niklas 1 Posted October 6, 2006 What are the exact differences between the xu9j4 and xu9j4z engines? Share this post Link to post Share on other sites
Super Josh 4 Posted October 6, 2006 Pistons crown height is lower to give the reduced compression. Valve springs are different too, at least according to the Catcam website. As maximum valve lift is quoted as lower, limiting the particular Catcam that can be fitted. Don't know if the Cams and pulleys are different too. Josh Share this post Link to post Share on other sites
B1ack_Mi16 67 Posted October 7, 2006 Pistons crown height is lower to give the reduced compression. Valve springs are different too, at least according to the Catcam website. As maximum valve lift is quoted as lower, limiting the particular Catcam that can be fitted. Don't know if the Cams and pulleys are different too.Josh The valve springs definately are the same in both these engines. Difference is in pistons as you say, and advanced camtiming on the inlet cam with (3) pulley while J4 has (2) on both inlet and exhaust. Don't think there any other mechanical differences. Share this post Link to post Share on other sites
niklas 1 Posted October 7, 2006 Ok, so pistons, inlet cam pulley, no cat and the motronic box are all the differences? Share this post Link to post Share on other sites
B1ack_Mi16 67 Posted October 7, 2006 Ok, so pistons, inlet cam pulley, no cat and the motronic box are all the differences? I would say so yes. Share this post Link to post Share on other sites
petert 586 Posted October 7, 2006 The cams and valve springs are definitely identical. The only difference is with the Mi16x4 cams, which have the same lift but more duration. piston compression heights: XU9J4 - 37.12mm XU9J4Z - 36.28mm Share this post Link to post Share on other sites
niklas 1 Posted October 7, 2006 Great! I'm thinking of J4-convertering a J4Z I have in the garage Share this post Link to post Share on other sites
Super Josh 4 Posted October 7, 2006 The cams and valve springs are definitely identical. So Peter, how do you explain the info on the Catcams website? They talk about 'Grey' and 'Green' O.E. springs. Here's the info.... XU9J4 XU9J4Z Notice the 'Fitted Length / Load' and 'Max. allowed lift / load' are different for each spring type. Now obviously, this won't be a problem when using the standars cams. But could be a problem when using aftermarket items. Cheers, Josh Share this post Link to post Share on other sites
steendp 0 Posted October 7, 2006 The later engine is the 2.0 litre 16v XU10J4 (150hp) and not the XU9J4 (147/160hp). Share this post Link to post Share on other sites
Super Josh 4 Posted October 7, 2006 The later engine is the 2.0 litre 16v XU10J4 (150hp) and not the XU9J4 (147/160hp). Are you saying that Catcams have it listed incorrectly on their website? As they state that the information is the same for both XU9 and XU10. I thought that the 2.0 litre was 155 BHP? A lot of confusing info Josh Share this post Link to post Share on other sites
steendp 0 Posted October 7, 2006 Are you saying that Catcams have it listed incorrectly on their website? All I'm saying is that the valvesprings between XU9J4A and XU9J4AZ is the same. I just thought that the difference between XU9 and XU10 was the reason why Catcams had different listings. Having said (written) that, I can now see the the valvesprings actually is the same for 1.9 and 2.0 16v engines. I dont know why Catcams are listing 2 different springs. I thought that the 2.0 litre was 155 BHP? Correct - my mistake. Share this post Link to post Share on other sites
petert 586 Posted October 7, 2006 So Peter, how do you explain the info on the Catcams website? They're wrong. I've also measured XU10J4 springs and they're identical to XU9J4Z as well. Share this post Link to post Share on other sites
