Dw12 Crankshaft

[B1ack_Mi16 67]

I agree, the -10cc dish woul give 10.7:1 compression, quite nice.

[welshpug 1,657]

depends how wild you go on the cams, ok for standard ones, not much else though!

[B1ack_Mi16 67]

Of course, I'm fed up with wild cams

[welshpug 1,657]

naaah, they're fine, if it all works together properly, and its mapped well.

[Putte205 4]

Not sure about xu10j2 rods, you might be right. Re-bushing xu10j4 rods will work fine for me, if possible I'd like to use as many standard parts as possible for a start and I can probably re-bush at my work.

 

Kristian, what cc do you use to calculate for head and gasket? 40cc head and 7,? for gasket?

 

Of course I have to check piston to valve clearance, and if needed it can always be adjusted.

[dcc 855]

Rod angle might be issue with such long stroke and long rods.

 

The ew12 block is shorter than the xu10 iron block, not sure what sort of rod and crank room youll have in an xu. Also not sure about the oil pump drive on dw crank in xu.

 

I am tempted to use the dw12 crank instead of the ew12 I have, but not expecting to rev my engine beyond 7500 due to rod length and having 96mm crank.

 

My engine will be around 13-1 cr, using either non vvt gti 138head or the 2.2 head meirions standard XU10J4RS head performs faultlessly on his 2.2.

 

The only concern id have using this crank in xu is half the bearing shells are matched to the block on an ew, it makes it very hard to just build the engine - you need a standard set of bearings, plastigauge and some patience while measuring. The ew using colours for tolerances. I am not sure how this will differ to the xu block with it not being a crank ladder.

[welshpug 1,657]

Specifically that is the case in an xu block as well.

[B1ack_Mi16 67]

Well regarding bearings etc. I suppose it's no worse than using XUD11 bearings on the DW12 crank, can't really see that as a problem at all. Just measure the crank journals to be within tolerance and order appropriate bearings.

 

But the block to rod clearance might of course be a problem, that is hard to address until it is tested.

 

The oil drive I think looked just the same as any other of my XU cranks, basicly I couldn't see any difference between the DW and XU ones. Apart from the Alu block cranks that have different thrust bearing width.

 

Maybe I'll just go for K20 (K568M875) pistons and machine down a bit. A reworked unschrouded cylinderhead to 44cc will give 11:1 exactly.

I was using head volume of 41cc in my calcs, is 40cc definately an orginal Mi16 head?

For HG I use 88mm bore 1.3mm thick = 7.9cc

[Putte205 4]

I cant see any big issues either. Journals are the same size so bearings cant be that hard to find suitable ones, and everything else can be machined to fit. But that we will find out when test mounting in the block.

 

Im unsure about cc, thats the info i found on here. Im going to use 2.0 mi16 head, but ill try to get it measured to be sure about comp ratio. I've seen someone on aussifrogs measure 40cc from gti6 head, when others say its only 36..

 

I'm not even sure I'm going N/A yet, could be fun upgrading my 2.0 T16 in my 205 for a 2.3 T16 if i find suitable pistons/rods

[Putte205 4]

How much is usally custom pistons? I'm tempted to go overboost. Looks like Nissan 300zx wiseco pistons would give me about 8,5:1 comp ratio with standard head, and 2 spare pistons... however pistons would be 3mm down the bore, so no better design than original T16

[dcc 855]

Why notjust buy proper pistons to your design?

[Putte205 4]

I am considering to do so, hence my first question. If custom ones aren't that much more I might as well.

[xy8 4]

Rod angle might be issue with such long stroke and long rods.

 

The ew12 block is shorter than the xu10 iron block, not sure what sort of rod and crank room youll have in an xu. Also not sure about the oil pump drive on dw crank in xu.

 

I am tempted to use the dw12 crank instead of the ew12 I have, but not expecting to rev my engine beyond 7500 due to rod length and having 96mm crank.

 

My engine will be around 13-1 cr, using either non vvt gti 138head or the 2.2 head meirions standard XU10J4RS head performs faultlessly on his 2.2.

 

The only concern id have using this crank in xu is half the bearing shells are matched to the block on an ew, it makes it very hard to just build the engine - you need a standard set of bearings, plastigauge and some patience while measuring. The ew using colours for tolerances. I am not sure how this will differ to the xu block with it not being a crank ladder.

No problems with oil pump drive . Rod to block clearance is tight in places (under 2 mm) , I used xu10j2 block and rods with dw12 crank.

Edited June 13, 2017 by xy8

[B1ack_Mi16 67]

I bought some cheap china H-beam rods for XU10J4RS years ago for this project, but the pin was custom at 22mm pin as opposed to 20mm for a standard RS rod.

 

Now I finally found some quite cheap pistons to buy.

 

Crank I will not offset-grind as that just makes it harder to get "spares" if the crank must be swapped (I'm trying to keep the costs low anyway), so keeping it at 96mm.

 

I have 3D modelled the rod as detailed as I possibly could, and done structural dynamic analysis for inertial loads at 7500rpm with the 96mm stroke. At least it seem to be little stresses due to the inertia / rotational force itself as the pistons are quite lightweight.

 

 

Animation of structural model:

https://imgur.com/a/KCbFktD

 

 

 

 

Edited October 15, 2020 by B1ack_Mi16

[IRISH_MI16 2]

On 10/15/2020 at 12:09 PM, B1ack_Mi16 said:

I bought some cheap china H-beam rods for XU10J4RS years ago for this project, but the pin was custom at 22mm pin as opposed to 20mm for a standard RS rod.

 

Now I finally found some quite cheap pistons to buy.

 

Crank I will not offset-grind as that just makes it harder to get "spares" if the crank must be swapped (I'm trying to keep the costs low anyway), so keeping it at 96mm.

 

I have 3D modelled the rod as detailed as I possibly could, and done structural dynamic analysis for inertial loads at 7500rpm with the 96mm stroke. At least it seem to be little stresses due to the inertia / rotational force itself as the pistons are quite lightweight.

 

 

Animation of structural model:

https://imgur.com/a/KCbFktD

 

 

 

 

What rods and pistons did you end up using after