Will A Gear reduction starter help my Carbed Z start faster?

[at-jefft]

Hello,

I have a Early 260z with Round top SU Carbs that I recently rebuilt. I have the opportunity to pick up a used 280zx starter (I believe all of them gear reduction). My question is will that help my Z start faster (like a modern car) and use less of the battery? Thanks, Jeff

[PanzerAce]

How long does it usually take to start up your car? I know mine sometimes takes a good 10-15 seconds of cranking depending on how long it's been sitting (triples + mech pump, gotta wait for them to fill enough before it has enough power to turn itself over).

 

Does the engine not want to turn over? Or does it just keep cranking for awhile before it catches?

[garvice]

Heads up, not all 280zx starters are gear reduction ones.

 

Edited: False/Incorrect Information. See Pharaohabq for correct information.

[Pharaohabq]

That's actually the other war around. A gear reduction starter Turns your Engine over slightly more slowly, but the Starter motor works less and turns faster, thus it's a stronger turn, and can crank longer. It won't make it start any faster, because your old Z uses a mechanical fuel pump to push the gas to the carbs and this the engine has to turn over enough time to push enough gas to start it. The Gear Reduction starter just uses less battery power to do the same job.

 

Phar

[BRAAP]

That's actually the other war around. A gear reduction starter Turns your Engine over slightly more slowly, but the Starter motor works less and turns faster, thus it's a stronger turn, and can crank longer. It won't make it start any faster, because your old Z uses a mechanical fuel pump to push the gas to the carbs and this the engine has to turn over enough time to push enough gas to start it. The Gear Reduction starter just uses less battery power to do the same job.

 

Phar

 

Exactly!

[Guest Rolling Parts]

Get one anyway. It's always good to have a spare. NOT having a spare means that if it goes out that you will have to wait a couple of days for a replacement. In a few years these things will get even harder to find.

 

As far as starting like a modern car, that's not the charm in having an old car with choke cables and carbs and primitive ignition. If you want to start like a new car then you need great EFI and a great ignition system.

 

EDIT:

A gear reduction starter has a lot more TORQUE at the same RPM. It's actually can spin an engine faster if you have high compression, weak battery, a different cam, different ignition curves, etc. I put one on my aircraft engine and spinning the engine/prop was noticeably faster than the old direct drive starter. So yes, it CAN spin faster with a higher torque / lower amperage starter.

[BRAAP]

Get one anyway.

Yes, get one. The later gear reduction starters are a superior starter to the older ones in how makes use of the batteries electrical power to turn over the engine at sufficient speed to support combustion for starting, and in most instances, are lighter weight.

 

 

… EDIT:

A gear reduction starter has a lot more TORQUE at the same RPM. It's actually can spin an engine faster if you have high compression, weak battery, a different cam, different ignition curves, etc. I put one on my aircraft engine and spinning the engine/prop was noticeably faster than the old direct drive starter. So yes, it CAN spin faster with a higher torque / lower amperage starter.

Yes again, more torque by virtue of gear reduction, so no it WONT spin the crankshaft any faster.

 

In keeping with the context of the original posters question, mostly stock L6, NO, the Z car gear reduction starter will not spin his Z car engine any faster than a traditional Z car starter, even if he did bump up the compression ratio!

 

The aircraft analogy really isn’t a good one here. For one it is a totally different engine design and secondly, the prop is effectively a huge flywheel that the Z car engine just does not have contend with. If trying to start your car while in gear on level ground, that would be a more fair comparison, then yes, the gear reduction starter will get the engine up to full cranking speed in less revolutions by virtue of more torque, and if the starter or battery were weak, may be bogged down to the point it slower than gear reduction, but only because it is being asked to work harder than it was designed to. Also, many aircraft still flying were manufactured back 1930’s-1950’s. Those old starters were just slow any how, even brand new version of those old starters, and replacing one with a modern starter, gear reduction or not, will spin faster.

 

For trivia sake, the gear reduction starter as used on Z cars since 1978 is the same starter, by design, as sold currently in the aftermarket as high performance gear reduction starters for the Small and big block Chevrolet!

[Guest Rolling Parts]

Yes again, more torque by virtue of gear reduction, so no it WONT spin the crankshaft any faster.

 

It will spin the engine faster in cold weather, if the battery is weak, and if he's clearing out a flooded condition from those chokes.

 

Yes! If everything is perfect and warm, the starters perform equally well. The REASON you buy one is that it's superior at not LOOSING crank speed.

 

I used the airplane engine example because you can TELL the difference visually by watching blades rotate. On cars it's really SUBJECTIVE because it's indirectly measured with noises (and tachs that don't read well at low RPM's). I'd wager that most people starting a Z (in ideal conditions) won't see/feel a difference. Also, the McCauley aluminum prop is about the same as the massive Nissan iron flywheel with the massive Nissan clutch assembly attached. You also see the difference of a weak battery a LOT faster in a plane than you can notice with car batteries. It's fair because the superiority and reason WHY car companies all use it now is more obvious and demonstratable than putting one on a car and immediately looking for a difference.

[BRAAP]

Yes! If everything is perfect and warm, the starters perform equally well. The REASON you buy one is that it's superior at not LOOSING crank speed.

.

 

Yes, I agree 100%

 

 

I used the airplane engine example because you can TELL the difference visually by watching blades rotate.

 

Again, your visual appearance of a faster spinning prop is not a Z car engine nor are you using Z car starters! The aircraft is a much older technology starter replaced with a modern design, as such it should be faster. Again, not a modern L-6 using either of the available L-6 starters as per the original posters question!

 

 

 

. Also, the McCauley aluminum prop is about the same as the massive Nissan iron flywheel with the massive Nissan clutch assembly attached.

 

Yes, L-6 clutch flywheel is comparable in static weight to a Mcauley aluminum prop, (don forget the aircraft also has a flywheel sandwiched behind the prop). No they are not comparable dynamically as seen by the starter upon engagement. Dynamically the aluminum prop has a larger polar moment due to its much larger diameter which has its mass further out way for the hub center vs the flywheel and clutch assy.

 

 

In your defense I will concede that by design, some aftermarket manufactures will design their gear reduction starters to spin faster than non gear reduction units. I don’t know of any specifically but I do believe they exist. But that as well as aircraft engines have NO relevance to the original posters questions regarding his 260-Z!

 

Now please, lets keep the discussion within the context and topic of this thread as posted by the original poster!

 

Thank you.

[Guest Rolling Parts]

Again, I only used the personal example to illustrate the technological difference between starters, not engine technologies. To me it help me to visually witness what was previously technical platitudes.

 

So specifically to the right here and right now on a 260Z, the gear starter is better for the reasons I stated and will spin a 260Z engine FASTER under the conditions I stated. Specifically to winter (as in right now for him being in cold Illinois) it will spin up a cold 260Z engine with a cold battery FASTER and LONGER than the original starter.

 

The answer to his specific question in the right now for a stock 260Z in frigid Illinois is (of course) YES. It will help it start faster and use less battery.

[WEBEZEEed]

Keep it really simple............just get a 6 volt cable, carries more amps for hot & cold starting, cheaper too!

[at-jefft]

OK, so Thanks everyone for the extremely thorough answer. ( I had a good giggle at the intetia pic)

 

So what I got out of that (correct me if I am wrong):

1. get a gear reduction starter, same performance but less taxing on the battery

2. in order to start faster I need to prime the carbs.

 

as for #2 I asked a question a while ago about putting an electric pump on my z just for priming and got shot down (http://forums.hybridz.org/showthread.php?t=150004) anybody wanna look that over and see what why I'm getting a different answer here. Thanks again.

[Guest Rolling Parts]

Use the choke.

No need to waste battery on an electric pump since the carb bowls are already full.

 

If this is just a generic question on hard starting then look up "dizzy swap" and "compression check". Good luck.

[at-jefft]

Use the choke.

No need to waste battery on an electric pump since the carb bowls are already full.

 

If this is just a generic question on hard starting then look up "dizzy swap" and "compression check". Good luck.

 

 

I do use the choke, and I have checked the compression (its good I forgot the actual psi though) and I have a 280zx dizzy ready to be installed. lol

 

It does take a good 10-15 seconds of cranking and I would like to shorten that if possible.

[Guest Rolling Parts]

Hmm, you might just have a timing problem, a fuel leak, old plugs/wires, bad valve seals, a vacuum leak, incorrectly adjusted choke cables, a loose manifold, a poorly adjusted carburetor float, a worn mechanical fuel pump, corroded/intermittent ground wiring, or... wow, this really could go on for a while!

 

The point being is that remote diagnosis will generate a LOT of seemingly different "answers" depending on what you ask and what information you volunteer. A different starter or a new pump is just taking a shot in the dark.

[at-jefft]

Hmm, you might just have a timing problem, a fuel leak, old plugs/wires, bad valve seals, a vacuum leak, incorrectly adjusted choke cables, a loose manifold, a poorly adjusted carburetor float, a worn mechanical fuel pump, corroded/intermittent ground wiring, or... wow, this really could go on for a while!

 

The point being is that remote diagnosis will generate a LOT of seemingly different "answers" depending on what you ask and what information you volunteer. A different starter or a new pump is just taking a shot in the dark.

 

 

Ok, So 10-15 seconds is not normal huh?

 

Thanks for the info.

 

@panzerace -The engine turns over fine but it just sits there and whirrs for a while.

[Guest Rolling Parts]

Ok, So 10-15 seconds is not normal huh?

 

Not normal for me.

I never run the starter more than ~5 second bursts at any time.

Are you energizing the starter and not releasing till the engine starts?

[Tony D]

The assumption the carb bowls have not boiled out dry is a bad one to make, even in frigid climates. Winter gas will prove extrememly volatile and can 'boil out' same as in the desert southwest if you have an unseasonably warm day (say it gets up to 30 when normally it's -10 outside and fourmulations take this into account).

 

My 71-Carbed 260Z will take extended cranking to refill the bowls with CA premium if I have a hot shutdown and leave it sit overnight. UNLESS I flick my little e-pump switch and prime the bowls. I use a facet pump inline up in the engine bay. I also use this pump when the car has been sitting at the airport for over a month.

 

If I prime the bowls and engage the starter system on the carbs (unless you got flat tops, it's NOT a 'choke'!) the car will fire off immediately. If not primed, much cranking is required to reprime the bowls.

 

As for Gear Reduction, the primary reason for installation on the ZX's was to keep system voltage higher so they didn't fry the ECU during cranking. If the battery drops to below 9V, some of the early ECUs would poof! Putting them on earlier cars won't do much for you (and in some instances they are actually HEAVIER than the starters they replace!!! So much for blanket statements...) other than stabilize system voltage during extended cranking.

 

If your float bowls are dry, a priming pump (like OEM installed on later cars, and had from the factory since day ONE in some markets for the 240) is the way to go. With a primed bowl and the starter system engaged, it should fire off pretty quickly. Running a transistor pump for 20 seconds is FAR less taxing on the battery than turning ANY starter to fill a float bowl by turning the engine over and running the mechanical pump.

 

The little ticking Facet pump will blow fuel right through the stock (or replacment) mechanical pump, and fill those bowls no problem, then simply stop pushing fuel once it's pressure limit is reached (around 3psi...)

 

Determine the cause, then go after it. Throwing parts will be expensive and may not solve your issue. But I put that primer pump on my car, and it's saved me with a nearly dead battery at the airport more than once! During the summer if it sits, that fuel goes away, period. The only way to fill it is cranking, or an e-pump.

[PanzerAce]

What Tony said. After *long* times sitting (or not so long during the summer), my issue is that there simply isn't any gas in the carbs. Running *just* a mechanical pump (and not having the starter systems hooked up) means I have to keep cranking for awhile before the cylinders see any gas at all.

 

If the car hasn't been sitting for that long though, it fires right up like most people expect.

 

@thread starter: What we really need to know is *when* you're having trouble starting the car. Cold engine that's been sitting for a few days? after it's warmed up? when?

[Guest Rolling Parts]

The assumption the carb bowls have not boiled out dry is a bad one to make,

 

Absolutely, ANY assumption about the condition of those modded (and home rebuilt?) carbs is probably a bad one; which is reason I mention fuel leaks, vacuum leaks, float adjustment and I should have included throttle shaft wear. Agreed, it's a time for diagnosing, not adding more parts.

 

As for Gear Reduction, the primary reason for installation on the ZX's was to keep system voltage higher so they didn't fry the ECU during cranking. If the battery drops to below 9V,

 

Yea, that might have been the reason for the ZX, but keeping a higher voltage is also a very good reason to get one in winter for a coil too; 12V to a coil is better than having it less than 9v. Weight penalty on a stocker? Actually I'm not sure that's an issue on the ZX nor a 260Z for non-racers.