Benefits to clutch start delete?
 

I know that in piston engines when you do a cold start with the clutch pressed it puts pressure on the bearings, thus eliminating the clutch start adds some life to your engine.

I am thinking of doing this to both my rx-7's unless some one has valid reason not to do so. Some insight is appreciated.

I don't know about effect on bearing life, most folks would delete the clutch interlock to improve the starter circuit (one less thing to go wrong between the ignition and the starter).

It allows you to start the car while in gear and run over anything in it's path..
Very Beneficial if you dislike your Exwife but want to make it look like an accident.

I a non clutch start will not increase the longevity of your engine. That would be like urinating in the ocean and saying you increased the overall sea level.

The only benefit i can see is if you lose engine power you can use the starter to move the car to a safer location. Or if your stating circuit is bunk as stated above it might help, but as other threads will show you this is not the best solution...

I had a suzuki samurai years back with crawler gears that i could start in 3rd gear when it was in low range. ;)

i would agree here. the only real benefit would be less electrical to go wrong. but then again; i always put my foot on the clutch as a habit when starting since i tend to park in gear

yah if you want to do like my neighbor and cave in your garage door then sure, eliminate it and put in a remote start kit.


in reality they are talking about the thust bearings on the crank shaft. if you are a dsm guy, those bearings wearing heavily are what cause crank walk. however in reality, its more from the brute force of the aftermarket clutches those guys like to use.

in a factory car, with a relatively factory clutch with no 36 plate, f1 shifting, millisecond-slams-into-gear-like-you-are-getting-rear-ended-by-a-freight-train clutch, theres 0 reason. even in a car that has a clutch like that, theres still 0 reason.

Oh come on.
Prior to the RX, none of my cars ever had the clutch switch and I don't recall mowing down any ex-wives or innocent garage doors.

The interlock is just another poorly thought out "safety" requirement.
Imagine this fairly common scenario:
Trans is in gear and the slave cylinder goes out.
Far as that switch is concerned, since the pedal will move, the car is safe to start.

It would have made much more sense to move that interrupt function to a neutral switch on the trans and ignore the clutch pedal altogether.

I would still probably disable it but at least wouldn't find it insultingly stupid.

Agreed. Using the neutral switch would make way more sense.

From a failure modes standpoint, I'd say moving the switch to the clutch fork/slave cylinder interface on the bellhousing is the best choice. Otherwise the option to start in gear is removed. Not that that is a huge deal, but if we're going to discuss failure modes...

I have had my civic for a while now, it has always been without the clutch start feature. I love not having to press the clutch, although not a big deal at all. I have never had problems starting it by accident and being able to move the car with the starter literally saved my life when my distributor gave up in the middle of a highway intersection.

I just like the simplicity, the less the better IMO, besides even if the benefit to the bearings on cold starts (Oil pressure barely building up on initial crank) is small it's a benefit non the less.

adds life to your engine?

Maybe if you use the car as a cab or to deliver pizza, I mean really how many times do you start your car in one day how much life are you supposed to be saving?

Your shit will blow up for reasons 8 times removed from the clutch wear, lol

I drive the car once or twice a month, as far as engine life it's not the blowing up that gets me, it's the wear (Probably negligible in our engines) upon start up, I just thought it could be another pro to the whole thing :lol:

Removing the option to start in gear is the whole fucking point of this safety feature.
In it's OEM location or moved to the slave cylinder as you propose, the switch is sensing the condition of the clutch, not if the transmission is in neutral which again, is the whole bloody point.

This makes no sense...you still have to press in the clutch to put it in first...if you really want to save the PP from the clutch, learn how to put it in gear without using the clutch, like a trucker

Start it in neutral and with the AWS the rpm's will climb to 3k, start in first and you'll see 1/2 as much.
Cold weather starts when in neutral will certainly put a drag on the starter. When the car was driven in cold weather when new, start in neutral then let the pedal up and the rpms dropped significantly because of the gear lube resistance.

It really only has a benefit to piston engines using a heavy clutch(high torque capacity). Pushing the clutch in on a cold start puts a lot of pressure on the main bearing thrust washers, so in theory, removing the safety switch will help extend bearing life

get an 86 they didn't have the clutch safety switch in the first year!

If you put the shifter in neutral and start without the clutch pushed in (assuming no interlock switch), you just put more load on the starter. The flywheel is connected to the transmission, so more torque is required to spin the engine.

Prior to '86 there wasn't clutch starter interlock on the RX-7s. It's just a safety feature for idiots at the wheel.

freeing up a few misconceptions here...

depressing the clutch and cranking on a dry engine does promote more thrust bearing wear, as does sitting in traffic idling with your clutch depressed for long periods of time. i've seen plenty of thrust bearings worn to nothing and often times you can tell which drivers had either heavy clutches installed or drove mainly in city traffic. cold starts do effect this as well to a lesser degree.

i have mine bypassed for the remote start, otherwise it is intact. but i don't hold the clutch in longer than is necessary to start the car so that it can get lubricated adequately.

even the worn thrust bearings still worked but i would say they were close to outliving their usefulness. yet to see one grenade due to wear, i suppose that is worth mentioning but in some cases the needles just fall out of the retainers while disassembling some engines. excessive thrust play does promote more bearing wear on the rest of the engine also since the shaft is slightly walking between wear paths, not to mention the metal shedding that the filter can't catch.


normally it takes over 100k miles to do any real damage though, stock these cars didn't show any major detriment from the standard systems but once they do get worn to a point then the wear begins to rapidly increase(once a step is formed in the thrust plate, usually close to the end of the life of the engine under normal use. once a step is formed and the surface worn then the metal begins to gall as it peels off the surface layer.).

Thank you... Having to press in your clutch for start up is somewhat useless regardless. Maybe if it was a heavily used daily driver or my civic

That's all well and good Ben, no doubt fodder for a pleasant discussion on extending bearing life, but not relevant to a discussion of the interlock switch.
Deleting the switch does not prevent you from pressing down the clutch during start.

It is a flawed implementation of a safety feature that also introduces a failure point into a basic system of the car.
To me, the interlock is exactly the same as the radiator thermoclutch- they both interpolate the condition they monitor remotely. The thermoclutch reacts to coolant temp based on airtemp through the rad core, the interlock assumes that if the clutch pedal is depressed, the car is not in gear.

If you truly believe the starter needs a "safety", hook it through a neutral switch and you actually have the prevention that the stock setup only promises.

My '86 Toyota 4x4 Hilux pick-up had a button on the dash (factory) that when pushed bypassed the neutral safety switch. I never knew why it was there but it was.

ok, well back to the topic then.

everyone here who has bypassed the switch has tried to start the car while in gear, if you haven't yet then you probably just haven't had it bypassed for very long. it is a good safety feature, luckily the cars i've done it on have not actually started.

and just yesterday while diagnosing a car the customer was turning it over while i was checking the fuel pump in the back... you know what's coming, the car had a bypass and he tried to start it in gear. but it has some usefulness, remotely starting the car or moving a dead car around with the starter.


for those acting like everyone else are idiots for starting their cars while in gear with the clutch out, look in the mirror. we're all human and we sometimes forget to do the simplest checks.

That explains why someone called "RockLobster" would be on an RX forum.
My Sammi is torn down to the bare frame in my garage. Ergo...
(OG FC in the driveway-86 GXL, no clutch interlock)