My only experience with a magneto ignition is in Minneapolis industrial engines that I used for irrigation. I have always wondered how they work on the street in a SBC. I see one for sale in the HAMB parts section. It says ready to run and says it is a locked unit. What does this mean and are they reliable over the long haul on the street? Always wanting to try something different but not wanting to piss away $700. Thanks for any advice.
Locked means no ignition advance . So its more for running in a certain RPM range mostly. Generaly high RPM like a sprint car , drag boat , drag car . It will run on a street car but not ideal at low RPM if timed for high rpm. These days your not going to gain much if anything and might loose compared to a high-end high output electronic ignition at a much much less cost. A mag is nice for its simplicity. Most have no external coil . You need one wire to go to a single swith then to ground . They look cool but do not give much if anything to modern stuff . I ran them in drag boats , sprint cars . If your getting a mag for a street car your going to want one with a built in advance
A locked mag has no ignition advance. Mostly race applications. An advance plate can be installed and is useful on the street. They come in 7 degree and 12 degree (mag degrees, so 14 and 24 engine degrees). If not converted to rare earth magnets they require periodic charging. Most engine elctronics are not compatible. Need a timing box to time. But make a nice hot rod ignition if you get up to speed with them.
For something that's mostly or only street driven it's hard to beat a distributor with both mechanical and vacuum advance. https://www.jalopyjournal.com/forum/threads/hot-rod-technical-library-basic-ignition-systems.983424/
also be aware that while they can be very reliable, if they do fail on the road repair is more involved than with a more conventional ignition.
The members have covered all your questions well. I will mention one other thing, the replacement parts (cap, rotor) are not corner store available and cost more. You have to want the unique look to put up with the issues. Also a cable driven tach could be part of that 'look' and again is going to be more than a regular 1-800 part.
Even with the advance plate, that will make it easier to start, any ignition with mechanical advance will consume more fuel than a vacuum advance. Magnetos (especially the Vertex type) are my favorite in vintage race engines, I have spares for both of my race cars.
Tanks for all the information. Makes it an easy decision. I did give the Joe Hunt mag lookalike that Speedway sells a try in a blown Flathead 32 roadster. I think it was the 4th one that finally worked and kept working. Car went to Portugal 10-12 years ago and I have heard nothing since I put it on the transporter..
Am I missing something here? With a street driven car with a proper tune-up and timing curve, I've always ***umed you'd end up with improved drivability and fuel mileage. Maybe I'm misreading your post ? ? ?
The difference is a magneto has no vacuum advance to help with fuel economy when cruising along at 70 mph and 18” of vacuum for example. Many here say they do just fine without it but I say they are not optimizing their tuneup.
Well said Larry, I have one of the best engine builders as a friend, he knows compe***ion and optimum street performance and mileage. He is big on vacuum advance, for the street.
It's absolutely correct you are leaving one tool on the bench running a mag on the street due to no vac advance. If you are running 4 or 6 carbs and looking for a certain look you need to be realistic about how many areas you take some risk before you are just fooling yourself. Many times I tell myself that just because you can, doesn't mean you should. Trouble is I don't always listen to myself!
My engine builder has threatened me that if I bring him my magnetos, he’ll take a hammer to them and just beat them into s****! He’ll tolerate the tach drive cast iron Corvette distributor as long as it has some kind of electronic conversion
I thought maybe that was exactly what he meant to say. It would have just been a bit clearer if he stuck a couple more words in there, like . . . "Even with the advance plate, that will make it easier to start, any ignition with mechanical advance only will consume more fuel than not also having a vacuum advance. . ." That sounds more gooder, don't it?
Nah, don’t want to break in a new one. He understands my sense of humor, and tolerates my flights of fancy in engine concepts. Plus I’ve been going to his shop for 26-28 years now. Which reminds me that I need to see him again soon about the 327 he’s building for me.
I have owned 2 , one Vertex , one Mallory . The Mallory used an external coil . Don’t ask me how that can be . I was 23 years old at the time . I would not advise one for street use . Fun factor and looks are top shelf , operating up and down rpm , ba*****t dweller .
I have run Lock & unlock DD , Drag No issues Mallory Vertex , some with external coil. I do not think hard to start when locked. Just like starting blower or tunnel ram with out choke . I think most that experience hard starts Not having a good starter & good power supply , One is to spin engine for 3-5 sec then remove ground for start up . I think There are ways to if you really want to make like va*** , modify housing use a springs & Trust needle bearing washers diaphragm or manually while driving. Pretty much all my engines have any where from 18-30 deg of initial with a distributor I use a remote stater ****on so I can spine engine befor flipping power on to ignition to prevent kickback or trying to fire sparkplugs with so much initial especially when Engine up to Temp learn to do befor start retard's @ least I did not know of if they where around in 80. Timing @ one time was manual adjusted While driving or ridding
In 1960, a 292 c.i blower spec SBC motor with all new parts, including a Joe Hunt Vertex Magneto . Hello, I have been shocked before in many situations with my brother’s cars. I was the maintenance kid so, I was near a lot of stuff on his cars. The first was changing sparkplugs and then seeing if they ran ok. My brother would tell me to stand away and then he started the motor. Good as new and it ran like a top. Yea for the kid mechanic. But, after spending time on our first SBC motor with 6 Stromberg carburetor power and a regular distributor, we were happy that it ran quite well. I was the designated spark plug change person and final motor checker prior to any start ups. Jnaki But, the second coming of the new 292 c.i. blower spec motor ***embly and hard work for months, we finally got ready to start up the new motor with a new Isky-Gilmer Belt drive, Edlebrock manifold, the new 671 supercharger and a Joe Hunt Vertex Magneto. All of the custom wires were in place and we used the standard Rajah Clips. So, now, we cleared everything away from the new 671 supercharged ***embled motor and with the hood removed from the Willys Coupe, my brother said he was ready to fire it up for the first time. It was one of those moments we all looked forward to as teenagers. Months of hard work and daily ***embly of the zillion parts were to come to fruition. So, as my brother was sitting in the bucket seat, ready to turn the key, I was checking all of the wires and clips to make sure everything was as it should be. So, with a thumbs up, I reached in to clip in the last plug clip. All of a sudden, my arm went back like someone had tied a rope to it and then yanked as hard as they could. My arm and my body moved back as fast as I felt something. My brother turned on the ignition key and instantly, while I was touching the power from the magneto to the spark plug. The motor did not fire up, but with the turn of the key, a super power shock ran through my arm and body. That caused me to be pushed back a step or two instantly. I did not know what or how that happened. I just had this dumb looking face at the experience. The whole time, my brother was inside the cab laughing his face off. He had turned on the ignition key and sent a surge through the wires. I was the end point of the surge and flew backwards. To me, it was not funny. But, to my laughing brother, that was the topper to the weeks and months of hard work and fun ***embly of our build. Ha ha ! When I got my head straight, I moved back to the fender and now, my brother said, "Welcome to drag racing…" With the next turn of the key, the powerful 671 SBC motor fired up and the loud rumble filled up the whole backyard area. Mufflers did little to quiet the sound. But, in all of the happiness for the two brothers with smiles on their faces, our little neighbor had wandered back to see what the big boys were doing on the car. She had come over many times as we were putting parts together and fixing the Willys Coupe. But, never started the loud motor. So, with the sound blasting away, she ran back to the kitchen yelling for our mom to help!!! It was too much for her. Boy, our mom was not happy and it was too late as we were backing up out of the driveway out to the street. A fast get away was necessary… YRMV
Even though tuning and tweeking is ½ the juice of this life, how much are you willing to do these days? I'd prefer simple. 1 factor I don't want to dink with is ignition. Do what works, whats easy.
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