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TR4/4A TR4 Distributor
- Thread starter KVH
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DNK
Great Pumpkin
Offline
If you are going thru the money of replacing your dist. why mess with the points, go mallory el ign. or have jeff redo yous with the el. ign added or for even more money the new 123 dist. is also now available. Remember with some of these new types you might have some tach work to do .
don
don
Brosky
Great Pumpkin
Offline
Have Jeff rebuild yours. My car runs great just at factory specs and will probably be better once I get it tweaked in. And again, my tach is not affected.
Here is Jeff's process in case you missed the previous post.
https://www.74tr6.com/distributor.htm
Good luck!
Here is Jeff's process in case you missed the previous post.
https://www.74tr6.com/distributor.htm
Good luck!
Geo Hahn
Yoda
Offline
Depends what your goal is but I don't see that you gain much by going with a replacement that still has points.
I actually prefer the points ignition but can see why some prefer the electronic alternatives.
I figure that if I'm willing to drive with a pre-WWII ignition technology I might as well stay stock.
I actually prefer the points ignition but can see why some prefer the electronic alternatives.
I figure that if I'm willing to drive with a pre-WWII ignition technology I might as well stay stock.
JeffS
Jedi Trainee
Offline
I'm not a big fan of the dual point Mallory distributor. I just took one "on trade" and they are a REAL bugger to get set up correctly. I don't understand the "improvement." The curve is adjusted by bending things! You also lose the vacuum advance unless you spend $500. For that kind of money, buy the 123! Of course a cheap rebuild/recurve is a good option!
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Alan_Myers
Luke Skywalker
Offline
Hi,
I've got the Mallory dual point/non-vacuum advance installed on my TR4. The car is still under construction, so can't compare it directly for you (plus it's been a long time since I used a Lucas dizzy).
However I've been around plenty of Mallorys installed on other cars and, overall, would have to say they work fine, are highly adjustable and are adaptable. There are many different curve kits available, to really dial a dual point in to a specific engine setup, for example.
Right now, if I had it to do over again, pretty sure I'd buy and install the Mallory Unilite on my TR4 instead. As it is, I'll likely be converting the dual point with Mallory's #562 EI trigger module.
Eventually the plan is to be running a Mallory CD/multi-spark ignition and high performance coil (probably VI-AL and #29440, respectively). The dual point dizzy will work with these, but ironically it's recommended that only one of the sets of points be used to trigger the ignition! With a capacitive discharge/multi-spark ignition, any points should last about 10x longer than usual (because the trigger voltage crossing them is far lower than the spark voltage they would normally carry). However, for $120 I'll just do away with the points entirely and install the module for it's high accuracy and dependability.
Keep in mind that I'm using Weber DCOE carbs, thus the non-vacuum advance dizzy is a necessity (original Lucas dizzies can be modified for this purpose, too). If you are running SUs or ZSs, or any other carb/manifold that has means of picking up vacuum, you'll most likely want the vacuum advance version of any dizzy you choose. One benefit of vacuum advance is improved gas mileage.
Mallory are very well made. But I'd call the dual point "old high performance technology" that today would be chosen if, for example, a vintage race class' restrictions require sticking with a point-type ignition, or if building a close replica of a vintage racer. The advantages of the double set of points are some redundancy and should provide a better path for stronger spark voltage, but they still have the usual limitations of points.
The dual point is cheaper to buy intitially than the Unilite. But buying the dual point and later converting it with the module works out to be more expensive. The Unilite should require little or no service over the years, too, so should "pay for itself" in that respect. Dual point service parts such as the points and rotor are a bit pricey.
By the way, Mallory, Accel and Jacobs ignition components are all from the same company: Mr. Gasket. www.mrgasket.com has lots of info on applications, etc.
Pertronix offers a module to convert Mallory dual point to EI, too. However, I am leery about mixing manufacturers, a bit more confident sticking with the same company will help with compatibility throughout the system. Plus, although I've heard many good reports about Pertronix stuff, I've also heard about a lot of failures and problems. Have to admit, though, I don't know if those issues are the fault of the parts... or the installers.
I don't know anything about Moss' "Race" distributor... wouldn't be surprised to open the box and find a Mallory!
If interested in it, $500 is *way* expensive for a Unilite. Shop around. Jeg's or Summit can get it for you, and I've seen them even cheaper at some other online stores.
/ubbthreads/images/graemlins/cheers.gif
I've got the Mallory dual point/non-vacuum advance installed on my TR4. The car is still under construction, so can't compare it directly for you (plus it's been a long time since I used a Lucas dizzy).
However I've been around plenty of Mallorys installed on other cars and, overall, would have to say they work fine, are highly adjustable and are adaptable. There are many different curve kits available, to really dial a dual point in to a specific engine setup, for example.
Right now, if I had it to do over again, pretty sure I'd buy and install the Mallory Unilite on my TR4 instead. As it is, I'll likely be converting the dual point with Mallory's #562 EI trigger module.
Eventually the plan is to be running a Mallory CD/multi-spark ignition and high performance coil (probably VI-AL and #29440, respectively). The dual point dizzy will work with these, but ironically it's recommended that only one of the sets of points be used to trigger the ignition! With a capacitive discharge/multi-spark ignition, any points should last about 10x longer than usual (because the trigger voltage crossing them is far lower than the spark voltage they would normally carry). However, for $120 I'll just do away with the points entirely and install the module for it's high accuracy and dependability.
Keep in mind that I'm using Weber DCOE carbs, thus the non-vacuum advance dizzy is a necessity (original Lucas dizzies can be modified for this purpose, too). If you are running SUs or ZSs, or any other carb/manifold that has means of picking up vacuum, you'll most likely want the vacuum advance version of any dizzy you choose. One benefit of vacuum advance is improved gas mileage.
Mallory are very well made. But I'd call the dual point "old high performance technology" that today would be chosen if, for example, a vintage race class' restrictions require sticking with a point-type ignition, or if building a close replica of a vintage racer. The advantages of the double set of points are some redundancy and should provide a better path for stronger spark voltage, but they still have the usual limitations of points.
The dual point is cheaper to buy intitially than the Unilite. But buying the dual point and later converting it with the module works out to be more expensive. The Unilite should require little or no service over the years, too, so should "pay for itself" in that respect. Dual point service parts such as the points and rotor are a bit pricey.
By the way, Mallory, Accel and Jacobs ignition components are all from the same company: Mr. Gasket. www.mrgasket.com has lots of info on applications, etc.
Pertronix offers a module to convert Mallory dual point to EI, too. However, I am leery about mixing manufacturers, a bit more confident sticking with the same company will help with compatibility throughout the system. Plus, although I've heard many good reports about Pertronix stuff, I've also heard about a lot of failures and problems. Have to admit, though, I don't know if those issues are the fault of the parts... or the installers.
I don't know anything about Moss' "Race" distributor... wouldn't be surprised to open the box and find a Mallory!
If interested in it, $500 is *way* expensive for a Unilite. Shop around. Jeg's or Summit can get it for you, and I've seen them even cheaper at some other online stores.
/ubbthreads/images/graemlins/cheers.gif
vettedog72
Jedi Knight
Offline
Opinions are like the cliché. I think you can do as well with OEM dizzy with the pointless conversion. If you want to have some real flame in the spark you need a big distributor head so the spacing between the electrodes hit by the rotor button have more distance between them to help eliminate a spark jump. Stock with a good bushing (does not have to be great with Pertronix) and a good vacuumed advance plate should put you in good shape.
JeffS
Jedi Trainee
Offline
A good stock distributor with the right curve will perform a well as any new distributor. The difficulty of adjustment can always be overcome. Stock replacement parts are also less expensive and easier to find! Spending more money doesn't necessarily get you a better distributor. Just a newer one!
trfourtune
Jedi Knight
Offline
here's a twist for you.i got a lucas distributor for a lotus excel,brand new,online,for $120.physical dimensions work out fine.electronic pick up.has vacuum advance but will lock it out for my dual dellorto's.
if you are going to push the stock revs with a stock points distributor you may have problems.an msd or other ignition module will help with the low rev mixture problems of webers or low port velocities at low revs.points get burned up faster with a hot coil.
i hate points.there are enough things to take care of.modern electronics are GOOD.
ROB
if you are going to push the stock revs with a stock points distributor you may have problems.an msd or other ignition module will help with the low rev mixture problems of webers or low port velocities at low revs.points get burned up faster with a hot coil.
i hate points.there are enough things to take care of.modern electronics are GOOD.
ROB
vettedog72
Jedi Knight
Offline
Has any one tried to fit up a new and big dizzy head (form a modern car) on a stock shaft? Looks like that would be a good upgrade that all the TR's could use. Then you could get some real spark and considerably increase the spark plug gap for what ever its worth in performance.
JeffS
Jedi Trainee
Offline
How new and big do you want? Davis Unified Ignition modifies the Chevrolet HEI distributor to work with our cars, but sans vacuum advance. That's big! The 45D is also larger than original, as is the Mallory. The only time you need BIG is when your cap is in marginal condition, as contamination between the cap terminals is what promotes cross firing. Spark won't just jump from terminal to terminal unless it has an easy path!
vettedog72
Jedi Knight
Offline
Why are the modern caps/heads larger than the old ones?
Brosky
Great Pumpkin
Offline
They actually started to grow when GM inserted the coils into the caps in the 70's and it's gotten worse from there.
Following most common rules in electronics manufacturing, they should be about the size of a silver dollar by now, but have gotten bigger instead of smaller.
Following most common rules in electronics manufacturing, they should be about the size of a silver dollar by now, but have gotten bigger instead of smaller.
