spooledup Posted June 23, 2010 Share Posted June 23, 2010 ive heard that if you have a RB25DET head and a VL commodore block (RB30) all that needs to be done is the bolt holes on the head need to be drilled out and retapped and then its a straight bolt on, i know its not much help to you guys wanting to do rb26/rb30 conversions but yehh Link to comment https://www.sau.com.au/forums/topic/106224-rb30dettt-gtr-conversion-thread/page/13/#findComment-5308497 Share on other sites More sharing options...
bubba Posted June 24, 2010 Share Posted June 24, 2010 ive heard that if you have a RB25DET head and a VL commodore block (RB30) all that needs to be done is the bolt holes on the head need to be drilled out and retapped and then its a straight bolt on, i know its not much help to you guys wanting to do rb26/rb30 conversions but yehh wut? 25DET heads need a gallery welded to suit the 30 block and AFAIK only 26 heads need the block drilled/tapped for bigger studs.. The only plug and play heads are the R32 RB25DE heads. Link to comment https://www.sau.com.au/forums/topic/106224-rb30dettt-gtr-conversion-thread/page/13/#findComment-5310165 Share on other sites More sharing options...
BoostdR Posted July 11, 2010 Share Posted July 11, 2010 Dipstick tube needs to be changed to the RB26 one as the rb30 is 35mm shorter. Or mark your rb26 Dipstick High level 35mm higher. Rb30 water outlet that fits in the side of the thermostat housing is smaller in diameter than the rb26 and has an extra small port of the top. Rb26 one can be fitted. (taps out, press fit) Oil filter thread need to be screwed out and replaced with the one from the rb26 block so the oil cooler, temp and pressure sensor can be fitted Cam sprocket cover and needs to be widened if using an OS giken style idler pulley adaptor. Lower cover needs to be widened and extened to meet the top cover. Rear block oil outlet(to head) needs to blocked off Water pump bracket needs to be modified as the top bracket bolt goes to the block instead of the head now. Fit your turbo oil return Tee before bolting the sump on. lengthen front Diff breather hose 38mm. When using ARP RB25 head bolts with 26 head. Extra washers may be required with a thin head gasket and shaved head as I ran out of thread. Main girdle bolts. 3x long required extra washers. The long bolt in the center needs to be grinded shorter to clear the front drive shaft. Don't forget to block the oil pressure outlet on the block under the rear knock sensor port off. Link to comment https://www.sau.com.au/forums/topic/106224-rb30dettt-gtr-conversion-thread/page/13/#findComment-5340981 Share on other sites More sharing options...
bubba Posted July 12, 2010 Share Posted July 12, 2010 Water pump bracket needs to be modified as the top bracket bolt goes to the block instead of the head now. Power steering pump.. not water pump. Link to comment https://www.sau.com.au/forums/topic/106224-rb30dettt-gtr-conversion-thread/page/13/#findComment-5341338 Share on other sites More sharing options...
BoostdR Posted July 13, 2010 Share Posted July 13, 2010 Power steering pump.. not water pump. thats the one! Link to comment https://www.sau.com.au/forums/topic/106224-rb30dettt-gtr-conversion-thread/page/13/#findComment-5345032 Share on other sites More sharing options...
Althotas Posted October 24, 2010 Share Posted October 24, 2010 When using ARP RB25 head bolts with 26 head. Extra washers may be required with a thin head gasket and shaved head as I ran out of thread. So whats the exact process with using the RB25 bolts with the 26 head, does anything need to be tapped etc? I'll be using a standard thickness headgasket and stuff Cheers Link to comment https://www.sau.com.au/forums/topic/106224-rb30dettt-gtr-conversion-thread/page/13/#findComment-5514010 Share on other sites More sharing options...
jangles Posted October 25, 2010 Share Posted October 25, 2010 (edited) use stock 25 bolts, unless youre going all out. you can get the block tapped out to suit the 12mm studs that the 26 uses standard but it is not required. RIPS one of the no doubt proven twin cam builders uses the smaller 11mm bolts.. they clamp down the heaad, the dowels locate it Edited October 25, 2010 by jangles Link to comment https://www.sau.com.au/forums/topic/106224-rb30dettt-gtr-conversion-thread/page/13/#findComment-5514749 Share on other sites More sharing options...
BIT SUS Posted February 24, 2011 Share Posted February 24, 2011 I haven't read it in this topic, but if I was to build a 30/26 for rwd use, what sump arrangement would be best? Would this eliminate the need for an adapter plate? And solve many bonnet clearance issues? Link to comment https://www.sau.com.au/forums/topic/106224-rb30dettt-gtr-conversion-thread/page/13/#findComment-5686924 Share on other sites More sharing options...
rockabilly Posted February 24, 2011 Share Posted February 24, 2011 rb25 sump bolt straight on no adapter bonnet issues yes in a 32 not a 33/34 Link to comment https://www.sau.com.au/forums/topic/106224-rb30dettt-gtr-conversion-thread/page/13/#findComment-5686965 Share on other sites More sharing options...
bubba Posted February 25, 2011 Share Posted February 25, 2011 Just have to remove (or bash flat) the crank scrapers at the rear of the sump otherwise the 30 crank will smash them to pieces. Link to comment https://www.sau.com.au/forums/topic/106224-rb30dettt-gtr-conversion-thread/page/13/#findComment-5687384 Share on other sites More sharing options...
JonnoHR31 Posted February 25, 2011 Share Posted February 25, 2011 or you can use the 30 sump if the block comes with one and you dont have a 25 one. my 25 sump wouldnt even sit in place with the scrapers, dunno how you'd manage to bolt it all up. and it fouled on the girdle, not the crank itself. Link to comment https://www.sau.com.au/forums/topic/106224-rb30dettt-gtr-conversion-thread/page/13/#findComment-5688638 Share on other sites More sharing options...
bubba Posted March 2, 2011 Share Posted March 2, 2011 You'd be amazed at what some people are capable of.. that includes fitting things that don't fit Link to comment https://www.sau.com.au/forums/topic/106224-rb30dettt-gtr-conversion-thread/page/13/#findComment-5695298 Share on other sites More sharing options...
bigjiz Posted April 19, 2011 Share Posted April 19, 2011 hey all im just about to start building a 30/26 but im worried i wont be able to get it roady for it, will i need a mod plate for it if so where can i get one from. i live in brissy Link to comment https://www.sau.com.au/forums/topic/106224-rb30dettt-gtr-conversion-thread/page/13/#findComment-5770425 Share on other sites More sharing options...
33SOM Posted February 12, 2012 Share Posted February 12, 2012 hey all im just about to start building a 30/26 but im worried i wont be able to get it roady for it, will i need a mod plate for it if so where can i get one from. i live in brissy Would like an answer to this Link to comment https://www.sau.com.au/forums/topic/106224-rb30dettt-gtr-conversion-thread/page/13/#findComment-6231553 Share on other sites More sharing options...
Simonster Posted March 20, 2012 Share Posted March 20, 2012 Keep it registered while the engine is built. Then just notify old transport of the new motor with the new engine number. Mine was a NSW registered car- so i had to get a roadworthy anyway- I didn't have any issues. Depends if the guy doing it knows what it is. When he sees the extra pice between the block and sump you could say its just extra bracing. Link to comment https://www.sau.com.au/forums/topic/106224-rb30dettt-gtr-conversion-thread/page/13/#findComment-6282256 Share on other sites More sharing options...
Marko R1 Posted March 20, 2012 Share Posted March 20, 2012 Mine was also registered with the rb2630 Link to comment https://www.sau.com.au/forums/topic/106224-rb30dettt-gtr-conversion-thread/page/13/#findComment-6282726 Share on other sites More sharing options...
bigjiz Posted March 20, 2012 Share Posted March 20, 2012 But what about the extra capacity? wouldn't they be onto it when the block no. starts with rb30 not rb26?, i thought u would need it compliance for the engine conversion Link to comment https://www.sau.com.au/forums/topic/106224-rb30dettt-gtr-conversion-thread/page/13/#findComment-6282834 Share on other sites More sharing options...
r32-25t Posted November 5, 2012 Share Posted November 5, 2012 What size oil restrictors are people using in their 30/26 I've got that back one block and a 1.5 in the front and can't seem to get enough oil to the head to feed the rear cam journal on the exhaust cam Link to comment https://www.sau.com.au/forums/topic/106224-rb30dettt-gtr-conversion-thread/page/13/#findComment-6609947 Share on other sites More sharing options...
luke gtr Posted November 5, 2012 Share Posted November 5, 2012 What size oil restrictors are people using in their 30/26 I've got that back one block and a 1.5 in the front and can't seem to get enough oil to the head to feed the rear cam journal on the exhaust cam doesnt sound right.blocked gallery, or large cam clearances? Link to comment https://www.sau.com.au/forums/topic/106224-rb30dettt-gtr-conversion-thread/page/13/#findComment-6610902 Share on other sites More sharing options...
r32-25t Posted November 5, 2012 Share Posted November 5, 2012 All been checked and checked, have a new idea if what it could be Link to comment https://www.sau.com.au/forums/topic/106224-rb30dettt-gtr-conversion-thread/page/13/#findComment-6611186 Share on other sites More sharing options...
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