Mark,

Would you recommend this setup for the Hi Torque mini-starters?

I actually did this on my Hi-torque about a year ago. The end of hot start problems and so easy even an old coot like me pulled it off.

I don't want an argument as to which is better but this is my logic:

1/ I've been doing this forever, not about to change. Before me guy's like Gene Berg have been doing it since the 60's, so this has been a mod done for over 50 years.

2/ The Ford solenoid is waterproof, at least damn water resistant, the SPST relay is not at all. So you must mount the bosch horn relay in the engine bay, run wires through the grommet, tap into a power source, use a fuse, drill a mounting hole and cut the factory wire or at least make an extension/adaptor.

3/ the SPST relay may be 30-50amp which should be enough on paper, but it still has very small contacts. The Ford solenoid must be rated for at least 500 cranking amps, likely much more.

4/ I've personally only had one failure, one that was so badly corroded after 8 winters that the bracket/bottom rusted right off at the rivets and the solenoid literally spilled it's guts in my hand when I took it off.
I've replaced several perfectly good looking SPST relays with a ford unit.

Technically I guess you can say I've had two failures, as a rookie I bent the mount by reefing on the plastic housing and broke one. That's why I instruct you to only bend the mount using two pliers, experience.

5/ The solenoid is fastened to the transmission starter bolt, not the body, so there's almost no vibration strain on the wires.

6/Unless you run across a concours weenie who likes to crawl under cars, just to be an ass pointing out everything that is not factory on a person's 914, you're the only person that will ever know.

7/ When I turn the key the first thing I like to hear is a spinning starter.

8/ I'll think of more reasons, hold my beer.

9/ KISS, this is such a simple fix.

If any of you guys who can't stand the thought of a Ford part on a Porsche, but have a Rennshifter, well you better toss that puppy in the trash.
Jwest now makes all his parts, but the early versions were a modified Ford Mustang shifter. The basic design has not changed.
So send that puppy to me and I'll dispose of it properly, I hate them so much I'll even pay you the shipping.

I bet the Cap'n would approve, but Slits would still bitch about something...

I miss them a lot, but your posts go a long way towards filling the gap they left.

Nice job

Cheers- Harry

Actually you've got that bass ackwards, Slits was a proponent and offered the Ford relays to us for $6; or less if he liked you. IIRC, Cap't Crusty was in the camp of those who oppose it. One thing is for sure; the opposing Camp's numbers have dwindled in the past couple of years.

Just food for thought, or should I say math

Vdrop = IR
12v at 8 amps on a 12 foot run with 22awg wire will see a voltage drop of 25.83%.
That 12v is down to 8.9v, border line for kicking the Bosch solenoid.
That's not counting the resistance of the connectors, fuse box, switch, age, heat, etc.

I don't know the actual length of the run or if that's the correct size wire, etc., etc.....but its a good enough example to show that a DC circuit has substantial losses even when new.

This is real simple to make and crimpers should be a tool in every car guys tool kit, but if if you really think there's a demand for this I could offer a complete plug and play wiring kit for something like $30 shipped USA and Canada.

If I were to offer a kit I'd look into using better strain relief connectors.
You would still have to buy a solenoid and do the mount mod.

So I've run across a (self created) problem and I wonder if Mark might chime in for a solution?

Previously I had wired in a Ford relay on my sbc converted 914 with a standard alternator per Mark's diagram (an-noted below) as I had been experiencing the well known "hot start" problem.
The fix worked great!
Then I decided to add a track "kill switch" mounted where track workers can get to it in an emergency and therein lies my problem.
When I wire it up per the manufacturer's directions (my diagram below), it works great with one exception...my hot start problem has returned.
Anyone got any idea's?

Marks diagram (an-noted) with no kill switch. Hot start problem solved.
Click to view attachment

My diagram including addition of a kill switch. Hot start problem returns
Click to view attachment

Right away I can see the battery wired wrong, battery + goes to the starter big post, in your configuration the alternator + wire also goes to the starter big post.

Kill switch shouldn't be wired into the starter, unless it's a battery disconnect, then it should be wired inline on the big battery cable. This needs to have no other wires between the battery + post and the disconnect in. All factory + wires should be after the disconnect out.

Only exception to above is some will run a seperate wire before the disconnect (direct to + post) for the radio clock.

You either still have something wired wrong or you damaged something from incorrect wiring. It doesn't matter if the alternator + wire goes to the big starter post or switched side on the disconnect. With the disconnect you don't want it to go direct to the battery as it defeats the purpose of the kill switch.

The disconnect, are you using one of the cheap plastic body china switches?
I only use the heavy duty metal body Moroso disconnect.

This is real simple to make and crimpers should be a tool in every car guys tool kit, but if if you really think there's a demand for this I could offer a complete plug and play wiring kit for something like $30 shipped USA and Canada.

If I were to offer a kit I'd look into using better strain relief connectors.
You would still have to buy a solenoid and do the mount mod.

Thanks for the reply-
Unfortunately, when I ran it with the Alt wire to the to the starter solenoid the kill switch failed to work and would not cut off the running car as it should. The only way I was able to make it work was to connect the Alt. wire to the switched side of the kill switch but then the hot start problem reappeared (either that or a new problem).

Not sure how the internals of the kill switch work but the battery should never be removed from the alternator when the engine is running. Modern cars use high power zener diodes as rectifiers in the alternator to snub the inductive kick if the battery is removed from the alternator when running. Almost any electronics in the vehicle could be damaged by the inductive kick.

Automotive test specification ISO 7637-2 pulse 5 is a killer pulse. This pulse is 100V for about 1/2 a second and simulates disconnecting the battery from the alternator.

If you're looking to protect the car from being stolen, you might want to try putting a switch in series with the spark unit, ECU, or the fuel pump. On my 930, I have a tiny toggle switch in series with the fuel pump relay. You can push the car or crank it all day and it won't start.

Mark Henry, I'll come up to Canada and pay you to do it..................hehehe JUST kidding, looooong drive. Thanks to ALL who gave such valuable information.

Nice car!
6" steel wheels?

Nice car!
6" steel wheels?

This thread should be in the Classic Forum.

Not to beat a dead horse but I found this solenoid. It's 12 volt and comes with a slide terminal to match the wire coming from the ignition switch.

https://www.oreillyauto.com/detail/b/standa...enoid&pos=6Click to view attachment Click to view attachmentClick to view attachment Click to view attachment

You don't need the Ford or this rarther heavy duty solenoid, I used a such smaller one sourced from Amazon, works just fine as you're only carrying small amperage.

I got introduced to the hot start problem in 1982. In 92, ish, I got the hot start band aid sold at aa. And it worked. But I was concerned it would fail. But this is that on steroids. Had lots of old fords, never had to replace the relay. I started modifying my car in the 80's, so this would be a permanent fix to a poor design on a car driven in a warm/hot climate. I'm to old to be push starting a car by myself. And it had a habit of not starting when I was alone...On a hill...Parallel parked between two cars, parked too close. Thanks.

Another option is Bosch WR1 starter Kit. $27-$36 depending on where you shop

I just use a IMI gear drive starter. No hot start problem since I put it on.

IMI High Torque Gear Drive Starter

No, it is not cheap. But I have been running the same IMI starter, without replacement , on my red 914 for years now. I originally put it on the 2.0L 4 cylinder to cure the hot start issue. I moved it to the 2.4L 911ST engine when I did the six conversion, and that same starter still spins the 4.0L monster motor with no issues.

I figure that starter will outlast the car. :cranky: