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914 - bus flywheel to crank bolts
Posted: Wed Oct 07, 2020 4:13 pm
by pnikas
Hello everybody ,
I am going to build a 2.4 type 4 for my bug using A 914 transmission , I will install a 914 clutch , as long as a 914 flywheel . Does anybody have the 914 flywheel to crank bolts measurements compared to the bus ones ? I have the impression that the 914 ones are longer .
Thanks
Re: 914 - bus flywheel to crank bolts
Posted: Wed Oct 07, 2020 4:20 pm
by V8Nate
Just out of curiosity can you just flip the 3rd member around so you don't have 5 reverse gears or are you making a mid engine bug?
Re: 914 - bus flywheel to crank bolts
Posted: Wed Oct 07, 2020 4:42 pm
by pnikas
V8Nate wrote: ↑Wed Oct 07, 2020 4:20 pm
Just out of curiosity can you just flip the 3rd member around so you don't have 5 reverse gears or are you making a mid engine bug?
Flipped the diff, installed a bug@5speed nose cone and front mount , now is the same as a 901 trans
Re: 914 - bus flywheel to crank bolts
Posted: Wed Oct 07, 2020 5:44 pm
by V8Nate
Badass!
Re: 914 - bus flywheel to crank bolts
Posted: Thu Oct 08, 2020 1:42 pm
by Steve Arndt
The bolts are the same.
Re: 914 - bus flywheel to crank bolts
Posted: Thu Oct 08, 2020 3:45 pm
by pnikas
Steve Arndt wrote: ↑Thu Oct 08, 2020 1:42 pm
The bolts are the same.
U sure ?
Most places sell them as different .
Re: 914 - bus flywheel to crank bolts
Posted: Thu Oct 08, 2020 6:55 pm
by dstar5000
THE NAME PORSCHE DEMANDS MORE $$$.....
Re: 914 - bus flywheel to crank bolts
Posted: Thu Oct 08, 2020 9:27 pm
by Piledriver
The 914 flywheel flange area is actually thicker, and the bolts are a little longer, at least the ones from the factory.
Having said that... The std t4 bolts are not the concern...
The worry is accidentally using the long 914 bolts in a bus flywheel and having them bottom out, not clamping the flywheel properly.
That scenario will fail miserably, quickly and very likely expensively.
Just be aware its a possible issue, and shorten the bolts if needed
(aka measure stuff).
Note that a vanagon 228mm setup works fine in a 911/914 trans, just needs the input shaft bearing or bushing installed.
That will hold more power with less pedal effort... the 914 one is forged though.
IIRC Wally converted a 914 fw (215mm) into a 228mm and installed the twin disc setup at one point, maybe Kennedy did the mods, been awhile, have slept since then.
I would not hesitate at all using std t4 flywheel bolts on a porsche flywheel, just be aware the heads may need shaved down some to not hit the clutch disc bits due to the thicker flange. Also, the disc will get closer to the bolts as it wears, and they wear quite a bit eventually.(228s take a lot longer)
Note that when you have the flywheel refurbed, the flange area under the bolts should be cut the same amount as the friction surface and plate mount faces for the same reason...
The type4store once carried some very hd flywheel bolts, and IIRC someone (in Europe?) sold bolts that basically had an almost press fit shoulder where it passed through the flywheel, may have been ream to fit.
Re: 914 - bus flywheel to crank bolts
Posted: Fri Oct 23, 2020 1:00 am
by Wally
Right on Pile!
BTW, those shouldered HD bolts are indeed 'ream to fit' (13,10mm iirc) and are (still) from BAS (Ahnendorp.com), CSP (also germany) also has theirs these days iirc or directly from from Thorsten Pieper:
http://www.tp-technologie.de/produkte%2 ... rauben.htm
Already 3 options for those as you see. It has never been this good!

Re: 914 - bus flywheel to crank bolts
Posted: Mon Oct 26, 2020 12:21 pm
by Clatter
Re: 914 - bus flywheel to crank bolts
Posted: Fri Oct 30, 2020 10:19 am
by cal 67
Porsche: ~25mm, Bus: ~20mm
Re: 914 - bus flywheel to crank bolts
Posted: Sun Nov 01, 2020 6:16 am
by dstar5000
THOSE ARE CLUTCH PLATE BOLTS....
DON
Re: 914 - bus flywheel to crank bolts
Posted: Sun Nov 01, 2020 8:46 am
by Piledriver
The good flywheel to crank bolts are closer to $10 each...
Type4store does not appear to carry them.
These look ~ideal... have the required thin 12 point head for a 12 point socket.
https://frsport.com/arp-204-2802-flywhe ... -1970-1976
...but the same part# on arps website looks wrong, they are for 911s and are triplesquare socket head cap bolts.
...probably work in an automatic flexplate on a t4.
Re: 914 - bus flywheel to crank bolts
Posted: Sun Nov 01, 2020 4:38 pm
by dstar5000
Piledriver wrote: ↑Sun Nov 01, 2020 8:46 am
The good flywheel to crank bolts are closer to $10 each...
Type4store does not appear to carry them.
These look ~ideal... have the required thin 12 point head for a 12 point socket.
https://frsport.com/arp-204-2802-flywhe ... -1970-1976
...but the same part# on arps website looks wrong, they are for 911s and are triplesquare socket head cap bolts.
...probably work in an automatic flexplate on a t4.
I BOUGHT A SET OF THOSE FOR THE FLEXPLATE AND TORQUE CONVERTOR THAT I HAVE....
Re: 914 - bus flywheel to crank bolts
Posted: Mon Nov 02, 2020 7:48 am
by Steve Arndt
These are what I have. The enlarged shank acts like a "dowel". The flywheel is reamed to precision fit the bolt shank.
https://www.ahnendorp.com/VW-Type-4---P ... anguage=en