nunoserrano 0 Posted March 20, 2008 Hi could some one post a pic off the 2 types off pistons that could be found on the Xantia/XM 2.0 8v Turbo and the specs like piston higth, rod leght , ? Thanks Share this post Link to post Share on other sites
colti 5 Posted March 24, 2008 Hi could some one post a pic off the 2 types off pistons that could be found on the Xantia/XM 2.0 8v Turbo and the specs like piston higth, rod leght , ?Thanks Just rebuilt my RGY motor.As standard it kicks out 145bhp using,i believe a 8.5:1 comp ratio.The pistons in this motor are flat top. The RGX motor puts out 150bhp on a 7.9:1 comp,using pistons with a bath tub cut out in the crown. Gave up trying to get stock or oversize pistons for these motors.Used my original pistons and got the block sleeved. Share this post Link to post Share on other sites
tom_m 0 Posted March 25, 2008 Just rebuilt my RGY motor.As standard it kicks out 145bhp using,i believe a 8.5:1 comp ratio.The pistons in this motor are flat top.The RGX motor puts out 150bhp on a 7.9:1 comp,using pistons with a bath tub cut out in the crown. Gave up trying to get stock or oversize pistons for these motors.Used my original pistons and got the block sleeved. its the other way round, the flat topped pistons give 8:1 and the dished ones give 8.5:1 Share this post Link to post Share on other sites
taylorspug 7 Posted March 25, 2008 (edited) How does that work then Tom, what gives the extra compression if that engine uses the dished pistons? Edited March 25, 2008 by taylorspug Share this post Link to post Share on other sites
tom_m 0 Posted March 25, 2008 How does that work then Tom, what gives the extra compression if that engine uses the dished pistons? i've not measured them so i'm not certain, but i think the top of the bowl of the dish comes higher up the bore than the flat tops, increasing the CR that way. when 16v heads have been tried the dished pistons hit the valves where the flat tops don't. Share this post Link to post Share on other sites
taylorspug 7 Posted March 25, 2008 Ah I see, interesting to know. Not that i get involved with those engines too much, but you never know when info is going to come in handy. Share this post Link to post Share on other sites
colti 5 Posted March 25, 2008 its the other way round, the flat topped pistons give 8:1 and the dished ones give 8.5:1 Appologies.Got my x's and y's mixed up To confirm my engine code is XU10J2TE,which has got flat top pistons and has got a higher cr of 8.5:1 but a lower bhp. Share this post Link to post Share on other sites
DamirGTI 323 Posted March 25, 2008 Hi ! RGY and RGX pistons/conrods are the same . Measurements Pistons: from the center of the guiding pin hole to the piston crown - 40mm. (+/- 0.025) from the bottom of the guiding pin hole to the piston crown - 57mm. dia. - 85.970mm. (+/-0.009) Conrods: length - 152mm. guiding pin hole dia. - 22mm. (-0.041 / 0.029) crankshaft hole dia. - 53.695mm. (+0.013) Regards ! Damir Share this post Link to post Share on other sites
tom_m 0 Posted March 26, 2008 Hi ! RGY and RGX pistons/conrods are the same . Measurements Pistons: from the center of the guiding pin hole to the piston crown - 40mm. (+/- 0.025) from the bottom of the guiding pin hole to the piston crown - 57mm. dia. - 85.970mm. (+/-0.009) Conrods: length - 152mm. guiding pin hole dia. - 22mm. (-0.041 / 0.029) crankshaft hole dia. - 53.695mm. (+0.013) Regards ! Damir if this is the case how is the CR increase achieved? Share this post Link to post Share on other sites
tom_m 0 Posted March 26, 2008 (edited) Appologies.Got my x's and y's mixed up To confirm my engine code is XU10J2TE,which has got flat top pistons and has got a higher cr of 8.5:1 but a lower bhp. rgy - flat top pistons, 7.9:1/8:1 compression, 145bhp rgx - dished pistons, 8.5:1 compression, 150bhp Edited March 26, 2008 by tom_m Share this post Link to post Share on other sites
nunoserrano 0 Posted March 26, 2008 Hi ! RGY and RGX pistons/conrods are the same . Measurements Pistons: from the center of the guiding pin hole to the piston crown - 40mm. (+/- 0.025) from the bottom of the guiding pin hole to the piston crown - 57mm. dia. - 85.970mm. (+/-0.009) Conrods: length - 152mm. guiding pin hole dia. - 22mm. (-0.041 / 0.029) crankshaft hole dia. - 53.695mm. (+0.013) Regards ! Damir Thanks Damir Iff some one have some pics off the 2 that will be nice thanks Share this post Link to post Share on other sites
Jakob 1 Posted November 5, 2008 (edited) its the other way round, the flat topped pistons give 8:1 and the dished ones give 8.5:1 Hi ! RGY and RGX pistons/conrods are the same . Measurements Pistons: from the center of the guiding pin hole to the piston crown - 40mm. (+/- 0.025) from the bottom of the guiding pin hole to the piston crown - 57mm. dia. - 85.970mm. (+/-0.009) Conrods: length - 152mm. guiding pin hole dia. - 22mm. (-0.041 / 0.029) crankshaft hole dia. - 53.695mm. (+0.013) Regards ! Damir if this is the case how is the CR increase achieved? What is the answer to this question?? same height would give the late disched pistons the lowest CR !?! Are all XU10J2 and XU10J2TE heads fore sure the same?? Edited November 5, 2008 by Jakob Share this post Link to post Share on other sites
DamirGTI 323 Posted November 5, 2008 I believe that theres difference in the piston dish volume in between the RGY and RGX engines unfortunately i don't have specs for piston dish volume for these two engines/piston types .. Anyway all the piston/conrod measurements bar the dish cc volume are the same in between the two engines (as stated above .) ... measurements are taken from the OE Peugeot book .. ..sorry i should'v been more precise Damir Share this post Link to post Share on other sites
Jakob 1 Posted November 5, 2008 (edited) I believe that theres difference in the piston dish volume in between the RGY and RGX engines unfortunately i don't have specs for piston dish volume for these two engines/piston types .. Anyway all the piston/conrod measurements bar the dish cc volume are the same in between the two engines (as stated above .) ... measurements are taken from the OE Peugeot book .. ..sorry i should'v been more precise Damir Ok thanks, but now having the same piston height, the late RGX piston will now have the lowest CR.... And what would that CR then be??? 7.9/8.0:1 or what is the correct figure??? It can't be 8.5:1 ... And to continue in that direction.....If we know the TDC piston clearance and the gasket height, PLUS the actual engine CR of both RGX (dished piston) and RGY (flat piston - assuming total flat!!), then I can get near both the dish volume of the RGX piston AND the disch volume of the XU10J2 head. Can anyone provide me with following: 1) XU10J2TE TDC piston clearance - measured from top edge of piston (RGX/RGY have same piston height) to top of the block ?? 2) CR of XU10J2TE RGX engine ?? 3) CR of XU10J2TE RGY engine ?? 4) OE gasket height?? Edited November 5, 2008 by Jakob Share this post Link to post Share on other sites
Jakob 1 Posted November 7, 2008 No one with information about the CR in 8v turbo engine XU10J2TE ??? Share this post Link to post Share on other sites
paulvancraen 0 Posted November 15, 2008 rgy - flat top pistons, 7.9:1/8:1 compression, 145bhprgx - dished pistons, 8.5:1 compression, 150bhp That's just not true... I don't know which ones have dished pistons but I do know that the RGY has 150 bhp,235 Nm and 8,0:1 compression. RGX has 146 bhp,225 Nm and 8,5:1 compression Just because the compression is higher does NOT mean it has more power with turbo engines... RGX = old type and RGY = new type. I think they just reviewed the engine and perfected it. Share this post Link to post Share on other sites
tom_m 0 Posted November 15, 2008 That's just not true... I don't know which ones have dished pistons but I do know that the RGY has 150 bhp,235 Nm and 8,0:1 compression. RGX has 146 bhp,225 Nm and 8,5:1 compression Just because the compression is higher does NOT mean it has more power with turbo engines... RGX = old type and RGY = new type. I think they just reviewed the engine and perfected it. sorry you're wrong Share this post Link to post Share on other sites
Rob Turbo 3 Posted November 15, 2008 The later engines have the dished pistons, the top of the piston is level with the top of the block at TDC, but the dish is quite large. The early engines have flat pistons, the top of the pistons are lower than the top of the block by a few mm at TDC. This is fact, I've had both and seen with my own eyes. As for the C/R, autodata has the following information. Citroen XM: RGX - 7.9:1 (150 bhp) RGY - 8.5:1 (145 bhp) Citroen Xantia: RGX - no C/R (150 bhp) Peugeot 605: RGY - 8.5:1 (139 bhp) RGX - 8:1 (150 bhp) Peugeot 406: RGX - 8:1 (150 bhp) So it would seem that the RGX is the later engine, with lower C/R, but 150 bhp, whereas the RGY must be the older engine, with a C/R of around 8:1 and varying power, although it's only 6 bhp difference, not sure why this is though? Share this post Link to post Share on other sites
Jakob 1 Posted November 15, 2008 The later engines have the dished pistons, the top of the piston is level with the top of the block at TDC, but the dish is quite large. The early engines have flat pistons, the top of the pistons are lower than the top of the block by a few mm at TDC. This is fact, I've had both and seen with my own eyes. As for the C/R, autodata has the following information. Citroen XM: RGX - 7.9:1 (150 bhp) RGY - 8.5:1 (145 bhp) Citroen Xantia: RGX - no C/R (150 bhp) Peugeot 605: RGY - 8.5:1 (139 bhp) RGX - 8:1 (150 bhp) Peugeot 406: RGX - 8:1 (150 bhp) So it would seem that the RGX is the later engine, with lower C/R, but 150 bhp, whereas the RGY must be the older engine, with a C/R of around 8:1 and varying power, although it's only 6 bhp difference, not sure why this is though? Thanks very much!! I have looked at a french forum (JSO) and found: le rgy fait 141 cv et est sorti jusqu'au 04/94 le rgx fait 147 cv et a pris la suite au 05/94 rgy plats et rgx creux It seems like RGX is the new one with the dished pistons (creux) and CR 8:1. Remember cv, ps etc differ from hp. Share this post Link to post Share on other sites
