petevb Posted September 24, 2007 Report Share Posted September 24, 2007 Has anyone looked at or know anything about using the Bentley W12 pistons in the R32? Background- the Bentley continental GT/ GTC/ Flying spur use a twin turbo W12, effectively 2x VW R32 motors stuck together. Compression is listed at 9:1. The Bentley motor uses the same 84mm bore, a similar head, but a shorter 90.2mm stroke- my math says using those pistons an R32 would result in roughly a 9.5:1 compression ratio, which would be great for a medium pressure turbo application. And the squish area would remain intact, unlike with the normal thicker head gasket approach. I can't find a thing on those pistons, though, from where to get them to what the pin diameter, height, etc is. Anyone know any specs or looked into this already? Link to comment Share on other sites More sharing options...
Mook Posted September 25, 2007 Report Share Posted September 25, 2007 Your best bet is to talk to the guys at www.eiptuning.com across the pond. They resell various turbo kits from HGP in Germany and have built some monster engines up to 500+ bhp. Link to comment Share on other sites More sharing options...
Decked Posted September 25, 2007 Report Share Posted September 25, 2007 no idea on pistons, but thes guys may know something.... http://www.cncheads.co.uk/vw_r32.html Link to comment Share on other sites More sharing options...
mb Posted September 25, 2007 Report Share Posted September 25, 2007 Looks nice work, not sure if the gains make up for the loss of the 2 cylinders however ? Link to comment Share on other sites More sharing options...
petevb Posted September 25, 2007 Author Report Share Posted September 25, 2007 [ QUOTE ] Your best bet is to talk to the guys at www.eiptuning.com across the pond. They resell various turbo kits from HGP in Germany and have built some monster engines up to 500+ bhp. [/ QUOTE ] Being from the other side of said pond, I think you're thinking of HPA (of Canada) being connected with HGP: http://www.hpamotorsports.com/ Both HPA and HGP like to lower the compression with a head gasket spacer, however, which is against my religion... EIP (and Streetwerkes) have aftermarket pistons, but I'd prefer to use OEM if possible: http://www.eiptuning.com/eip/vw6cylinderpistons.html EIP have also gotten a very bad rep recently- rumor is the are on the verge of shutting down, FYI. [ QUOTE ] no idea on pistons, but these guys may know something.... http://www.cncheads.co.uk/vw_r32.html [/ QUOTE ] Well the do know something about heads. I've spoken to them before, and they are claiming about +10% intake and + 28% exhaust flow at .45" lift. Not cheap, though, and you need to send them you're head, as they don't have any R32 heads in stock. No info on pistons, however. Back to the original question, it seems like some dealer with access to the VWAG parts ordering system would be able to just order those Bentley pistons, I would think?? Link to comment Share on other sites More sharing options...
Dan32 Posted September 26, 2007 Report Share Posted September 26, 2007 VW dealer can order anything from VAG group (whether Bentley is considered this I don't know) with the correct part number and paying for it upfront. Link to comment Share on other sites More sharing options...
Mook Posted September 26, 2007 Report Share Posted September 26, 2007 [ QUOTE ] I think you're thinking of HPA (of Canada) being connected with HGP [/ QUOTE ] That's the one [ QUOTE ] Back to the original question, it seems like some dealer with access to the VWAG parts ordering system would be able to just order those Bentley pistons, I would think?? [/ QUOTE ] I would think so as well - give it a try and let us know what you find out. Link to comment Share on other sites More sharing options...
petevb Posted September 27, 2007 Author Report Share Posted September 27, 2007 [ QUOTE ] VW dealer can order anything from VAG group (whether Bentley is considered this I don't know) with the correct part number and paying for it upfront. [/ QUOTE ] Well so far I've found that those part numbers are hard to come by. The VW dealer doesn't have them, and the couple Bentley dealers I've contacted so far haven't been any help. Any ideas? I'd order one outright just to measure it... Link to comment Share on other sites More sharing options...
JaminBen Posted September 28, 2007 Report Share Posted September 28, 2007 Hi Pete, this is Ben from the 'tex... A month ago I visited an independant VAG development subcontractor, whose shop is a stone's throw from Wolfsburg. He participates in the making of various VAG prototypes, and he is currently building a 1.6T (from the 2.0T), a T-T 3.0 VR6 (from a 3.6 VR6), both engine using variable vane turbos and slated for use in conjunction with hybrid drivetrains (!). When I saw the W-12 from the crazy Gti prototype in his shop (!!!), I asked the same Bentley-pistons-to-FI 3.2 question. He was quick to disregard that option as too expensive, and absolutely un-necessary. In his opinion, the oem 3.2 pistons and 8.5 or 8.8mm gaskets do a fine job, even on T-T 550 Chp applications. I'm going back to see him in ten days. I'll ask him more about it if you want. Irrespective of cost, it would be interesteing to know if the specs work out properly. Ben. Link to comment Share on other sites More sharing options...
petevb Posted September 28, 2007 Author Report Share Posted September 28, 2007 [ QUOTE ] Hi Pete, this is Ben from the 'tex... A month ago I visited an independant VAG development subcontractor, whose shop is a stone's throw from Wolfsburg. He participates in the making of various VAG prototypes, and he is currently building a 1.6T (from the 2.0T), a T-T 3.0 VR6 (from a 3.6 VR6), both engine using variable vane turbos and slated for use in conjunction with hybrid drivetrains (!). When I saw the W-12 from the crazy Gti prototype in his shop (!!!), I asked the same Bentley-pistons-to-FI 3.2 question. He was quick to disregard that option as too expensive, and absolutely un-necessary. In his opinion, the oem 3.2 pistons and 8.5 or 8.8mm gaskets do a fine job, even on T-T 550 Chp applications. I'm going back to see him in ten days. I'll ask him more about it if you want. Irrespective of cost, it would be interesteing to know if the specs work out properly. Ben. [/ QUOTE ] Thanks Ben, Yes, I'd be very interested to hear what your contractor friend says. I'm well aware that the low compression gaskets will do the job for the power levels I've got in mind (~450 hp, but low tq to save the DSG). I just have something against lowering the compression that way. As I'm sure he knows: I've heard squish area (the small ~1mm gap between the flat part on the edge of the piston and the flat part on the edge of the head) referred to as "artificial octane"- having the squish area allows you to add a point or more of compression on the same octane gas. When you add a thick head gasket you destroy this squish area- it ceases to work once the the gap opens up above 2mm or so. This isn't the end of the world, as you can just lower the compression further, but it leads to a less efficient and responsive engine running more boost (and hence more torque) for a given power level. That's why you'll never see an OEM significantly lowering the compression that way... Thus if the option is available and not far more expensive I'd prefer the piston route for lowering the compression. Unfortunately most aftermarket pistons come with other drawbacks. Most require new rods as well, as they have either different pin diameters (22mm instead of 20mm) or different pin heights. They also tend to be made of higher expansion ratio material, meaning you can't run a factory piston clearance, leading to more engine noise/ wear, etc. Thus IF the Bentley pistons have the same pin diameter/ height, etc they sound really interesting. Maybe if you get a chance to chat with him and he doesn't say you're completely insane you could ask if he could source a set? Sounds like he'd certainly be the guy with contacts to get a hold of one... I'd certainly be interested in what he says one way or the other. -Pete Link to comment Share on other sites More sharing options...
petevb Posted September 30, 2007 Author Report Share Posted September 30, 2007 FYI, I just received the following info from another source: "Just looked into it at work. pistons can not be sourced separately. only option is for a whole new engine, they figure if it needs a piston it needs a whole new engine because there is no tolerance for any machining and won't sell it separately." Sounds like they will be very difficult to find. I don't even know who makes them to try and source them directly (Mahle or Kolbenschmidt, perhaps?). Maybe your guy could get them Ben, but otherwise I'm not holding my breath... Link to comment Share on other sites More sharing options...
JaminBen Posted October 1, 2007 Report Share Posted October 1, 2007 Ok. I'll ask him when I pick the car up next week. Link to comment Share on other sites More sharing options...
graeme86 Posted October 1, 2007 Report Share Posted October 1, 2007 BML code R32 engine (sold in Australia) has slightly lower compression pistons, so car can run on 91 RON, if thats of any interest. Only lowers to about 10.85 I think instead of 11.25. You could use a thinner gasket Wouldn't having a low compression piston (or one with a different pin height) still lose the quench area? Or would they be made still flat around the edge for the squish but have a deep centre chamber? Link to comment Share on other sites More sharing options...
petevb Posted October 1, 2007 Author Report Share Posted October 1, 2007 [ QUOTE ] BML code R32 engine (sold in Australia) has slightly lower compression pistons, so car can run on 91 RON, if thats of any interest. Only lowers to about 10.85 I think instead of 11.25. You could use a thinner gasket Wouldn't having a low compression piston (or one with a different pin height) still lose the quench area? Or would they be made still flat around the edge for the squish but have a deep centre chamber? [/ QUOTE ] The new US MK V R32s also have the 10.85:1 compression. I believe VW did this through using a *slightly* thicker head gasket- the pistons and head appear the same. It's only .4mm thicker, so it doesn't completely screw the squish area. With the Bentley the made new pistons with a deep bowl in the center as you said, but the pin height and sides of the piston (the squish area) remain the same. That's why they're so good- lower the C/R without reducing the squish. Ben- I appreciate you looking into this... -Pete Link to comment Share on other sites More sharing options...
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