madden87 Posted July 24, 2008 Share Posted July 24, 2008 My car is a 260z with 3.90 gear ratio. I have a STOCK 350 with the worst heads possible and a th350 tranny. this is just my starter engine, but I would like to go faster. My buddy has a couple old chevy's he takes to the track so he is helping me a little, but after seeing my car run last weekend I don't think he wants to help me anymore (he does not want me to be faster than him). I only ran 13.4 at 94mph but I also had to get off the gas at about 1000 feet because I started floating valves. Simply put, I did not have enough gear. I will fix part of that by replacing my tires with 235/60 15. This will give me another 3" in the back. I want to replace the heads and cam at the same time as my tires. I was thinking about iron eagle 180cc or the 200cc. I don't have any idea which cam I will need. My buddy will still help me with everything, but I want to make sure he does not try to talk me out of something that might be a little better. any help would be great. Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted July 24, 2008 Share Posted July 24, 2008 My car is a 260z with 3.90 gear ratio. I have a STOCK 350 with the worst heads possible and a th350 tranny. this is just my starter engine, but I would like to go faster. My buddy has a couple old chevy's he takes to the track so he is helping me a little, but after seeing my car run last weekend I don't think he wants to help me anymore (he does not want me to be faster than him). I only ran 13.4 at 94mph but I also had to get off the gas at about 1000 feet because I started floating valves. Simply put, I did not have enough gear. I will fix part of that by replacing my tires with 235/60 15. This will give me another 3" in the back. I want to replace the heads and cam at the same time as my tires. I was thinking about iron eagle 180cc or the 200cc. I don't have any idea which cam I will need. My buddy will still help me with everything, but I want to make sure he does not try to talk me out of something that might be a little better. any help would be great. Welcome to the support group, now please stand up and tell us that your addicted to speed! Thanks, now you should feel better. The dart iron eagle 200's would be a good choice especially if you plan on more upgrades later. IME they do not adversely affect the bottom end torque. If you opt for the 64cc chambers you can get some compression which will help cam selection. I am assuming your running a stock converter so you will want to stay around 225 degrees duration at .050 and get as much lift as you can. The intake would be another area of cheap upgrade, try the edelbrock dual plane manifolds or the weiand. Some headers would be good too. It never ends BTW. Quote Link to comment Share on other sites More sharing options...
madden87 Posted July 24, 2008 Author Share Posted July 24, 2008 Thanks for the info. I do have a performer rpm intake on it. I meant to say that the internals of the engine are stock. The converter is stock. I will build another engine over the winter so I am just looking for a little something more right now. Actually, I would like to complete a full pass without floating valves. Any prefferences on cam selection? Also, is there a big difference between the 180 and 200cc models? Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted July 24, 2008 Share Posted July 24, 2008 The dart iron eagle 200's would be a good choice especially if you plan on more upgrades later. IME they do not adversely affect the bottom end torque. If you opt for the 64cc chambers you can get some compression which will help cam selection. I am assuming your running a stock converter so you will want to stay around 225 degrees duration at .050 and get as much lift as you can. The intake would be another area of cheap upgrade, try the edelbrock dual plane manifolds or the weiand. Some headers would be good too. It never ends BTW. thats generally good advice but depending on your intended use of the car it may need to be tweaked a bit, since your basically asking for instructions on a decent combo, ID sure like to know more about the intended use for the car , and any restrictions like the car needing to pass emmision testing etc,and your reasonable budget for the project, now since its an auto trans Id strongly suggest first setting a hp goal to shoot for and sellecting a parts list to reach that goal within your budget and skill levels, and Id point out that that 3.90:1 rear is a nice asset in a performance application but youll want a 3000 rpm stall speed converter and about a 10.5:1 cpr and a solid lifter flat tappet cam to take full advantage of that rpm range and ythose 200 cc heads.....post all the info you can on the car, your goals and what your budget and skills are, it will help, BTW almost any HYDROLIC cam is going to be much more limited than a decent flat tappet solid lifter cam, simply because the hydrolics generally max out at about 6000-6300rpm and a decent solid flat tappet lifter cam easily hits 6800-7000rpm with the correct springs and valve train geometry Quote Link to comment Share on other sites More sharing options...
madden87 Posted July 25, 2008 Author Share Posted July 25, 2008 I will drive the car on the street around my community and thats about it. Mostly it will be trailered to the track (sometimes I will drive there if I am lazy). I do not need to worry about emmision testing. I am mechanically inclined, just never touched the internals except for replacing a cam or heads. I would like to stay under $1500. I would also like to get a set of heads that I can use on my next engine when I get around to building it later this year. We are looking at around 400-450hp on the next engine. I would just like to get as much as I can out of this engine, but I will not do anything else to the current engine besides head and a cam. I was very disappointed that I could not finish a 1/4 mile pass. The new tires will be on next week so that should help but I really need some combo that can get me to 6000rpm or so. I did plan on getting a 3000 rpm stall, but I did not plan on putting it in until I install the next engine. I can do it earlier though. That is mostly because I live near Phoenix and it is HOT out here. I figure this cam will not transfer over, but if the heads do I will happy. Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted July 25, 2008 Share Posted July 25, 2008 heads http://www.jegs.com/i/Brodix/158/1021004/10002/-1/760699%7C10187 cam http://www.crower.com/misc/cam_spec/cam_finder.php?part_num=00321&x=18&y=6 lifters http://www.competitionproducts.com/prodinfo.asp?number=651080DL stall converter http://www.jegs.com/i/JEGS/555/60401/10002/-1 Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted July 25, 2008 Share Posted July 25, 2008 Since you are leaving it all stock inside IMO would stick with the hydraulic cam since you don't want to spin it as much as a solid will go. Your building another engine later so maybe you want to go cheap and easy with parts that you can use later to get where you want to go with your usage now. Go with the 64 cc Dart iron eagles with hydraulic springs. Use the 201271 grind. I find that that works really well with a stock converter, gives you some lope, and great midrange torque. I have run that cam and it will top out at about 6000 rpm. The tight lobe center comes on quicker and lower than the wide lobe center. In the z it is a pleasure to drive. Dart makes those heads in a 49 cc option which will allow you to get high compression with flat tops. Circle track guys use them all the time and I just built an engine for a guy using those for a rule restricted motor. You can make around 500hp with those heads btw. so if budget is a concern, then I would recommend them since they will get you to your goals. Quote Link to comment Share on other sites More sharing options...
madden87 Posted July 29, 2008 Author Share Posted July 29, 2008 I have seen a lot of people argue the point, but what is the difference between aluminum and iron heads? I understand the weight difference and that you can run a slightly higher compression ratio with aluminum because it displaces heat faster. Is it bad to run aluminum heads on an iron block? Also, since my bottom end is stock would it be a problem running a 49cc head. I don't know what the compression would be, but I would assume it would be on the borderline for a set of cast pistons. Thanks again for all the information. Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted July 29, 2008 Share Posted July 29, 2008 I have seen a lot of people argue the point, but what is the difference between aluminum and iron heads? ALUMINUM is far cheaper and easier to repair, lighter in weight and easier to port, add the fact that the price is usually only a couple hundred more than cast iron and your foolish to use iron I understand the weight difference and that you can run a slightly higher compression ratio with aluminum because it displaces heat faster. Is it bad to run aluminum heads on an iron block? Also, since my bottom end is stock would it be a problem running a 49cc head. I don't know what the compression would be, but I would assume it would be on the borderline for a set of cast pistons. Thanks again for all the information 49cc will boost the cpr top high for pump fuel in most cases . hope that helps Quote Link to comment Share on other sites More sharing options...
sstallings Posted August 2, 2008 Share Posted August 2, 2008 Madden87 Regarding your question about aluminum heads paired with an iron block: This is fine as long as you keep your coolant up-to-date. If not, the coolant will allow electrolysis, which is similar to what happens inside your battery, where the slightly acidic water, and low volatge electricity scavenge aluminum from where ever it can be found in the system. If that happens to be an inexpensive water neck, it doesn't cost much to replace, but it could also be your expensive heads or intake manifold (I speak from expereince - not the good kind). I change my coolant every year and use radiator caps with a consumable anode as insurance (see www.radcapproducts.net) so that my heads, intake, and water pump are protected from damage. The same is true for the stock L24-L28 Datsun engine which has an iron block and aluminum heads. I've seen some heads that were pretty messed up by running water only as coolant. Steve Quote Link to comment Share on other sites More sharing options...
Pyro Posted August 4, 2008 Share Posted August 4, 2008 dart 200cc iron eagles with 64cc chambers and straight plugs. Get the heads with larger 1.470 valve springs. As a minimum, block hugger headers, 2-1/4 dual exhaust with dynomax super turbos mufflers and a x-over pipe should be used. Install a compcam 292H and a 3000 rpm stall converter. I hope the block has flat top pistons because you need 10:1 cr with this cam. If you have dished pistons then use a thinner head gasket (0.023") and a compcam 280H and a 2800 stall. With traction the 292H setup will run high 11's at 116 mph, the 280H setup will run low 12's at 112 mph. Then you can always drop another second and pick up 10 mph with a 125hp of N02. Quote Link to comment Share on other sites More sharing options...
madden87 Posted September 18, 2008 Author Share Posted September 18, 2008 Just an update. I am still waiting for the heads, but I will list what I went with. I ordered the Dart Iron Eagle 200cc heads with 64cc chambers. I went with the Lunati Voodoo 268 cam. I believe the specs on this cam at .050 are 227/ 233 degree which with 1.52 ratio rocker arms gives me at .510 lift. After talking to a tech at Dart he recommended I go with 1.437 springs so I did. My friend rebuild this motor about 5 years ago, but could not remember what pistons he put in it. (I got it for free so I did not care). When we got the heads off I had a nice surprise and found.030 over flat top pistons. Not forged, but not dished either. I have a performer rpm intake, but I did not thing the runners would be sufficient so I ordered the CNC matched Victor Jr. from Summit. I will also ditch the 600cfm holley carb I have on it now and install a 750cfm. I ordered a 1" spacer also. Is it worth the sacrificing bottom end for top end with my set up since my cam only goes to 6200rpm? The initial reason for the performance upgrade was because I had to back off the gas at about 1000 feet because I was floating valves at 5300rpm. I have a 23" tall tire with 3.90 gears. I was done at 94 mph. This new combination should get to about 110-112mph. I will ask for wheels and tires for christmas from the wife. The heads should be here on Tuesday. Sucks that today is Wednesday!!! Any thoughts on my choice of parts? Let me know. Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted September 18, 2008 Share Posted September 18, 2008 I went with the Lunati Voodoo 268 cam. I believe the specs on this cam at .050 are 227/ 233 degree which with 1.52 ratio rocker arms gives me at .510 lift. After talking to a tech at Dart he recommended I go with 1.437 springs so I did. .... I have a performer rpm intake, but I did not think the runners would be sufficient so I ordered the CNC matched Victor Jr. from Summit. I will also ditch the 600cfm holley carb I have on it now and install a 750cfm. I ordered a 1" spacer also. Is it worth the sacrificing bottom end for top end with my set up since my cam only goes to 6200rpm? " that looks like it will be a nice street strip combo,but if your still running a stock stall speed converter I think youll see a few driveability issues with the 268 cam, youll probabbly want to upgrade to a 2800rpm stall speed, and while youll certainly see hp gains over the original combo once its correctly tunned, and YOU can certainly try both intakes with that cam and the larger 750cfm carb and the new heads, and taller tires, I think youll find that the orriginal rpm dual plane intake(possiably with the 1" spacer) will give the best results with the cam you sellected, now Im certainly not suggesting the vic junior won,t have a slightly higher effective rpm peak, but I think youll quickly find the total tq curve below about 4500rpm, gave up a noticable amount of torque vs what you gained in horsepower in the 5500-6500 rpm range with that cam and the taller tires, etc. Id be very surprised to see the vic jr produce better ETs, than the rpm intake once youve installed the taller tires, new cam, big port heads and 750 cfm carb(again possiably with the 1" spacer) as a general rule single plane intakes work better once the cam durration exceeds about 235-240 durration at a minimum , simply because the intakes designed to produce better hp than the dual plane mostly above 5500rpm, and your cam is starting to run out of its intended rpm band by that point, killing off much of the potential gains yes a great deal depends on your driving style and the traction your getting, but adding tire dia. tends to put a premium on the use of mid rpm torque. btw as I pointed out earlier in the thread a solid lifter flat tappet cam generally provides an extra 600-800rpm over a hydrolic cam, you probably could have gained a bit more with a carefully sellected solid lifter design PLEASE,once its tunned correctly let us know what the results are Quote Link to comment Share on other sites More sharing options...
Pyro Posted September 18, 2008 Share Posted September 18, 2008 use the RPM intake and a 3310 holley (750 vac secondary). you need a 2500 stall with that cam. use ZDDP oil additive if you want the cam to live. Also break in the cam with only the outer springs. Quote Link to comment Share on other sites More sharing options...
madden87 Posted September 18, 2008 Author Share Posted September 18, 2008 Thanks for the advice. I was going to stick with the performer rpm originally, but my firiend said to go with the victor jr. because the intake ports on the head almost match the 1205 gasket. The local track is only 35 miles away so I will try to go back to back weekends and let you know which combo worked better. I hope it is the victor jr. so I did not waste my money, but it would be nice to see my friend wrong just one time. I have not seen that yet. Quote Link to comment Share on other sites More sharing options...
madden87 Posted October 11, 2008 Author Share Posted October 11, 2008 I finally made it to the track to test some of the new parts I installed. I did not use the 750 carb. When I put it on it had a vacuum leak and of course the local parts store did not carry the gasket kit I needed. I drove it to the track and dropped the exhaust after teching. My first run was 13.06 at 103mph. I was not upset. My shifter cable was out of adjustment so I was launching in second, not first. I fixed that problem and the night got worse. My times were averaging 13.5. I was ready to call it a night because the other cars we brought were also down. I put the exhaust back on and made one more pass. It was 13.8. But with the exhaust back on I noticed the engine did not sound or feel right. I adjusted the carb and advanced the timing and pulled off at 12.94 at 108 mph thru the exhaust with a 2.1 60' time. I still to not have a stall so I bog bad off the line. The last run made me feel better and the parts I added. I will order the stall next week. I am looking at a 3000. I know it is a little big for this car, but the motor will be pulled and rebuild after the first of the year so I am buying the stall for that engine. Quote Link to comment Share on other sites More sharing options...
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