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FE Power Forums => FE Technical Forum => Topic started by: 6667fan on August 01, 2018, 06:38:22 AM

Title: Clutch safety switch or interlock switch
Post by: 6667fan on August 01, 2018, 06:38:22 AM
Local track tech wants a safety switch incorporated into my 67 Fairlane. Anyone here who has done that and could share which components they used? What year did the Motor Company stair installing those? Thanks, JB.
Title: Re: Clutch safety switch or interlock switch
Post by: BattlestarGalactic on August 01, 2018, 07:43:10 AM
Not mandated by any sanctioned bodies, so I call BS.  I've been up and down the East coast and NEVER been asked that question.

It was likely mid 80's when the clutch switch came around?

There are clutch switches used for 2 steps and the like, so something along that line would work for brake lights too.  Any kind of momentary push button mounted low enough for the pedal to push on it.
Title: Re: Clutch safety switch or interlock switch
Post by: e philpott on August 01, 2018, 08:10:18 AM
The local Track tech is a idiot , just because they work at the Track makes them think they know the rule book by memory
Title: Re: Clutch safety switch or interlock switch
Post by: 6667fan on August 01, 2018, 08:53:33 PM
Problem is, rule or not the guy says I have to have it next time I’m there. I don’t want to challenge him on it and have him get pissed and find something else to focus on. So I figured I would try to work a switch in there. Wiring is already there from a kill switch, ( cranking). Was hoping someone had been through this with a 66/67 intermediate. I had been looking at switches that would mount up top so as soon as pedal started depressing circuit would be complete. Are there ones that are designed to work at the bottom of clutch pedal travel? That might be easier. Thanks, JB
Title: Re: Clutch safety switch or interlock switch
Post by: Rory428 on August 01, 2018, 11:58:01 PM
I would ask "Mr. Tech Guy", where in the rule book is says that you have to retrofit a clutch interuption switch in a car that was never equipped with one from the factory. I have raced my stick cars all over the West coast, in brackets, Stock Eliminator, at NHRA National Events and Divisional points meets, and never ONCE had a Tech guy tell me I needed such a device. I have had the occasional Tech guy ask about a nuetral safety switch, but as soon as I told them it was a clutch car, or they noticed that when they looked inside, they always said, never mind. Even my 85 Mustang Stocker, which would have come with a clutch switch from the factory, if it had been a factory 5.0L 5 speed car (it started life as a 2.3 4 cyl automatic car), never had a switch when I raced it, and never had any issues with Tech, even 1200 miles from home. Sounds like your Tech guy may be on a bit of a "power trip", a call to either the Disional Tech Office, or your tracks head Tech guy should get him straightened out in short order.
Title: Re: Clutch safety switch or interlock switch
Post by: John67427 on August 02, 2018, 03:18:20 PM
How old is this tech guy? Where and how is that to be done? Even some vehicles from the ‘80’s didn’t have clutch switch. I know you don’t want to make waves but if NHRA doesn’t require it “and they have some goofy rules” I’m with Rory on show me where that rule is in any rule book!
  You could use a micro switch that the pedal hits thru your set up.
Title: Re: Clutch safety switch or interlock switch
Post by: Pentroof on August 02, 2018, 04:05:57 PM
Jim, is this Lebanon Valley you're talking about?

Doesn't make sense. I wonder if they had an incident where someone was injured in the pits and their insurance company made them come up with some sort of corrective action.

Sanctioning bodies make the rules for racing, but not for being on the property. At the end of the day, it's still private property. To me, it still seams easier to include a statement on the waiver than requiring a retrofit on probably more than half of the cars at a given event.
Title: Re: Clutch safety switch or interlock switch
Post by: Heo on August 02, 2018, 05:27:11 PM
If i remember it like it is, the 66 Fairlane probably 67 to
have a contact for the brakelight on the pedal and pushrod
for the master cyl. You should be able to use one on the clutch pedal
i think..and feed the current from ign switch to starter relay through that
Title: Re: Clutch safety switch or interlock switch
Post by: Posi67 on August 03, 2018, 12:57:33 AM
This subject came up recently locally on another forum and the response was similar. Fact is... it's not an NHRA requirement and Rory is correct. I had an issue regarding carb linkage a few years back with a track tech and was told not to come back until it was "fixed". I sent a message to our Div 6 tech superintendent and was told I was correct and the local guy was wrong. He also sent the track and tech department his ruling and told them to ensure they were enforcing rules as written. Never got any flack after that.

That all in mind, you can easily put a switch on the steering column that will contact the clutch pedal. I did that for my 2 step and it's nothing fancy but works. Personally, I wouldn't let some jerk bully you but you do need support from someone with higher authority than Forum posters.   
Title: Re: Clutch safety switch or interlock switch
Post by: C6AE on August 03, 2018, 02:30:52 AM
Jacobs engine brake clutch switch...

(https://static.avspare.com/cat2/se/senr/senr8113b00021.png)
Title: Re: Clutch safety switch or interlock switch
Post by: BattlestarGalactic on August 03, 2018, 07:39:00 AM
^^  Yup, installed one on my Mack.  Put it low enough and behind the pedal so it wont engage til near the floor.  That should make the tech guy happy.
Title: Re: Clutch safety switch or interlock switch
Post by: 6667fan on August 03, 2018, 07:58:40 AM
I sent an email to the Northeast Division rep for the NHRA about it.
 The track in question is  Lebanon Valley and the tech is a seasoned guy.
 My brother in-law suggested a switch similar to the one C6AE posted. He called it a body up switch and it mounts on the frame and reacts to a dump body raising up. Thanks all. JB
Title: Re: Clutch safety switch or interlock switch
Post by: C6AE on August 03, 2018, 01:47:21 PM
Lol- I forgot about that one... All of the old Chevys used a mechanical brake light switch. We use them as a " bed up" light switch.
Standard Electric still makes them either normally open or normally closed. Still in stock in my local auto parts store, about $15...

(http://cdn8.bigcommerce.com/s-wbg7d4r/images/stencil/500x659/products/181/965/70704-1__29339.1524192601.jpg?c=2)
Title: Re: Clutch safety switch or interlock switch
Post by: 6667fan on August 09, 2018, 06:17:52 PM
I heard back from the Northeast NHRA rep. He said the interlock is not required,( which of course many of you experienced racers knew), but I had to make sure so I won’t get tripped up next time I go to the Valley. The rep said he would call the main man at the track to let it be known the safety switch is not required. JB
Title: Re: Clutch safety switch or interlock switch
Post by: gdaddy01 on August 09, 2018, 08:21:26 PM
Glad you got that cleared up , there is enough to do trying to race , without unnecessary set backs
Title: Re: Clutch safety switch or interlock switch
Post by: Posi67 on August 09, 2018, 10:43:13 PM
Also good to know you have a Rep who will get back to you and do follow up with the track. Some people can't stand to be corrected even if it's done politely so hopefully this "Tech" guy doesn't get all wadded up. Print out a copy of the Rep's decision and keep it with you at the track.
Title: Re: Clutch safety switch or interlock switch
Post by: John67427 on August 11, 2018, 10:27:17 AM
Glad you didn't go thru the grief of wiring something that is not necessary.