Jump to content
SAU Community

Recommended Posts

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

Link to comment
https://www.sau.com.au/forums/topic/301079-rwd-awd-det-block-differences/
Share on other sites

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

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.

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!

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

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!

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.

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

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • My take on gg2 48mm, 54mm, 58mm, and 62mm compressor map for same size compressor vs gg1 : All gg2 only outflow gg1 above 20 psi. As all g gen 2 surge line at lower left of comp map move to the right, all gg2 sacrifice spool vs same size gg1, surge line move to the right worst for 54mm gg2. So for same size compressor if you want best response, use gg1, if you want max hp at >20psi use gg2 but you will be laggier vs same size gg1. Max compressor efficiency drops to max 75% on all gg2 vs max 76%-80% of same size gg1. Iirc lower efficiency means hotter iat less dense air so lower hp at same operating point of comp map. Also curious why gg2 is mapped to lower max rpm vs same size gg1 (only 48mm size both gg1 gg2 mapped to same rpm) : 54mm gg1 165,000 rpm  vs  gg2 160,000 rpm. 58mm gg1 150,000 rpm vs gg2 140,000rpm. 62mm gg1 145,000 rpm vs gg2 140,000 rpm. If gg2 can safely spin to gg1 rpm then they can flow a bit more than as mapped. Good thing that all gg 2 interchange compressor and turbine housings with same size gg 1. So gg1 owners can buy gg2 chra only if planning to boost >20psi.
    • My stuff is all with Shannon's, granted, I don't really have imports I'm driving on the road, however, I've had multiple cars at the same time with them. Presently we have the Landcruiser on laid up cover, Sarah's Kluger on full cover, and the house insured. About 18 months ago Sarah wrote her Subaru Liberty GTB off, insured with Shannon's, and the payout, and buy back of the wreck was super quick. In 2020 we had the VF Commodore totalled in a major hailstorm. Storm was on the Saturday, I called on the Sunday and lodged it, vehicle was towed on Tuesday night, assessment team called on Wednesday to say it was a total loss and get payout details, money was in the bank on Thursday morning. Have had a few other claims both at fault, and not at fault, over the years, and never had an issue with them.   Funnily enough, they're also the cheapest insurer I find for things like Sarah's Kluger.   I will say I'm less impressed dealing with them lately around "the experience", as a lot of their staff that you deal with aren't car enthusiasts. Shannon's has a much more main stream feel ever since they decided to become "big corporate", laid a heap of staff off, and then hired a bunch of non enthusiasts. At the same time they've been making a push to be less "call us and we'll personally have someone who cares help" to "hey, this computer can do stuff for you" and are trying to get more square pegs to fit round holes. (That's just the vibe I get from them). Again, have had no issues with claims with them, but get a bit of a "less personal" feel from them.
    • A thing I wasn’t happy with with enthusiast was during the initial phone call they told me they’d insure it for 130k but needed photos.   I then sent them photos and they told me $80k as there were other cars either similar modifications available for around that price, I told them to send me the links to said cars so that I can buy them. i then sent the modification list with prices of the parts (no labor) and the price then came to 115k, which is still shy of the 130 that was agreed in the initial phone call 
    • Ask me a bit later this week before payday
    • I agree that delayed payment probably isn't the most suitable solution. It seems a solid complete transaction would be best. As I wouldn't be using this sale as a line of credit that would typically earn interest, we can probably arrange a much cleaner single transaction deal. I can do $92.52 today. Would you prefer EFT, or Cash on Pickup?  😛
×
×
  • Create New...