I has a magnet to a 392 Hemi that came from a 60’s, 70’s racing engine. Problably methanol and maybe 80’s Donovan stuff (?) It look decent and marks is still on screws inside and a nice cap. I has not decided use it or use the std distributor. Was this racing magneto locked or did the use advance curve or just light springs so they was pratically locked. How to know ( less test it )
Yes, grab the drive gear and with other hand try twisting rotor clockwise. If it has an advance plate there will be a bit of movement and will spring back as you let go. If no movement it's locked. Most you will find, especially from race use, will be locked. The advance plates are available in 7 and 12 degrees (mag degrees). The springs don't really provide much of an adjustable curve. They tend to come in early. But for the street it's a bit easier starting than if running a full lock.
Rotor is stiff. I did ask since I don't know rate on spring or how the plates work, lock or not. I guess its lock. As I know it came from racing. Question. Why would it be easier start lock for street use ? My idea of the 392 I has is to has a std dual carb intake and use dual Carters, or a early Weiand with dual Carters and the magneto. But the concept is one hang in a std 392 ( Ford 32 5W coupe late 50's style, Lasalle trans, Olds 58 rearend )
If the mag is any good, be careful twisting on it with your hand close to the high tension lead. A good mag will shock the devil out of you.
Make sure you measure the length of the input shaft - from the bottom to the intake manifold rest. The length for a 331-354 is different from a 392. I've seen quite a few folks advertise mags for early Hemi's and not know or identify which Hemi they are for. In the picture, my mind's eye says you have the short one (not 392) - but that is just a guess. The reason you don't really want a locked-out mag for a street engine is that you're asking the starter to push against the spark hitting before the piston is anywhere close to TDC. This puts a pretty big load on the starter. If you have some advance plates in it (like the 12- or 14-degree ones), you multiply their value by 2 (for crank advance) and then you'll know what your initial advance needs to be set at. This means the starter only has to deal with the low initial advance - not the full advance (which will come in later).
Starting a Mag for Street or Race is same, No matter Lock or Not Mag "grounded out " switch to Off"" Toggle switch , ect. Having a Remote starter ****on or key switch Get the Engine Spinning over for 3-5 second's , Switch Ground to Open "On " To check lock or not , you're just twisting to see if there's play in the rotor ****on and gear, To test mag spin it with your finger and hold the little electro close to something metal and it should jump along dark blue Lightning ark volt. MAG 44 Real dangerous to mess with that mag You need to know what you're doing
I'd send the mag out to a known mag builder and have them go through it, recharge the magnets, etc.. If you want to spend a bit more money, have them put NEO magnets in it (rare earth) - they don't need to be recharged every few years like the standard Vertex mags.
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