Jump to content
SAU Community

Recommended Posts

i bought a motor and gearbox setup and just curious about it before i put it in my R31.

what i was told be the bloke i bought it off was he had it in his drift R31 car before he destroyed the rear end of the car

its aparently a VL turbo block with forged internals rb20 redtop head with rb26 internals in the head as i say wat i was told

and the gearbox is from an GT-R with the transfer case cut off and sealed up apparently they have a stronger centre shaft

hes said it was pushing 450hp-650hp depending on wat turbo/intercooler setup was used and recons it runs 500hp day in day out

now im just wondering if it could work, and or wat peoples opions are about it will attach a picture

post-64604-0-65934200-1295267075_thumb.jpg

Link to comment
https://www.sau.com.au/forums/topic/350747-rb20-redtop-headrb30-block/
Share on other sites

ok i was told from someone else that a rb20 redtop head was the only 20 head that bolted straight on aswell as the r32 rb25

well sound like im one step up from before anyway lol cheers

it looks like a rb20 head to me in every way, as far as im aware the rb20s dont flow as much air due to the smaller valves.. without knowing exactly whats been done its hard to speculate what sort of power its capable of, but i guess 400-450hp may be more realistic than 650hp.. i would stick on a gt30r n see how it goes

People used to bolt rb20 heads to rb30 blocks in the old days (like, early 90's) because rb25 and 26 heads were still rare and prohibitively expensive. There is a lot more modding to do to the rb20 head to fit to the rb30 block (eg bore size is different) compared with the other conversions but people did it because they didn't have much choice in those days. Nowadays nobody does it for the reasons mentioned above.

In terms of flow, it stands to reason that the head and valvetrain would be modified because stock for stock, taking off the sohc head and putting on the 2.0 twin cam doesn't net that much of a benefit, you have to mod the 20 head to make the whole thing worthwhile IMO (which is what appears to have been done in this case).

it looks like a rb20 head to me in every way, as far as im aware the rb20s dont flow as much air due to the smaller valves.. without knowing exactly whats been done its hard to speculate what sort of power its capable of, but i guess 400-450hp may be more realistic than 650hp.. i would stick on a gt30r n see how it goes

It's definately a HR31 RB20 NICS Red top head. No doubt about it.

Not R32.

As for it being a 3ltr. Look @ the block number.

Either way a LOT of dicking around to get that kinda setup to work - as frankly, it doesn't without some serious time/effort and even then the results are poor as the head simply does not flow.

yer even silvertop heads arent worth it because they dont flow but using a NICS head, might aswell buy an excel....

you can see from the pic that its a 30 block, the tensioner has been relocated above the water pump.

i remember about 14 or so yrs ago there was a vl commo that ran a red top rb20 head. apparently theres alot of wok to get them to fit, but as said above back in the day they were the only cost effective option. have a poke around on the commodore forums u may be able to dig up some info.

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

    • Update: Tunehouse looked into the problem and identified a wiring issue between the camera unit and the connector. They managed to get it working , but did warn me at some point it will stop working again. From their perspective it is unserviceable and will need replacement. They did some research and found that the new replacement camera would be Approx $1400 supply only (their fitting cost would be $190) . They did provide the part number (28442-JL05B) and a quick google of the part number shows that these are rather expensive brand new (seemingly no longer in manufacture) for the places that still have them in stock, with the used option potentially presenting  the same issue down the track at some unknown point. They are happy for me to supply the part so that they can fit it. Decisions, decisions... I can definitely recommend Tunehouse (thankyou Vee37!). Cost for the diagnosis was as quoted  ($190) , car was ready on time and communication was top notch. Their workshop is super clean and modern, and there was plenty of car candy parked out the front on the day I went.   Would definitely go back.   
    • to fix the voltage drop issue I swapped out the old 150amp alternator which turns out is a brand known for having issues and replaced it with the black 180amp alternator beside it 
    • For anyone interested, the Way Back Machine has that Japanese website archived with pictures, etc: https://web.archive.org/web/20051023225805fw_/http://www.a31cefiro.com/air_con.htm "Simply swapping the wiring of the harness will not allow it to function properly. For the outdoor air sensor and sunlight sensor, disconnect the wiring connected to CN1-11 of the air conditioning harness from the harness and connect the sensor side wiring to earth. For the indoor air sensor, disconnect the wiring connected to CN2-3 of the air conditioning harness from the harness and connect the sensor side wiring to earth. The connector PIN numbers listed here are the genuine A31 PIN numbers. To avoid incorrect wiring, check with a tester before wiring. Also, disconnect the wiring in a location close to the sensor. The disconnected harness side wiring will not be used, so be sure to insulate it." Wish someone sold a conversion harness to just plug-and-play a Kouki 180sx digital climate control into C33/A31. I'm decent with wiring but feeling kinda lazy about taking this on. Edit: Did some more digging and found a helpful Minkara blog post about the conversion as well: https://minkara.carview.co.jp/userid/1831116/car/1360568/2284209/note.aspx "After installation is complete or the battery is replaced, you need to go into self-diagnosis mode and set the internal air recirculation. The way to do it is to "hold OFF with the key on for more than 5 seconds, set the number to 5, then press 卍→C." ↑↑↑It probably won't make sense unless you actually try it (・∀・)." Lol wtf
    • Maybe SAUNSW could see howany members would do a motorkhana day if Schofield's is still available for a reasonable price...
    • Skip the concrete, we just need to smooth a field. Mark knows how to drive a grader Duncan   I reckon 100x100 flat area for skid pan style, and then some sort tracks for rally... Duncan's already got a rally car on the premises to...
×
×
  • Create New...