Z-Gad Posted June 12, 2005 Author Share Posted June 12, 2005 Regarding idle quality, vacuum went from 21" to 14" of vacuum. Idle has a little more rumble to it, but engine revs very smooth and cruises as though it had a stock cam. It is super smooth in acceleration and drives like a stock car until you floor it and reach around 3700 rpms. According to the graph, hp vs rpm is identical until around 4000 rpm's (right after I have full boost with this turbo). After 4000, the stock cam rises more gradually while the new ISKY continues on a steady climb. As far as the "stockness" of the car, the only thing really stock is the long block. It has all stock internals and stock headgasket. The head has no portwork. It is a P90A which I converted to mechanical lifters by having a machine shop make me some inserts. The motor has unknown miles as it came out of a rolled 280zx turbo parts car. The exhaust manifold has a T-4 flange welded to it as well as an external wastegate flange, but no portwork done to it either. My intake manifold is an N47 w/ welded up EGR, ported runners and ported for the 60mm throttlebody. Intake piping is all 2.5" from turbo to intercooler and intercooler to throttlebody. I would not expect similar results by adding a cam to a stock turbo car though. I believe this cam is well matched to the parts currently on the car. Quote Link to comment Share on other sites More sharing options...
DemonZ Posted June 12, 2005 Share Posted June 12, 2005 Nice job on the cam swap. What size lash caps you have to use? I have a hydro head that was pegged for porting practice, but if you have an economical solution for the conversion to mech. I'm all ears. Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted June 12, 2005 Author Share Posted June 12, 2005 DemonZ - lifter adaptors ran me ~$200. They sit up a little higher than the stock mechanical lifter bosses in the hydro head, so believe it or not, stock lash caps allowed excellent rocker arm geometry. I used the nuts/pivots from the mechanical head in the adaptors. Initial investment was a bit high, but I have a few hydro heads that I can play with and move the adaptors head to head. BTW, this is the 3rd head that the adaptors have been in already . I figure that the hydraulic heads will be more abundant in the coming years as many have scarfed up the non-hydraulic heads. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted June 12, 2005 Share Posted June 12, 2005 I think a good cam would make a big difference even on a stock L28ET with stock T3. On my dyno runs and a few others I've seen running stock block and T3, torque usually starts falling off very soon (just past 4000rpm in my case) and very rapidly... I think a cam would really go a long way to extending the torque curve a bit farther, though I also think part of the reason it does start dropping off torque so soon is actually the fault of the T3 it self, so really have no idea how much longer the torque curve would carry on with a good cam. I have added this upgrade to my list of things I want to do, anyways, though I only expect to gain maybe 15 hp from it.. Quote Link to comment Share on other sites More sharing options...
aarang Posted June 12, 2005 Share Posted June 12, 2005 Z-Gad, got any specs or prints for those hydro lifter adapters? I was thinking about doing adapters also as I have 2 extra P90a heads. I was thinking it would be just like a giant heli-coil, so to speak. Maybe you could produce and sell them....? (hint, hint) Aaron Quote Link to comment Share on other sites More sharing options...
Tony D Posted June 12, 2005 Share Posted June 12, 2005 not all P90A's are hydraulic! Check before condemning a junkyard canidate, the hydraulics have a nice smooth barrel instead of the adjusting nuts at the pivot end of the rocker arm. Of 6 Turbos in the junkyard in the past four months, only one was a Hydraulic P90A, all the rest were mechanical P90A's. Makes you wonder exactly when in 83 they went "hydraulic" as some of these cars were 83's! Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted June 13, 2005 Author Share Posted June 13, 2005 I don't expect there would be much of a market for the adaptors for what it costs to make them. I just took a hydraulic lifter to the machine shop with a mechanical lifter boss and pivot and told them that I would like the O.D to be that of the Hydraulic lifter and the ID to be that of the pivot thread. I also wanted the ring for the 'Mickey Mouse' looking rocker arm spring keepers, and in 3 days I had a set. Quote Link to comment Share on other sites More sharing options...
echocluster@hotmail.com Posted June 13, 2005 Share Posted June 13, 2005 i have a setup that is close to yours in my 71 240z. i didnt get a cam because i heard that it didnt do much for the turbo. now i want one like yours. i am up in canada and would like to know if you have number that i can reach the guys that did the cam for you? or even a web site would do too. your numbers look real good! Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted June 13, 2005 Author Share Posted June 13, 2005 http://www.iskycams.com/ 323.770.0930 I spoke with Ron. He usually isn't in until after 1:30 pm Cali time. He was a great guy to deal with. Quote Link to comment Share on other sites More sharing options...
echocluster@hotmail.com Posted June 14, 2005 Share Posted June 14, 2005 so did you have to send him a cam to regrind? or did he grind up one that he had? Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted June 14, 2005 Share Posted June 14, 2005 Doesn't Isky make a cam for the L28ET or is it all custom? What about the turbo cams MSA sells? Does ANY company make a cam specifically for the L28ET? Quote Link to comment Share on other sites More sharing options...
Thumper Posted June 14, 2005 Share Posted June 14, 2005 From what I have read all the isky cams are custom to what the customer wants. And you get a custom cam designed for your car for about $10 more than a pre-made one shoe fits all cam from msa. Also I've read the schneider cams are using older designs and grinds then isky does. I did a search on isky cams and turbo cams and found alot of reading material to keep me busy for awhile. Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted June 14, 2005 Author Share Posted June 14, 2005 so did you have to send him a cam to regrind? or did he grind up one that he had? I did not have to send a core. I spoke with him for a few minutes, told him what I was interested in, and he said that he would get on it. ~ 2.5 weeks later (suprisingly quick), the cam arrived at my door. I do not know whether it was a billet or regrind, though I suspect a regrind as it came to <$200 total, shipped from California to Orlando. As far as the a generic L28 turbo cam, you can contact http://www.webcamshafts.com/datsun-auto.html#1 I actually had placed an order through them with a little modification to their listed grind, and a week later was told that they could not give me the 114* lobe center I requested. They said that the most they could do was 112*, which was not what I wanted, so I cancelled my order w/ them and called Isky. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted June 14, 2005 Share Posted June 14, 2005 Good stuff Zgad. I'm planning to install my cam/valve relieved P90 along with some ARP studs in the next couple of weeks. I don't know if I'll get to a dyno, but I'm curious to see if the cam helps or hurts my current system. It's the Schneider cam, stage II from MSA I believe. Since I'm running a factory ECCS with the fuel cut at 6400 rpm, I may lose low end, and not be able to use the top. We'll see anyway. Quote Link to comment Share on other sites More sharing options...
Pyro Posted June 14, 2005 Share Posted June 14, 2005 Good post and good numbers! If you are using weak springs, I'm sure you will gain even more HP at higher rpms with the proper springs. That 122mph trap speed is impressive! That is the speed of a 400hp engine in a 2800lb car! The dyno must be way off. However, can't argue with the 1/4 mile dyno. I have always believed the turbo also needs to match the cam. Especially after changing over to a T3/T04b-h3 wheel and liking the new turbo less than the stock T3 which was a good match for the stock cam. So, I installed a MSA stage 1 turbo cam (made by schneider cams). 114 lobe centers, 260 intake, 250 exhaust .450 lift. A real turbo cam with less exhaust duration and wide lobe seperation. I'm also using the crane springs and retainers and 0.160 lashpads. Had the rockers resurfaced at DeltaCams for 3.00/each. (350.00 cam swap) The MSA turbo stage 1 cam kicks in about the same time full boost hits at 3500 rpm (14psi) and pulls to hard 6500 rpm. The engine makes 5 psi at 3000 rpm. The old T3 would full boost by 2800 rpm which was perfect for a cam that quit pulling at 5000 rpm. And I still miss the torquey t3 with stock cam for pure street driving. Idle vacuum droped from 19 to 15 and engine is much smoother driving down the highway and has a slight lope at idle. Good job! Keep us updated. Have any 1/4 mile trips planned in the future? Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted June 14, 2005 Author Share Posted June 14, 2005 Pyro - Thanks man, The 122.2 mph was w/ the former 3.1 stroker motor and T-66 I used to run set to 20 psi. I was making nearly 400 rwhp by 1/4 mile calculations, but did not dyno it in that form... Current daily driver setup will have to wait until August or so before it makes it to the track. Since it is my transportation and I have not had the best of luck with rear end parts, I choose not to put the sticky tires on it until after I have another mode of transportation. Quote Link to comment Share on other sites More sharing options...
Afshin Posted June 15, 2005 Share Posted June 15, 2005 Hey SleeperZ, nice to see you back on the forum Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted June 15, 2005 Share Posted June 15, 2005 Hey SleeperZ, nice to see you back on the forum Agreed, Sleeper how/where you been man? So guys, I take it it's not really worth going with a hotter cam if still running the stock T3?? I'm really trying to move the powerband up a little ways... right now torque is strong and flat from boost onset at 2800rpm to 4000rpm where it starts dropping very sharply, at a rate of almost exactly 50 ftlbs per 1000rpm (from 300 at 4k to 200 at 6k). Would a cam help this at all or is this just the stock T3 running out of breath? I'm not looking for miracles... I don't expect a flat torque curve all the way to 6k, just hoping to bring it up a little, even an extra 500rpm of flat torque would be great. I'm not looking to upgrade to a hybrid turbo as the cost is prohibitive right now and my fuel system probably couldn't handle it, but a cam would be within my means, IF it's worth it?? Quote Link to comment Share on other sites More sharing options...
Pyro Posted June 15, 2005 Share Posted June 15, 2005 Z-Gad, I see. stroker mph...... But still good numbers for a L28. 300+ at the wheels is still a very fast Z! Bastaad525, Sounds like your engine is falling off too fast. Should make good power until 4.5 or 5K (just like you want). Maybe stronger valve springs or some 0.040" spring shims would help. Play around with the ignition timing. A little more advance will give you a little more rpm. Is your fuel pressure maintaining during high rpms? Another stock pump in parrallel would help keep the pressure up during high volume demand. Are you using the stock wastgate? I feel the stock wastegate is restrictive as compared to a striaght pipe off the turbo used with an external wastegate. I think you could get the stock T3 running much better. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted June 15, 2005 Share Posted June 15, 2005 Agreed' date=' Sleeper how/where you been man? [/quote'] Thanks. The Z has been parked since last fall after I lost my alternator at a track day. I overheated slightly because I'm cooling with an electric fan, and I developed an exhaust leak. I'm removing the head to find the problem, probably just pulled an exhaust stud, but I will be putting on my P90 with the turbo cam in place of my stock P90A (non-hydraulic). I've been busy working on my diesel daily driver, so the Z interest has been low. Quote Link to comment Share on other sites More sharing options...
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