Does anybody know what size spark plug wire is supposed to be used on a brown Vertex magneto cap. Is it a 7mm or a 8mm wire? Thanks Sent from my SM-G930V using The H.A.M.B. mobile app
Hi guys. In my quest to give a mid to late 50's look to my 32 roadster SBC 350, i bought a Joe Hunt magneto and i'm looking for some infos or links to do things the best possible way. First what is the best way to connect the spark plug wires to the mag cap ? If you have some tips and tricks about the most efficient timing setting procedure, i'll be all ear...and if you can tell me the main things to avoid, that would be really helpfull. Looking forward to read from you. Be safe. Regards. Rod.
Rod, 1. If it has not been used in a while the magnets may have to be recharged. A lot of guys now upgrade to rare earth magnets. You get an amperage boost and they do not need recharge. 2. You will need a buzz box to time it. 3. Spark gap is 0.018" to 0.022". 4. Most mags do not have advance. You can have installed a 7 or 12 degree advance plate (mag degrees) to get 14 or 24 engine degrees of advance. 5. Plug wires are held in the cap by screws on the underside of the cap. 6. The plug wire numbers on the cap are the mag firing order, not engine firing order. 7. You need a very good kill switch. Do not cheap out on it. 8. The mag is not compatible with just about all engine electronics and your radio. 9. To get the most performance do not run suppression plug wires. 10. If you are not familiar with a mag, send it out to someone to have it serviced. I use Spud Miller in Oregon.
Thanks for your information though i should have given a few more details about the intended setting. I just bought the mag new from Joe Taylor and had it shipped to France so i don't need to have it overalled hopefully. I'm gonna get a buzz box to time it and after doing some good research, i start to understand how it works but thanks to your help i think i'll be able to avoid as many issues as possible. The engine is stock for now but i'll be installing a Comp Cam "gentle" camshaft and replace my 2x2 Rochester by a 3x2 from Vintage Speed. I have no radio nor any other electronic devices in the car. I bought a spark plug wire kit from Speedway motors : MSD Ignition Street Fire Spark Plug Wires Distributor Boots: 90° HEI (Male Post) & Socket (female). I read that spiral core wires would absorb quite a bit of energy from the mag .. but i bought the kit before the mag ... should i change it though i don't intend to race the roadster. I bought Accel spark plugs resistance free. I understand that i should just insert the wire but read somewhere that it woulb safer to pinpoint or cut a little v in the wire to facilitate the tightenning and don't mess the internal thread of the mag cap..... As i redo all the car, i'll post some pictures of the work in progress... it might interest someone !!! Be safe and do feel free to give me advice regarding the mag timing process, i've read quite a few things but good reliable infos are priceless. Thanks again for your concern. Rod.
Good morning members. It's been quite a while since i updated my rebuilding of the 32. I'm in the process of reassembling the body to the chassis but i want to precisely tune my ignition timing with my Hunt magneto. I did make the engine start pretty well, it revs good and all but the issue i have is that my timing mark is way out of the timing tags when checking it on number 1 cylinder with the strobo. The 0° mark of the damper is nearly at 12 o'clock !!!! So i can't have a precise indication for the dialing....Would anyone have pictures of the mag properly installed on a SBC 350 so i can check if the initial position of the mag body is right ? This what i have come to for the moment but regarding the position of the damper timing mark, something is not done properly. Thanks for your help. Regards. Rod.
It is perfectly acceptable for most magneto cars to use a timing light and flash on the timing mark on the flywheel, just like you would on a car with a distributor. Some non-powered timing lights may not work, as they are made to operate on DC current (the magneto generates AC current). Using a timing light with a magneto will typically show up one degree late for every 1000rpm of engine speed. You can overcome this by using a buzz-box instead of a timing light. Cheers, Harv
Hi Harv, thanks very much for the answer. I used the buzz box to get the closed position on number 1 cylinder at TDC but doing so, it was very difficult to start the engine and it even back fired and flames came out of the air scoops !!! So i had to advance the ignition quite a lot and now it starts allrigth, the iddle is good but the timing mark shows maybe 30 or 40 degres of advance..... So i'm thinking that maybe i'm not too bad on timing but not on cylinder 1 anymore ... that's the reason why i'd like to get pictures of a properly set Hunt or Vertex mag and see the relative position of the cap regarding the engine.
@rodolphe you may get more responses if you start a thread and proper title to get the attention of more folks.
An SBC is going to want (roughly) 30-40 degrees of total advance. Methinks you are in the right place (advance or retard a little to where it runs best and call it done). Would not worry about maggie body orientation. Cheers, Harv
A buzzbox is used to show when the point's OPEN and the mag fires. Have you verified TDC to be sure your marks are correct? How much advance is built into the mag? 30-40 degrees total advance is in the ballpark, like Harv says, but if you have 30-40 degrees of initial advance plus whatever mechanical advance is built in, you're probably gonna have problems. A picture of your rotor position at TDC would help us help you.
Are you sure that your mag has an advance plate? Many don't. They come in 7 and 12 degrees (mag degrees). You would want a 12 degree plate. You said the mag was gone through before shipping to you, did you get any paperwork? Or perhaps you can get some info from the previous owner?
I bought the mag brand new at Joe Hunt and it has 24 degres of mechanical advance. I'll post a picture of the rotor position at TDC. I tried to point it toward cylinder 1, then check with the buzz box the opening point. In fact, what is said on the owner "manual" for the setting is to substract 24 to the total advance wich i believe is around 32 degres and once the buzz box rings, to advance the timing by 8 degres to get the initial timing set. I'll post pictures of the rotor this evening......i'm in France. Cheers and thanks for your interest in my issue.
Here's a picture of the position of the rotor, having the cylinder 1 at TDC. Let me know what you think about it and if you have pictures thatt could help, that would be much appreciated. Have a good evening.
Look's like it's in the right spot to me. You should be good to go. I'd post a pic of mine but it's exactly 180 degrees from where your's is because I have the wire's coming out towards the back of the engine to clear my intake. Also, if those are suppression core plug wire's get rid of them and use solid core wires and NON resistor spark plugs.
Hi guys, thanks for your answers, looking forward to seing the pictures of your set up 427 Sleeper, i plan on changing the plug wires too and yes Harv, no radio in the rod, the chebby is the best music you want to ear indeed. I'll recheck everything and post the result. Have a good day.
You most likely have done all of this, but this is what works for me: 1. I have a fully degreed dampner and I have verified the timing pointer against TDC. 2. I set the timing pointer to 8 degrees BTDC for #1 cylinder on compression stroke. 3. With the mag out of the engine and cap off I mark the mag body to show the rotor position of the cap tower that I use as #1 cylinder. You can use any tower you want. When I put the number stickers on the mag cap I do it in numerical order so it showes me the mag firing sequence, not the engine cylinder number. I mark the plug wires with the cylinder number. 4. I use a temporary wire to ground the mag while setting the mag into the engine with cap off. I verify the rotor position relative to the mag body and install the cap. Then hook up the buzz box to confirm spark event and clap down mag and install mag ground. 5. At this point mag is installed with initial static at 8 degrees BTDC. I have a 12 degree plate in the mag. Engine should fire up and idle fine from a timing perspective. Should you feel the need you can check everything with a timing light, but I do that very seldom.
Thanks for the procedure Jim. I'll recheck what i have done very soon and post the result. Hopefully with all those infos, i should be able to get something good. Have a good evening. Regards. Rod.
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