Switches and fuses

I tore the (original 1958 harness) wiring out of my Elva Courier and intend to run all new wires and switches. Moroso makes a fused switch panel that would meet my needs--#74131 (at the Summit site go to:

https://store.summitracing.com/partdetail...mp;autoview=sku

I've heard that some folks don't think it smart to use fused circuits on race cars as just providing something else to take you off the track during an event.

Any opinions will be appreciated.

Best--Michael Oritt

Fuse it. In the event of a crash and fuel leak you don't want pinched wires to start a fire. I have an ATC style fuse block with separate switches. Sized properly they shouldn't cause a problem.

No fuses here.

I run no fuses, but if you feel the need for some sort of protection, aircraft spec circuit breakers. At least if they trip you can try to reset on the track. Mount them at finger tip length so you do not accidentally trip them.

fused switch panels are great but a breaker box would be better. I agree that it's important to fuse a link for several safety reasons and the breakers will allow you to reset as was advised in the earlier reply. As important would be the choice of amp amount through each. Go as strong as you can and remember all forms of fusing will need periodic replacement. I make it a point to replace fuses every third weekend even if they are working fine. I refuse to let a $.25 item spoil a session. Breakers or the modern plastic two leg fuses are just as subject to vibration so whatever you use replace them regularly. Make it a part of your routine maintenence.

I do strongly recommend a battery switch within arms reach that interrupts the EARTH wire NOT the power one.

In the event of an accident, If your car splits the ground wire, it will not create a high current short.
(very unlikely in a glass fibre car anyway)

You, I assume have a dynamo & not an alternator, so merely breaking the battery circuit will shut the car off.

I like to run 2 switches & a start button.
One for fuel & one for coil and accusump (if used)

If however, your car is road legal......There are other considerations.

Race cars should be simple /ubbthreads/images/graemlins/grin.gif

"I do strongly recommend a battery switch within arms reach that interrupts the EARTH wire NOT the power one. In the event of an accident, If your car splits the ground wire, it will not create a high current short."
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Dave--

I was under the impression that master disconnect switches were supposed to be in the + lead and were supposed to shut off the battery's supply to all circuits as opposed to simply disconnecting ground which could theoretically be "re-established" in a wreck. Can you elaborate on the possible scenario that you describe?

BTW I am running a Denso 50 amp alternator and the car is not for street use. The only switched circuits I envision are for ignition, fuel pump(s), lighting, and possibly an auxiliary fan. I plan to hook the Accusump into the ignition switch.

Best--Michael

Theoretically you can weld stuff together with a battery and a coat hanger.
Never tried it.......But.

The idea behind cutting the earth is that if it does ground out in a wreck....
It will only close the circuit which can be shut off anyway using the switches.
The power cable on the other hand will make MANY-MANY BIG sparks and lots of Lucas style smoke perhaps igniting something in the process.

Of course, If you crash so hard that you have to take a little nap......
It might be a good thing to have an inertia relay for the fuel pump(I don't have one)

Also....You need a single pole double throw master switch for the alternator.(4 Terminal)
The other 2 terminals are for the coil or FIELD (NOT stator) wire.
(I use it to switch the coil)

""""""""BTW I am running a Denso 50 amp alternator and the car is not for street use. The only switched circuits I envision are for ignition, fuel pump(s), lighting, and possibly an auxiliary fan. I plan to hook the Accusump into the ignition switch""""""

M.O.

I would leave out the igntion and use PUSH BUTTON circuit breakers for f. pump, lighting and fan. If you run an oil pressure and coolant pressure light then use one for that circuit too. Use the ring and screw type terminals and not the spade terminal breakers. Availaible at Waytec or Del City or others. Fusing the ign might shut off the motor NOW! if a problem.

Doesnt matter if the main master switch does the + or the -. Use a Cole-Hersee snap action switch # 2484 or 284-16 or 75903 for DPST (four pole for alt/gen). Do not use the plastic master switches.

"""""""I plan to hook the Accusump into the ignition switch.""""

I would recommend NOT using the electric solenoid as they are problematic and some have flow issues.Use a manual ball valve and if you can't reach it use a decent cable or linkage.


"""""""Moroso makes a fused switch panel """"""

There are many other ready made panels...Longacre etc....BUT you might start from scratch and do it "your way"....get the Cole Hersee and Del City catalogs for a start....dash mount the breakers ...use mil-spec toggle switches with screw terminals and no spade lugs, that goes for indicator lamps, senders etc.

Use marine grade wire or 221*F rated and not the cheapo stuf. Keep a wiring diagram, make it simple and dont "overguage" in wire size.

Hope this gives you some ideas.

Jerry--

Thanks for the information. Re your feelings on not using the solenoid valve for the Accusump--my understanding is that the reason for using an electric valve is that (beyond the usual prelube feature on start-up) it gives you a reserve of oil under pressure in the cylinder which will be supplied to the engine if the pressure drops below the value of the valve when running--the valve will open when pressure is below the value and will shut when the system has been recharged. I ordered the 35-40 psi valve as my idle is about 2K and OP never drops below 40.

I would appreciate any comment on this thinking.

Best--Michael Oritt

Haven't had enough time w/ mine to comment.
For now I'm trying the new regulator + solenoid valve. (35 lb)

Like JerryB, I made my own switch panel but I used LongAcre switches & regular Napa wire.
(I like the marine stuff but didn't know about it at the time)

Just to play devil's advocate, I used one of these fused panels in my FP car and installed a fuse panels in a few other cars, never had a problem. I know plenty of guys that do it both ways.

Even on seemingly obvious matters consensus is sometimes illusive. I have decided to go with either fuses or resettable circuit breakers--I just can't see the upside of having unprotected wiring.

Thanks to all for your input.

""""I just can't see the upside of having unprotected wiring.""""

I agree...the only circuit I suggesed not to fuse is the 12v. B+ to the coil. As for panel mounted breakers the Waytek numbers are 46481 thru 85 (10 to 40a) but they are spade lugged. I forget the supplier for screw (ring terminal)connection. They cary AN/MS part numbers and are readily availiable tho.

Re ..Accusump Systems.

An electric valve has restriction. Canton has a new ..what they call EPC valves but the disadvantages and complexities outwegh the advantages (in my mind) and I havent seen any figures of high volume to even begin considering its use.

A decided advantage of an electric solenoid is, when wired with the 'on' switch is that you can't forget to open or close the manual valve, as it's all automatic, orrr...if the driver is far away from plumbing as in a boat.

A manual valve is trouble free, can be used for priming/pre starting and is much simpler.

You can read up on these differences in the Canton catalog or website to make a decision. Even with a manual valve there might be a flow problem to the motor as the oil volume needs to be right now if the oil pressure drops or aireates.

Dry sump systms are the way to go of course but pose packaging problems in some small cars....to say nothing of the lack of currency.