DemonZ Posted June 6, 2006 Share Posted June 6, 2006 I ordered the Isky cam with Z-Gad specs. Problem is when it came, the exh. spec. is off by 2 degrees from what I ordered. Per spec. it's supposed to be 266, I got 268 (Isky print out, and stamping on back of cam). What would you guys do? Z-Gad watcha think about 2 measly little degrees? Quote Link to comment Share on other sites More sharing options...
TheNeedForZ Posted June 6, 2006 Share Posted June 6, 2006 Only the exhaust lobes are off? Can you send it back? Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted June 6, 2006 Share Posted June 6, 2006 Send it back, have them give you another. Otherwise you'll be screwed. Quote Link to comment Share on other sites More sharing options...
Guest 73Turbo240z Posted June 6, 2006 Share Posted June 6, 2006 what makes this so interesting... is that we had a Z-gad grind in the Pinks Z, i'm going to go dig up the paperwork on that... Quote Link to comment Share on other sites More sharing options...
Guest 73Turbo240z Posted June 6, 2006 Share Posted June 6, 2006 Quote Link to comment Share on other sites More sharing options...
Guest 280ZForce Posted June 6, 2006 Share Posted June 6, 2006 what makes this so interesting... is that we had a Z-gad grind in the Pinks Z, i'm going to go dig up the paperwork on that... uh oh...is isky at fault for all the trouble that was caused now for giving wrong spec cams? Quote Link to comment Share on other sites More sharing options...
Guest 73Turbo240z Posted June 6, 2006 Share Posted June 6, 2006 I'm not a camshaft master, so i'll wait for others to chime in on how bad that could make things... Could be as simple as when they saved Z-gads grind into a PC, they punched the wrong button, and now everyones been getting cams 2 degree's off... Quote Link to comment Share on other sites More sharing options...
DemonZ Posted June 6, 2006 Author Share Posted June 6, 2006 It looks like only the exh. are off. Interesting the same grind has a different timing table. The overlap is off too. Got 57, should be 44. I will ask for the correct one. Quote Link to comment Share on other sites More sharing options...
Guest 280ZForce Posted June 6, 2006 Share Posted June 6, 2006 It looks like only the exh. are off. Interesting the same grind has a different timing table. I will ask for the correct one. yeah, that's weird everything is the same except the #s for opening and closing for intake timing, exhaust timing, intake duration and exhaust duration. i'm not a cam expert either...but I'm sure 2 degrees off and the other #s varying on each cam they sell can cause some problems. if a cam is made to a certain spec...i think those specs should be dead on w/ every production unit they manufacture, just like any other part. even as dr_hunt said just w/ the 2 degrees off your pretty screwed. Quote Link to comment Share on other sites More sharing options...
DemonZ Posted June 7, 2006 Author Share Posted June 7, 2006 After being put on hold for 10min at a time, and calling every 30min. (he gets in after 2:30 now) I finally spoke to Ron Iskendarian himself. He said there is no such thing as a 266 deg. grind, as his master is 268 and that is what they have on file. (He recalls that I did specify 266, but when he went back to the grinder, HIS spec. was 268 , therefore he just pulled the master and put it into the machine that spits out what in my mind is our "questionable" cam). I am guessing its a machine like how they duplicate keys. He was nice enough to explain his process for a couple minutes and starts to get a little frustrated, I think from me attempting to question where the discrepancy might lie. All I have to go on is what Z-Gad wrote. I mention that another car running the same cam is having problems, could it even be possible that... He puts me on hold again. I gather my thoughts while I wait. About another 10 minutes later. He comes back on, and sense I am testing his patience again. "Ok I'll tell you one more time... there is only one cam we have that is close to that grind...". At this point, I feel I need to interject him before he goes down the same line and puts me on hold again. I politely interupt, "there is no way you could've done a one-off with 266, and did a master later on with 268?" Ron: " No. I do all the development work...." and there would've been a master or he would know.... or something to that extent. He goes onto assure me that they wouldn't screw me, and that the 2 degrees would not make much of a difference. He continues with pretty much the attitude that the error is on my end (I don't know if it is), but I would just like to be clear on what I ordered. Out of fear of being put on hold again, I politely interupt, "sorry to interupt but, I also ordered 44 deg. overlap..." Ron says, "yes, thats the only way it will work...". I reply, "but I got 57 deg. that's what it says on the printout." This made him stop and think. He said he'd pull the file and call me back. That was 4pm. I have my fingers crossed. It took me 4 calls the first time just to get the cam ground in the first place. Each time he said he'd call me back, I had to call him to make a connection. He seems like a nice enough guy. He even threw in a T-shirt for my troubles the first time, and got the cam out to me in about a week. But Ron sure is a busy guy. Quote Link to comment Share on other sites More sharing options...
JIM73240Z Posted June 7, 2006 Share Posted June 7, 2006 wow. i was ready to order one just like that. i guess i will wait to see what the outcome is. maybe comp cams or other can do it without all of the questionable customer service. i am still tyring to figure out the exact specs for the custom grind for my application. jim Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted June 7, 2006 Share Posted June 7, 2006 Ah, well, it looks like that may be the problem in the pinks motor. I cam degree would have revealed the same as what you found. When you custom order a grind, then it's custom order unless your using master cam lobes already in their library, which includes making the master lobes, both intake and exhaust. Hmm, 44 to 57 degrees of overlap would have a huge impact on how the motor runs up top under boost. Hmmmm. Quote Link to comment Share on other sites More sharing options...
Thumper Posted June 7, 2006 Share Posted June 7, 2006 I am not a cam master but I would not think the 2 degrees would make a world of difference. I would be more worried about the 44 to 57 degree diffence on the overlap. I hope z-gad reads this and confirm his numbers from his previous post. Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted June 7, 2006 Administrators Share Posted June 7, 2006 Ok guys, I can’t bite my tongue any longer Two degrees difference in exhaust valve duration won’t make SQUAT difference, as felt seat of the pants. Yes, it will make a difference that can be read on a dyno, but that difference will be SO small that even the most anal driver on this forum would NOT be able to feel the difference in the seat of his/her pants. If this were an engine for the IRL, NASCAR, or Top Fuel, then yes, maybe squabbling with the cam grinder over a measly 2 degrees duration would be justified, but not over a Datsun L-series cam? If someone is dead set on taking some national level championship with his L-series Z car and was spending tens of thousands of dollars on that car in an effort to build that car to a very specific level, then I would say go ahead and pitch a bitch, but for a hot street car or even a part time racer, 2 degrees duration isn’t going to cause you to loose the race. No ones driving skills on this forum are THAT good!!! Our driving skills have WAY more affect on the outcome of a race than a measly 2 degrees exhaust valve duration. As for this measly 2 degrees possibly being the PINKs cars power issue, HOSRE PUCKY!!! Their HP peak came in at 4900 RPM. The HP peak should be in at least by 5700 RPM, more like 6000-6500 RPM. That is a HUGE discrepancy and for the LAST TIME GUYS!!! If that discrepancy is cam timing related, it would be something like 10+ degrees off, or a “tooth” off on the timing gear, not a measly 2, 4, or even 8 degrees! There is something else causing their lack or RPM!!!! Now as for the overlap issue, (this is where the gripe “might” be justified), generally speaking, high performance Turbo cams are ground with wider lobe separation, i.e. less overlap. I haven’t ran the numbers on this particular cam and don’t have time this evening, but if memory serves, that ISkY cam “should” be ground on 114 LCA which is a “wide” lobe separation with little valve overlap, i.e. good cam in a Turbo application. Now if it is ground with 106-109 LCA, then it would make great “off boost” power and even reduce lag at the expense of top end “boosted” power. Being as the PINKs car has such a drastic discrepancy in where the peak HP is vs where it should’ve come in, I strongly believe there is something else wrong, i.e. ignition. I honestly feel the PINKs issue is ignition related. I just read here in the PINKs forum where their MSD ignition box is inoperative now and the car wont even run!!! I haven’t been present to see, hear, or tune that engine, but based solely on what I’ve read thus far, it definitely sounds like an ignition issue, NOT a cam issue! Next would be the fuel map because they could never get the mixture correct on the top end as the ignition wouldn’t light the darn fire in the first place!!! MSD products are excellent, WHEN they work. We at Rusch Motorsports will NOT sell or endorse MSD components because of their poor reliability. Functionally, MSD is great and we would love to offer their products but because of their poor dependability, we don't. I have seen many a MSD coil and 6A box fail in all sorts of ways leaving the driver stranded. It even happened on an episode of PINKS in the middle of a race for crying out loud… Ok, I’m now stepping off my soap box and going to bed. Good night guys, Quote Link to comment Share on other sites More sharing options...
Drax240z Posted June 7, 2006 Share Posted June 7, 2006 You know Paul, I feel the same way about MSD stuff. I use it on my own car, only because I owned it before I had seen so many fail. I wouldn't choose to run an MSD brand box on any car knowing what I know now. I've had drag cars on the dyno with brand new, fresh out of box MSD ignition boxes causing huge issues, replaced them with another brands box and the cars have run flawlessly without any other changes. That's enough to make up my mind. Quote Link to comment Share on other sites More sharing options...
Guest iskone Posted June 7, 2006 Share Posted June 7, 2006 Well at least it wasn't the cam. Thanks for clearing that issue up. EDIT: Wait just did the math. When the numbers are punched in for the pinks cam I too get 57* of overlap straight up w/ the 114 LSA. Did I screw up the math??? Hmmmm I used the 280/290 for those numbers but when I used the 276/278 numbers I get the 44* of overlap. In any case my IO/IC, EO/EC numbers don't match up with eithewr set of numbers. Side note: What box would you use? On My car I have a Crane XR3000 and a Blaster 2 coil. My engine turns to 7500 (Specs in my sig) however my dizzy is a Supra dizzy that is mounted horizontally on the paasenger side of the block and is spun by the crank. I've NEVER had spark issues, just timing LOL Isk Quote Link to comment Share on other sites More sharing options...
DemonZ Posted June 7, 2006 Author Share Posted June 7, 2006 RE: PinksZ Camshaft related issues have not been ruled out. It has not be verified that cam timing is ON with any precision (last I read, nobody degree'd the cam still). BTW, one tooth off is 18 deg. IIRC. Also 44 vs. 57 deg. of overlap is significant. The sum of small slop here and there could account for premature redline. A bunch of small errors can add up to a big one. Until verified, it's guesswork. RE: Z-Gad Isky grind A seperate issue, simply stated is, it was not what I had ordered. I "thought" (per Z-Gad specs.) I ordered a plain burger, and I got a cheese burger instead, hmmm.. but wait maybe I DO want a cheeseburger?! For me at least, the calories of gross power is not the end all. It's the taste! It was Z-Gads impression of the well roundedness, flexability and smoothness that sounded yummy to me. Ultimately, I am not pointing fingers or want to place blame or bad mouth anyone on this. I just wanted to give some background from my experience so it would be useful to others that might want to go down this same road. Most of all, I am here to learn. So anyways, Paul, I am curious in your machinist capacity, why are two identically spec'd camshafts this different (look at mine vs pinks-Z print out). Looking at the timing events, mine are 4 degrees different across the board from that of PinksZ. I understand there are tolerances in the real world, and dimensionally speaking, I'm not splitting microns here. I would not guess that .0001 or whatever tolerance the cams are ground to would translate into several degrees difference. Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted June 8, 2006 Administrators Share Posted June 8, 2006 ............So anyways' date=' Paul, I am curious in your machinist capacity, why are two identically spec'd camshafts this different (look at mine vs pinks-Z print out). Looking at the timing events, mine are 4 degrees different across the board from that of PinksZ. I understand there are tolerances in the real world, and dimensionally speaking, I'm not splitting microns here. I would not guess that .0001 or whatever tolerance the cams are ground to would translate into several degrees difference.[/quote'] Hmmm… (I just now noticed your thumbnail of your cam card)… It does appear that ISKY has marked your cam card with everything advanced 4 degrees more than the PINKs variant. Not sure why that is. I also noticed that ISKY called the PINKS cam “Datsun 6-cyl 240-Z [7151], and yours is labeled Datsun 6-cyl 280-Z [7181]. The Pinks cam is NOT drilled for internal oiling, i,e, we installed a spray bar, I’m assuming that your cam is drilled for internal oiling, though that shouldn’t make any difference in the grind specs. Hmmm… You could always install the cam straight up using an adjustable cam sprocket, get the fuel and ignition dialed in, take it to a dyno and make WOT pulls with the cam at varying settings retarded and advanced and then compare all the dyno runs, pick the one that satisfies your power needs best and set the cam there. This would be the IDEAL way to degree in a cam. As for Isky’s 4 degree discrepancy, got me?!?!?…. Sorry I don’t have any answers that would help put your mind at ease over this one. If it were me, I would call Ed Iskenderian back up, lay out the specs for both cams and ask why is my cam advanced 4 degrees more than the PINKs cam, or, if I trusted the grind specs, (which I do), I would just install it, take it to the dyno and dial in the cam timing to what the ENGINE wants… Good luck, Quote Link to comment Share on other sites More sharing options...
DemonZ Posted June 8, 2006 Author Share Posted June 8, 2006 I still have not got a call back from Ron. Yes, my cam came with internal oiling holes (no plug in the end, glad I checked). It is puzzling why mine and the PinkZ have different valve events. But what really has me wondering is the 44 overlap I asked for vs. the 57 we got. If he doesn't call me back tomorrow, I guess I will have to give him a call, AGAIN. I don't know why this feels like I am pulling teeth. Quote Link to comment Share on other sites More sharing options...
DemonZ Posted June 8, 2006 Author Share Posted June 8, 2006 Hmmm… (I just now noticed your thumbnail of your cam card)… It does appear that ISKY has marked your cam card with everything advanced 4 degrees more than the PINKs variant. Not sure why that is. I also noticed that ISKY called the PINKS cam “Datsun 6-cyl 240-Z [7151]' date=' and yours is labeled Datsun 6-cyl 280-Z [7181']. The Pinks cam is NOT drilled for internal oiling, i,e, we installed a spray bar, I’m assuming that your cam is drilled for internal oiling, though that shouldn’t make any difference in the grind specs. Hmmm… You could always install the cam straight up using an adjustable cam sprocket, get the fuel and ignition dialed in, take it to a dyno and make WOT pulls with the cam at varying settings retarded and advanced and then compare all the dyno runs, pick the one that satisfies your power needs best and set the cam there. This would be the IDEAL way to degree in a cam. As for Isky’s 4 degree discrepancy, got me?!?!?…. Sorry I don’t have any answers that would help put your mind at ease over this one. If it were me, I would call Ed Iskenderian back up, lay out the specs for both cams and ask why is my cam advanced 4 degrees more than the PINKs cam, or, if I trusted the grind specs, (which I do), I would just install it, take it to the dyno and dial in the cam timing to what the ENGINE wants… Good luck, I think I solved the 4 degree discrepancy. My cam card says the whole cam is 2 degrees advanced (upper right hand corner). PinksZ cam card says nothing (I assume its zero). Two cam degrees advance would make 4 degrees on the crank, and that would explain the VO/VC differences in the two cams. So it turns out the two cams are the same (except on mine whole cam is advanced 2 deg.)... whew! I would rather not play guinea pig right now as I have all sorts of issues and sub systems to sort out before I can run it. So I just want baseline componentry for starters. To me, the cam is still questionable in the 44 vs 57 overlap issue. I hope to have that resolved soon. Quote Link to comment Share on other sites More sharing options...
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