The best Starter for the 951
01-30-2019, 11:00 AM
#16
Race Car
The sleeve and alternate bracket definitely fixes the issue.
We had this problem with an 8V race car and on the rare occasion it would happen (hot race engine, increased compression), you'd swear the starter mount portion of the bell housing was gonna shear off.
Not something you like to hear 5-700 miles from home at a race event.
Finally decided to investigate, replaced setup with larger ID bracket and sleeve, never had problem again.
On the life of a starter in general, again, race cars (and street) exhaust stays extremely hot for 1.5 hours continuous, I use the factory 944T heat shield and cover it with reflective gold stick on heat shield from Pegasus Racing. Been carrying a brand new Bosch starter as a track spare for 7+ years and haven't needed it yet.
T
We had this problem with an 8V race car and on the rare occasion it would happen (hot race engine, increased compression), you'd swear the starter mount portion of the bell housing was gonna shear off.
Not something you like to hear 5-700 miles from home at a race event.
Finally decided to investigate, replaced setup with larger ID bracket and sleeve, never had problem again.
On the life of a starter in general, again, race cars (and street) exhaust stays extremely hot for 1.5 hours continuous, I use the factory 944T heat shield and cover it with reflective gold stick on heat shield from Pegasus Racing. Been carrying a brand new Bosch starter as a track spare for 7+ years and haven't needed it yet.
T
01-30-2019, 10:45 PM
#17
Rennlist Member
Engine in car, but I had the intake off. The hardest part was loosening up the socket head bolts - I believe I had success using three extensions from under the car along the bellhousing. I replaced these bolts with standard hex-head type on reassembly.
Gaping wasn't a problem using a thin washer temporarily glued to the sensor. It is pretty tight in there though, and I was almost certainly swearing.
Gaping wasn't a problem using a thin washer temporarily glued to the sensor. It is pretty tight in there though, and I was almost certainly swearing.
Turn the motor to tdc and install the sensor with the washer to set the gap, tighten down the bracket applying light pressure to bracket preventing it from moving away. Remove washer from the sensor. Probably wise to replace both sensors while your in there since they are a know weak point on our cars. Much easier to do with the intake removed.
The sleeve and alternate bracket definitely fixes the issue.
We had this problem with an 8V race car and on the rare occasion it would happen (hot race engine, increased compression), you'd swear the starter mount portion of the bell housing was gonna shear off.
Not something you like to hear 5-700 miles from home at a race event.
Finally decided to investigate, replaced setup with larger ID bracket and sleeve, never had problem again.
On the life of a starter in general, again, race cars (and street) exhaust stays extremely hot for 1.5 hours continuous, I use the factory 944T heat shield and cover it with reflective gold stick on heat shield from Pegasus Racing. Been carrying a brand new Bosch starter as a track spare for 7+ years and haven't needed it yet.
T
We had this problem with an 8V race car and on the rare occasion it would happen (hot race engine, increased compression), you'd swear the starter mount portion of the bell housing was gonna shear off.
Not something you like to hear 5-700 miles from home at a race event.
Finally decided to investigate, replaced setup with larger ID bracket and sleeve, never had problem again.
On the life of a starter in general, again, race cars (and street) exhaust stays extremely hot for 1.5 hours continuous, I use the factory 944T heat shield and cover it with reflective gold stick on heat shield from Pegasus Racing. Been carrying a brand new Bosch starter as a track spare for 7+ years and haven't needed it yet.
T
Thanks All!
02-03-2019, 01:38 PM
#18
Rennlist Member
Interesting - I haven't come across this thread before... I slotted my bell housing when I did my clutch. Ever since then I get what I'm now guessing is the starter kickback. I couldn't figure out what that knock was about. It doesn't happen all the time. Should an '89 already have the sensor sleeve?
02-03-2019, 02:48 PM
#19
Rennlist Member
Just added the shielded reference sensor sleeve/bracket to my 85 NA 8V race engine. Seems to have totally fixed the starter kickback issue which developed right after I slotted the bell housing. FWIW, I have the Ideola high torque starter but I think you're going to have this problem regardless of which starter motor you have if you don't shield the reference sensor.
02-03-2019, 07:57 PM
#20
Nordschleife Master
Interesting - I haven't come across this thread before... I slotted my bell housing when I did my clutch. Ever since then I get what I'm now guessing is the starter kickback. I couldn't figure out what that knock was about. It doesn't happen all the time. Should an '89 already have the sensor sleeve?
02-10-2019, 03:13 PM
#21
Drifting
Speaking of starter heat shields... Yeasterday, to fix a sticking bendix, I R&R'd my starter. The heat shield on my '88 951 is bolted to one of the torque-tube bolts! It's the most annoying thing, consuming much time and foul language.
Funny thing is on writeups for starters, even those on a turbo, I never see this heat shield design. It's brutal!
Funny thing is on writeups for starters, even those on a turbo, I never see this heat shield design. It's brutal!
02-12-2019, 09:21 PM
#22
Rennlist Member
From what I understand from the Technical Bulletin issued by the factory was that from 87 Porsche notched all bellhousings for ease of maintenance. They then quickly found that it caused issues (interference) with the starter and added a sleeve to prevent it. Adding to the problem some earlier bellhousings (82-86) were also notched by the dealerships (or by owners) to aid maintenance. In some cases sleeves were not added to the earlier cars though anything after 88 should have a sleeve fitted at the factory. Basically 30+ years on anything could have happened so it’s best to check, especially if you are having issues with starting. Btw the issue usually doesn’t cause a “no start” issue, it is more of an occasional bucking or hesitant start that can feel quite violent. Here’s the TSB: