RB30-POWER

haha, so true.

What speed are you pulling in first gear @ 7500rpm in the GTR?

Yeah the GTR's even in stock form are animals. Even stock, I would have a fair guess and say they would mince your GTST, even with 207rwkw.

Ok, so there might be a problem with the oil cooler then... What problems was he having? I was looking at it all and couldnt see why the rb30 valve would make a difference, it should only bypass oil, if the filter causes a restriction. The oil cooler connects to the block just as an ordinary filter would and should operate just the same as a standard filter, regardless of the extra bypasses in the cooler itself? Well then if that is a problem, if i bunged the rb30 bypass up with a grub screw it would function exactly as the RB25 would, correct? The oil pump i removed had a wider collar for the crank drive than the RB30 pump had. But the RB25 crank drive was identical in all specs to the RB30. With regards to the oil stuff in the cylinder. The motor had done approx 40,000 when i got it the other day. It was a complete running rb25det. No oil in the inlet manifold and i dont think the valve stems would be stuffed on every cylinder on a low k motor to allow oil in. I think its fuel as it wipes off easy as?

I have for sale one RB25DET bottom end only. (From series II car) I have taken the head, oil pump and dipstick for my twin cam conversion. The motor would suit someone that either has a blown rb25 bottom end or wants a fresh one, without the cost of rebuilding theirs. The motor had only done a legit 40,000k, it looks like new still. It was a bit of a shame to pull it down really as it was a complete mint RB25DET series 2 with hardly an km's. Im located in Newcastle NSW. Any reasonable offer accepted as i need it gone.

Ok, stripped my RB25DET motor today to start the conversion. I found the oil cooler will basically bolt straight up to the RB30 block without drama, the rb30 will have the extra filter bypass valve, but that shouldn't matter. Should function as normal. The Series II RB25DET oil pump will bolt straight up to the rb30 crank without drama. (It must be only the r33 gtr and up that has a larger oil pump?) I think i will get the VCT gallery welded up in the head. If i use a bung it may crack due to the thermal expansion rates of the head and bung? And would anyone like to confirm where and how much weld they built up on the rb25 head water gallery for better clamping in the below picture, please? Cheers Mick

As topic states im chasing the following. RB25DET, factory alloy cross over pipe. (goes from throttlebody across the cam covers) and The rubber inlet tubing from the air flow meter to the compressor inlet. Name your price and see if we can work something out. Cheers Michael

Thats a general rule of thumb for most motors. 78degC sounds preety fine to me. I mean if it were lower than the thermastat temperature then it would be a problem. i.e If you said it was running at 50degC all the time, then there would be a problem.

And remember if you only get it sometimes, I bet its on the cooler days that it cuts out because the air is more dense. Which will cause the AFM to read more air, naturally.

Well the factory torque peak figure for the rb25det is at 4400rpm (295nm) Generally where peak torque is, this is where the motors volumetric efficiency is at its greatest (where it can take in maximum air per cycle) Thats basically what cams do, they move the peak volumetric effiency point around the rev range. And where the rev point that the motor can use maximum air is, you are going to get maximum torque. So anyway, back to the point, around 4400rpm is where the RB25 cams allow the motor to take in maximum air. So my guess would be that is why its cutting there. (Thats the point where the motor makes peak torque and uses maximum airflow it can, which must be just tripping the Air Flow meter cut) You could always get a fuel cut defender, this holds the air flow meter voltage as high as it can without actually cutting. Some more info on VE here. http://www.epi-eng.com/ET-VolEff.htm

Its a series II that i am stripping if that makes a difference with regards to the cam covers?

Just a couple of quick questions, Does the RB25DET oil cooler bolt straight to the RB30 block, or is it different somehow, maybe the filter bypass valve is different or something? I haven't removed it yet for actual inspection myself, but im sure someone would know? Also what is this extra drain for, i assume oil? Should i extend the line and plumb it into the sump? Because I have seen a few conversions where this line has just been crimped shut, therfore no drain, is it critical. Once again I havent removed it yet for actual inspection. Cheers for any help

When you see R33s for sale for around $15k. Not many people are going to look further, especially the $20k+ mark. Most owners are just boy racers and will take whatever they can get cheap and flog that out. To find a genuine buyer who is interested in the bigger picture, it will take a while, especially being an import, hard to get parts, hard to insure, boy racer image, blah blah... I've seen GTR's for just a tad over $20k mark now.

No idea how thick the wheel centre is, but you could only take a couple of mm or so at best. It woudn't be recommended as the wheel will lose alot of structual strength and could fail with a few potholes etc.

Just remember if you are using spacers and you had an accident and your insurance company finds out, you will get reamed hard

fins or ribs, whatever you want to call them i suppose.

Hard to explain. But the 32 calipers have some small fins on the side of the caliper towards the top of where Nissan is embosed on it. The 33 calipers are slightly larger and are smooth all over and have no fins. Hope that makes some sense.

Remember these cars are already tuned for hi octane jap fuel. So advancing the timing further is possibly asking for trouble.

3lit3 Fors3, lol at that signature

Make sure that you have a fully functioning genuine Nissan Thermostat. Rated at 76.5degC (stamped on it) $30 from Nissan if thats the problem. The thermostat is designed to commence opening at 76.5degC and be fully open at approx 90degC. So yeah, the temp should be within this mark when at operating temperature. Also with age the Clutch Fan can be engadged all the time, and not allowing the motor to warm up properly. The clutch centre is viscous type, and should only tighten up when its warm. And the last thing, make sure the guage is right that you have the temp reading from. Does it use an independant sensor or is it piggybacked to the factory sensor? If its piggybacked you can get wrong readings.

I would consider 86-92degC normal operating temp for these motors. 86 cruising 92 idle with air-con on + hot day. If its way lower than that, you are going to get bad economy and accelerated engine wear.

If the motor has been fully rebuilt they do tend to run a little warmer due to them being tight. Probally not to this degree though. When you start the car when its cold can you hear the clutch fan (should be louder when cold because the clutch oil runs to the bottom of hub). My point is it should be engaged when you first start the car. After a couple of minutes it should dis-engage and go quiet. It should then re-engage when the motor comes up to temperature. If the hub is functioning and your sure of that, it may be one of two problems. If the radiator was removed and allowed to dry out so to speak from sitting empty while motor was getting worked on. It may have had some internal corrosion/sludge flake off the tanks and block some of the rows effecting cooling capability. If you reverse flush the radiator, (the opposite way that they water normally runs) you may blow any debre/crap out of the radiator thats causing possible trouble. If you are sure the radiator is fine as well. The next thing would be to look at the FMIC and how much it is impeding flow to the radiator. If it is a large bar and plate and the only way to the radiator is through the cooler, my guess is this may be your problem. I've fitted heap of coolers with never having any negative effects to engine temp but there has always been an alternate way for the radiator to get air flow, not just from through the cooler. (Not familiar with the setup you have so cant comment) The only other things it could be is faulty water pump (unlikely) excessively retarted timing which causes manifold to glow red hot and overheat motor. (unlikely). You have already mentioned that the thermastat is ok?

Excuse my ignorance, im not a daily visitor to this site, but I can try to offer some suggestions to you. What car do you have? When did it start overheating?

A 16" thermo isn't going to cool better than the factory clutch fan anyway. A working clutch fan will pull way more cfm of air than those crappy thermos ever will. I don't think this will fix your problem.

If you have a vacuum leak after the Air Flow Meter. The car will run like shit if at all. Seal up any holes left from the old re-cirulation type BOV if you are not using it anymore. Also make sure the spring tension on the BOV is set correctly or it will leak there as well.