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6volt to 12volt flywheel conversion
Split nut - April 5th, 2004 at 06:37 PM

I'm trying to fit a 12 volt flywheel on a 1200 previously 6 volt engine. I have taken the 6 volt flywheel off and tried to put the 12 volt one on but can't get it to go all the way on because there's a lip on the crankshaft that marries up nicely with a step on the 6 volt flywheel. The 12volt flywheel hasn't got the same lip and therefore I can't get the damn thing to go on far enough. I've never heard of this and was always told it was an easy, take the 6volt off and put the 12volt on in it's place, operation.

The only other thing I can think of is to put the 6 volt flywheel on and change the starter to a 6 volt starter and run it still on 12 volt. It's going in a 68 (1500) beetle for a friend, so it needs to be reliable. If it were mine, I wouldn't worry and just run the 6 volt starter, but I'd like to do the flywheel conversion if possible.

Also, this is the first time I've pulled the motor out of a beetle. We had all sorts of strife getting it out. Is there any tricks I need to know to get it back in???

Thanks.

Ross.


vw54 - April 5th, 2004 at 07:42 PM

Yep you have found the problem, the crankshafts are different and there fore the flywheels wont interchange easy.

You either have to strip the engine and have the crankshaft machined to make a step in it ..... or

Have the 12 V flywheel machine out where it mates to the crank to allow it to fit to the 6V crank.

Ive just done this myself the latter is easier

NEXT the bellhousing is smaller in a 6V gearbox plus the starter shaft bush is different. This area also has to be looked at

Dont mix n match the flywheels and starters either as they have different amounts of teeth and they wont engage when trying to start the engine.

Seach this subject in the forum as its been talked about before.


Split nut - April 5th, 2004 at 08:03 PM

Thanks Dave,

The car (being a 68) is a 12volt already. I want to keep it that way, the problem is that it's not mine and time is short. The change of a 6 volt flywheel isn't going to bother anything except for the starter change to a 6 volt to match the flywheel and of course the bushing in the gearbox to match the starter. The main problem is that the fella that owns the car, understandably doesn't want to mix and match parts. It's already 12 volt and he wants to keep it ALL that way.

The only other change would be the clutch size from 200 down to a 180mm.

I might have to try to get the flywheel machined.

Any other suggestions appreciated.

Thanks.

Ross.


vw54 - April 5th, 2004 at 08:05 PM

Yes OK so getting the flywheel machined out would be the quickest and easiest and less item to change as well.

If you can get hold of an early crankshaft to measure without it being in the engine would be easiest as well.


vw54 - April 5th, 2004 at 08:06 PM

Where abouts are you located fill in your profile ???


Split nut - April 5th, 2004 at 08:12 PM

Dave,

I'm in Hervey Bay QLD (300k's North of Brisbane). I know I should fill in my profile, but can't work out how.

Ross.


68AutoBug - April 5th, 2004 at 09:13 PM

The 180mm clutch should work OK with a 1200cc engine...
Does the owner of the 1500 Beetle know that its NOT going to Perform like the original engine...
I didn't know that the 12v flywheel didn't bolt onto the 6v crankshaft... without machining ... learnt something Here..
I don't know of any tricks to pulling an engine out & replacing it... its just a Mongrel of a job.... I have a removeable rear fiberglass valance which makes taking the engine in & out a piece of cake, with the tyres only an inch off the ground.. by Myself...
Best of Luck... Shame You couldn't find a 12v 1500 or 1600 engine to bolt back in...

Lee


Split nut - April 6th, 2004 at 07:54 AM

Yeah, I explained about the power drop. The problem is that his engine is shagged and he needs something reliable and the 1200 has only done 5000 miles since rebuild. I had another 1600 here that I could have put in, but it's an unknown quantity.


lugnuts - April 6th, 2004 at 03:27 PM

You have to tilt the motor down at the muffler end to get the drive shaft through the clutch release plate,once it s through you can push the motor in and straighten it up,getting the driveshaft all the way in is just fiddling around and trial an error.


crazyluke - April 6th, 2004 at 08:58 PM

remove the section of tinware b4 u wack it back in and make sure the cluth plate is dead centralon the flywheel. u may have to grind out about 1mm of meat in the bellhousing to fit 12v f/w but u can do this by bolting up the engiine while its running (only the last 1/2 inch though. i think a certain 12v f/w will go straight on possibly a 200mm job. all that aside, a 6v starter will last for bloody ages on 12v if its not a bitch to start.