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I have made a conversion flywheel out f a type4/wbx hub from a auto flexplate that i have machined into a german type1 200mm flywheel.
the stock flexplate was attached to the hub by 10 "rivets"
mu initila plan was to use the 10pcs of 5mm countersunk and 10 pcs of 6mm hex bolts with some minor TIG welding.
the problem is the 6mm hex bolts come to close to the flywheel seal.
so i want to weld it stuck.
i have access to MIG and TIG
BUT have worries about warping.
the hub has a pressfit to the flywheel
should i preheat the flywheel prior to welding and do you have any other tips?

thx

How do you plan to balance the fly wheel ?

balance it my Schenck balancer

looks like mild steal ? cant tell from the pics .if it is you shouldnt need to pre-heat .if its a hardned steel like 110-18 then I could see doing a little pre-heat .from the first pic it looks like aluminun and there again it depends on what type 5356 or what ?

not shure regarding steel quality.
german flywheel supposed to be a forging of some kind

could be cast steal if it is definatly tig it .if you try to stick weld cast steel it can get hard to the point of being brittle .I ran into this prob at work and had to heat a piece cherry red jjust to get a hole drilled in it .Im not realy sure what cause this prob but the parts that i tig welded were no troble to drill and tap.

machining the german type 1 flywheel makes very nice long "spirals" .
not as the WBX/type4 flywheels which is cast and only produces small chip when turning it.
also the cast type4/wbx flywheel turns rock hard when welding.
i tried TIG welding 2 tiny small holes on it (where the TDC pins sit) and the drill went down imediatly .

anyone know what DPR does to his conversion flywheels?
I'll make a test on a scrap flywheel

Hi Fastback,
here the FW Jose send me last year: seems to be a T1 200mm welded and machined on the center

I'm still more curious about what went into Wallys 228mm setup made from a (forged) 914 215mm FW.
If you turned the ring gear back ~6mm as well as taking the plate mount/friction surface back ~2mm, it appeared to leave a clean friction surface.

On tyour setup, I'd probably preheat it some to keep expansion etc under more control, and TIG it.
Kinda hard to get perfect results w/o a lot of experimentation as DPR has surely done.

I think the "how are you going to balance it" comment was meant more like "where are you going to put more holes for balance?" (grinder is better anyway)

I kinda suspect a simple surface fuse won't cut it structurally, V cut and fill both sides.

I would venture a guess DPR may use an automated submerged arc setup, perhaps also for building up cranks.
That can be thought of as MIG, but the results are different, as the weld is covered deeply with a granulated barrier/flux material, also retains heat.
(commonly used for large structural weldments)

well i took a chance and welded it,
I preheated the assembly to 200°C in a pizza oven and TIG welded it with a mild steel rod.
it did not warp at all and the weld did not get hard either.
could easily drill in both weld and flywheel
so fingers crossed that it holds up!

regarding balancing , the flywheel has more enough meat in it to balance if not the Schenck balancer can be also be setup to add material.

That thing is psycho!

look's a bit nifty with the 36-1 trigger pattern

ED 2.4; does the DPR seem to be welded completely in the center and then machined to WBX/type4 pattern or does it seem to be spliced from 2 pieces?
do you have a pic from the backside also?

Hi Fastback,
sorry but no more pics and engine is finished now,and yes the center was clearly be completely welded and machined to a T4/WBX pattern ,
but on the crank side ,the rear seal "lip" with the o-ring groove seems to not be welded ,i think it's the original machining ,
after a little thinking ,the "lip" shape of the FW have a T4/WBX diameter (of course)so the base it's not a forged T1 FW as i previously said ,sorry
Now i think it was a damaged old forged T4 FW(PP and balancing holes were dirty) that Jose have welded the damaged bolt holes .