Batfink 201 Posted January 27, 2008 For my engine build I want to run the lightest pistons I can to reduce stresses on my crank. How do the mi16 pistons compare in weight to other pug engines with the same bore?? K. Share this post Link to post Share on other sites
Sandy 191 Posted January 28, 2008 Bare weight without pin: Mi16 standard "B" 365g Mi16 Omega 360g XU7J4 standard 326g Share this post Link to post Share on other sites
petert 588 Posted January 28, 2008 Wiseco's 11.25:1 83.50mm forged piston is approx. 340g without pin & rings. Share this post Link to post Share on other sites
James_R 3 Posted January 28, 2008 You'll be wanting some full on slipper's then esp with a 1600 engine you'll need some fairly big domage on the crown to get the CR up. Awesome news on the XU7 though Share this post Link to post Share on other sites
Batfink 201 Posted January 28, 2008 Hi james. not sure i understand. As I am planning on using custom length rods will there still be compression issues? This would keep the TDC at the same point as a standard mi16 engine so no decking or anything needed? I dont get compression ratios and all that jazz lol Share this post Link to post Share on other sites
James_R 3 Posted January 28, 2008 compression simply is swept+unswept / unswept swept = bore x stroke so a 2L = 1998/4 = 499.5 unswept = combustion chamber vol+ head gasket + piston dish or dome (so can add ot subtract from unswept) you can work the unswept backwards from CR and swept volume by dividing swept/ CR-1 so s16 for example is 499.5/10.4-1 (9.4) 53.1cc's so if you use a XU7 = 10.4:1 then use the same pistons, headgasket but swap to a Mi head (has a 40cc chamber 36 for GTI-6 head) compression goes down to 9.6ish (based on 1760cc's) So you'd either need to make up the 4cc's in dome on the piston to maintain the old CR. Share this post Link to post Share on other sites
stux 0 Posted January 28, 2008 Pistons without pin & rings: - D6C - approx. 350g - DFW - approx. 329g - 83.50mm JE Pistons (D6C) - approx. 320g Share this post Link to post Share on other sites
B1ack_Mi16 67 Posted January 28, 2008 I can add my new 2.2 T16 (87mm bore) pistons are only 316 grams each.. and that's with 87mm bore Share this post Link to post Share on other sites
ifcho 0 Posted January 28, 2008 (edited) Do you know what cc/CR would come out of a 1.6 crank + rods and 1.8 pistons, with a standard xu5ja head and mi16 head? Edited January 28, 2008 by ifcho Share this post Link to post Share on other sites
welshpug 1,661 Posted May 19, 2008 Do you know what cc/CR would come out of a 1.6 crank + rods and 1.8 pistons, with a standard xu5ja head and mi16 head? I'd like to know this too... Share this post Link to post Share on other sites
Sandy 191 Posted May 19, 2008 Low! The 1.8 pistons and the 1.6 crank/rods would be 4.2mm below the deck. A ported XU7J4 head would be massively preferable to an Mi16 head for this configuration IMO. Share this post Link to post Share on other sites
welshpug 1,661 Posted May 19, 2008 I did loads of searching after posting there and found why exactly the XU7 pistons are so light, 4.5mm shorter than XU5 ones!! Share this post Link to post Share on other sites
