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914World.com _ 914World Garage _ Flywheel for 6-conversion to 901 gearbox
Posted by: rwfms Mar 6 2017, 09:30 PM
I bought a new 901-102-026-01 OEM flywheel which was recommended for a 6 conversion using the stock 901 gearbox. After 7000 miles the ring gear is toast but the starter gear looks ok. I suspect the problem is with the starter/starter gear. While searching for a new flywheel I found vendors don't necessarily agree on the part number. One vendor carries only the -01 wheel specifically for this application. The other vendor carries a -01 and a -02, both OEM, and insists the -02 is the only one that fits. Anyone know if there is a difference in the two wheels or is it just a vendor numbering issue? Also any thoughts on the ring gear problem?
If anyone has a new or like new flywheel for this app you are looking to sell, I'm in the market.
Thanks
Ron
Posted by: wndsrfr Mar 7 2017, 06:27 AM
I bought a new 901-102-026-01 OEM flywheel which was recommended for a 6 conversion using the stock 901 gearbox. After 7000 miles the ring gear is toast but the starter gear looks ok. I suspect the problem is with the starter/starter gear. While searching for a new flywheel I found vendors don't necessarily agree on the part number. One vendor carries only the -01 wheel specifically for this application. The other vendor carries a -01 and a -02, both OEM, and insists the -02 is the only one that fits. Anyone know if there is a difference in the two wheels or is it just a vendor numbering issue? Also any thoughts on the ring gear problem?
If anyone has a new or like new flywheel for this app you are looking to sell, I'm in the market.
Thanks
Ron
Just had the same thing happen to me, wonder if there's a bad batch of flywheels out there.... is your starter o.e. type or not?
Posted by: Perry Kiehl Mar 7 2017, 06:37 AM
I'll bet you are not using a Bosch starter.
"I'll take Hi-Torque starters for $1000 Alex"
BTDT, get a factory starter.
Posted by: gereed75 Mar 7 2017, 07:50 AM
What is the deal on hi torque starters. I just started using one as they seem widely accepted. Had not heard there was an issue. Wha's up?
Posted by: 6freak Mar 7 2017, 08:12 AM
I never could understand why someone would use them with a stock engine when the stock works very! and at 1K 
Posted by: jd74914 Mar 7 2017, 08:21 AM
IIRC some of the high-torque starters have gear engagement depth problems and need to be shimmed.
Posted by: Root_Werks Mar 7 2017, 09:03 AM
I bought a new 901-102-026-01 OEM flywheel which was recommended for a 6 conversion using the stock 901 gearbox. After 7000 miles the ring gear is toast but the starter gear looks ok. I suspect the problem is with the starter/starter gear. While searching for a new flywheel I found vendors don't necessarily agree on the part number. One vendor carries only the -01 wheel specifically for this application. The other vendor carries a -01 and a -02, both OEM, and insists the -02 is the only one that fits. Anyone know if there is a difference in the two wheels or is it just a vendor numbering issue? Also any thoughts on the ring gear problem?
If anyone has a new or like new flywheel for this app you are looking to sell, I'm in the market.
Thanks
Ron
If I remember correctly, the only difference is the marks. An early 911 flywheel works fine, but doesn't have the additional marks for adjusting valves.
Posted by: rudedude Mar 7 2017, 09:17 AM
Had the same issue with my stock flywheel when I used the high torque starter for new high compression motor. Now back to stock starter which works fine with new flywheel.
Posted by: brant Mar 7 2017, 09:47 AM
What is the deal on hi torque starters. I just started using one as they seem widely accepted. Had not heard there was an issue. Wha's up?
I've had 3-4 different hi torque starters over the years
The better ones all work perfectly
it was one of the cheap, ebay versions that used to sell for around 100bucks
it had basically the wrong nose cone, which allowed the engagement depth to be too deep.
I believe the OP will verify, that it is the inboard ring gear teeth edge that are gone/50%gone.
you can hold your hi torque up to a stock starter or better hi torque starter and see the difference in plunge depth of the bendix when pulled out to full extension
if it throws too far out, or too deep when compared to stock..... then you need a shim on the mounting surface.
Some of these starters actually came with this correct shim
I have one with the shim on my street car that has now been used for many many years.
Posted by: Perry Kiehl Mar 7 2017, 12:19 PM
I really do like the idea of a lighter weight more powerful starter.
I'm not 100% sure I could tell you which one will or will not eat your flywheel, so I don't recommend them.
To carry the banner for our dear departed Crusty one, I've never had a Bosch starter lunch a flywheel, and I wouldn't buy anything else.
If you bring me your car and XYZ starter I'll put it on, but that's it.
Posted by: rwfms Mar 7 2017, 05:43 PM
I bought a new 901-102-026-01 OEM flywheel which was recommended for a 6 conversion using the stock 901 gearbox. After 7000 miles the ring gear is toast but the starter gear looks ok. I suspect the problem is with the starter/starter gear. While searching for a new flywheel I found vendors don't necessarily agree on the part number. One vendor carries only the -01 wheel specifically for this application. The other vendor carries a -01 and a -02, both OEM, and insists the -02 is the only one that fits. Anyone know if there is a difference in the two wheels or is it just a vendor numbering issue? Also any thoughts on the ring gear problem?
If anyone has a new or like new flywheel for this app you are looking to sell, I'm in the market.
Thanks
Ron
Just had the same thing happen to me, wonder if there's a bad batch of flywheels out there.... is your starter o.e. type or not?
OE Bosch 003 911 023A was on the car. Not sure if it is a 914 starter or a starter off a '69 911, I had both.
Posted by: rwfms Mar 7 2017, 05:57 PM
I bought a new 901-102-026-01 OEM flywheel which was recommended for a 6 conversion using the stock 901 gearbox. After 7000 miles the ring gear is toast but the starter gear looks ok. I suspect the problem is with the starter/starter gear. While searching for a new flywheel I found vendors don't necessarily agree on the part number. One vendor carries only the -01 wheel specifically for this application. The other vendor carries a -01 and a -02, both OEM, and insists the -02 is the only one that fits. Anyone know if there is a difference in the two wheels or is it just a vendor numbering issue? Also any thoughts on the ring gear problem?
If anyone has a new or like new flywheel for this app you are looking to sell, I'm in the market.
Thanks
Ron
If I remember correctly, the only difference is the marks. An early 911 flywheel works fine, but doesn't have the additional marks for adjusting valves.
Thanks!
Posted by: 914Sixer Mar 7 2017, 07:10 PM
I prefer the 74- up 911 starter. The starter is 1.5 hp, almost twice the horsepower of the .8 stock starter. Plug and play. It is best to up the gauge of the cable from the battery to the starter when you make the upgrade.
Posted by: rwfms Mar 7 2017, 08:44 PM
I prefer the 74- up 911 starter. The starter is 1.5 hp, almost twice the horsepower of the .8 stock starter. Plug and play. It is best to up the gauge of the cable from the battery to the starter when you make the upgrade.
Thanks Mark
Posted by: porschetub Mar 8 2017, 12:52 AM
the starter stock is more than enough,Bosch make great starters when I reconditioned them years ago most only needs a clean and lube,the worst I found needed commutator machined and new brushes and these were old starters back then,save the reduction high torque starters for high comp petrol motors and diesels 
.
Sounds like the OP may have had a flywheel with no induction hardened teeth...easy to check with a hand file the tips should be bloody hard.
Posted by: rwfms Mar 8 2017, 12:46 PM
the starter stock is more than enough,Bosch make great starters when I reconditioned them years ago most only needs a clean and lube,the worst I found needed commutator machined and new brushes and these were old starters back then,save the reduction high torque starters for high comp petrol motors and diesels .Sounds like the OP may have had a flywheel with no induction hardened teeth...easy to check with a hand file the tips should be bloody hard.
Thanks for the tip. I'll let you know when I get the gearbox out.
Ron
Posted by: Larmo63 Mar 8 2017, 02:51 PM
With regards to the original question, on my 2.7 build, should I go Kennedy for the flywheel, PP, TOB, clutch, etc, or buy OG Porsche stuff?
6 bolt flywheel, stock 901 gearbox.
I've gotten various opinions.
Posted by: mepstein Mar 8 2017, 03:25 PM
We buy a fair amount of those type of parts from kep. Always works out well.
Posted by: forrestkhaag Mar 8 2017, 07:30 PM
For what it is worth, I bought the KEP product as to clutch, t/o, etc with the correct ring gear for my 901 (on recommendation from Steve after years of his use ((on a 915)) w/o issue).
It bolted up to my 911 3.0 and starter motor and the 901 w/o issue. Now to actually start the beast.... 
Is there an emoticon for scared shitless?... 
Posted by: porschetub Mar 9 2017, 12:36 AM
the starter stock is more than enough,Bosch make great starters when I reconditioned them years ago most only needs a clean and lube,the worst I found needed commutator machined and new brushes and these were old starters back then,save the reduction high torque starters for high comp petrol motors and diesels .Sounds like the OP may have had a flywheel with no induction hardened teeth...easy to check with a hand file the tips should be bloody hard.
Thanks for the tip. I'll let you know when I get the gearbox out.
Ron
Sorry to seem forgetful but did we work out what your engine was ,sorry but never googled your part number for the flywheel presume a 6 bolt ?
Posted by: rwfms Mar 9 2017, 09:00 AM
the starter stock is more than enough,Bosch make great starters when I reconditioned them years ago most only needs a clean and lube,the worst I found needed commutator machined and new brushes and these were old starters back then,save the reduction high torque starters for high comp petrol motors and diesels .Sounds like the OP may have had a flywheel with no induction hardened teeth...easy to check with a hand file the tips should be bloody hard.
Thanks for the tip. I'll let you know when I get the gearbox out.
Ron
Sorry to seem forgetful but did we work out what your engine was ,sorry but never googled your part number for the flywheel presume a 6 bolt ?
'70 911 2.2E, 6bolt
Posted by: rwfms Mar 9 2017, 09:09 AM
the starter stock is more than enough,Bosch make great starters when I reconditioned them years ago most only needs a clean and lube,the worst I found needed commutator machined and new brushes and these were old starters back then,save the reduction high torque starters for high comp petrol motors and diesels .Sounds like the OP may have had a flywheel with no induction hardened teeth...easy to check with a hand file the tips should be bloody hard.
Thanks for the tip. I'll let you know when I get the gearbox out.
Ron
Sorry to seem forgetful but did we work out what your engine was ,sorry but never googled your part number for the flywheel presume a 6 bolt ?
I think Root Werks is right about the timing marks on the flywheel. I haven't confirmed that with the vendor but I will.
Posted by: larryM Mar 11 2017, 01:48 PM
I prefer the 74- up 911 starter. The starter is 1.5 hp, almost twice the horsepower of the .8 stock starter. Plug and play.
be aware - there was a run of those 1.5 starters that had a "thin" nose bushing - which tended to crack - resulting in chewed-up ring gear
i trashed 2 new 914-6/901 flywheels with one of those 1.5 Bosch starters (that i b'ot new) before i found that cause on a pelican thread - i no longer know the link but it was circa April 2012 after i posted the message below:
- you can just get the ring gear replaced by RIMCO - they do a nice job and understand our stepped flywheels http://forums.pelicanparts.com/porsche-911-technical-forum/715620-901-215mm-flywheel-ring-gear-repair.html
i now run a genuine IMI HiTorq on my 3.2 - and on my 454 chevy - both b'ot on eBay
- if ya just want a good used higher torq oem 3.2 Bosch starter ('89) - i have one on shelf FS
.
Posted by: mepstein Mar 11 2017, 01:56 PM
I prefer the 74- up 911 starter. The starter is 1.5 hp, almost twice the horsepower of the .8 stock starter. Plug and play.
be aware - there was a run of those 1.5 starters that had a "thin" nose bushing - which tended to crack - resulting in chewed-up ring gear
i trashed 2 new 914-6/901 flywheels with one of those 1.5 Bosch starters (that i b'ot new) before i found that cause on a pelican thread - i no longer know the link but it was circa April 2012 after i posted the message below:
- you can just get the ring gear replaced by RIMCO - they do a nice job and understand our stepped flywheels http://forums.pelicanparts.com/porsche-911-technical-forum/715620-901-215mm-flywheel-ring-gear-repair.html
i now run a genuine IMI HiTorq on my 3.2 - and on my 454 chevy - both b'ot on eBay
- if ya just want a good used higher torq oem 3.2 Bosch starter ('89) - i have one on shelf FS
.
Great info!
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