecy high enough to cover slingle spark at the upper end of rpm range they claim. 1000 rpm and 3 sparks can be covered by a vibrator circuit that only really works 3000 -7000 rpm
Stuff like Fords EDIS has computation time taken into account, on any EDIS 4 6 or v8 , the 36-1 wheel will have its TDC mark x* of rotation before TDC dpendent on cylinder count . software expects it and it gives it leaway to spark in time, every time regardless of RPM in the designed range
i think youd be running into switching issues on say a v12 doing 12000 rpm
delcos HEI was used on V12 Jags, although not branded as such.
they had pleanty of issues, but igntion wasn't one.
if the timeing light says the spark is at the right time and you pay due care to dizzy phasing. I don't see an issue even if the trigger event was a well before the spark was needed, you tune to get the spark at the correct time.
i run the orginal dizzy re built re curved 28* all in with a GM HEI...does the job and cost me £30
Dave
1) connecting the trigger up backwards, yes the igntion works but the timing drifts with rpm looks like slow switching. see digram below, If you trigger off the point under the axis you have what looks like slow switching that varies so much with RPM you can't work out whats going on.
2) certain MSDs seem to have a step where they retard at the point where they switch from multi spark to single spark. the multispark is supposed to be a feature, im suspsicious its just in place so they can run the Inductor/capcitor vibrator at a frequnecy high enough to cover slingle spark at the upper end of rpm range they claim. 1000 rpm and 3 sparks can be covered by a vibrator circuit that only really works 3000 -7000 rpm
Stuff like Fords EDIS has computation time taken into account, on any EDIS 4 6 or v8 , the 36-1 wheel will have its TDC mark x* of rotation before TDC dpendent on cylinder count . software expects it and it gives it leaway to spark in time, every time regardless of RPM in the designed range
i think youd be running into switching issues on say a v12 doing 12000 rpm
delcos HEI was used on V12 Jags, although not branded as such.
they had pleanty of issues, but igntion wasn't one.
if the timeing light says the spark is at the right time and you pay due care to dizzy phasing. I don't see an issue even if the trigger event was a well before the spark was needed, you tune to get the spark at the correct time.
i run the orginal dizzy re built re curved 28* all in with a GM HEI...does the job and cost me £30
Dave
Last edited:
pishta
I know I'm right....
Just to bust you balls: 186,000 fps is a Velocity of Propagation of 100 (%), its not the same in all transmission media. Matter of fact 24g telephone transmission wire is only a VOP of 60 while RG/6 coaxial cable is 82. Electronics do pull advance at higher RPMs by nature , just compare a modded ECU from 4secondsflat to an OEM Chrysler ecu. I have a Bosch module based RTR LA distributor that's missing a cap spring...any sources? Has a loop on one end and a hook on the other.
It is miles per second, not feet per second.
According to Dr. Hugh Holden [ see link below ] who has done extensive studies on HEI type igns, the ign output retards at high rpms due to distortion of the flux wave created by the mag pick up. This is really academic because most people either use a timing light or dyno to find the best ign timing for max hp. Either method accounts for any delay in the spark delivery.
www.worldphaco.net
According to Dr. Hugh Holden [ see link below ] who has done extensive studies on HEI type igns, the ign output retards at high rpms due to distortion of the flux wave created by the mag pick up. This is really academic because most people either use a timing light or dyno to find the best ign timing for max hp. Either method accounts for any delay
www.worldphaco.net
Rat Bastid
Dunamis Metron
Duster 72
Well-Known Member
Ok guys wasn't trying to start another thread for people to argue just pros and cons how about a vote?
Rat Bastid
Dunamis Metron
Posts 2, 3 and 6 pretty much sum it up.
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