proengines

Put the VG30 bolts on the shelf or ebay and buy the ones that fit. Rod bolts aren't something to take a risk with. you do need to resize the rods once you fit bolts, you can't fit them while the rod is in the engine, it takes quite a bit of force to remove the old bolt and you only need a tiny bit of misalignment to put the tunnel out of shape. You'd be better off leaving the standard bolts in there rather than stuf around fitting the wrong ones. Might be a better option to buy a set of used 26 rods which the bolts will fit and are a heap stronger than the 25 ones.

I've got an almost new (about 500km) HKS 264 intake cam here going cheap if you want it. It's to suit the vvt 25. From memory, thats as big as HKS goes for a bolt in.

The VG30 ones fit the RB26 rods, For the RB25 you can use SR20 bolts.

.0035 maybe?

Hi Bernie, the RB30's use a different conrod bearing to suit the larger diameter conrod journal so you can't use RB26 ones. The mains are the same dimensions, the RB26 mains have more oil feed holes which you don't need in an RB30 but won't hurt anything using them. Cheers, Greg.

Unless you had another reason I wouldn't be pulling it out or apart. A collar or 33 crank is a good idea as part of a rebuild but a lot of money if you're paying someone to pull the engine out and strip it just to do that. If the oil pressure is ok I'd leave it as it is and pay a couple of grand extra on the mortgage or a holiday.

That sounds fine. Neither is a worry.

I won't k-line these heads, they don't last. Use CA18 guides as described above. heat the head to remove them and heat the head and freeze the guides to install them. The only time i've seen guides worn is where they have had k-lines fitted, I've also seen a CA18 head where the guide has come loose. K-lines have their place, just not in these engines.

Gday Paul, they are just normal metric sizes, you shouldn't have a problem getting them.

The crankshaft runs on a hydrodynamic wedge of oil which can be squeezed out when the crank sits for a bit and the crank sits against the bearing. Once you turn the crank you pull oil between the crank and the bearing and the crank floats on it. I'd still check the end float, most bearings are made at the maximum thrust flange width which can reduce the thrust clearance anyway. It's quite common to have to sand the thrust face of the bearings to provide the proper end float. Cheers, Greg.

Check the end float on the crank, you need to set the thrust bearings up to both sit hard against one thrust face of the crank while you tighten the main bolts.

Theres no problem taking the threads out to 12mm. You are going from 11 to 12mm at the same pitch. I redrill the counterbore first, then drill the centre of the thread to the tapping drill size for a 12mm thread. When you tap the thread, you have to make sure that you catch the tap in the original thread or you will end up with a mess rather than a thread. I do it all in the mill, it keeps it straight and square. If they do it in the mill, they will need to pop it into neutral on the spindle to get the tap started, then engage it and cut the thread. Using a HSS tap, its no problem to power tap it using the mill. I do the whole process on one bolt hole at a time, it's a bit slower because you are constantly changing tooling but it keeps everything aligned spot on. There's no problem helicoiling them if they need it.

Theres some interesting rumours going around. I haven't shut down, I'm still at the same address, just in one workshop instead of the two I had before. I have got out of general reconditioning and am concentrating on this type of work, as well as producing parts like the sump adaptors and crank collars (and oil pump gears when I get some spare time.) The easiest way to get hold of me is by e-mail, sales@proengines.com.au or phone 0448 826256. I got rid of the landline as I spent all day answering it and couldn't do any work while I was. Leave a message on the mobile if I dont answer and I'll get back to you. Cheers, Greg.

Run them with the nominal clearance built into them. That is, if they are .5mm pistons finish the block at 86.5mm. CP knows a lot more about pistons than anyone here or their mate and thats the way they make them, with the correct clearance built in at the nominal size. You'll probably find it's .003"ish. There's a lot more to it than just the material they are made from.

.014-16" exh, 015-.017" inlet will be fine

If the bottom of the guide is cut off at an angle it will wear quicker than one that is the right length and square on the end. The valve probably wont wear but the guide will. Saying that, it can still take quite a while for them to wear and if it was worn far ehough to affect the compression it would pour smoke out and make some valvetrain noise. Pull the exhaust manifold off and have a look down the port and you should see if there is oil runing down the guides. Check the turbo while you're at it, had one of my engines diagnosed by a supposedly reputable workshop with valve stem seal problems which have ended up being a turbo seal. A leakdown test is probably worthwhile first.

Those pistons will run .05mm or so clearance. They are not your usual forged piston which is forged from a billet, they are more along the lines of pressure cast. Being hypereutectic, the coefficient of thermal expansion is a lot lower than a piston forged from a lower silicone content alloy, so not so much difference in size from cold to hot. It would be a lot cheaper to buy a set of pistons than to have the block sleeved.

Cheers Rockabilly for the nice words, it makes it worth the weeks it took getting everything digitised and making sure it all fits. Thanks for your faith buying it from the other side of the world! Let me know once you have it all up and running. As for the twin vs single, I did a 25/30 a couple of months ago, a fairly basic engine with forged pistons, rods, mls gasket, std valves with some porting and a pair of 256/264 cams, not using the vvt, just a pair of adjustable gears. The engine is in a 33 GTST running a single 35/40 1.06 rear housing (from memory) on a chinese manifold, Plasmaman plenum, 660cc injectors etc. It makes boost from just under 3000 and pulls like a train. It made 364kw at the wheels a couple of weeks ago when it was being tuned and masses of torque. Any more power would be useless in a 2wd on the road. Personally, if I was starting from scratch I would go single, it's a lot cheaper and simpler to do. Then again, in a GTR everything else is already there for the twins so why not stick with them unless they need to be replaced.

Those pistons are Hypatec liquid forged. They are a semi forged piston and are hypereutectic. They are sold by Precision International, they are not a bad piston though I haven't used them in any turbo engine. More info here: http://www.precisionintl.com/HTML/product/...hypatec_lf.html

Standard 25 or 30 head bolts are 11mm. You shouldn't have a problem at that size but I'd check the length of the bolts against each other and replace them if there is more than .5mm or so difference in the underhead length.

I haven't used those springs bit if they are a double you will need to machine the seat area for the inner spring. There should be an installed height in the instructions, though it's probably in japanese. Most decent machine shops should be able to set up the springs for you.

The standard bore isn't nitrided. There is no problem boring RB's oversize, I did one late last year to 88mm and it's been making over 700rwhp without any problems. Even at 88mm you only reduce the thickness of the cylinder walls by 1mm. I wouldn't sleeve one unless you had a valid reason to, a split bore or the like. As for the pistons, if they are still on size and not cracked there shouldn't be a problem reusing them. Have a good look at the pin bores as they might have some galling due to the lack of oil supply. If the pin bores are damaged, throw them away. otherwise, clean up the skirts with scotchbrite and make sure there is nothing foreign embedded in them. Also, fit some new rings. I wouldn't do it on a customers engine but for your own it is not a problem if the parts are ok. Weigh up the cost though, sometimes a new set won't cost a whole lot more by the time you pay someone to measure and crack test them, buy new rings and circlips etc. Rings for many of the forged pistons about can cost over $300 a set with proper steel top rings etc.

It's probably easier to swap the CAS to suit the drive if you can get hold of one at a decent price. Most of the importers here would probably not be interested in swapping a cam that someone overseas sold to you. Sometimes it may cost a tad more to buy parts here but along with the bit extra you spend you also get support from the sellers. Tuneagent and Hi Octane sell the Poncams for a good price and usually have them in stock.

That should help with the bearing and tunnel sizes. If you work to around .002" clearance on both the mains and conrod bearings and around .004" end float you wont have issues. Unless the crankshaft needs to be ground, just polish it. The main bearing tensions are the same as an RB26 and if you're not using aftermarket rods, fit a set of ARP VG30DETT rod bolts. You will need to trim the length of them to clear the cradle. It's a good idea to fit an RB26 oil pump as well as a drive collar while you have it apart. Apart from that the bore size is 86mm standard, the same as the 26. What are you doing to get the compression up to a decent n/a ratio? You could run an RB26 piston and deck a fair bit off the head which will get you well up in the 9's, all depends how much you take off the head. If you're using an RB20/25 sump you will need to bend the little baffles at the rear to clear the conrods when they rotate. I hope this helps Cheers, Greg.

Hi Mark, thats not one of mine. Mine uses either a bolt on internal pickup or a blockoff plate for the pickup hole if you're using an external pickup. The bolts fit properly, all the drilling, countersinking and tapping is done in a CNC mill, as well as the silicone groove. Pick below to show the difference. Cheers, Greg.