lithium4750 Posted March 25, 2006 Share Posted March 25, 2006 Anyone know the specs (duration, lift) of a stock 260 cam? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 25, 2006 Share Posted March 25, 2006 Here's all of them. The 260 cam has just slightly more duration and less lift than the others. It is, by an infinitessimally small amount, the largest of the puny stock cams. If I had one, I'd send it off to Delta or similar for a regrind and have them make something out of it that wasn't so small. EDIT--forgot my linky: http://www.atlanticz.ca/zclub/techtips/cam/index.htm Quote Link to comment Share on other sites More sharing options...
lithium4750 Posted March 26, 2006 Author Share Posted March 26, 2006 depending on my money situation I will probably get another one from z car parts. How does .480 lift and 274 lift sound? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 26, 2006 Share Posted March 26, 2006 Sounds a lot less puny. That should work okay with SU's or stock FI. It's on the small side for triples or aftermarket FI. If you search you'll find that there are coil bind issues with lifts over .460 and valve stem seal issues with lifts over about .470 or .480. They aren't difficult to overcome (just run different valve springs and seals) and the result is well worth it. If you're running a stock FI system you have to be pretty conservative due to the inflexibility of the crappy ECU. Quote Link to comment Share on other sites More sharing options...
lithium4750 Posted March 26, 2006 Author Share Posted March 26, 2006 Yeah I got stock S.U.'s and a guy suggested that one to me. I'm going to get some new springs to go with it. 130 bucks is cheap insurance than runnin the risk with the stock springs and damaging a piston. But do you think new rockers are totally neccessary? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 26, 2006 Share Posted March 26, 2006 Opinions vary. Mine is that new rockers are not necessary on a regrind. If I was going with a Schneider cam, I'd have them replaced. Delta Cams can resurface your existing rockers if you want for $3. Or search and there is a thread about how to do it yourself along with a bunch of warnings not to... Quote Link to comment Share on other sites More sharing options...
oinojo Posted April 16, 2006 Share Posted April 16, 2006 Opinions vary. Mine is that new rockers are not necessary on a regrind. If I was going with a Schneider cam, I'd have them replaced. Delta Cams can resurface your existing rockers if you want for $3. Or search and there is a thread about how to do it yourself along with a bunch of warnings not to... has anyone tried reusing their stock rockers with a regound cam? Im looking to have my cam reground and was wondering if my rockers would damage its lobes. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted April 16, 2006 Share Posted April 16, 2006 Me. No damage yet. Used my stock rockers on my first mild regrind. Then I went to a bigger regrind, and used the stock rockers again. Put 15K or so on the first one, then put another 30K on the second one. Quote Link to comment Share on other sites More sharing options...
Z-point Posted May 6, 2006 Share Posted May 6, 2006 It's on the small side for triples or aftermarket FI. If you search you'll find that there are coil bind issues with lifts over .460 and valve stem seal issues with lifts over about .470 or .480. Hello all, Jon, what you saying is. With a triple 44mm Mikuni the better choice is a stage 3 cam? And why? I ask you this because my plan is to build an: E31 with a stage 2 or 3 cam A L28 with flat-tops And triple 44mm Mikuni’s Like to use this for stage rallying. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 6, 2006 Share Posted May 6, 2006 The Mikunis make top end power. The tiny stage 2 and stage 3 don't make power high enough in the RPM range to fully utilize the Mikunis. I have something roughly equivalent to the Stage 4 and it is still too small IMO. I happen to have an L28/E31 and 44's, so my engine might be a pretty good example for you. It pings on pump gas (our 92 is equivalent to your 95 octane I believe) and mine requires 95 octane in the RON+MON/2 formula. I'd suggest you go BIGGER on the cam than stage 2 or 3. You will have those other issues to deal with of the coil bind and the valve stem seals. Quote Link to comment Share on other sites More sharing options...
Z-point Posted May 6, 2006 Share Posted May 6, 2006 Top end power isn’t always necessary in stage rallying. There are hardly straight linesJ. You also need low power to pull out from corners etc. Therefore I thought I’ll take number 2. three is fine too but 4?? That’s more for track racers isn’t? Please explain more about the issues of the coil and seals. Took this of MSA Performance Camshaft, Stage II, 70-83 Z/ZX Non Turbo Grind: 17033. Lift(In/Ex): .480/.480. Duration(In/Ex): 274/274. Characteristics: Good idle, power range 2000-6000 RPM. Great slalom grind, works well with stock carbs or triple Webers. Performance Camshaft, Stage III, 70-83 Z/ZX Non Turbo Grind: 17034. Lift(In/Ex): .460/.460. Duration(In/Ex): 270/280. Characteristics: Rougher idle, excellent performance. Pulls hard from 3000-6500 RPM. Performance Camshaft, Stage IV, 70-83 Z/ZX Non Turbo Grind: 17036. Lift(In/Ex): .495/.495. Duration(In/Ex): 290/290. Characteristics: Rough idle. Midrange and top end power cam for well setup car. Drag or track racing. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 6, 2006 Share Posted May 6, 2006 If you want power out of corners you can either get some really low diff gears so that the rpms stay higher or use different carburetors. That's my take on it. I'm sure you can find someone to tell you that the stage 3 is perfect if that's what you're looking for, but I think it's way too small. When the lift gets over about .470 the coil springs bind. You need to replace the springs to prevent this. Right about at the same amount of lift the valve spring retainers hits the valve stem seal. There was a thread about that by speeder where he found a new stem seal that will allow lifts over .600 I think. Quote Link to comment Share on other sites More sharing options...
Z-point Posted May 6, 2006 Share Posted May 6, 2006 If you want power out of corners you can either get some really low diff gears so that the rpms stay higher or use different carburetors. . I already bought myself a 4.6 LSD R200 Just in case.... and I'll look into that thread.. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 6, 2006 Share Posted May 6, 2006 There you go! So you don't need low end. You need top end, and lots of it. Quote Link to comment Share on other sites More sharing options...
johnc Posted May 7, 2006 Share Posted May 7, 2006 FYI... SCCA EP rules limit valve lift to .500 with no limit on duration all the while using slightly modified stock SUs. These 2.4L engines make 250hp and more at the crank on a 12 to 1 CR. I even know of one of these engines, with a sight drop in CR, being run on the street here in SoCal. He tends to irritate a lot of Honda folks, especially when they see the SUs and no forced induction. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted May 7, 2006 Share Posted May 7, 2006 These 2.4L engines make 250hp and more at the crank on a 12 to 1 CR. What kind of revs is he turning? If he makes 160 lbft torque at his hp peak that would be 8200 rpm. Wow!!! Quote Link to comment Share on other sites More sharing options...
johnc Posted May 8, 2006 Share Posted May 8, 2006 They are 8,000 + rpm motors. Quote Link to comment Share on other sites More sharing options...
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