6 cylinder conversion… what do you really need

For you flat four Porsche 912 fanatics

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Spit Nolan
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6 cylinder conversion… what do you really need

Post by Spit Nolan »

Ok not everyone’s cup of tea doing this, but should someone be doing it, what do they actually need to be able to get it all up and working.

So obviously a complete 6 cylinder engine..
An oil tank that would need to be installed into the inner wing.
Engine mounts welding in.
A 6 cylinder tacho instead of a 4 cylinder.
A fuel pump.
Electrics wise, it looks quite different to the 912, so what do you fully need?
Any other wiring modifications etc?

Plan this for a 2.0 carb’d engine so no injection etc to worry about.
Yes how long is a piece of string, but humour me please guys :)
‘67 912 “Scruffy B*stard”
‘68 VW Bay Westy Campmobile - very original family camper.
SeanP
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Re: 6 cylinder conversion… what do you really need

Post by SeanP »

Oil tank
Engine mounts
Engine mount bar and cradle
Tach you can use one of Bob Ashlocks converters
Fuel pump for Carbs
Loom is the same on a 912 you just have to find the spare wires tucked in the engine bay and behind the dash for whatever gauges you want to run.

Make sure that the engine has a 901 gearbox flywheel or find one.
CDI box if you want to run one
Oil lines for the oil tank
Oil filter fitting and filler neck on the oil tank. If running an early tank
Fuel lines to carbs
engine tinware
Alternator regulator
Exhaust
Make sure that your brakes and suspension are up to scratch

In the middle of converting a LWB 912 to a 2.2E on carbs at the moment.

Hope that helps

Sean
1966 912
1969 912/6 hotish rod in build
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Bruce M
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Re: 6 cylinder conversion… what do you really need

Post by Bruce M »

Step1:
Check what the DVLA will say if you send them a V5 change to the capacity & cylinder count, and then if you think it’s likely they will ask to inspect the car, will they consider it a non standard chassis (welded engine mounts) and a modification under the rules.
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KS
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Re: 6 cylinder conversion… what do you really need

Post by KS »

Bruce M wrote: Mon Jun 19, 2023 2:54 pm Step1:
Check what the DVLA will say if you send them a V5 change to the capacity & cylinder count, and then if you think it’s likely they will ask to inspect the car, will they consider it a non standard chassis (welded engine mounts) and a modification under the rules.
V5c doesn't specify number of cylinders, only capacity. Change of capacity is unlikely to raise any questions.
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Spit Nolan
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Re: 6 cylinder conversion… what do you really need

Post by Spit Nolan »

Thanks guys… Sean that’s great mate thank you!
‘67 912 “Scruffy B*stard”
‘68 VW Bay Westy Campmobile - very original family camper.
jury
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Re: 6 cylinder conversion… what do you really need

Post by jury »

I think this is still correct :


So after afew months of head scratching I think I have finally solved the problem of attaching the '70 911 Gearbox to the original '68 Stub axles. The rumour was that using 914 parts would be the answer. Andy (Lightweight_911) had kindly supplied me with some 914 Output shafts, and I picked up some 914 C.V's and Driveshafts on Germany Ebay. The 914 Driveshafts are 47,0cm long, the magic number I needed was 41.5cm , so after considering having the 914 shafts shortened ( don't really know how this would be done without he things snapping when in use ) I looked again at the original Driveshafts that came with the car.........41.5cm!!! and these have the same splines as the 914 C.V joint !!! Can it really be that straight forward :shock:

So long story short....I believe that this is finally the correct combination:

Image


All the C.V's are currently in a friends Ultrasonic Cleaning Bath, so I can check the condition. HOWEVER, I do need another 901 driveshaft if anyone has one lying around....the other Shaft that was fitted looks like it came from something else.

I believe that this is the original, and what I need:
- 41.5cm Length
- 27.0MM Across Splines
- 33 Splines
Image

Image



Cheers
Chris
# 465

1967 912 Polo Red
1968 912/11 RAL 7001 ' MOD ROD '
1990 964 C2 Velvet Red
1991 VW Vanagon GL (SOLD - Vanagone)
2017 Coleman CT200U

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Bruce M
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Re: 6 cylinder conversion… what do you really need

Post by Bruce M »

That looks suspiciously like a VW beetle driveshaft (laster version has the pair of ridges to locate the inner end of the CV boot). Those are 415.5mm long and 33 splines. They take a CV with a 24mm wide inner cage so total length of spline is 27-28mm.
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