The Best Machine Shop for RB Motors

[WetGTR]

Thought I start a thread relating to people who have the knowledge to disassemble and assemble their own engine’s and want to rebuild and or upgrade their RB bottom ends or Heads.

Now any engine builder who has done good work will always say that a good machine shop is the key to success but a lot of machine shop’s say they can do the work, maybe so but were looking for machine shops who are experienced at RB motors.

Who has built their own engine’s and found a good (experienced) machine shop?

To make this clear for some people, were not looking at mechanics or workshops/performance shops. This is about where they get their cranks balanced, grinded, head work done and so forth

[riceline]

I got my engine rebuilt/bored/balanced/blueprinted/installed by Power Break Engineering at Windsor in Qld

Great guys in there (Exp Garth the guy in charge)! All accept one of them is old. They are not the quickest in the world but they seem to take there time and do it right first time.

They are not RB specialists. They seem to work on everything. But they did balance/blueprint my engine. Rebuild and port the 25 head. Put it all back together and its been going sweet for over a year now.

[GTRgeoff]

I like to guage by the number of pictures of race cars/boats in the reception.

In Melbourne I used Duggans Balancing - Newlands Road Reservior. Good work with balance, o rings and thorough cleanup of the crank and block ready for new forgies and GTR rods. Nicely priced too. 1200 all up with a thorough quote and work checklist, all I had to do was lube and assemble. Even found the crank was bent so after straightening, with the crank girdle torqued I could get a few turns of the crank by a single spin by hand.

Also not RB specific and deal with all engines.

[ylwgtr2]

has anyone here have access to the artillary do there own machining or do it for a living?

[WetGTR]

Interesting you say that.

It would be nice if someone here could do or advise on machining, boring, head work, etc

Maybe the does or don't or things to look out for

[GTRgeoff]

It's a long time since I did any engine reconditioning myself so I'll decline the opportunity to make an ass of myself. ylwgtr2 would be our best resource given recent projects undertaken :wavey:

[WetGTR]

ylwgtr2, do you know the do's and don't for machining RB motors or maybe what people should be looking out for if parts were sent to a machining shop?

Another thing, why is it that when people build rb engines, some last and some don't and lets assume all have a good tune by a reputable tuner?

I dare say it's got to be something engine builders are checking, going over or something machine shops are doing?

Have you any idea's or has anybody else got some feedback.....

[proengines]

I have a machine shop and do quite a few RB's, if I can help with any questions you'd like to ask or photos of the machining operations etc.. let me know and I'll do what I can to help.

[WetGTR]

proengines, you might be able to shine some light......

Some people believe that machining and working on one engine is the same as any other engine, refering to balance this, blue print that, tighten this up to this torque rate, etc.

Do the RB engine require something extra being an advanced motor in technology terms or is just the same as any other engine?

Is there special things that need to be looked at when machining, for example never machine a crank because even though you can it creates extra wear on other parts.

[ylwgtr2]

These engines are an overgrown motorcycle engine so working on them to motorcycle guys is sort of a second nature....most average mechanics i have found just dont use there brains these days.....is far as boring goes it depends on the pistons used for clearances ie forged,cast,silicon content ect diffrent ones expanded more depending on there structure.Crank grinding well i would rather buy a new crank for 1k than mess with grinding a used one...but thats just me

[ylwgtr2]

a big killer of any engine is dirty bores...if you get your block bored and are assembling yourself make sure its clean!!!!!Obviously make sure the gallerys are clean but for those that dont know give the bores a good scrub with hot soapy water then blow it all off dry and use a stark white rag with transmission oil on it and run it up and down the bore's and make sure the rag doesnt stain

[proengines]

I'd have to say that compared to what is around today, as an engine the RB's aren't particularly advanced. For starters, a cast iron block is very 1980's, the crank isn't fully counterweighted, the main cradle is bolted on with the same bolts as a datsun 1200 uses etc.. but saying that, it is very strong. Also, for when it was designed it was very advanced. The head is brilliant for when it was designed and capable of big power, I don't understand though why Nissan didn't flatten the valve angle a tad, make the combustion chamber a bit shallower and run less of a dome on the pistons, Id say it would burn better with less chance of detonation if it was. Something similar to an SR20 or EJ20 subaru is a nicer piston/chamber combo.

Machining and assembly wise, we do spend a fair bit of time on them, you just cant afford to have a problem because people drive them pretty hard and it's an expensive job to pull them out and fix them. Having engines blow up is also a pretty good way to guarantee you wont get many more to do as well.

Basics below:

Block- strip, chemical clean, remove oil gallery plugs, CBN mill deck surface to set piston heights, bore and hone with a torque plate and main cradle tensioned, check mail tunnels and tunnel hone if needed, remove casting dags.

Crank- remove oil gallery plugs and tap for screw in plugs, check for size and straightness, micropolish, balance. I prefer not to grind them as there is a chance of grinding through the case hardening . I suppose you can have it rehardened but I'd prefer to replace the crank if it was that bad.

Rods- I prefer to replace them with an aftermarket rod, it's pretty cheap insurance. Otherwise, the STD rods crack tested, beam polished, shot peened, ARP bolts, closed and honed, new small end bushes, balanced. With new rods, we check the tunnel sizes and hone the rods to achieve the proper bearing crush and clearances, the small ends usually need to be honed to suit the pins being used. Balance the rods to +/- .1g both big and small end.

Oil pump- Replace if worn, otherwise clean, reassemble and fit new relief valve and spring.

Head- depends on the customer, but at least chem clean, check straightness, pressure test, soda blast, new exhaust guides, 3 angle or raduis valve seats in Serdi machine, reface valves, PCD mill head face, reassemble with new springs, set tappets. Other work depends on what the customer wants, we do a fair bit of porting and it's a shame not to port the head, especially an RB26 as you can get quite substantial gains in a relatively short time. We've played with them on the flowbench and 15-20cfm is pretty easy to pick up. I'm currently doing some testing for one of our suppliers with some stainless 1mm oversize head valves. They have a slightly undercut stem and a lot nicer finish than the STD valves, along with a nice profile so they should show some good gains. We also mill the sides of the bucket bores to clear the cam lobes if high lift cams are fitted.

Pistons- Measure, debur any sharp edges, clean, especially in pin bores as they usually still have honing grit in them.

Parts- Pistons- forged, very cheap insurance. Brands are much of a muchness, we've used Wiseco, ACL/Ross, Venolia, JE, Arias, CP, SPS and a couple of others. If I had to choose for my own I'd use Wiseco but thats just a personal preference. Venolias are a bit noisy but I've never seen one broken, they use a lower silicone alloy to most other piston makers and it is a little tougher but the noise is annoying. Rings- nothing that doesn't use a steel top ring. I'm still to be convinced that gapless rings are a huge benefit. Conrods- We've used Argo and REV. Both are good rods, I haven't used Crower yet in an RB but they are a nice bit of gear. The big end bore in the argos has been spot on, the REVs needed to be honed, this is because they finish them close to bottom size so the engine shop can hone them to set clearances, both needed the small ends honed for the same reason. Balance is good on both. Bearings- We use King, I'd rate them as the best but people have differing opinions. The king bearings are an alecular material and only run a thin coating of bearing material on a very hard backing. From seeing them after being used, they dont lose the spring in the backing even after being awfully hot. ACL race series bearings run a close second. I havent used Nismo bearings so I cant really comment, except that the price is pretty excessive. Gaskets- Genuine Nissan except for the head gasket, I rate the Cometic gaskets, three layers of stainless steel coated in a very thin layer of viton rubber and they fit perfectly around the bores, water holes etc. Valves- Genuine Nissan are top quality, Ferrea are better, Pep Pro are excellent. Springs- We use Performance Springs, great quality springs, made in Australia. Retainers/Locks- Genuine Nissan, although if it was a racing car running at big revs for a long time something titanium would be worth a look. Valve guides- Genuine guides work fine, I want to get bronze guides made but need to order them in the hundreds of each at $20 or so each so it's a lot of dollars to have sitting on the shelf waiting for heads to put them in. (anyone interested in a few sets?) Cams- We've used HKS and Tomei, both work well, same for cam gears. Sump baffles- we make our own, similar to the Jun baffles. Bolts/Studs- ARP main and head studs if the budget allows.

Assembly- We assemble our engines in a room separate to the machine shop so you dont have machining dust floating about. Dummy assembly before machining the deck is worth doing to set the piston heights and check for any interference between parts, there's always the chance of it happening using aftermarket parts from different suppliers. Then lots of cleaning, we hot tank the block again after machining, brush out all the galleries, scrub with soapy water and a brush, then the white rag treatment in the bores and tunnels. We soda blast the alloy parts and wash them off with hot water and blow them dry. Measure piston to bore clearance for each piston and bore, measure ring gaps and file if necessary, fit bearings to block and conrods and measure tunnel sizes, sometimes even with new rods you need to hone them to achieve the proper clearances, clean and measure crank, again brush through oil galleries. Fit new oil gallery and welch plugs.

We assemble all our engines with Nulon assembly lube on everything except the gudgeon pins and bores, we use 30w oil for that. Basically, once all the clearances are checked it's a matter of bolting the pieces together, we continue to check as we go. We use ARP assembly lube on the threads and under the heads of the bolts, this saves torque being wasted overcoming the friction and stretches the bolts so they clamp properly. We tension as we go and also give it a final once over before the sump is fitted.

We use either three-bond or wurth grey silicone for the sump and rear seal housing, mainly because of the colour, I hate the look of orange or blue silicone squeezed out the sides of the sump etc..

We preassemble the heads and set tappet clearances/crush depending on what head it is.

Then it's a matter of cleaning the block deck with carby clean to remove all oil, fit the head dowels & gasket and check for clearance around the bore, bolt the head on, tension it and then fit up the water pump, timing idler and tensioner, timing gears, Belt, covers etc.. followed by the accessories. The only difference is if we use a copper head gasket, we give the head and block a light smear of three-bond white motorcycle silicone to seal the water and oil, this is only on blocks that are o-ringed and the heads with receiver grooves cut. Lately, we have been using Cometic MLS head gaskets and from what I have seen so far they take as much punishment as a copper gasket but without the drawbacks in regards to coolant or oil seepage and there is no need to O-ring the block. It's kind of a disadvantage to us as we miss out on the labour for o-ringing the block but if they work better I'd prefer to use them.

I think thats about it but I probably have missed something. I know this is pretty long winded but basically it's a matter of measure, measure, measure, clean, clean, clean, quality parts and a fair bit of time, rushing is a sure recipe for disaster. If you want any photos of particular processes let me know.

[lwells]

proengines: Wow. Thanks for taking the time to post all of that.

With any luck I will have a job in Canberra next year and I think I have found a place to spend some money

One question: in regards to run in, what's your thoughts on the best method?

Cheers,

Lucien.

[Ronin 09]

Thank you very much for taking the time to write that - it is quite an insight into where all the dollars go!

[crack]

Thank you very much for taking the time to write that - it is quite an insight into where all the dollars go!

:werd:

[B33st]

proengines, i vote for pictures from beginning to end then stickying this thread.

[R33S2]

Proengines your post deserves a medal of honor it should be be posted as a sticky 4 sure

[mark99]

Bearings- We use King, I'd rate them as the best but people have differing opinions. The king bearings are an alecular material and only run a thin coating of bearing material on a very hard backing. From seeing them after being used, they dont lose the spring in the backing even after being awfully hot. ACL race series bearings run a close second.

Great post. Worth adding to the above, is that whist the King and ACL Race bearings are both high quality bearings, they are two differing styles of bearing each with their own advantage. In terms of pure load carrying capacity the ACL Race is the superior, being a tri metal design compared to the Kings bi metal design, the ACL will always be able to withstand higher loads. However this comes at a price, the King bearing can cope with a larger amonut of "debris" or poor surface finish a lot better than a tri metal bearing. Basically the King can cope with any small particles running through the oiling system, by having a thicker top layer, wich allows for small particles to embed into the bearing and not damage the shaft or bearing in any serious way. King are great for if the engine assembly is not perfectly clean (not that you want to aim for that) or cast iron crankshafts where surface finish is a lot more critical comparative to steel crankshafts.

[GTRgeoff]

Mate that was an outstanding effort, and thanks also for taking the time. No wonder the ACT guys rate you so highly, well from what I've picked up on anyway, but it is well deserved.

Perhaps one of our ACT members will offer to take a tour and take some pics to include as you have already gone above and beyond.

Pictures aside, the only way you could exceed yourself would be to offer some thoughts on run in for your engines.

As for pistons. This is interesting and supports your favourite brand so well done again. http://www.importbuilders.com/pistoncomparo.html

[aridyne]

Excellent Proengines, appreciate the insight.

What form of $$$$ are we looking at.

I have a spare RB25 Block that I want to rebuild and one RB engine builder quoted me $9500 for the rebuild and parts, some of the engine bits will be reused with new pistons being the main go and he mentioned something about "plasterguide" so they can measure down to the micromillimeter the gaps etc.