speedstylez78 Posted December 30, 2003 Share Posted December 30, 2003 hey i have a 78 280z and got a new cam for xmas. the . the cam i got for motorsport the specs on it are 460 lift with 270 intake duration and 280 exhaust duration . i put the new springs and everything in and adjusted the lash to 8 intake 10 exhaust and advanced the timing a little. but the car seems to be slugish and slower. i have a few air flow upgrades like cold air intake 60mm throttle body MSA 6-2-1 headers full exhaust with 2.5 in. piping and a magnaflow muffler and the pistons are bore .03 over other than that the car is stock. i was wondering if any of you had and tunning tips to get the power and acceleration back out of the car. thanks Justin Morrow speedstylez78@yahoo.com see my car at http://www.geocities.com/speedstylez78 Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted December 30, 2003 Share Posted December 30, 2003 sorry for this being off-topic but what color is your car? it is beautiful! best of luck. mike Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted December 30, 2003 Share Posted December 30, 2003 Maybe a timing advance issue? Quote Link to comment Share on other sites More sharing options...
TimZ Posted December 30, 2003 Share Posted December 30, 2003 My money is on cam timing - do you have an adjustable cam sprocket? The stock sprocket will allow you to advance the cam timng by 4 or 8 degrees, which is worth trying. My guess is that you might need to retard the cam timing, in which case you will need a different sprocket. I would recommend using the Nissan Motorsports 8-hole sprocket, rather than the vernier types (Personal preference - I don't like worrying about my sprocket coming apart and screwing up my motor ) Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted December 31, 2003 Share Posted December 31, 2003 More compression wouldn't hurt either, and my experience with that particular cam is it is fussy. I only had it run really strong in one engine, and it was an L26 with a seriously milled E-88 ala E31 lookalike. Do you have dished pistons? You may want to consider milling the head a little bit to raise compression. Quote Link to comment Share on other sites More sharing options...
speedstylez78 Posted January 1, 2004 Author Share Posted January 1, 2004 the car is daytona blue the blue of the 350z's. thanks i am starting to build a turbo kit which should increase my 8.7 to 1 compreesion, i am not going to run much boost maybe 6 or 7 pounds. also with the turbo kit i am going to get bigger injectors and an adjustible f.m.u. i talked to a couple of guys and they said it would be ok to run with this cam how much do the cam gears run? that may be be my next thing i am running 15 degrees at idle should i increase the timing more? Thanks alot Justin Morrow speedstylez78@yahoo.com see my car at http://www.geocities/speedstylez78 Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted January 1, 2004 Share Posted January 1, 2004 That cam will not work with a turbo, I have actually tried it, and it sucked. Sounded good at idle, but man was it a pig, stock cam is much better for a turbo. Look if you want a cam, and are going turbo, get a small one. Like the comp cams 260H or something. I have a little crower in my ZXT, and it is .428 lift, and 218 duration at .050, with no overlap. No overlap is what you are looking for. 110 degree LCA. You may want to open that up to 112 degrees. But your cam is an NA cam, designed for higher compression, and mods like that. You need to be turning your engine to about 7k to get the goods out of that cam. Quote Link to comment Share on other sites More sharing options...
DAW Posted January 1, 2004 Share Posted January 1, 2004 The cam timing may be off but that is not the big problem here. If you have a stock 280Z bottom end and head (N47) then you have only 8.3:1 c.r. and that's not going to make any significant power with that cam (or any other cam for that matter). At this point, IMO, the fastest easiest path to a significant gain in power would be to either get an F54 L28E short block (or whole engine and sell the head) and swap it for the short block in you 280Z. This will give you a bolt-in c.r. increase from 8.3 to about 10:1. Or you could remove the pistons from your short block (short block still bolted into car), have the tops machined down just until the edge of the dish is gone, swap the L28 rods (130.4mm) for a set of late L24 rods (133mm). This will give the same 10:1 c.r. and the added benefit of improved rod/stroke ratio. An alternative on this approach is to buy a set of new pistons made by Sterling which have 86mm (L28) dia. but the correct pin ht. to use with the L24 rod length. If you decide to do any of these approaches don't make extra work for yourself. You can remove the head and intake assembly (once the headers are unbolted) as a single piece and it doesn't take much time to open up a lot of space to get to the shortblock. Personally, I would bolt-in an N54 short block and have fun with it while building or shopping for a separate turbo engine. DAW Quote Link to comment Share on other sites More sharing options...
speedstylez78 Posted January 3, 2004 Author Share Posted January 3, 2004 hey daw so the L24 rods will bolt up with my crank? if i did this what kind of h.p. and torque would i be pushing. could i have the head shaved a little for some more c.r. and get some better fuel delivery for more power or would that be unsafe with my few mods. thanks alot justin morrow speedstylez78@yahoo.com see my car at http://www.geocities.com/speedstylez78 Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted January 3, 2004 Share Posted January 3, 2004 My money is on cam timing - do you have an adjustable cam sprocket? The stock sprocket will allow you to advance the cam timng by 4 or 8 degrees' date=' which is worth trying. My guess is that you might need to retard the cam timing, in which case you will need a different sprocket. I would recommend using the Nissan Motorsports 8-hole sprocket, rather than the vernier types (Personal preference - I don't like worrying about my sprocket coming apart and screwing up my motor )[/quote'] If you look closely, you'll see the fastners came out, and one still half way out. This allowed the gear to spin, and guess what.... yep, bent valves... Quote Link to comment Share on other sites More sharing options...
DAW Posted January 3, 2004 Share Posted January 3, 2004 Justin, the L24 rods are a direct bolt-in but use only late '72-on rods (after engine serial # L24-096180) as they have large bolts (9mm vs 8mm) and are stronger. The Maxima L24E rods can't be used, they have smaller journals. Late L16 rods (after serial # L16-369553) from pick-up trucks will work too. I would discourage any further shaving of your N47 head if you go to flat top pistons (for a street driven engine) because ping/fuel octane problems become a headache once you get above c.r. 10:1. You'd also be bringing the valves closer to the piston tops if you cut the head, better to overbore the block to increase both displacement and c.r. Your cam and increased c.r. go together and the sum is greater than the parts. Good luck. DAW Quote Link to comment Share on other sites More sharing options...
preith Posted January 3, 2004 Share Posted January 3, 2004 I think we might be getting a little ahead of ourselves. I agree with TimZ, its most likely cam timing, meaning its off a tooth. A friend of mine had the same symptoms on his Z, and this turned out to be the case. Technically the L24 rod is not a direct bolt-in. As DAW eluded to earlier, you will have to mill the pistons in order to compensate for the additional height. Also like DAW said, go with flat tops before you mill the head. Phil Quote Link to comment Share on other sites More sharing options...
Guest norm[T12SDSUD] Posted January 4, 2004 Share Posted January 4, 2004 My money is on cam timing - do you have an adjustable cam sprocket? The stock sprocket will allow you to advance the cam timng by 4 or 8 degrees' date=' which is worth trying. My guess is that you might need to retard the cam timing, in which case you will need a different sprocket. I would recommend using the Nissan Motorsports 8-hole sprocket, rather than the vernier types (Personal preference - I don't like worrying about my sprocket coming apart and screwing up my motor )[/quote'] If you look closely, you'll see the fastners came out, and one still half way out. This allowed the gear to spin, and guess what.... yep, bent valves... Is that the Nissan motorsport part ? If so, I think I'll just stay with my stock cam sprocket. Later,norm Quote Link to comment Share on other sites More sharing options...
jeffp Posted January 4, 2004 Share Posted January 4, 2004 I looked at the various sprockets out there and the HKS was the winner for me. Te MSA sprocket has all the adjusting holes nd I did not like that idea of preset adjustments. The AZ acar sprocket looked like it was susceptable to coming lose. I got the HKS sprocket and an able to adjust any degree + or- 15 degrees. The down side is you need a degree wheel to do the timing. So you will need to know the lobe centers, and @ what lift the figures were taken at. Then its just a matter of setup of the degree wheel (easier said then done) and dialing in the cam. Then if you take the time to dial in the timing tab on the damper it is easier the next time to do the job. Cam timing is not to hard and you know when it is wrong. I think one tooth is like 19 degrees or so, way to much timing for any cam. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted January 4, 2004 Share Posted January 4, 2004 that cam rocked with straight up with stretched timing chain and 10.3:1. Quote Link to comment Share on other sites More sharing options...
preith Posted January 4, 2004 Share Posted January 4, 2004 I looked at the various sprockets out there and the HKS was the winner for me. Any HKS part# or vendor for that...had difficulty finding it on HKS's page. Quote Link to comment Share on other sites More sharing options...
speedstylez78 Posted January 5, 2004 Author Share Posted January 5, 2004 ok i think i am going to do both, the cam sproket and the rods. if anyone out there is selling the hks sprokets and/or some late 72 on L24 rods i would like to find soon. kinda of subject but went to the strip yesterday(the car was runing good enough for a couple of runs) and ran a 9.71 at 71.2 mph in the 1/8 its not to bad but think once i get all this stuff taken care of i will be alittle quicker thanks for all your help Quote Link to comment Share on other sites More sharing options...
TimZ Posted January 5, 2004 Share Posted January 5, 2004 I looked at the various sprockets out there and the HKS was the winner for me. Te MSA sprocket has all the adjusting holes nd I did not like that idea of preset adjustments. The AZ acar sprocket looked like it was susceptable to coming lose. I got the HKS sprocket and an able to adjust any degree + or- 15 degrees. The down side is you need a degree wheel to do the timing. So you will need to know the lobe centers' date=' and @ what lift the figures were taken at. Then its just a matter of setup of the degree wheel (easier said then done) and dialing in the cam. Then if you take the time to dial in the timing tab on the damper it is easier the next time to do the job. Cam timing is not to hard and you know when it is wrong. I think one tooth is like 19 degrees or so, way to much timing for any cam. [/quote'] I believe that Joel got that from Malvern Racing. The Nissan Motorsport one is the one with eight preset holes, allowing adjustment in 3 degree increments. Personally this is what I liked about this gear - it's reliability will be exactly the same as stock. Sorry, but I have yet to see a vernier syle sprocket that isn't susceptible to this kind of failure. Jeff - do you have a pic of the HKS piece? What's different about it? IME, the 3 degree increments work just fine for optimizing the cam timing, especially if you don't have the luxury of properly degreeing the cam (not a trivial task - and not one that is easy to do correctly with the motor in the car). Quote Link to comment Share on other sites More sharing options...
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