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Rwd & Awd Det Block Differences?

GTS4WD

By GTS4WD,
in Engines & Forced Induction

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GTS4WD Grand Master

GTS4WD

Posted
Posted

Hey guys!

Have an AWD 25DET at home, wanna throw it in something RWD.

How different are the mounting faces between an AWD block and RWD sump?

Anyone have photos of an AWD block without the diff to compair bolt pattern between the block and the RWD sump?

Anyone done this?

I have no doubt it can be done, but what mods need to occour if any need to be done?

Any info is greatly appreciated.

While im here,

Can you drop the piston out the arse end of the block via the sump without taking out the crank?

Is there enough spacec or does the crank have to come out too?

Cheers,

Cris

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gfunkk Rising Star

gfunkk

Posted
Posted (edited)

guess im not the expert but all we had to do to put a stagea 4WD rb25 into my mates RWD r32 was change the sump and pickup, and both these things bolted straight on im pretty sure

the other option that we considered was to just remove the front 4WD shafts and weld up the holes that are left behind, but i think the 4WD sump wouldnt clear swaybar... sorry cant remember

Edited by gfunkk
GTS4WD Grand Master

GTS4WD

Posted
  • Author
Posted

Right.

So let me get this straight.

You keep the AWD oil pick up where it originally was located and machine out some of the baffle in the RWD sump so as the oil pick up fits.

Because I have noticed there is another oil pick up location spot (with 2 bolt holes but no oil hole between them) towards the middle of the block. Which means there would not be an baffle cutting needed. But id have to drill a 3rd hole for the oilto go up through the oil pick up.

Im feeling its easier to modify the baffle rather than drill into the block.

And just to confirm aswell. Yes. The bolt pattern is the same. A RWD sump will fir on an AWD block.

Cannot confirm vice versa.

gfunkk Rising Star

gfunkk

Posted
Posted

the second oil pickup port your talking about doesnt actually work

yeah the best way is to undo the shafts, take them out then weld up the two holes they left

infact the AWD sump is better than a normal rb25 sump apparently its better with heat!

D_Stirls Veteran

D_Stirls

Posted
Posted (edited)

The 4WD block has a wider sump flange to fit the wider 4WD sump and has both the holes for the both the RWD and 4WD sumps. The RWD block is narrow and the 4WD sump won't fit. As for the oil pick-up i can't confirm anything as i haven't done my conversion yet.

I'll take a picture if you want but it'll have to be after x-mas.

Edited by D_Stirls
GTS4WD Grand Master

GTS4WD

Posted
  • Author
Posted

ok.

To confirm for future ref.

The 4WD RB25DET block CAN be converted to a RWD sump.

Remove the diff including the sump from the block.

A RWD sump will bolt up.

Only one hole on the RWD sump needs to be enlarged to fit the sump bolt.

The oil pick up must remain where it was originally located as the oil gallery does not extend to the second mounting point.

This requires you to chop a little of the sump baffle to fit the oil pick up pipe.

Clean both mounting surfaces of the block and sump, put new gasket goop, bolt up and your all smiles!

Why bother spending twice the price on a RWD 25DET anymore?

Thanks for the help everyone!

blind_elk Grand Master

blind_elk

Posted
Posted
The 4WD block has a wider sump flange to fit the wider 4WD sump and has both the holes for the both the RWD and 4WD sumps. The RWD block is narrow and the 4WD sump won't fit. As for the oil pick-up i can't confirm anything as i haven't done my conversion yet.

I'll take a picture if you want but it'll have to be after x-mas.

So, if the sump flanges are different widths between the AWD/ RWD blocks, then the sumps ARE NOT interchangeable.

The simple solution is to have a sump custom made to suit the AWD block in a RWD application.

fletch rb30 Enthusiast

fletch rb30

Posted
Posted (edited)

post-50583-1261887895_thumb.jpg

Rb25/26 awd block shown in photo.

You can see the notch in the girdle where the front half shaft goes though the sump. Below that is the oil pickup mount on the rwd version of the block. it cannot go here due to the half shaft tube running below it. The pickup mount to the front of it is the awd pickup.

The outer row of 10mm bolt holes is for the awd sump, the inner row (6mm) will fit the rwd sump. You can grind a little out of the side of the pickup flange and beat the side of the tin rwd sump a bit and it will bolt on.

A few of the holes on the rwd sump line up with 10mm holes in the block. You can ream them out if you want, but a bit sump glue will seal it up no worries

edit- just realised the photo i have attached is of a awd block that has been modded to suit a rwd pickup. They have put a grub screw into the awd pickup mount and drilled the rwd pickup mount. You could do this, but it will require stripping and cleaning the engine after drilling and tapping etc

Edited by fletch rb30

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