Guest Anonymous Posted July 6, 2002 Share Posted July 6, 2002 An Aust made RB-30 block & crank can be had for $300-400US which is 3 ltr and the parts and pistons for NA and turbo are widely avail. The RB30 was a SOHC cross flow.The RB30det was avail in a Holden Comadore Turbo and was durable and fast. Now,an RB25det head is a 24 valve crossflow design with twin cam & Variable cam timing from a Skyline GTS-T. These heads sell for approx $700US (I checked).S/H The RB-25 head will bolt straight onto a RB-30 block with the only mod needed is a oil way for the Variable cam timing. So we have a 3 ltr 24 valve variable cam engine that can take a turbo. Note this has been done in West Aust. Add a Garret steel turbine GT30r turbo,and the availability of an electronicly controled cam timing,that fits in to a Z easly,.......any thoughts ? (An RB26DETT head would also fit but is big $ and the stud size is larger.) I would love to do this.Sorry if this is old news. Quote Link to comment Share on other sites More sharing options...
kalium99 Posted July 8, 2002 Share Posted July 8, 2002 Very common idea in australia...all though it isnt done a hell of a lot I dont think.The RB26 head breathes much better than the RB25....but $$ does beome an issue I guess. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 20, 2002 Share Posted July 20, 2002 theres a guy in aus that builds those for $3000 USD, less turbo and ecu. Quote Link to comment Share on other sites More sharing options...
RB30-ZED Posted July 20, 2002 Share Posted July 20, 2002 A used RB30 short motor ( no cylinder head, as a lot of the single OHC heads cracked )can be bought for less than $500US here in Australia. I got my RB25VVT head for $225US, why not build your own? Steven Quote Link to comment Share on other sites More sharing options...
Guest Zpeed Posted July 22, 2002 Share Posted July 22, 2002 i'm most likely planning on doing this also... and u have the displacement of a 3ltr twin cams, and the whole lot.. so it will go hard... Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 8, 2002 Share Posted August 8, 2002 I HAVE SEEN A COUPLE OF THESE CONVERSIONS(RB25DE HEAD ONTO RB30)BOTH RUNNING HYBRIB GARRETT T3/4 TURBOS, THE LEAST POWERFULL ONE PRODUCED 290KW AT WHEELS, VERY NICE CONVERSION,I'M SERIOUSLLY LOOKING AT DOING IT, THERES SOMETHING WRONG IF YA CANT MAKE 400-450HP EASY, GO HARD OR GO HOME. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 14, 2002 Share Posted August 14, 2002 Can the rb25de head be put on the turbo rb30? How easily does the rb30det fir into a 240z? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 27, 2002 Share Posted August 27, 2002 As the RB30 block is taller than the rest of rb engines, once ya fit the RB25DE head to rb30 block will it all fit below 240z bonnet- has anyone done this mod in a 240z, and if so is there any pics out there, thanx Quote Link to comment Share on other sites More sharing options...
RB30-ZED Posted August 29, 2002 Share Posted August 29, 2002 Yes i have the three litre block and RB25 head with the over the top manifold, under the bonnet of my 240, you can see some pics of it at, http://zdriver.com/rides/detailride.php?cat=1&relIdx=14&vehId=1118&Vote=Yes or my home page. Steven Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted September 12, 2002 Share Posted September 12, 2002 So about this guy that builds them. Anyone know who he is or where? and if he will do the rb26 head if we got the cash? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted September 12, 2002 Share Posted September 12, 2002 Also are you guys talking about the engines out of VL's? Quote Link to comment Share on other sites More sharing options...
RB30-ZED Posted September 14, 2002 Share Posted September 14, 2002 Yes Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted September 16, 2002 Share Posted September 16, 2002 Has anyone built a normally asperated version of this combination? I prefer non-turbo simplicity, weight, and handling through the twisties. From what I've read, the RB25/26 heads have a larger combustion area than the RB30, so the compression ratio would go down from around 9:1 to 8:1. Could the compression ratio be brought back up without installing different pistons? If there are no clearance issues, then a head shave and thin head gasket could be just the key. This might even solve the need for a longer timing belt. Matthew 73 240Z torn apart edition Matthew 73 240Z torn apart edition Quote Link to comment Share on other sites More sharing options...
Guest Zachb55 Posted September 16, 2002 Share Posted September 16, 2002 hmm, would this be reliable and powerful? sounds like a nice setup with an rb26 head for pretty damn cheap, i wonder what it would cost to put together here in the states... Quote Link to comment Share on other sites More sharing options...
RB30-ZED Posted September 16, 2002 Share Posted September 16, 2002 Hi Mathew, my engine is a N/A and yes the compression ratio will drop to around 8.3:1. But the RB25 pistons have the same diameter and has a bigger dome top, the only difference is in the pin height which is less than 1mm higher in the RB25. I used the RB25 pistons and decked the block 0.8mm, this gave me 10.5:1. See it here! http://www.240z.org/photopost/showgallery.php?cat=500&user=1957&thumb=1 Also http:/au.photos.yahoo.com/arkij60 Steven Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted September 16, 2002 Share Posted September 16, 2002 So whats this im hearing about a larger timing belt? Just what mods do you have to do to build this thing up? Is it just the belt or are there other things aswell. I'm from Australia too and think this swap would be a ton cheaper then alot of the others ive looked at. So any info you could give me would be great. Quote Link to comment Share on other sites More sharing options...
RB30-ZED Posted September 16, 2002 Share Posted September 16, 2002 Here is every thing you need to know. http://trinity.frontierisp.net.au/~rowan/twincam.htm Steven Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted September 19, 2002 Share Posted September 19, 2002 Thats a great sight I think Im gonna send a frame to get 3/4 chassied and set up the methenol injection.... Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted September 20, 2002 Share Posted September 20, 2002 One other question, Did you have to fab engine mounts ect to put a rb30 in like people have to with rb26's and such. What about mounts from VL's are those usable in anyway ect? Just courious cos I like the more simple "bolt in" swaps then the ones where you spends 1/2 your time at an enginer getting mouts/driveshafts done. Quote Link to comment Share on other sites More sharing options...
RB30-ZED Posted September 21, 2002 Share Posted September 21, 2002 You do have to make up new mounts, cut and shut a sump, move the top spout in the radiator, make up throttle linkage, exhaust, gear box mount, engine management ect ect, but isnt that the fun of doing the job. if this type of work is not for you , you would be better off going and buying some thing you like than half doing the job. Steven Quote Link to comment Share on other sites More sharing options...
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