prestolite VS holley
- Thread starter reuben
- Start date
Michael Mayben
IHPA Tech Moderator - Retired & No Longer Online
Why would you "need" the bb for this question???
We have much information posted in threads right here in this sub-forum so that anyone can make an informed decision about this quandry.
Performance-wise, as long as each distributor has the correct advance curve for the engine app and build, and is mechanically sound, then it's a toss-up if you are retaining either of the systems in "stock" form. Consult the appropriate sections of the service manuals for all those engine/distributor combos and look at the myriad variations in curves that were used by part number and you'll see many are not the correct choice for certain apps.
The biggest problem is wear, that is why distributor performance deteriorates over time. Wear in the vacuum advance system, wear in the mechanical advance system, incorrect "air gap" if it's an electronic trigger system, and most problematic, too much end play which allows the dynamic timing to go to hell.
Both of the systems you reference are plain old inductive systems, the prestolite has the controller built inside, the gold box system has an external controller.
If you are going to all the trouble of building a motor, why not build a performance ignition system to go with it? And either of those distributors can provide a basis for that without stuffing some kinda boneyard conversion pieces inside. And whatever ya put in the distributor is worthless unless it's in first class condition mechanically.
This is a start regarding performance ignition systems and upgrades, that thread will always be a work in progress as more folks relate their experiences:
http://www.forums.IHPartsAmerica.com/ignition-tech/644-ignition-system-performance-upgrades.html
Right now...if I was going to chose the best solution for a complete system either for an I-4 or sv app, it would include:
1) a delco cast iron distributor for sv application along with an "adjustable" vacuum advance cannister and a full selection of tuning parts for altering the advance curve (easily obtained); fully rebuilt and the end play set to close tolerance.
2) a crane xri "lobe sensor" module to replace the breaker points in the above. A pertronix conversion module works just as well but I feel the crane module is superior in design for a delco distributor.
3) either a msd or mallory "6 series" cd ignition box, along with an "adjustable" timing control add-on unit (not mandatory but "nice-to-have").
4) either the msd or crane "low primary resistance" e-core type ignition coil...those coils must be triggered through the cd box, they won't work worth a dam and will very problematic if not used with a box...do not believe the marketing hype.
5) your choice of plug cables depending upon selected bling factor and cost.
6) weatherpak connections on all wire runs.
7) proper looming and dressing of wire runs to prevent environmental problems and enhance serviceability down the line.
The above referenced system will run a spark plug air gap of up to 0.050" just fine, no reason to go any greater than that, either of those coils can and will produce a "voltage available" of 40kv+ if called upon.
We have much information posted in threads right here in this sub-forum so that anyone can make an informed decision about this quandry.
Performance-wise, as long as each distributor has the correct advance curve for the engine app and build, and is mechanically sound, then it's a toss-up if you are retaining either of the systems in "stock" form. Consult the appropriate sections of the service manuals for all those engine/distributor combos and look at the myriad variations in curves that were used by part number and you'll see many are not the correct choice for certain apps.
The biggest problem is wear, that is why distributor performance deteriorates over time. Wear in the vacuum advance system, wear in the mechanical advance system, incorrect "air gap" if it's an electronic trigger system, and most problematic, too much end play which allows the dynamic timing to go to hell.
Both of the systems you reference are plain old inductive systems, the prestolite has the controller built inside, the gold box system has an external controller.
If you are going to all the trouble of building a motor, why not build a performance ignition system to go with it? And either of those distributors can provide a basis for that without stuffing some kinda boneyard conversion pieces inside. And whatever ya put in the distributor is worthless unless it's in first class condition mechanically.
This is a start regarding performance ignition systems and upgrades, that thread will always be a work in progress as more folks relate their experiences:
http://www.forums.IHPartsAmerica.com/ignition-tech/644-ignition-system-performance-upgrades.html
Right now...if I was going to chose the best solution for a complete system either for an I-4 or sv app, it would include:
1) a delco cast iron distributor for sv application along with an "adjustable" vacuum advance cannister and a full selection of tuning parts for altering the advance curve (easily obtained); fully rebuilt and the end play set to close tolerance.
2) a crane xri "lobe sensor" module to replace the breaker points in the above. A pertronix conversion module works just as well but I feel the crane module is superior in design for a delco distributor.
3) either a msd or mallory "6 series" cd ignition box, along with an "adjustable" timing control add-on unit (not mandatory but "nice-to-have").
4) either the msd or crane "low primary resistance" e-core type ignition coil...those coils must be triggered through the cd box, they won't work worth a dam and will very problematic if not used with a box...do not believe the marketing hype.
5) your choice of plug cables depending upon selected bling factor and cost.
6) weatherpak connections on all wire runs.
7) proper looming and dressing of wire runs to prevent environmental problems and enhance serviceability down the line.
The above referenced system will run a spark plug air gap of up to 0.050" just fine, no reason to go any greater than that, either of those coils can and will produce a "voltage available" of 40kv+ if called upon.
Michael Mayben
IHPA Tech Moderator - Retired & No Longer Online
No sweat reuben, that's why we do this schnizz!!!
So...post the details of your engine build regarding any cam changes, compression changes, induction system changes, etc. Big part of this is your total electrical system status, are you trying to "get by" with the oem wiring crap, or doing a complete system from scratch?
Then post the part number and any other id you see on each distributor so we can see exactly what you have to work with. Pics are real helpful of the interiors of each, and use a feeler gauge between the drive gear and the end of the body and post the "clearance".
The Holley number is stamped on the body, the prestolite number is on that tag riveted to the body, see this thread for identification tips:
http://www.forums.IHPartsAmerica.com/ignition-tech/642-ihc-vehicle-distributor-identification.html
The "total" ignition package I described can be done in steps as the budget allows, that is why I refer to that stuff as a systems approach. Each piece works with the piece that comes after and does not affect operation in the mean time, just makes things "better" I'm no different than anyone else, I have to do stuff like this as the cash and trade situation develops too, I won't be on social security until next month!
And...if you just need to make it run now...then you can just install any distributor (within reason!) temporarily, along with a simple wiring system just for the ignition function that can be moved from vehicle to vehicle.
So...post the details of your engine build regarding any cam changes, compression changes, induction system changes, etc. Big part of this is your total electrical system status, are you trying to "get by" with the oem wiring crap, or doing a complete system from scratch?
Then post the part number and any other id you see on each distributor so we can see exactly what you have to work with. Pics are real helpful of the interiors of each, and use a feeler gauge between the drive gear and the end of the body and post the "clearance".
The Holley number is stamped on the body, the prestolite number is on that tag riveted to the body, see this thread for identification tips:
http://www.forums.IHPartsAmerica.com/ignition-tech/642-ihc-vehicle-distributor-identification.html
The "total" ignition package I described can be done in steps as the budget allows, that is why I refer to that stuff as a systems approach. Each piece works with the piece that comes after and does not affect operation in the mean time, just makes things "better" I'm no different than anyone else, I have to do stuff like this as the cash and trade situation develops too, I won't be on social security until next month!
And...if you just need to make it run now...then you can just install any distributor (within reason!) temporarily, along with a simple wiring system just for the ignition function that can be moved from vehicle to vehicle.
Michael Mayben
IHPA Tech Moderator - Retired & No Longer Online
Ok, I looked at your "build" thread and I assume the motor issa 345? If so, then your "target" setting for base timing is gonna be 8*btdc. Once it's running and driving, then perform the "power timing" process I describe here:
http://www.forums.IHPartsAmerica.co...es-pertronix-require-timing-readjustment.html
Since the motor I see in your posts has the prestolite unit installed and the wiring is set up for that, I'd definitely stick with it for now. Just verify the air gap of the trigger unit while the cap is off using a non-magnetic thickness gauge.
The presto p/n idn4002r is the same unit discussed in this thread:
http://www.forums.IHPartsAmerica.com/ignition-tech/1327-prestolite-496004c91-distributor.html
So that unit will work just fine for ya "curve-wise".
The IH p/n for your Holley distributor should actually be: 469648-c91 and was oem onna 345 after 1974. The curve specs are so close to the prestolite that they can be considered nearly the same.
When you are ready to build a performance ignition system (and after educating yourself about this stuff), then post a new thread just for your project system.
http://www.forums.IHPartsAmerica.co...es-pertronix-require-timing-readjustment.html
Since the motor I see in your posts has the prestolite unit installed and the wiring is set up for that, I'd definitely stick with it for now. Just verify the air gap of the trigger unit while the cap is off using a non-magnetic thickness gauge.
The presto p/n idn4002r is the same unit discussed in this thread:
http://www.forums.IHPartsAmerica.com/ignition-tech/1327-prestolite-496004c91-distributor.html
So that unit will work just fine for ya "curve-wise".
The IH p/n for your Holley distributor should actually be: 469648-c91 and was oem onna 345 after 1974. The curve specs are so close to the prestolite that they can be considered nearly the same.
When you are ready to build a performance ignition system (and after educating yourself about this stuff), then post a new thread just for your project system.
Last edited:
Michael Mayben
IHPA Tech Moderator - Retired & No Longer Online
No, the decel crap is redundant at this point. Just plug the plugs, do not connect a vacuum source to the decel pot.
reuben
Member
Ok back from the dead.
I bought a parts Scout and it has a running(?) 304 in it. It has a Holley dist with a gold box.
The numbers are
0426 and 467073-c91
my first question is how should I wire it. I put in on of the harnesses that Jeff sells. I am going to be running this motor all stock 2bbl carb. No smog crap. The Scout it came from was a '76
I bought a parts Scout and it has a running(?) 304 in it. It has a Holley dist with a gold box.
The numbers are
0426 and 467073-c91
my first question is how should I wire it. I put in on of the harnesses that Jeff sells. I am going to be running this motor all stock 2bbl carb. No smog crap. The Scout it came from was a '76
Michael Mayben
IHPA Tech Moderator - Retired & No Longer Online
Michael Mayben
IHPA Tech Moderator - Retired & No Longer Online
And here is the oem schematic for an sii with gold box, both I-4 engine and sv option.
Notice the discrepancies between the pertronix drawing and the oem drawing.
This schematic shows both a breaker point distributor and the gold box system...typical IH bullshit "tech" references...how confusing!
Notice the discrepancies between the pertronix drawing and the oem drawing.
This schematic shows both a breaker point distributor and the gold box system...typical IH bullshit "tech" references...how confusing!
