930 starters

[Bill Musarra]

As the saying goes,,,, if it can go wrong it probably will go wrong. I am now in the market for a starter for my 930. What is the consensus?? I had the Hi Torque starter. I chose it because it had a clockable face and allowed me to put the starter in without altering frame members. Well at my final tune up yesterday(second time for this actually) the starter started making some funny sounds. We observed the same grinding sound and intermittent action that happened when it tore up the ring gear(this will be the third time in 3 months if it did it again). When we used the starter without the ignition key on, it turned the engine consistantly without all the calamity. Later on we saw sparks flying out the back of the unit at two screw mounts. The volt meter was jumping wildly from 14 volts to 10 volts also. We surmised also that the starter just wasn't turning the engine over fast enough to trigger the starting function of the ignition system, or it was acting intermittently. Maybe 300 rpm of so. As most of you know I am running the 351 Wiindsor bored and stroked to 396 with AFR 205 heads with flat top pistons, so the c.r. is not high. We called the session off. I haven't pulled the starter yet as I am fairly depresed over this new(rather old really) problem. Had this acted as it should I would be out there drving the car as we speak.
What I am looking for is SPECIFIC starters. If porsche, I need the model that will work best. There are several refubished units on Ebay.

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Porsche 944 Turbo S2 - Starter

Porsche 924 944 Bosch Starter SR39
<TABLE cellSpacing=0 cellPadding=0 width="100%"><TBODY><TR><TH id=v4-50 class="vi-ia-hdAl vi-ia-attrLabel vi-ia-attrColPadding" noWrap align=left></TH><TD class=vi-ia-attrColPadding width="50%" headers=v4-50></TD></TR><TR><TH id=vi-ia-attrSectionLastRowTd class="vi-ia-hdAl vi-ia-attrLabel vi-ia-attrColPadding" noWrap align=left></TH><TD id=vi-ia-attrSectionLastRowTd class=vi-ia-attrColPadding width="50%" headers=v4-51></TD><TH id=vi-ia-attrSectionLastRowTd class="vi-ia-hdAl vi-ia-attrLabel vi-ia-attrColPadding" noWrap align=left></TH><TD id=vi-ia-attrSectionLastRowTd class=vi-ia-attrColPadding width="50%" headers=v4-52></TD></TR></TBODY></TABLE>Mfg Pt. # 0-001-108-021
Interchange #SR39x, 17023
Poster sells alternators and starters of all types

Porsche 911 High Torque Bosch Starter SR68X

Mfg.#R68X
Interchange #001312110, 6986012660, 91160410101

Porsche 924 Bosch Starter 1986 1987 1988 2.5L 944 1986 1991 2.5L 2.7L and 3.0L

Mfg.# SR39x

Interchange # 0-001-108-021
Auto electric co.
Other starters by this seller are:
Porsche Starter 944 1986 1987 1988 89 1990 1991 2.7L 3....
911 930 Porsche NEW STARTER 1966 68 70 72 74 76 77 80 8...
Pt. #911-604-101-01
Porsche 911 930 NEW HD STARTER 1966 67 68 70 71 73 75 7...
Pt.#0-001-312-100 also SR 68x
PORSCHE 911 BOXSTER NEW STARTER 1997 1998 1999 2001 200...
Pt.#996-604-104-00 SR0430x
This guy has almost every Porsche starter there is.

High Torque Starter for Porsche 911SC (1978-1983)

This one is a new unit that apears to be the same as I have. All the others are referbed or reconditioned units

So lets hear what you guys are using. Lord knows my choices(or luck) have been awful.

Bill

 

[Dave Deerson]

For 4 track day use seasons I have never had an issue with my Hi-Torque starter for the 930. I have the 930 behind a mild LS6 with the Kennedy midplate/clutch/Hi-torque starter setup. Like all other parts out there, you may have gotten a rotten one out of the box. Since all they are under the skin(or fancy clockable face) is just a Mitutoyu or other design Japanese starter, I would give it to my local Starter/alternator rebuilder and have him go through it. I just had a cheap Summit racing unit done over for a customer this week, and the OEM spec parts he used were far better then the junk that came out of it. The customer said that it had never sounded that good ever. As for buying a rebuilt unit from an unknown source........
I would be wary of the parts used in the rebuild from an unknown seller. How come there is such a large price discrepancy between a Pep Boys alternator and one from a reputable local shop that uses Valeo or other OEM quality parts? I have also witnessed may Pep Boys alternators and starters fail in as little as a few days!
So try your local guy to see if he can refurb the unit you have, that way you are certain of the history and quality of the parts used .

 

[Terry Oxandale]

Bill,

Because of the history of starter issues with your project, have you looked really closely at the relationship between the ring gear and the starter gear to insure proper orientation, plunges, etc? I realize you're using identical parts that others are using in regards to the plate, and machining, but something seems to be different about your problems, but I don't know enough about it to say what it is.

 

[Bill Musarra]

Terry,
In the past when this problem first raised its ugly head, I took the measurements of the throw of the starter gear and looked at the footprint of the teeth in the ring gear. These numbers were where they should be, and the footprint of the starter teeth matches the full face of the ring gear. Now that it is recurring, I will be checking those #s again. If need be I will have a machinist look at it as well. I know several that would be willing to give their opinion. It could be that with this problem and the wildly fluctuating voltage, the starter gear is intermittently retracting and advancing as it looses electrical contact and is then catching the teeth of the ring gear as the motor is trying to stop its movement. For example, when you tap a starter, the starter moves the flywheel complex a bit and when it releases, the forces that are there(the building compression in several cylinders etc.), tends to force the motor to turn back in the wrong direction, be it for only several degrees. If this is what is happening here, you have a set up for broken teeth. We had the computer hoked up while this was going on. We were seeing rpms in the range of 100 to 300 which may be below the threshold for the start function to kick in and may well be below the speed that would keep the rock back from occurring.
Thoughts?? Opinions???
So I'll ask the question, what rpms are you guys getting with your starters engaged??
I plan to take the starter to the guys that set up my one wire alternator and get their take on this, see if the starter is salvageable, or what alternatives are there. I plan to get a new battery for the car as the one in there now is a red top bought back in '07. I'll let it be the dedicated battery for the winch.

Bill

 

[Terry Oxandale]

Bill,

When I've rotated a motor over only with a starter to check compression (all plugs out except the cylinder with the gauge), the motor rotated at roughly 180 RPM. Even with compression involved when all plugs are back in the motor, the RPM is very close as I time the valving cycles and then multiply by 2. Based on other observations with low battery voltages, thick cold oil, and other issues, I've seen an air/fuel mixture ignite at very low RPMs (50 or so?)

 

[Bill Musarra]

Terry I don't doubt what you are saying. But are you talking a distributor setup or computer?? My ignition system (for now) is completely computer driven(FAST XIM). I will double check but I believe it needs to be above a base rpm to initiate the ignition sequence. I plan to have a discussion with the FAST guys about this and several other items.

Bill

 

[Seymour Snerd]

.It could be that with this problem and the wildly fluctuating voltage, the starter gear is intermittently retracting and advancing as it looses electrical contact and is then catching the teeth of the ring gear as the motor is trying to stop its movement. For example, when you tap a starter, the starter moves the flywheel complex a bit and when it releases, the forces that are there(the building compression in several cylinders etc.), tends to force the motor to turn back in the wrong direction, be it for only several degrees. l

This is going to sound weird, but I wonder if you have an electrical wiring problem external to the starter. Here's the thought: it sounds like the engine is trying to start but that just as it does so the starter loses its drive (thus the jumps between 10 and 14 v). Could there be some interaction between your ECU and the starter such that right when the ECU decides to start firing it also causes the starter to quit? If so that would cause a kind of oscillation where the starter gets the ECU going but the ECU then shuts off the starter and vice versa. To investigate this theory you would run the starter with a mechanical switch (like one of those alligator clip hand-held pushbuttons) directly from battery to starter terminal, so there is no way anything is getting in the way of the starter current. When the starter is being told to run, the voltage should not ever jump up to 14. That's a smoking gun right there. The sparks out of the starter sound like the starter contactor (aka "solenoid") opening and closing rapdily which might be another evidence that someone is jerking the poor starter around.

Do you have any switches (eg oil pressure sender or signals from the ECU) that inhibit the starter? Do you have any switches (same eg) that inhibit the ECU or ignition or fuel pump? Those are all possible culprits. All it take is two of those working at cross purposes.

Also if you suspect the ECU min RPM threshold is involved, is there some way to temporarily disable that, IOW tell the ECU to just run the engine, dammit?

BTW I'm with Terry on the RPMs. Ignoring EFI, etc, for the moment, engines themselves will start being cranked at 2 revs/sec (i.e. 120 rpm). Think of one of those WWII radial engine film clips where the propeller revolves about once per second and the engine still fires right up.

 

[Bill Musarra]

Allan,
With concerns to the electronics. the wiring to the starter involves 3 wires. One from the battery, one from the starter to the alternator(one wire setup) and one to the solenoid from the start button. This setup is done so that I can spin the motor with the ignition switch in the off position. Of the culprits that you mention, I think are clean. The fuel pumps have two cut offs. One is from the inertia switch and the other is from the low oil pressure switch which has a bypass button hidden in the door/dash interface. Door has to be open to see and use. Neither of which are tied into, or controlled by the electronics, just the everyday wiring of a car.
As to your examples of rpms to fire, I think those systems are magneto controlled, which would fire on just one comnpression cycle much like a lawnmower. So I am off to the garage after a respit to cool me off from the anger this problem has arroused. Will post the findings.
A question I haven't asked yet. Since the ring gear is a smaller diameter that the norm for a V8, is a high torque starter motor really needed. I understand the physics involved, but would a Porsche starter be enough for these engines, and would it spin the motor faster?? I believe the Hi Torques use a gear reduction to get their power?? I really don't think I will use a Porsche unit as the DRBs would involve cutting the frame members to get it to fit.

Bill

 

[Jac Mac]

IIRC Porsche & most Hi-Tork starters use an inertia basis to throw the pinion into engagement with the ring gear..eg the pinion is already starting to revolve as it engages the ring gear..( Most USA/Aussie production starters have the solenoid actually push the pinion into gear/engagement by an internal lever prior to the starter starting to turn- the old Ford 'Rat-Trap' does the same- in these the pinion does not turn until engaged )

To me it sounds almost as though you have an internal short or connection within the body of the starter somewhere that is causing it to turn after the start button is released , thereby throwing the pinion into engagement with motor running.

Comp ratio- your up close to 11 to 1 with the 72cc head & flat tops @ 396cu in, maybe even a bit more if you have pistons level with block @ TDC, more important cam timing & how much it affects cranking pressure.

One note for Alan W, most radials have prop reduction drives, hence while the prop might appear to be slow rotating, the motor will be turning over about 2.5 times faster( depending on the ratio in use)

 

[Scott Calabro]

A little drifty but any round engine tech is cool.....

For Alan and Jac, although I have a suspicion Jac has seen a setup like this first hand!

Partial Reduction Gear

 

[Jac Mac]

Yep, get to see a bit of everything down here with them running turbines in the Fletchers & Mandeville restoring anything worth a damn....right now there are three guys tearing whats left of their hair out at mandeville after an F1 Evolution had to force land about four hours into its initial 40 hr test flight program, brand spanking new USA built motor...should have bought a KIWI!!!

Bill, I would remove the starter from its mount on the car & clamp/mount it onto either the trans/engine block or chassis, leave it all wired up, then push/tow start the car in third gear, that way you can operate the starter with motor running etc & observe what if anything is happening in the starter dept when you operate the starter button or do anything in an electrical sense.

 

[Bill Musarra]

Jac,
The starter doesn't hang up when the button is released. It does it's crap while trying to spin the engine. I puilled the starter and there were filings hanging off of it. I removed all the plugs and turned the engine to find a gear tooth missing. So I will have to order another. The teeth on the starter are rounded and worn so that will have to be replaced as well. I plan to take the starter to the shop on Monday and get their analysis. If need be I will take the car to them and let them have a look at the wiring to see if I am missing something.
The problems reared their heads while doing the tune up and changing variables in the computer setup and probably with some decline in the battery charge. With the charger attached the motor did spin a bit faster, but the damage may have already been done. The engine always started reather easily before the tune, but it was very sluggish when I drove it around the block. The settings on the computer were just enough to get it started and as some of you remember it was running rather rich at that time. We have had a lot of trouble with the program(tuning), but it has been put on a good number of cars by my engine guy without these kinds of issues, though they were american iron types. If this continues I will abandon this systemn and go to one of the other "simpler" setups for ignition. Pulling the trans is getting rather old, and there are other things I want to do with this car.

Bill

 

[Ian Anderson]

Bill

Do you have the correct coil fitted?
So many run at 9 volts normally through a resistor that drops the normal running voltage to the 9 volt level and to compensate for the voltage drop during cranking a full 12 volts is fed from the starter motor to the coil fir initial fire up.
Other coils are set to run on 12 volts.

Now if you have a 12 volt coil on a 9 volt set up you only get3/4 full spark and the resultant problems that causes.
These can include reluctant starting, backfiring etc

Ian

 

[Bill Musarra]

You guys have given me a lot of questions to ask the electric shop. Much appreciated.

Bill

 

[Bill Musarra]

Removed the starter and took it to the starter shop. Looking only at the starter this is what they thought.
1. The arcing was from the two screws in the rear coming loose.
2. The starter is not fully engaging into the ring gear.
3. The starter is "walking on the face of the ring gear" from the lack of engagement(seperate action).
4. From the noise the engine is making, grinding, jumping voltage, and spark knocking sounds, the timming should be retarded 20º during the starting of the engine and then returned to its normal timing once started. This would be accomplished by an MSD box or reseting the electronics. This was based on their experience with an engine(drag) that was eating up starters. Once retarded, the noise went away. My electronics has a spark table that is easily reseet. Will have to look at it to see where it is set.
Here is what they had to look at.

Here is the pics of the ring gear(s).The first is the last ring gear used.

Amazing how they picked up on the "walking" from just the starter teeth.The group shot is the oldest gear on the right.

They are all facing the same direction. Remember that the first ring gear was damaged from the distributor gear juming a tooth and backfiring. It was running fine until then. The second one had the noises and the starter allen bolts that hold the starter to the adapter(clockable face) came loose. The last one is the one from this time. No issues with tightness.
The guys at KEP just said they agree with the timing and that all surfaces should be checked for flatness of mating to its adjoining pieces so there are no alignment issues. Pressure plate to flywheel etc.
Here is the new gear for the starter.

Will try these to see if it corrects the problems. Any other suggestions out there.

Bill

 

[Terry Oxandale]

How will you address the issue of the starter gear not going all the way into the flywheel gear? The photo seems to verify that it's not extending out far enough to fully engage.

 

[Bill Musarra]

Unless something isn't fitting as it should(flat) then there are only two options. One is to cut down the mating surface with the starter on the trans. The other is to machine the surface of the starter. I guess I could go really rad and machine the mating surface of the trans and the adapter or the adapter itself..... Nah!! I will do the math(measurements) and find if these things need to be considered. I am and will be incontact with Hi Torque about them as well. These starters were made to fit the KEP equipment among others. So if the measurements don't add up they will be the ones to help with the answers. Just have to hope for the best for now, as this should not be a problem.

Bill

 

[Seymour Snerd]

One note for Alan W, most radials have prop reduction drives, hence while the prop might appear to be slow rotating, the motor will be turning over about 2.5 times faster( depending on the ratio in use)

Of course.... duh... thanks.

Bill -- yes if your starter wiring is that straightforward my theory goes right out the window.

 

[John]

Bill,

I read you thread re: Porsche 930 ring gears - my starter just chewed up a couple of teeth on my ring gear.

Do you have any tips or suggestions on the best way to pull the transaxle to replace the ring gear. I have my 930 transaxle mated to a small block Chevy!

Are there any steps you would recommend that would prevent a repeat of this problem!

John
:thumbsup:

 

[Bill Musarra]

John,
There must be a rash of these ring gears going bad from one thing or another.
For your first part. I looked over the ancient info I have on the KVA. Not much help, but here goes for the generic info of pulling the trans alone. First disconnect or remove all pieces that hook the trans and shifter and slave cylinder. Pay attention to the adjustment screw on the lever. It has to be aligned just right or the clutch won't release. Just right is that there is little to no play on the lever against the throw out bearing(1 to 2mm.). Either remove the slave cylinder or the lever, as the lever has to rotate as the trans comes out. Lever is held in place with a metal o ring or C clip. Remove the tires and wheels. Disconnect the axles at the trans and compress the shafts in toward the wheels and rotate out of the way. Support the engine with a 2x4 on a hydraulic jack and release all frame mounts to the trans. If there is a cross brace over the trans, remove it. It may be what holds the trans in place(if it is there needs to be a rear support to the trans, it can flex. It may require the exhaust to be loosened or removed. Mine worked with just the mufflers taken off. The adjustment screw is right under there and is tough to get to with the pipes installed. Release the trans securing bolts to the frame, and raise the back of the engine an inch or two. Leave the engine mounts in place. If there are any brackets to the side of the trans remove them.That should give you enough room to pull the trans with an engine hoist utilizing the balance bar and some tie down straps. Pay attention to the angle of the trans on comming out. It has to go back in the same way it came out. It seems obvious until you are struggling to get it lined up.
This next part is for the "normal" fork and throw out bearing If you have a hydraulic throw out bearing release setup, you are on your own. Never seen one. Normal means you have a lever on the top of the trans that hooks up to the slave cylinder. Look in the side view hole and the bottom vent hole as to how the fork and throw out bearing are held together. The TOB has two "ears" that are vertical and the fork arms are in front of it. As you begin to move the trans away from the engine look at them again and see how they come apart and mate up. The fork is in front of the "ears" of the TOB and has to be rotated forward as the trans goes backward in order to get the fork away from the ears. If you have any other issues you want done, pull the entire engine and trans together. You need all the room you can get even if it is just to clean up the the engine bay.
After removing the trans and if you have the Kennedy setup the ring gear is bolted to the pressure plate. Removing these bolts undoes the pressure plate and allows the pressure plate fingers to go toward the rear and the clutch to drop out. As the fingers go toward the rear, the throw out bearing will be released and should fall out, or come out without anything holding it. Pay attention to how this goes together. The fingers will be facing out of the clutch area when loosened, and in when tightened down. The pressure plate is a puller rather than a pusher like American pressure plates.
For reinstalling you will need a clutch alignment tool found at most auto supply stores.They come with multiple pilot bearing flanges(?) or end pieces. Reinstall the clutch,pressure plate throwout bearing and ring gear. There should be a cone shaped sleeve that goes over the installation tool. It lines up the clutch. Make sure the clutch is supported well or the trans will never go in. When installing the trans, if you have the "normal" throw out bearing and fork setup( has a lever that hold the throw out bearing and a lever on the top of the trans to the slave cylinder. Use the top lever to align the bottom lever onto the throw out bearing. The "ears" on the bearing have to be aligned vertically and the fork comes in between the ears and the fingers as you advance the main shaft into the pilot bearing. You can watch it line up from the side view hole and the bottom vent hole. Do it slowly. If the ears move slightly, use a long skinny screw driver to jiggle it back into place while rotating the top lever ever so slightly to get the fork lined up. Logistically it may be easier to do with the engine sitting on the floor.

Issues with the ring gear.
Things to look at. If you have electronic ignition you have a crank trigger. Look at your manual(s) and make sure it is set properly. Too much timing on start up and the engine has to work like hell to turn over. This can cause the engine to try and turn backwards when firing too early. This will break teeth. Believe me I know. Seem logical, but is sometime missed. If your electronics are programable, timing ought to be somewhere about 20º on cranking and max out around 32º total at WOT. Your crank trigger may be much higher but it is telling the computer where the crankshaft is in order to fire at the right time. Same for the cam sensor. Though its function is to tell the computer that the #1 cylinder is the one that is coming up.


Distributor. With a stock distributor or electronic cam sensor, if it has jumped a tooth or worn one off, it will be backfiring up through the carb or injectors. This too will try too turn the motor backwards as well and destroy teeth.
Starter. Check to see if the starter is bolted together tightly. If you have a high torque starter, put thread locker on all bolts large of small. Mis alignment of starter and ring gear = failure. If this is a new setup, count the number of teeth on the ring gear (I believe it is supposed to be 131) and the number on the starter gear(believe it is 9). Look at the wear pattern of the old ring gear and the starter. It should be engaging about 7/8th to 9/10ths of the starter gear. If it is a starter that you have had for a long time consider a new gear as well. Take the starter to a reputable shop and have them check it out. Full extension, rotating forward as it goes out, and spins good. Rarely it is a bearing in the starter.
Check the mounting holes for the bolts of the starter. If they are egg shaped, you got a problem. Be sure to use lock washers and locktite red or blue.
That should cover almost anything that can cause a tooth to break. One last thing, make sure you have the correct starter. it should be the 101N I believe. It would be in your paperwork.

Hope this helps. If you run into a problem, PM me and we can swap phone #s.

Bill