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New distributor with electronic ignition; opinions please!

Bob H.

Bob H.

Contributing Member
Many of you know I'm in the midst of an engine rebuild on a 1987 Crusader Model # 350 / 7.4L Gen 4 ( many of you may be getting bored with reading about it, sorry!). Everyone here pretty much agrees on replacing the distributor, and I have found the stock Mallory replacement. Now our plan has always been to upgrade the ignition system to electronic. Based on past posts/input here I've decided to go with the PerTronix line.
So here is the quandary; do I buy the stock Mallory, then buy the kit to make the change to electronic, plus the coil? Or do I buy PerTronix's marine graded, billeted distributor that already comes equipped with electronic ignition system? I end up having to buy new coils with either purchase but by purchasing PerTronix's distributor I save close to $80.00. Supposably reliability is the same but if I stick with the stock Mallory, I keep the option of being able to convert back to a points/condenser system in case of an emergency.
Which would you chose?
 
I, personally, haven't been impressed with anything from pertronix....why not just get a pair of Mallory distributors?? When you say "electronic", are you referring to the trigger or the whole primary side of the ignition? The key is being able to optimize your advance curve....if you aren't worried about that, then the EST systems can be purchased, turnkey, as well...
 
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makomark said:
I, personally, haven't been impressed with anything from pertronix....why not just get a pair of Mallory distributors?? When you say "electronic", are you referring to the trigger or the whole primary side of the ignition? The key is being able to optimize your advance curve....if you aren't worried about that, then the EST systems can be purchased, turnkey, as well...
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Feedback from the machine shop was that the Mallory distributor was reliable, but had a limited advance curve compared to a modern version. That's why I started to look for options. Since they are primarily a speed shop they wanted me to go with MSD, but their systems were twice the price of Pertronix.
Mark what don't you like about PerTronix?
And just to clarify ( and because I'm not afraid to ask the stupid question!); by "the whole primary side of the ignition" do you mean replacement of points/condenser/coil? If so that is our intent.
 
The mallory system is more than adequate for a production level of performance....you are building a marine engine, not a race car, so the speed shop "lessons learned" are directly applicable....The pertronix stuff I've seen isn't made in a high quality manner....I've seen many failures - can't say why but their rate is high. My gut says you get what you pay for.

The only stupid question is the one not asked....based on your post, you want to go 'electronic' for the trigger system. Mallory has at least two versions, one magnetic and one using an IR diode....either work fine and you should be able to order the distributors with the "conversion" already installed. That approach lets you keep the mechanical (tailorable) advance mechanism. They may have may have more offerings, I just haven't keep up with their newer offerings.
 
I've been running Davis Unified Ignition in both my Crusader 454 Gen 4 engines for 2 seasons and they are great. HEI and mechanical advance that they tailor to the boat/engine specs. Around $325
 
makomark said:
The mallory system is more than adequate for a production level of performance....you are building a marine engine, not a race car, so the speed shop "lessons learned" are directly applicable....The pertronix stuff I've seen isn't made in a high quality manner....I've seen many failures - can't say why but their rate is high. My gut says you get what you pay for.

The only stupid question is the one not asked....based on your post, you want to go 'electronic' for the trigger system. Mallory has at least two versions, one magnetic and one using an IR diode....either work fine and you should be able to order the distributors with the "conversion" already installed. That approach lets you keep the mechanical (tailorable) advance mechanism. They may have may have more offerings, I just haven't keep up with their newer offerings.
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Thanks for the clarification and input on this! I'll definitely give my Mallory distributor a call.
 
hottoddie said:
I've been running Davis Unified Ignition in both my Crusader 454 Gen 4 engines for 2 seasons and they are great. HEI and mechanical advance that they tailor to the boat/engine specs. Around $325
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Good to know! I've heard of the Davis systems but there doesn't seem to be anyone in my area that sells/distributes them. I have some time tomorrow to do some online searching.
 
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Bob H. said:
Feedback from the machine shop was that the Mallory distributor was reliable, but had a limited advance curve compared to a modern version.
The marine engine type and build dictates the advance and the advance curve.

That's why I started to look for options. Since they are primarily a speed shop they wanted me to go with MSD,
Steer clear of automotive speed shop suggestions. These are NOT Marine engines.
The Marine engine requires a specific advance and advance curve.

but their systems were twice the price of Pertronix.
Pertronix with their version of Hall Effect triggering is substandard, IMO.

Mark what don't you like about PerTronix?
I'm not Mark, but I'll give you my take on Pertronix!

Pertronix uses Hall Effect for the triggering, of which intrinsically is OK.
Pertronix embeds their small magnets into the plastic triggering wheel.
Their wheel is of small diameter.
Typically see a larger diameters used for Hall Effect, and seldom plastic wheel embedded magnets.
Errors of up to 1.5 degrees have been reported with the P units.
I don't know if these are distributor degrees or crankshaft degrees, but if distributor degrees, the 1.5 become 3 at the crankshaft.
Crankshaft degrees are what we are concerned with.


And just to clarify ( and because I'm not afraid to ask the stupid question!); by "the whole primary side of the ignition" do you mean replacement of points/condenser/coil? If so that is our intent.
I can't answer that for Mark..... but it is always wise to replace the entire system with matching components.
Click to expand...

You have many options for a new ignition system:


Mechanical advance with VR triggering
Mechanical advance with photo eye triggering
EST with photo eye
EST with photo eye in the HEI version.
Mechanical advacne with Photo eye in the HEI version.

.
 
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Installed the Mallory ( Now Sierra) YLM624AV last month. Best thing I ever did. Replaced the Pertronix conversion system in original distributors 1988 454's. Starts easier, runs smoother, timing/advance excellent. Definitely more power and turns higher RPM's. I am sure that some of this is due to the age of the old distributors as well.

RR
 
round4 said:
Installed the Mallory ( Now Sierra) YLM624AV last month. Best thing I ever did.
RR
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Excellent choice! :D
The YLM series is Mallory's VR version, as appose to their Photo-eye system the YLU series.
Chrysler Corp pioneered VR in the 70's, it has been tried and proven to work very well.

VR = Variable Reluctor.
Unlike the cheesy small diameter magnet embedded plastic wheel, the reluctor is precisionally machined from steel of which is then later magnetized.
With care given to the precision of machining, the small diameter of the reluctor is no issue.
 

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RicardoMarine said:
..............


You have many options for a new ignition system:


Mechanical advance with VR triggering
Mechanical advance with photo eye triggering
EST with photo eye
EST with photo eye in the HEI version.
Mechanical advacne with Photo eye in the HEI version.

.
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Majority rules! Thanks Rick, I will have time today to do some Mallory searching and shopping.
 
round4 said:
Installed the Mallory ( Now Sierra) YLM624AV last month. Best thing I ever did. Replaced the Pertronix conversion system in original distributors 1988 454's. Starts easier, runs smoother, timing/advance excellent. Definitely more power and turns higher RPM's. I am sure that some of this is due to the age of the old distributors as well.

RR
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More stupid questions; I'm finding Mallory distributors/parts online pretty easily. Is Sierra a generic equivalent ? Or do they just sell Mallory under their name brand ?
 
Bob H. said:
Majority rules! Thanks Rick, I will have time today to do some Mallory searching and shopping.
Click to expand...

Bob H. said:
More stupid questions; I'm finding Mallory distributors/parts online pretty easily. Is Sierra a generic equivalent ? Or do they just sell Mallory under their name brand ?
Click to expand...

If my understanding is correct, Mallory is now owned by the ACCEL Performance Group, although you'll still see the Mallory name on these.

If purchasing through Sierra, use caution.
Sierra has been listing the XXX-624-AV as the electronic ignition system for this engine (Marine SBC and BBC standard LH rotation)!
However, Sierra has been substituting the YLU for the YLM.

YLM unit (M= magnetic ) is variable reluctor.
Whereas the YLU unit (U = unilite ) is photo-eye.

IMO, the YLM using VR is more reliable.

Either uses the same mechanical advancing system.
Either can be tweaked for the curve or TA via a Sun, Allen or King distributor machine expert.


Edit:

EST = electronic spark timing. This style advance (above BASE or Initial advance) is accomplished with a control module that delays the actual spark event.
It then manipulates the delay via the electronic algorithm per engine RPM.
IOW, all of the advance that the engine sees (above BASE or Initial advance) is a result of this delay being manipulated.

Mechanical advance = a centrifugal flyweight cam and return spring system.
This style advance relies entirely on the mechanical function for advance above BASE or Initial advance.



.
 
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RicardoMarine said:
If my understanding is correct, Mallory is now owned by the ACCEL Performance Group, although you'll still see the Mallory name on these.

If purchasing through Sierra, use caution.
Sierra has been listing the XXX-624-AV as the electronic ignition system for this engine (Marine SBC and BBC standard LH rotation)!
However, Sierra has been substituting the YLU for the YLM.

YLM unit (M= magnetic ) is variable reluctor.
Whereas the YLU unit (U = unilite ) is photo-eye.

IMO, the YLM using VR is more reliable.

Either uses the same mechanical advancing system.
Either can be tweaked for the curve or TA via a Sun, Allen or King distributor machine expert.
.
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Gotcha. To be safe I'll only be searching the "YLM" under the Mallory brand. One final question on this; theses components are for the port engine which is "LH" / standard rotation. I want to do an identical upgrade for the starboard engine, which is "RH" rotation. The cost for this is running twice the price of the standard rotation distributor, sometime even more! What's the difference here besides the drive gear and thrust washer? Why such a higher cost?
 
Bob H. said:
One final question on this; theses components are for the port engine which is "LH" / standard rotation. I want to do an identical upgrade for the starboard engine, which is "RH" rotation. The cost for this is running twice the price of the standard rotation distributor, sometime even more! What's the difference here besides the drive gear and thrust washer? Why such a higher cost?
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OK.... either engine rotates the distributor and oil pump in the CW direction, and same with the advancing mechanism operating in the CW direction.

With the standard LH engine, the helical gear cut and gear direction causes an up-lift force on the gear/shaft.
The washer between the gear and housing take care of the up-lift thrust friction.

With the RH engine (and with sprocket chain driven camshaft), the helical gear cut and same gear direction causes a down-load force on the gear/shaft.
The upper area under the mechanical advancing mechanism takes care of the down-load thrust friction.

So... unless your REV RH rotation engine is fitted with a twin "gear" cam drive (rotates cam same as LH engine), the helical gear cut is going to cause this down-load thrust friction....... in which case you'd need the YLM 624 BV.


If you pull both distributors out, look to see if the helical cut is opposite from one to the other.
If they are the same cut, then your REV RH engine camshaft is twin gear driven..... in which case both engines can use the YLM 624 AV.



I can't tell you why the higher cost!
Perhaps supply/demand!
 

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Once again Rick, you provide another great explaination that even a backyard bumbler like me can understand!
Now is a good time to pull the starboard side distributor and check those gears. If pricing keeps running this high; $300.00 for the "AV" and $700.00 for the "BV", that purchase may have to wait until next season!
 
unless your engines have been rebuilt before, you'll only need to "A" versions...standard GM productions units have used gears for their reverse rotation engines for decades....until they stopped building them.....you can pull the RH engine's distributor up a bit (after loosing the clamp) if you wanna check the gear on it...or pull it entirely if you want a visual...mark it first or just retime it once your are done.
 
makomark said:
unless your engines have been rebuilt before, you'll only need to "A" versions...standard GM productions units have used gears for their reverse rotation engines for decades....until they stopped building them.....you can pull the RH engine's distributor up a bit (after loosing the clamp) if you wanna check the gear on it...or pull it entirely if you want a visual...mark it first or just retime it once your are done.
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Now that's good news! Mark you always seem to find ways to save me time and money, much appreciated!
 
makomark said:
you can pull the RH engine's distributor up a bit (after loosing the clamp) if you wanna check the gear on it...

Click to expand...

Mark, when I first read that, I did a; "Hmmmmm... how's Bob going to see the gear?"
Then I realized what you meant!

Bob, if I'm understanding Mark, his idea is great. (which means that his pencil is sharper than mine! :D )

Here's the AV gear used with the Standard LH engine...... (or with the REV RH engine using dual gear camshaft drive)
When this gear is lifted from the camshaft gear, it will rotate the shaft CCW a bit until it loses contact.

images


Here's the BV gear used on a REV RH using chain driven camshaft.
When this gear is lifted from the camshaft gear, it will rotate the shaft CW a bit until it loses contact.

images


If both distributor shafts rotate CW as they're being lifted, then your REV RH engine's camshaft is dual gear driven, as Mark suggested.

Bob, with this $aving$..... I think that we should all go out to dinner on you! :cool:


.
 
RicardoMarine said:
Mark, when I first read that, I did a; "Hmmmmm... how's Bob going to see the gear?"
Then I realized what you meant!

Bob, if I'm understanding Mark, his idea is great. (which means that his pencil is sharper than mine! :D )

Here's the AV gear used with the Standard LH engine...... (or with the REV RH engine using dual gear camshaft drive)
When this gear is lifted from the camshaft gear, it will rotate the shaft CCW a bit until it loses contact.

images


Here's the BV gear used on a REV RH using chain driven camshaft.
When this gear is lifted from the camshaft gear, it will rotate the shaft CW a bit until it loses contact.

images


If both distributor shafts rotate CW as they're being lifted, then your REV RH engine's camshaft is dual gear driven, as Mark suggested.

Bob, with this $aving$..... I think that we should all go out to dinner on you! :cool:


.
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I know Rick! Doubtful I'll be able to get to either of your neck of the woods soon, but I do owe you both!
Gratitude for the advice/input on this project is one thing. I don't know if I mentioned this or not, but I've been racing abit of a biological clock here; I'm scheduled for a kidney transplant 05/20/2015 and are striving to finish this project before then. Assistance from You, Mark and everyone else here is gonna make that a reality.
 
Damn...good luck on both!!

If you wanna save a little more time, with the original point-style distributor, just pop the cap and see which way the rotor "advances"....if its the same as the other distributor, you don't have to pull the clamp...of course, the advance mechanism has to be free and working for this...
 
makomark said:
Damn...good luck on both!!

If you wanna save a little more time, with the original point-style distributor, just pop the cap and see which way the rotor "advances"....if its the same as the other distributor, you don't have to pull the clamp...of course, the advance mechanism has to be free and working for this...
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Thanks Mark!
By the time I read this I had already sneaked-a-peek by inching the distributor out a bit. All good! Gonna be able to go with "AV" type distributors on both motors. Should get the exhaust manifolds back by the end of the week too. So far so........
 
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