proengines

Shane, have you thought about machining up a pattern now you have the program done and having the girdle cast in cast iron? Would only take some bulking up in machined areas to leave enough to machine back. Casting would definitely cost less than the 7075 billet and be a a lot less machine time once it was done, plus the benefits of cast iron over alloy in terms of expansion, maintaining bolt tension etc.. Just an idea, I really like what you have done here.

Very nice work! what material did you make it from?

Hey Michelle, did you get the engine back together ok? we really need to get the clubman back in one piece and out there, when is the next meeting?

Heat is what causes them to lose the tension to "clip" into the bearing housing. A lack of oil to the bearing is usually the cause.

I was just reading through and noticed there were no pics of the head so I attached some below. Someone asked what the weight differences of the pistons were, lightest was 366.9, heaviest 368.3, the pins were within .1g. Matching them up with the lightest piston on the heaviest rod small end I had to remove a max of .7 grams from some rods. The crank was balanced as well. The crank balance from Tomei is very good but you can get it a touch better. The kit fitted with no mods to the block or pistons. Overall the 2.8 is a really nice kit. Kat, I saw the dyno graph from the initial tune the other day, very nice torque curve! Will be nice to see once everything is sorted completely. Some pics of the head: Cheers, Greg.

No. .0005" extra is much better than .0005" too little. The clearance they specify is normally the minimum clearance that will work in the vast majority of situations. In all honesty, most of the cheap bore gauges that people use to check a bore are only accurate to .0005" anyway and depending if the block was allowed to cool before the final honing and measurement they can move that much anyway.

The VG rods are a touch longer, have the same diameter but narrower big end journals and take 22mm piston pins. If you use them you also need to have a piston made which locates the rod in the piston. If I was you, I'd buy a set of Spool RB30 rods, they drop straight in and are a better rod than any similarly priced rod on the market and even quite a few at up to twice the price. I've used well over 20 sets of the Spool rods and couldn't recommend them enough. They have a little more metal than Eagles in places where it counts and are much better finished than Scat rods. The sizing is spot on which is important if you're assembling it at home and the balance is better than some of the really big names. As for "American" quality, any rod from America that costs under $200 each most likely comes from China anyway and may have the tunnels given a final rub on a hone in America (probably by an illegal immigrant anyway). Happy new year. Greg

It's just talk, I use them in anything I do that I can buy them for. There is no way a bearing can be "too strong", they could be too hard or too soft but the ACL's are neither. ACL makes Nismo's bearings for them, exactly the same material and everything else as the race series.

Thanks guys, I'm not normally one to get into an argument but it was the "only ones that actually fit properly" comment that got me given the many hours of digitising and test fitting it took to make sure they do. Mine are probably more expensive that some others around but it is a complete kit and there's no dicking around, plus we make them from steel which takes a lot longer to machine and is harder on tooling but to make a plate with the same tensile strength from 5083 aluminium would have meant it needed to be around 15mm thick which just wont fit properly, plus it is fairly ductile so it doesn't "spring back" like steel when it's twisted or bent and considering the diff is mounted on the adapter things just didn't add up. We did consider hard anodised 6061 or 7075 alloy but the cost would have been through the roof for no real benefit as even hard anodised 7075 has a surface only as hard as mild steel (mind you, 7075 is a lot nicer to machine than steel). The 6061 and 7075 alloys are great when there needs to be a strength/weight compromise, for instance brake hats or suspension components. I'd much prefer to sell just the adapter plates for $600 and let people get their own bits and pieces but people seem to want something they can just fit up and that's it. For example, to make a pickup that fits there's $100 worth of stainless mandrel bends and adapters, a laser cut flange and support tab plus a couple of hours to cut, jig up and weld it all together. Add the price of an oil return T-piece plus the fasteners, templates, instructions and good protective packing and it does add up. Anyway, I'll pull my head back in now as requested. P.S. NYTSKY, you don't need an adapter to fit a 25 sump on a 30 but you will need to bend down the baffles at the rear as the conrods will hit them.

I'm not one to get into an argument "3lit3 32" but you obviously don't know wtf you are talking about in regard to the Pro Engine adapters. They fit perfectly as I'm sure many people from here, the UK, US, Canada, Japan and even Estonia can attest to. Thanks Beer Baron for picking that up. I'm happy for someone to recommend someone elses product, not happy if they do it by putting shit on another product that is well known to be spot on. Cheers, Greg.

Hey guys, just a quick note in case there's any confusion. Thats not one of my adapter kits Cheers, Greg.

Detonation/pre-ignition is probably the biggest killer of conrod bearings on GTR's when the boost is wound up. Most of the time you'll find there's no oil pump problem etc.. Have a look at the other conrod bearings, if they have marking on the upper bearing from 10 thru 1 o-clock it's usually a good sign of detonation. It happens because the mixture fires too early and the piston is pushed back down the bore while the crank is still trying to push it up, this squeezes out the oil film and you have metal on metal contact between the crank journal and the bearing.

Here's a recent 25/30 conversion. RB30 bottom end Spool Rods Wiseco pistons 9:1 ACL race series bearings crank collar, RB25 pump Cometic 1.3mm gasket head ported, std valves vvt removed, Tomei 256 intake cam, HKS 264 exhaust cam fabricated exh manifold, GT35/40 .7 front, .82 rear front facing plenum, std TB Engine is on boost by 3000, very driveable.

9:1 is a nice compression, you will need to knock some ignition timing out with higher boost. If you are planning to run higher boost all the time go low to mid 8's:1. One I did recently is running 20lb boost at 9:1 with no problem, makes around 360rwkw and oodles of torque, it does have some timing knocked out when it comes on boost. It's running a 35/40 with a 1.06 rear housing and makes boost at 3000 or so. It's very driveable. If you're only after 300 or so go for the smaller turbo. Use forged pistons, anything cast will break a lot more quickly with any detonation, forged pistons give a little insurance against a bad tank of fuel, it doesn't need to be revving high to break ring lands. Most forged pistons also come with a steel top ring which is a bonus. Talk to Brad at Spool imports about a set of rods. Dont bother using the standard rods for the price he sells H-beams for, they are a very nice rod. Prepping a set of standard rods will cost you almost as much and they are still used rods that have been stretched and compressed a million times.

Check your pressure with a mechanical master gauge before you worry too much. The fact that it is increasing when you rev the engine is a good sign. If it is using an RB30 pump it should only have around 15psi at idle anyway, increasing once you bump some revs into it. If you have 70psi once you bring the revs up it cant have a big internal leak.

I think he lists them to 4.4 but can do thicker from memory.

bnr#@, it depends what cams you are using. I prefer to fit the heads with no cams so I can use a shorter socket to tighten the head bolts/studs. Have you seen how many degrees a long 10mm allen key can twist when you are tensioning the bolts? Anyway, just looking at the photo again, is that a metal something jammed between the exhaust valve and the side of the chamber?

Talk to the shop who did the job first. As for the Port match, the exhaust gasket means very little, if they matched it to the gasket you have shown your head would be completely f**ked. Port match doesn't mean a match to a gasket, particularly if it's that much bigger. As for the intake, it's not real close, did they have the manifold to match it to? With one valve being bent, are you sure that all the shims were sitting properly in place when the cams were bolted in after you fitted the head? I've seen similar damage because of this.

www.precisionshims.com.au speak to Chris, He did a set for me recently for a set of small base circle Jun cams. 03 97230199

$900 is a fair bit of money, depends how much you value your own time. For $900 you get an adaptor plate that fits, the bolt holes are drilled, tapped and countersunk in a CNC mill, a silicone relief is milled in the plate, the same design as the original sump so it actually does seal oil, you get every fastener needed to bolt it all up, laser cut steel templates to notch the block, a pickup that fits inside the sump, so no need for complicated external pickups even detailed instructions on how to fit it. Then again, you could buy a piece of 10mm steel plate for $30, a bench drill at super cheap for $50 and a piece of chalk and do it yourself... It sounds like a lot of money until you try to do it yourself. A few people on this forum or gtr.co.uk have bought them and seem quite happy with them. Maybe I should add a sticker with some catchy jengrish phrase like "The joy of sump bolting" and make it $1000

No real issues as such. I have seen some that have started to flake, as in the bearing material has separated from the backing but only due to severe detonation. I use ACL race series in everything that they are available for now, I've seen a set of rod bearings out of Sainty's top fuel engine which still looked like new after quite a few runs. I also have a set here from an ej25 I did that made well over 500rwkw and they are the same, look as though they just came out of the box. The ACL's seem to cop a lot more before they start to have problems.

I'd put the cooler on the pressure side between the pump and the engine. I suppose you could run both sides but it makes for a lot of extra plumbing. so... is that solid works or autocad you used to draw that up? :laughing-smiley-014:

Use the ACL race series bearings designed for the RB30. RB26 conrod bearings are different to the RB30 size. You can use RB26 mains in an RB30 but for no real benefit because there is no groove behind the bearings to feed oil to the extra oil holes. Dont pay big money for Nismo bearings. ACL is about to or is already supplying them with their bearings. The ACL's are the best bearing you can buy in my opinion and very reasonably priced. I think they will be offering them in the future with the Calico coating which would be worth giving a go.

Thanks Geoff. What you really need to do is get an accurate measurement of everything. If the clearance is that large, you need to find whether it is the bore being too big or the piston collapsed. take it to someone who can measure it with a micrometer or bore gauge. If the bore is the right size, I'd imagine that the pistons have collapsed. They can do this if they are severely overheated. I haven't seen a set of pistons in years that have been made to the wrong size, they are made to give the correct clearance at the nominal size. The shape of the top ring land is a very good indicaton of detonation, the same with the hammering on the top conrod bearing shell. The ring gap increases very quickly as things change, for every .001mm in bore size, you get .00314mm increase in ring gap (Pi x Diameter). The same deal as the outer face of the ring wears. If you measure the radial depth of the ring in different positions it will show the wear on the ring. They rarely wear as much right at the gap. Take the parts back to whoever did the job and ask them to check it, if it ended up being a warranty job, they have first right of repair anyway. They may even help you out with fixing it.

Bearings and ring lands reek of detonation.