TX63CONV

Wiring up my new test stand. See diagram below for accuracy.

Am I missing anything?

What gauge wire for the solenoid, coil, etc.? I got the gauge numbers in the pic from the AIM.

Is there a ground off the ignition switch? There is a center post on my switch that is not labeled.

rongold

You need to put a resistor in the 18 gauge pink wire from the ignition switch to the + side of the coil. An OEM style ballast resistor will do, or a coil with a built in resistor---either one will work.

K2

You might consider losing the ignition switch and simply wiring in a starter button and a kill switch to the coil. Simpler and you can crank the motor over with the button with the kill switch cutting current to the coil. This is convenient if you need to bump the motor over for adjustments or build oil pressure prior to starting.

TX63CONV

I'm running a flame thrower coil which I believe already has the resistor?

jim lockwood

You definitely need either a ballast resistor or a coil that functions without one. Mount the resistor on a stand off, so it gets plenty of cooling air around it:




It may pay you to also go beyond the "get'er done" approach of just doing the minimum needed to make the engine run. What if something goes horribly wrong while your engine under test is running?

You'd want a kill switch for all the electric circuits. This needs to be right at the battery. If you have an alternator on the engine, the switch needs to be a two-pole, single throw type so you can interrupt not only the battery lead but also the alternator output:



You should also consider adding a master circuit breaker (silver rectangle, left) and individual fuses for the various support circuits, like gauges, ignition, starter solenoid:



And, in my opinion, most importantly, always add a fuel cut off valve:



Go the extra distance to include these things and, if something goes really wrong, you've got a chance to do a safe shut down.



Jim

5thvet

Wow, nice setup Jim....Looks like you've done this before!

jim lockwood

Thanks for the kind words. Yep, those detail shots are of the engine test stand I made for my own use.

Can't help thinking about "worst case" scenarios and trying to plan for them. I'm an engineer.... or was, back when I was a productive member of society.

Jim

JohnZ

Not as classy as Jim's, but one of my older pre-run setups (on my Grand Sport chassis) is shown below - partial cluster and key components mounted on a 2x4 "dash" zip-tied on the frame.

First photo shows the engine side - the ballast resistor is on the left, then the Mallory coil, then two junction blocks - one +12V, and one for ground. Second photo shows the driver's view. I used a one-piece harness for the whole car - that's why you see all the un-used circuits coiled up. Neighbors weren't real excited about the open 4" sidepipes.

bowens24

Hello,
Could someone help me understand what I might be doing wrong with the below wiring? I get the car to start but it imediately dies. I think somehow I lose spark. Can someone lead me in the right direction?



Thanks in advance for your help.
Bruce

Steve439

Very nice Jim, how about a photo of the whole stand?

JohnZ

Is the device on the side of the coil a "resistor", or a capacitor?

bowens24

John,
You are right it is a capacitor not a resistor. Do you have any idea of what I might be doing wrong?

Thanks for the reply
Bruce

Steve439

Seems like that's what would happen if the coil wasn't correctly getting power from the on/off switch.

JohnZ

What are you using for an "on-off" switch? Sounds like you're getting power to the coil (+) from the "R" terminal on the starter when it cranks (and starts), but not getting power to the coil (+) after it starts.

Jim_C

Bowens24
Why do you show 3 connections to the On/Off switch? There should be only 2. One to the battery and the other to the coil and start button.
CUL Jim

bowens24

Jim/Steve/John,
that was my problem. Thank for the help. The switch has two ON's and if it is switched to one side only one side has power. I was using all three terminals, now I am using only 2 terminals. She starts and runs now.

Bruce

mickatbp

How will the wiring diagram (from Bowens24 be changed if the generator is included in the cct (used to keep tension on the fan belt to run the water pump?

JohnZ

Makes no difference - there's nothing in that circuit to charge the battery anyway (no alternator or voltage regulator) - it runs on the battery alone. Use the generator as an idler to maintain belt tension, and don't connect anything to it.

out2kayak

You should also consider a spot on the stand for a fire extinguisher along with fuel / electrical cut-off capabilities.



-- Joe

Mr D.

Here is a engine start box I built that is now mounted to a Start Stand I'm building.