M20 Dreaming

Hi people, I have had the word from MSNZ that my roll bar is good and my C.O.D and Log book will be issued in the next week or so which is a big hurdle crossed. I have been having an issue with no spark from the Mag. I spoke to a mate who runs midgets and sprint cars and also is the owner of a American speed shop here in New Plymouth. I tried a different coil I borrowed from him and no joy. so I took the generator off the base and spun it with a drill and we get spark!!! He said they had the same issue in the past and its because the starter can't turn the engine over fast enough. Not a problem for sprint cars because they push start them. I'm thinking of 24 volts up the starter to get it to spin quicker, any ideas anyone ???

Cheers Leon
 

Terry Oxandale

Skinny Man
I don't know Leon. I'm struggling with going parallel instead of series on the battery, but don't know the specs on your battery. With DC, you're not going to have any inductive current limiting, so not sure what the windings of the starter motor are going to see at 24 VDC (could get hot fast).

I was having the same symptoms, but different problem (voltage sag on cranking kept the LS2 sensors from reading any RPM during cranking). Anyway, I changed out the battery from an Optima, to a better, more expensive batter. Yeah, it's a beast in front of the passenger's feet, but since changing the battery to a larger one, I've never been left stranded after a stalled engine. Assuming with your usual quality work, you've got plenty of capacity in your ground and supply to the starter and ignition. Would a smaller generator pulley be helpful (faster spin at crank speed)?
 
I hear what your saying Jac Mac as the original cars used a small ring gear and I'm guessing this is part of the reason as well as less mass to swing. I'll try the 24 volts first we used to do this to make 12 volt winches perform on our comp trucks, I know that they are a different motor in some ways and are made for long duration winding but short bursts should be OK. I guess I'll find out. changing the ring gear is a big job now. cheers Leon
 

Ian Anderson

Lifetime Supporter
Supporter
Unless by some crazy coincidence an old 6v starter from a VW would mesh with the ringear.

I know I ran a 6v starter on 12v on my very high compression formula V and that was the only way I got it to start from the battery.

ian
 
I hear what your saying Jac Mac as the original cars used a small ring gear and I'm guessing this is part of the reason as well as less mass to swing. I'll try the 24 volts first we used to do this to make 12 volt winches perform on our comp trucks, I know that they are a different motor in some ways and are made for long duration winding but short bursts should be OK. I guess I'll find out. changing the ring gear is a big job now. cheers Leon
Hey Leon, Not sure it's the solution to your problem, but with my set up, I was let down with the supply of the battery I was going to use and have limited space to place a large Battery.
So, what I've done is installed a Fullriver HC40 AGM battery in the car, but taken the "00" leads to the rear and installed a 350 amp Anderson plug. I have just ordered another HC40 battery and will make up a trolley with this on it, as well as a charger. When plugged in it will be charging both batteries.
Now I will have 2 x 500 CA batteries giving me 1000 CA at start up, the battery in the car will be at 100% charge when I head out, so, if I do stall it or go backwards off the track and need a re-start it will deliver. Plus a spare identical battery sitting in the trolley to pilfer if the one in the car fails.
Hope this helps.
Regards, Udo.
 
Well we had a day of trying to start the car and we were able to make a noise if only for a second at a time. The 24 volts was the trick to getting the starter to spin the engine fast enough to get a spark. The issue now is the fuel system, I have to add a surge tank as the pump doesn't like to pull and the tanks are lower than the pump and getting it to prime the system doesn't work. A surge tank will sort this issue. Thanks for your guys input, its always welcome and it good to bounce ideas of each other. Udo you are right about having good batteries it made a big difference when we got it right.

Cheers Leon
 
Well a mile stone reached today, I have a Log Book and Homologation Number so the car is now officially recognized by MSNZ just waiting for the C.O.D but at leased it can now compete in an event. Just need for it to actually go now, that's going to happen this weekend. I picked up a surge tank today so will get it plumbed up and give it another shot at running. Fingers crossed.

Cheers Leon.
 

Terry Oxandale

Skinny Man
So...a question I have is about the surge tank. For this to eliminate your problem, you would still need to get fuel to the surge tank, which would mean a pusher pump at the main tank (regardless), to fill the surge tank? So either way, I'm thinking a relocation of pump is needed as well? Is the surge just an added benefit of uninterrupted fuel flow?
 
Hi Terry, The reason for the surge tank is to give the main pump a head to pull from so a lift pump will keep the surge tank full and all the by pass lines will go back to the surge as well. The High speed by pass and the secondary by pass are on the top of the tank the primary by pass still goes back to the left main tank, the surge also has an over flow going back the right side main tank. the lift pump is in behind the seat. it will have to draw direct from the battery as the car has no charging system.
 

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A little more clarity, the original cars have a belt drive fuel pump which is located down low on the motor so the head from the main tanks keeps the pump fill. my pump is cam driven and is at the same level as the top of the main tanks, hence the need for the surge tank.
 
Another hurdle over come today. Finally got the engine to run in the car. It has taken some changes to the fuel system and the ignition system, we have given up on the Mag and put in a MSD. The Mag was just too hard to get started and was going to start wrecking stuff so as much as I resisted changing in the end I bit the bullet and It wound over a couple of time's and burst into life and everything was good, oil pressure, fuel pressure, throttle response is instant though I only gave it a few very small blip's it's obvious it's going to be a beast. Next step is some testing on the track.
 
Yeah Rod, that is what I did, stripped the generator out and just have the points as a trigger very simple and still looks the part.
I have a video but having trouble loading it. I have done it before but can't for the life of me remember how I did it, I know I put it on YouTube then attached the link so I'll try to get it on here. I have now had it running again and bought it up to temp and had a good check for fluid leaks. Just has a small oil leak but pretty sure its the valve cover needs more tightening
 
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