Ahl 4 Posted March 30, 2006 Im going to buy a catcam inlet shortly, but I was thinking about getting the old version of the 4900526, (275 duration) the one that required modification to the head to avoid the lobes fouling. Does anyone know the model number of the old one? Also would anyone recommend it over the new one or does anyone have experience of both? Share this post Link to post Share on other sites
Revla 2 Posted March 30, 2006 Im going to buy a catcam inlet shortly, but I was thinking about getting the old version of the 4900526, (275 duration) the one that required modification to the head to avoid the lobes fouling. Does anyone know the model number of the old one? Also would anyone recommend it over the new one or does anyone have experience of both? Matt @ QEP would be the best person to ask this I think?? Share this post Link to post Share on other sites
B1ack_Mi16 67 Posted March 30, 2006 Matt @ QEP would be the best person to ask this I think?? I remember these cams were popular of the old range at least, but they're maybe a tad wild for what you're describing. http://cortex.fa-s.ntnu.no/~kristian/205gt...ers/catcams.jpg Share this post Link to post Share on other sites
Mattsav 1 Posted March 30, 2006 (edited) The old profiles are 4900516, 4900520 & 490521 If you search the for the part no's on the catcams site the specs are still there. There's not a lot of difference between the inlet of the new 4900526 and the old 4900516. I've got inlets for 4900526 as well as sets of 4900527, 4900528 and a set of the old 4900521's on the shelf. Edited March 30, 2006 by Mattsav Share this post Link to post Share on other sites
Ahl 4 Posted March 31, 2006 Thanks for that Matt. I feel the 521's are probably too peaky for a road car, plus i'll be running the car on standard management to begin with. So the old 516 has slightly higher lift. I see that it also has a degree less duration at 1mm but has 110 degree lobe centres instead of 112 degrees and 2mm lift at TDC as opposed to 1.75mm. Is this significant at all? Significantly more dwell angle? or is it just a slightly different shape of lobes and the old ones are basically the same but with more lift? Share this post Link to post Share on other sites
Mattsav 1 Posted March 31, 2006 The 1mm duration has been adjusted to compensate for the slightly lower lift. The centerline is changed to suit being run with the std exhaust cam (thus changing the lift@tdc) The area under the lift curve of the 2 inlets will be pretty much the same. Share this post Link to post Share on other sites
