Hi I just got these very nice R56 Pauter Connecting Rods to go with some CP pistons. Pauter are custom so I went with a center to center length of 138 instead of 138.5 it lowers the compression a bit and I got them made to accept Honda bearings with location tabs the stock do not have tabs and could move. Changing length does affect geometry so check dwell, the heads don't have much squish area but its something to consider. the stock chambers are 42 cm^3, 10.5=(399.5+42)/42 so my 77.5mm over size pistons end up at 10.1:1


The R56 Supertech valves don't show in the catalog online that I could see. I was not happy with the margins on the stock valves the cups were off center.

**Note: Bearing crush is the main holding force on bearing shells. Tabs help in instalation and possible migration or creep. Honda B18C bearing shells offer more sizes and types.




I Got both the Rods and the valves from Steve at Top End performance.

 

interested to see how this build goes, if it works out for you, i might do something similar

Subbed

 

Keep us posted because I might follow in your foot steps when it is my turn.

 

I Have the Mini up and running and I like my build so far it seems good ,
it made it through a track day and home, the bottom end seems ok. There is some noise with the CP pistons until warm but with a solid Flywheel the direct injection is like a diesel but that is what it should be doing, it hardly uses any fuel at idle so no big deal there. The other option in pistons is the Mahle Motor Sport which can run a tighter clearance the deciding factor should be about how to get the best sealing set up as the low crank to rod ratio means there is a lot of force on the cylinder walls at 90 deg and under full power you may see more blow by. Total seal rings might be an option but some people seem to get mixed results. Any way this set up works and I would recommend it.

 

looks good, so someone built your car or did you do it?

 

Nice rods! I had mine made to the same specs. It ups the quench gap from .035 to .054 so it's still short of the general .060 limit. Anybody considering a similar path should be aware that you will not be able to use the thicker 1.2mm JCW gasket to lower compression another .25. Doing so would raise the quench gap to .066 and probably result in detonation problems.

 

Just out of curiosity did you use GSR style bearings from a Honda B18C engine and mill off .5mm in width from each side, have Pauter make you a custom set of bearings, or something else altogether? I just had Brian make a set for me. All the local machine shops were swamped and it would have taken two weeks for them to get to.

 

consider the amount you have to plane off the cylinder head first you dont want more compression also direct injection is a bit different I think you could be a bit over on the quench but I have to go fix something from messing about and finding my missing turbo surge so I will bow out on that, better safe than sorry right. I just had them taken down actually on a lapping stone measured up alright.

 

Doh... Why didn't I think of that? We even have a large lapping stone where I work for lapping turbine engine components. Next time I'll know better. Thank you for the tip kind sir. Now I think I'll go find a crowbar and pry my head out from where it shouldn't be.

 

Your head is fine you were doing the best thing unless you spend lots of time working with this kind of stuff. About the rods I seem to remember that there was plenty of side clearance more than what Pauter was recommending our engines do like to run at max temp but I wonder if there is some room to go a bit fatter on the bottom ends of the rods not that I think they need it but maybe the next size apr stud would work then, probably to close though. also I seem to remember that the Honda bearings may be ok width wise anyway so if someone is following check that out. I was just staying close to stock sizes.

About squish and Quench If I remember right our cylinder heads dont really have an area to get that close to the piston to do much and I think the direct injection wants a different kind of air flow I think that is why There are the 3 valve heads for some engines with it, to create a large swirl I will have to look at my spare cylinder head again to see. its always good to type first then check but oh well

 

Since we are on the bottom end Be careful taking your block apart use a heat gun and leave 2 bolts in on both ends a bit loose so that when it gives you dont hurt the locating studs there are two small ones and they will be locating your mains caps. The crush height in the Mains is about 0.0012 which is large but look how thick the shells are they will set your clearance when pressed into the top half of the block. have your bed plate checked it sets the centerline the top half may have a bit of tapper I think it works out in the end. I polish my cranks myself the machines in the shop are scary, light with 1500 or 2000 grit you are only redirecting tiny burrs and removing any high ones new grit for each journal the grit does the work. I used Permatex Ultra Grey on the block and the trans it seems good it has a working time so do what ever meditation you have to do, set up everything, and check twice. A dry or even wet run may be best. Be careful of the small grooves in the block flanges they are meant to direct the sealant away from the bearing caps you dont want any under the bearing caps but you need to get to the edges so the case will seal. Practice your bead size on some sort of scrap to get an idea of how much you need it will be fine I know your caps are dry ok. OH go around bolt holes after you do the inside you want an even surface for the bolts . to check your clearance I used the old school bit of thickness gauge if you are carefull tighening down and checking the crank for movment you wont hurt the shells and it is accurate as long as your shim is, it will tell you if you are in the range you want to be I think I was at about 0.0018

 

Any updated impressions on your build after you've spent some time with it?

 

10,000++ miles knock on wood.... track time, Winter wipe-outs, Trips, other drivers, runs just fine. Great rods and valves I like the balance I ended up with, of course I have not done a tear-down. I might like lighter rods but they would have to be a lot lighter 100g+ and still bullet proof so would be exotic metallurgy. I would say some head porting a must and check the valve seat depths. The CP 10.5:1 pistons are fine no noise issues, of course with a solid flywheel the idle is unique to DI engines you must be prepared for it. The slightly shorter rods are fine but look at the ratios could be interesting to go more but only for shorter life engines I think. Absolutely use the recommended ring gaps and go to a big turbo no downside with a good tune. With 10.5 pistons I have been thinking water meth but only because of hot weather and sitting in traffic I did have to make a quick turn going into boost on a hot inter-cooler...... does not matter how good they are no flow no cool no fun. If you are doing a build in the North East let me know if I have some time I might offer a hand Im also making a carbon fiber valve cover with adjustable vacuum control and multi stage filtration set up a bit crazy but if you would like to try. Any way I still like these engines a lot. Next I think a resurrection project from a wrecked early gen2 Mini when I find one, wider stance, crazy roll cage, removable rear roof, BIG TURBO, Maybe go for a 10,000 rpm screamer. Oh before head work have it planed and mark the overhanging area I would cc these things.

 

Thanks for the feedback Euler. Sounds like your build is holding strong

I am in need of a rebuild on my JCW. I'm on the west coast or otherwise I'd hit you up for some help..

I'm leaning towards the CP or Mahle pistons. I'm not trying to get maxed out power. I just want "good" power/numbers and some reliability.

Any advice how to achieve that?

I already have a bigger turbo and a meth kit.

I don't really want to change compression, as that seems like it could cause more issues if its not handled correctly with the tune etc.

Looking around at piston options they all seem to be 10.5 or the lowered compression of 9.5 not the 10.0 that the N14 JCW is. Is that just the difference in the JCW head gasket, lowering the .5 from an S?

 

If you already run a larger turbo and are relatively happy with the power and tune but want to have a solid bottom end to tweek things with room to spare, the head work and connecting rod length are the place to start, look up connecting rod to crank ratio stuff you will see that we have good mechanical advantage but if staying in the 6500 rpm range working the ratio is worth considering but an advanced sort of thing 1mm range should be ok as long as clearances work out, .5mm I know works I think at some point I will try a super stroker. On the cylinder head, work here will leave you room to work your intake and exhaust track and see real response to changes if you get or do a good port you should even see less need for more psi in your boost as the flow can be way better. I favor really attacking the intake ramps but others feel they turn the air flow, be sure to open the area around the valve and pay attention to the transition DI engines dont need to worry about fuel air separation at this point. Most valve jobs are three angle these days but quality here is all important you can go for more angles but three will work. Cams try what ever you want
I have an N14 so they are easy to change, the stock cams can get you quite far as we are really pushing 1.6 liters and using all the timing already available is going to make good power. PS I think even bigger turbos could be fun even if you have to wait for 3000+ RPM's to boost, just the lower end ratio, relatively short gearing, and DI with good head work
will spin it up quick then hold on, hmmm spinning wheels at 5000rpms. Its a lot of work but if you do the engine trans pull after taking off the front you may see how with some practice it could be ok to contemplate switching things up more frequently the best value is not always to go for a build you plan on leaving in for 100,000 miles plus and I'm sure you will have lots of new ideas once you are done. Dont forget even with Water/alch injection you dont run constant boost so the atention to the crank case breather system still needs to be woked out as the boost will clean off build up made when not in boost. Ask around you may have someone in your area who has done a build or you could offer some help to someone already started there are so many tiny details you work through like just how to support the engine during work, flimsy engine stands are way bad I like building a low wood cradle with a spot to put my weight on it, set at a short stools height. Above all have fun and dont look to get a factory sort of build. PS for anyone who is doing a first time build and this is the main car practice on something else at least get something from the junk yard and do a teardown and rebuild with existing parts just cleaning and measuring. Reliability is in the details of the work, check, stop, think, check, goooooooo........ oh some kind words to the speed gods, well lots of kind words to the speed Gods,,,, offer them your first born child,,,,, your soul,,,,, you know that kind of stuff. Oh I like the CP pistons polish or coat the tops though, maybe asymmetrical pistons if you can get them made take some side load off.

 

Sorry got lost and forgot to answer about compression ratios. As the chamber gets smaller, small differences make a bigger difference there is a thicker gasket but also with Pauter Rods you can choose different lengths so its important to understand how that effects things, we are tuning not designing a new engine but go through the mechanics its important not to have a formula. The factory casts are not perfect, then you have to plane the head, maybe deck the block, then CC what you have, check your numbers remember if you have to bore even the .5mm adds to things then shoot for a max of 10.5, 10 will leave you room look at the numbers even a little carbon on the pistons over time could alter the set up. You can shape your chambers to tweak things as necessary. 9.5 is still a high ratio and leaves more room to play with timing if you want but I am finding 10ish an ok point. You will see stuff about deck height and quench. There is only a small area on the piston and I think it has more to do with air charge shaping, DI engines use the actual injected fuel as part of the cooling and we run oil squirters and if your running water/meth injection you get the part about intake air temps and the benefits of keeping them down. On these engines that will see street use Its a balancing act that happens from 0-2000 to 3000 RPMs Ive run naturally aspirated engines at 9.5 that were plenty snappy so its not like you would give up everything but you will have to curve things a bit more towards the 3000 rpm side, its the air flow on a 1.6, to play the tubo game well at this size you need to get the engine flowing, moving, the quicker you are reving up at this point the faster you get to boost, at 9.5 you blast a bit harder and edge the timing up once in boost. A Track only engine it is easy to say 9.5 all out on the timing you wont be below 3000 rpms and turbo on boost for instant access. As far as what the factory did I wouldn’t worry about it, but there is a bit of personal preference and choice here thats up to you, it is tuning just dont go over 10.5. when reading remember a lot of the stuff is not DI based so keep that in mind.

 

Appreciate this is a thread resurrection. I'm just interested in any extra info people have.

This was all very interesting stuff. We are building a R56 that will be running 8.0:1 compression ratio. Rods standard length by Carrillo. Compression ratio reduced by the custom pistons from CP. We will try the thicker JCW head gasket.

I'm wondering what main bearing shells I should be using? I see Mahle do the shells for the rods to crank but not seen anything for the mains?

In other areas:

We have done lots of things to try and increase the clamping of the engine including upgrading to 12mm ARP studs for the head and the off the shelf ARP main studs etc.

Currently we aren't going to mess with the std cams or std head. Just make sure it is clean with good three angle valves that actually do seal properly. If we feel the head is a limiting factor we will then address that.

We are looking at adding a second turbo in compound /Series so we keep bottom end response of the JCW turbo and add more at the top end.

Cheers

RW

 

Ha, Well on the bearings they are Vandervell and can be gotten STD 25 50 like normal for the mains plus the OEM per shell is in steps of 0.0004
BLACK 1.822-1.826
GREEN 1.826-1.830
YELLOW 1.830-1.834
ORANGE 1.834-1.838
BROWN 1.838-1.842

I switched to Honda bearing shells for the rod ends.

But I have come to the decision that there are some more areas that need some attention.

Namely the engine needs better temperature control and I feel that 210 is a better setting. The performance rings on most pistons low tension can loose a bit of spring and cause sealing issues really consider your ring package its super important.

Next for me the whole point of my MINI is to carve up the corners, with some suspension work, and with how good tires have gotten over the last couple of years, you can pull over one g just around town. Consider a large radius corner and pull over a g for several seconds and a wet sump is just not up to this, oil foam is almost as bad as a dry pick up. So I have been working on a dry sump after almost solving the Valve cover mess. A dry sump will provide constant oil and vacuum on the crank case so the turbo inlet is free. this also means you can work towards an almost zero vacuum on the turbo inlet which is good for the turbo seals.

With direct injection and water meth and oil squirters and proper temperature control you should be able to do 9 to 10 comp with no problems.

remember boost psi is a measure of resistance you should find ways to increase flow through head work before going to super boost.

next the question is the crankshaft how much flex are you prepared for with a rod to crank ratio of 1.6 you have a bit of leverage. consider the whole maybe a bit more rpm some gearing tweeks and aerodynamics will get you where you want to go.

Also I have been thinking of the point I want the torque to drop off. its great to have torque stay so far up the rpms but at what cost to overall engine stability after say 7500 Im thinking of letting it drop off. Or you could go custom forged crank but be sure you get something that is worth the outlay.

 

Hi There is a bit more to the bearings for N14

Original before 8/10 2011? when change over happened. So Current Green is a good choice Gap about 0.0015-0.0019

BLUE 1.821-1.825
BLACK 1.825-1.829
GREEN 1.829-1.833
YELLOW 1.833-1.837

 

IF increasing head bolt torque be sure to use a torque plate for cylinder work, these blocks are paper weights. Maybe go for medium tension rings.
and mains clearance of around 0.002 to allow flex if your going to really push cylinder pressures. I was fine with .003 clearance on the CP pistons I have, even a hair less. polish the tops or coat. After break in check your blow by at 2000 rpm. I use the upside down oil cap, then check every once in a while. If this is a Mini you are keeping plan a refresh date so you can reuse your parts and make changes as needed.

 

Thanks for all the input. Appreciated.

Just had my torque plate made. Water cut aluminium. I have the piston clearance cp decided for me based on a 7500 rpm and 350bhp build spec.

We will regularly leak down check the engine.

I just have the cp piston rings. I'm not sure I understand medium tension rings can you explain or should I just Google?

I'm speaking to Mahle about the shells. Well the original shell company they merged with that I forget how to spell. I assumed they would just give me "shells" for a standard crank but I'm reading your reply and see that different shells for different spec?

I've thought about a custom bilet crank but not sure if I need one?

Thanks
Steven RW

 

http://www.enginebuildermag.com/2013/03/bearing-clearances/

I found this and feel slightly better educated

 

Going to 8:1 and larger head studs suggest you are going to go for a big Turbo and try and push as much charge into the cylinders as you can? you may be going over 400hp. The crank would seem to be the issue, it will certainly flex a bit more so a few 10thou more will be helpful and provide a bit more cooling. the actual oil film supporting the crank remains the same and the oil flow rate should be ok to about 0.002+-. tighter tolerances are fine if you can confirm the whole build is up them. you just dont want to go so large that baubles form or oil flow is compromised, Oil flow, not pressure is what you are after.

getting a good seal at the valves and head gasket is a good goal, the same goes for the rings, low tension can add less resistance and potentially more power but only if the seal remains. medium or standard tension will have a bit easier time maintaining seal. Crank case pressure is a whole subject, Low tension metric rings work best with decent vacuum, vacuum is hard to guaranty and maintain. there is so much about rings try talking to the CP piston people and reading up a bit but remember most tech is about other engines and needs to be applied to your engine. Oh seal from rings works on the intake too, the best engines produce good vacuum in the intake off boost often because of good cylinder and ring work. check your off boost vacuum I get from 11 psi up to about 17psi depending on where boost is kicking in.

 

OH Ring tension is about the outward spring force of the rings against the cylinder wall. if you stay to 350hp roughly 350 ft-lb the crank is fine still flexes though, going much over 400hp I might start to think of a forged crank but flexing is always an issue no matter what unless you resize journals etc. many euro oe cranks get pushed to 500hp, but the torque these Mini cooper engines make has to be considered.

 

Thanks for all your input.

We currently plan to rebuild initially with standard cams. We will be continuing to rev to 7k as we did before the engine was stripped down for rebuild and mods. Any thoughts on valve springs? I appreciate we are not revving too high yet but with so much potential boost I thought I'd upgrade them now anyway. Supertech beehive springs? Any inputs or views?

Thanks.

Ps my engine is on the Rebore machine today. With its big torque plate bit head studs and we also added bigger exhaust studs so we can hang more turbo off there safely.