homemade one-time Engine test stand

[defiance]

So I'm about to the point where I can start my engine.  I'm wanting to tune it on the dyno, but dyno time is expensive, and with things like homebrew fuel injection, getting it up and running "basically right" could take quite some time.  So, before taking it to the dyno shop, I want to get it running and get all the bugs I can worked out.

I'm planning to put together a rudimentary one-time engine test stand, but having never done such a thing, I just want to run this by you guys and make sure I'm not missing anything.

So I plan to start with an old pallett I have lying around - Dunno where I got it, but the runners on it are HUGE - larger than the 4x4 I have sitting around, but probably not quite 6x6 either.  Anyway, it's a hefty pallett.  I found some 400# casters for pretty reasonable, so I plan to put those on it ... Mobility isn't really necessary, but it can't hurt for as cheap as these things were - .  I've already modified an old 3gallon gas tank I had to have two 3/8" fittings (supply/return).  I'll use a pair of 4x4's 12" long on each side to build up to the motor mounts.  Since everything is all in the garage right now anyway, I'm just going to use the car's radiator (it's alum with dual electric fans) and transmission (I'm running a small seperate cooler for it anyway, so hooking it up adds maybe 10 minutes).  I bought a set of cheap gauges from auto zone ($25 tach and $20 cluster with mech oil/temp/volt gauges), then found a 20A switch for power and a button for the starter.

So is there any reason this won't work?  It only has to survive one use, then it'll get thrown out anyway.

[rt green]

gonna hook it up to a trans?  exhaust? coolant tank? just going off of what i've seen pictues of. itwould be coo for you to run down to the nearest vo-tech to see what they use for running stands.

[aifilaw]

I've done this before, so I can tell you you are missing a few things.

You need to place a load on the engine, I put a tranny on it, ran a driveshaft into where a sheave hooked via belt to a large fan after rmeoving the old electric motor from it.
Anything that can survive about 3000 RPM should be fine for your testing and not fly apart, but without any load you are missing an important aspect to your tuning.

I used a water hose to keep it cool, but you would be better off buying a fountain pump from lowe's or home depot and cyling it through a 55 gallong tank to keep your engine temp up if you want to do any serious tuning, and obviously 60-degree water on an engine that is up to temp is going to cause warping and issues for any sustained operating period.

[defiance]

I've got the actual radiator from the car, which runs with electric fans, so it should keep the temps in the right operating range.  I also have the trans from the car in the plan.

I'll look into something I can use to generate a load, but even if I don't do any tuning under load, it still accomplishes what I'm looking to do.  What I'm worried about are things like spark plug wire order, sensors reading through to the ECU properly, no "noise" in the ECU distributor VR sensor wiring, engine starts, idles properly, timing set, runs at a good temp, a/f ratios good at idle...

With all the wiring for the whole harness done by myself, and with a huge portion of it re-done after pulling the engine - which was almost 2 years ago now - and considering it's homemade efi - there's LOTS of room for those sorts of errors.  So I have this recurring nightmare of showing up at the dyno shop and spending easily 4 or more hours just getting it *running* properly, before even starting any tuning...

I'm cool paying dyno time for an hour or two of actual tuning, I just don't want to pay for troubleshooting, given how long that might take!

[aifilaw]

there will be a vast difference in your fuel trims and especially timing with and without a load on the engine, but if you just need to make sure it works, then no need for a load.