AlanM Posted March 9, 2006 Share Posted March 9, 2006 Can someone explain the difference between 256/264/272 cams, not in terms of profiles/geometry/dwell times etc but in terms of performance/reliability and pros and cons of each. Link to comment Share on other sites More sharing options...
Alex Posted March 9, 2006 Share Posted March 9, 2006 Firstly have you had a search as they have been discussed etc? The higher the number the more airflow you'll get at high RPM's but it's always a trade - you might lose some lowdown power and the valve springs take more of a beating. (HKS cams have staggered lift along with staggered duration). If you want more reliability better idle manners stick with 256's if you want a race engine head to 272's. A good compromise is 256 on the intake and 264 on the exhaust. Link to comment Share on other sites More sharing options...
Ian C Posted March 9, 2006 Share Posted March 9, 2006 I'm wondering if unstaggered is the way to go on a single turbo conversion as you don't have the uber-restriction in the exhaust stream any more... 264/264 perhaps. Hmmm -Ian Link to comment Share on other sites More sharing options...
Guest Bijal Posted March 9, 2006 Share Posted March 9, 2006 Firstly have you had a search as they have been discussed etc? The higher the number the more airflow you'll get at high RPM's but it's always a trade - you might lose some lowdown power and the valve springs take more of a beating. (HKS cams have staggered lift along with staggered duration). If you want more reliability better idle manners stick with 256's if you want a race engine head to 272's. A good compromise is 256 on the intake and 264 on the exhaust. yes, alex is correct... however the 264's will not require head work (maybe shimming at the most) if setup correctly you will have no idle issues. i am running 264 cams both in and out and my idle is like stock supra. however the mid range and top end is helped A LOT!!!! mixing cam profiles is good but can be hard to setup sometimes...it also depends on what ems you go for and how its tuned..and what type of results you are after for mixing the cams. hope thats useful too. bijal Link to comment Share on other sites More sharing options...
b_have Posted March 9, 2006 Share Posted March 9, 2006 264 in and out for me also. Link to comment Share on other sites More sharing options...
Guest Terry S Posted March 9, 2006 Share Posted March 9, 2006 yes, alex is correct... however the 264's will not require head work (maybe shimming at the most) if setup correctly you will have no idle issues. i am running 264 cams both in and out and my idle is like stock supra. however the mid range and top end is helped A LOT!!!! mixing cam profiles is good but can be hard to setup sometimes...it also depends on what ems you go for and how its tuned..and what type of results you are after for mixing the cams. hope thats useful too. bijal You dont need head work for 272's either! Link to comment Share on other sites More sharing options...
Chiefgroover Posted March 9, 2006 Share Posted March 9, 2006 I used 264's and lost a load of bottom end. I havent used 256's so cant comment on them. UK specs s/h might just be the ticket for you? Link to comment Share on other sites More sharing options...
terribleturner Posted March 9, 2006 Share Posted March 9, 2006 Excuess my ignorance but is it possible to get a set up to loose top end and get better bottom?? Link to comment Share on other sites More sharing options...
Guest Bijal Posted March 9, 2006 Share Posted March 9, 2006 You dont need head work for 272's either! every head we have worked on with 272 cams we have gone and advised customers to also opt for a BUILT HEAD. reason for this is simple, the 272 cams are EXTREMELY HARSH on the head, therfore it is advised..but in the end its the customer's choice. Link to comment Share on other sites More sharing options...
Guest Terry S Posted March 9, 2006 Share Posted March 9, 2006 every head we have worked on with 272 cams we have gone and advised customers to also opt for a BUILT HEAD. reason for this is simple, the 272 cams are EXTREMELY HARSH on the head, therfore it is advised..but in the end its the customer's choice. OK............................. Link to comment Share on other sites More sharing options...
Guest Bijal Posted March 9, 2006 Share Posted March 9, 2006 Link to comment Share on other sites More sharing options...
b_have Posted March 9, 2006 Share Posted March 9, 2006 I used 264's and lost a load of bottom end. I havent used 256's so cant comment on them. UK specs s/h might just be the ticket for you? Get it back by adding another 15deg of ign timing. Link to comment Share on other sites More sharing options...
Sharpie Posted March 9, 2006 Share Posted March 9, 2006 I'm wondering if unstaggered is the way to go on a single turbo conversion as you don't have the uber-restriction in the exhaust stream any more... 264/264 perhaps. Hmmm -Ian Keep talking I had to buy a bag to fit them in and then the TSA had a good nose around too on the way home. (Glad I read the sign at Seattle airport which, said to leave the bag unlocked) Link to comment Share on other sites More sharing options...
Ian C Posted March 10, 2006 Share Posted March 10, 2006 every head we have worked on with 272 cams we have gone and advised customers to also opt for a BUILT HEAD. reason for this is simple, the 272 cams are EXTREMELY HARSH on the head, therfore it is advised..but in the end its the customer's choice. What's the harsh bit? I mean, in what way are they harsh? And what do you mean by a "built head"? Just wondering like, most people including myself don't really know what you mean - I'm just willing to admit to it -Ian Link to comment Share on other sites More sharing options...
BURT Posted March 10, 2006 Share Posted March 10, 2006 same here 264 inlet/ exzorst Link to comment Share on other sites More sharing options...
Chiefgroover Posted March 10, 2006 Share Posted March 10, 2006 The yanks reckon that 264's etc beat up the lobes some after higher mileages, and reckon different springs are the way to go. Like PHR springs. Link to comment Share on other sites More sharing options...
AlanM Posted March 10, 2006 Author Share Posted March 10, 2006 Thanks for the comments guys. Remembering where I live I do not want anything which requires re-setting on a regular basis so can I take it that if I went for 264 (with 15 defree adv?) that this would not need retuned every couple of months? Link to comment Share on other sites More sharing options...
Lucifer Posted March 10, 2006 Share Posted March 10, 2006 Yes you are correct, but more like every 10k you would need to check and maybe reshim as they are harsh. However It really depends on whan you want to get out of the car and what turbo(s) you have, if still on twins, why loose all that low end? Link to comment Share on other sites More sharing options...
Guest Bijal Posted March 10, 2006 Share Posted March 10, 2006 Yes you are correct, but more like every 10k you would need to check and maybe reshim as they are harsh. However It really depends on whan you want to get out of the car and what turbo(s) you have, if still on twins, why loose all that low end? good point there..very true. stick to 264 mate...if you have got money burning a hole in your pocket then give it to me and have a built head with 272!!! bijal Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 10, 2006 Share Posted March 10, 2006 The yanks reckon that 264's etc beat up the lobes some after higher mileages, and reckon different springs are the way to go. Like PHR springs. More bloody American tosh. The cams have BIT more duration and a tad more lift, in some cases, than stock, they are about as harsh as a babies bum. Utter rot. Link to comment Share on other sites More sharing options...
Guest Terry S Posted March 10, 2006 Share Posted March 10, 2006 More bloody American tosh. The cams have BIT more duration and a tad more lift, in some cases, than stock, they are about as harsh as a babies bum. Utter rot. Link to comment Share on other sites More sharing options...
CJ Posted March 10, 2006 Share Posted March 10, 2006 As a new owner of a J-spec manual would I see any advantage by putting in 256 / 264 cams? Link to comment Share on other sites More sharing options...
jason m Posted March 10, 2006 Share Posted March 10, 2006 As a new owner of a J-spec manual would I see any advantage by putting in 256 / 264 cams? Apart from using all the money up from the orange car? I spoke to CW about this - he said a pair of 264's for the track would be nice at the top end. Link to comment Share on other sites More sharing options...
CJ Posted March 10, 2006 Share Posted March 10, 2006 Apart from using all the money up from the orange car? I have a spare set Link to comment Share on other sites More sharing options...
Chiefgroover Posted March 10, 2006 Share Posted March 10, 2006 More bloody American tosh. The cams have BIT more duration and a tad more lift, in some cases, than stock, they are about as harsh as a babies bum. Utter rot. Yeah I kinda reckoned the same, an excuse to sell valve springs, but thats American marketing for you. Link to comment Share on other sites More sharing options...
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