inline6

A few things to point out in relation to what you said: You know, sometimes it is better not to listen to all of the internet talk. Yes, I try to verify info from more than one "good source" before I believe it whenever possible. Anyone who has spent a lot of time on the hybridz site or others for that matter can discern who those people generally are. The Schnider cams are not a good buy, due to the metal and how it was hardened. This is still debatable, as many have had and continue to have success with Schneider cams. The first cam I bought for my car, which I never installed was probably a Schneider - I bought it off of someone on eBay. It was made from a CWC cam blank. I discovered all the discussion about those blanks (many cam grinders use them - not just Schneider) after purchasing it but before I put it in the head. I decided to send that cam off to Comp Cams for nitriding as a precautionary measure - some insurance for not having a problem, if you will. That cam had other issues, and I ended up not using it. Incidentally, I don't think anyone (Schneider, Isky, Sunbelt, etc.) is hardening these l-series cams. I think they just grind/re-grind, and then parkerize. Looks like to me the cam was still to soft, the rocker pads looked good, a little worn due to the soft metal coming off of the cam, but for the most part they looked good. A cam that has gone through an ion nitriding process such as mine will have a harder surface than one that has not. So, my cam isn't too soft. The problem is elsewhere. You guys are more then welcome to try NEW things, but it is going to more then likely cost you, and a repair and replacement of the cam and rockers. You mentioned you had SINGLE springs with a .550 lift cam, if what I read was correct. ONLY SUNBELT that I know of runs the SINGLE spring configuration on their cams, I think from memory the seat pressure is about 75-80psi on the seat. Have fun with RPM's over 7K. Yes, I agree - Sunbelt is also the only one I know running a single spring configuration. My cam is a Sunbelt cam. The valve springs are Sunbelt as well. Seat pressure at installed height according to the supplied info is supposed to be 54 lbf. As installed in my car, it came out to 56 lbf. Red line on the valve train is 7700 RPM - I am running titanium retainers. This stuff is not rocket science guys, go with the people who have BLAZED the trail for you and forget about all the new cool stuff, I really don't consider what Sunbelt did to be new at this point. As far as I can tell, this cam and spring setup was developed many years ago (I can find mention of their cam development in the forums on hybridz from 2005) and it has been proven. They may not have been one of the original trail blazers but they have a good reputation - I base this on what I can see from the previously mentioned "good sources" of information on these forums saying nothing but good things about them, and, I don't know if he is still racing a 240z, but I think they were the engine builders for the multi-national title winning Greg Ira? Also, you mentioned the oil holes in the cam, Don't even think about drilling a oil hole on the lobe where the ramp starts. The hole was placed right where it needs to be. Some of the holes are not where they should be - period. Long story, but I'll make it short. Had a 490/290 in a Datsun 510. It was put together by Malvern racing. The springs were Nissan Comp. I ran it for a short period of time and had no issues, but coming back from college late one night, I spend some extended amount of time at high rpm and I wiped one lobe and one rocker due to lack of lubrication. The engine builder for Malvern Racing took the cam to his varsol tank and pushed fluid through it to watch the flow. The lobe that wiped happened to have its oil hole on the trailing side of the lobe, just after the closing ramp - basically 180 degrees away from the best place for it. With the new cam (same grind) we made one change only. Using that existing hole as a pilot, he drilled all the way through it to the other side, so a hole would be in front of the opening ramp. I never had another problem and I drove the hell out of that 510.. I do understand the concept of doing what has worked... following the recommendations of experts who know what works and what doesn't. I now believe the nitriding of the Sunbelt cam was a mistake, one that happened because I was hard headed. Following are direct quotes from emails with Sunbelt back in late 2009 when I was working with them to get the cam: "The cam blanks used by your cam grinder have never been "CWC" blanks. Though Kinetic has tried Nitriding and Parkerizing in the past, the fine polish finish on the lobes has worked best for lobe durability. I asked Jim to confirm the cam grinder used the same came blank (Estas) as usual." And my response: "...as it stands now, I would feel more comfortable with a Nitride treatment, but I don't want to ruin the fine finish on the lobes if that is beneficial. You guys are the experts, just tell me which way I should go. The couple week turn around won't be a problem for me because the car is down for the winter. How should we proceed?" And finally: "I spoke to our cam guy about the Ion Nitride process that they use and he says the finish is a lot better than the old nitride process..." and " talked to Jim, go ahead and send us the cam and we'll get it nitrided. He said he really doesn't think it's necessary but he understands the peace of mind thing." So, my recommendation to those who read through this later is this: If you are considering nitriding your L-series cam, don't. It isn't necessary and may cause you the problem I encountered. You must get good lubrication to your L-series cam before the initial start of a new/worked on engine. Do whatever it takes.

LOL! Yeah, well, for the $800 dollar replacement cost, I should get something besides a lump of cast iron, but I won't.

The only reason I did it is at the time I was buying the cam (several years ago) was that there was a rash of discussions about the soft "cwc" blanks that it seemed every cam grinder was using. I just thought that nitriding the cam would eliminate that issue. Of course, the cam I ended up wasn't a cwc.

Since I am waiting on the shortened Z31T axles, I went ahead and pulled the valve cover off to check the cam. After not even 15 minutes of running at low rpm just sitting in the garage, the lobes are showing ominous signs... In fact one of them has started ejecting its surface just like before. At this point, I believe nitriding is the cause. I read in a couple of places about nitriding cams causing the surface to be "too hard" or I guess having the surface made brittle. So, the theory is that the impact, or perhaps the heating and cooling, or something else about this application, is causing the surface to "craze" or fracture and then fall off in tiny, tiny bits. So, the cam is trash.

Oh, I actually don't need to have welding or straightening done - I was using search to try to find some info about Kinetic Sunbelt and this thread came up in the results. Good to know though. If I had to redo my engine, I'd want to go with welding the head rather than milling a ton off like I did last time.

Hey John, Do you know where Jim is these days? I called Kinetic today and they said he is no longer there. Garrett

I got the resurfaced rockers and the cam back from DeltaCamshafts Friday. The rockers looked really nice. I bought them new, and the rocker pads had some very minor pitting which I didn't care for. The same ones which I got back from DC looked much better than when new. I installed the cam today (put lots of assembly lube on) and fired the engine up. A very different experience than the first time, when I couldn't get it to start, this time it fired right up and of course, had oil pressure immediately. I'll run it for a couple hundred miles and then take the valve cover off and have a look-see. Can't do that though until I get the shortened Z31 T CV axles back from the Driveshaft Shop. G

Here is mine. It is a Magnaflow stainless tip. It started out at 18" in length. I cut off what I needed, and sold the remainder of it on ebay. http://forums.hybridz.org/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=45861 http://forums.hybridz.org/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=45860

Which Mikuni's, 40's or 44's? What is the history on them? New... old... bought used, unknown history? Do you have a timing light, and can you see what the timing is set at? If it was me, I'd look up the timing value to use for that distributor (use the value for whichever datsun it came off of - 280zx? I just don't know which car it came from) and set it at that. And, I'd check and reset the carb float levels. Typically, you can remove the tops of the carburetors without ruining the gaskets. Then go about setting the float heights - the distance between the top surface of the floats (two per carb) and the underside of the carb cover. Note, that each one of them needs to be checked. If one is lower than the other, you have to bend them,like grabbing a wish bone of a chicken and moving one up and the other down... until they are nice and level compared to each other. Then set the distance between the tops of the floats and the bottom of the cover at 12.0 to 12.5 mm. I cut a thin strip of metal and grind/sand to the precise length. Then hold that with needle nose pliers between the float and the chamber to check/adjust the height. Typically you hold the carb cover at 90 degrees compared to the floor when checking, so that the floats don't have gravity pulling them down away from the needle valve or pushing hard against the needle valve. You want just enough pressure from the float arm against the needle valve to depress the pin it contacts, but not to open the valve itself (it has a noticeable stopping point, right before the valve itself opens). There are a couple of ways to adjust the heights, but I prefer to just bend the tab on the float arm... where it contacts the needle valve. It only needs very slight movement there to effect the needle valve closing point. Are you familiar with the jets in the Mikuni's? Do you have other sizes on hand?

Group buy threshold has been met. Please delete this post. We only need one more person to get the discount. Here is the thread with info: http://forums.hybridz.org/topic/112204-order-for-shorter-z31-turbo-axles-from-the-driveshaft-shop/

That's like three people who have done this. I'm like Tony, I could never figure out how people were doing this with the worm gear on the crank... but I understand now how this could be done if you make a special long shaft (no gear on it) that just drives the oil pump.

Cam and rockers sent off to Delta cams. Rockers will be resurfaced, we'll see what they can do on the cam. I'm thinking best case scenario, they can polish out the lobes equally. I think 2 thousandths would clean everything up.

Cam had a liberal dose of Redline assembly lube. Engine sat for about 4 months in my garage before I attempted to start it, but lube was in place when I went to start and it hadn't turned over until then. As I described above, I pulled the spark plugs, then watching the oil pressure gauge, spun the engine over for something like 30-45 seconds continuously with the starter motor. After the oil pressure needle started moving up the scale, I kept spinning for around 10 seconds. I think it was under 45 seconds total, but don't know for sure. So, if this happened at initial start, it had to wipe the lube off of the lobes and not have oil show up for a while... Based on what experienced builders have said, this is entirely possible and probably even likely. It seems no amount of turning over before getting oil pressure is the best way to keep this from happening.

At the time, I was reading alot about "CWC" blanks and cam lobe failures. I actually started the project with a 490/290 Schneider cam I bought off of ebay. It was a "CWC" blank. I found a place online that nitrides cams (Web Cams). I figured nitriding would fix that issue no matter what the blank, and didn't get push back from Web Cams (nor Kinetic with the later cam) about the matter. So, I sent it off to Web Cams and had it nitrided. Unfortunately, they didn't check the cam before nitriding, and it turned out that the three inner main journals were "octogons" instead of round. I still have that camshaft - it is basically "a display item", if you will.

My engine builder is telling me that ZDDP shouldn't be used long term... that it is good for break in, but not after. He says it acts like an abrasive or a polish - it helps parts mesh together, but is only detrimental long term. Just thought I would toss that out there. As far as "priming" my new engine... I had the spark plugs out, cam nice and lubed... and I turned the engine over with the starter continuously for about 45 seconds while watching the oil pressure gauge. I saw the needle on the gauge swing up... and I kept the starter engaged for another 5 or 10 seconds. I was thinking this was a good way to prime the engine... and it obviously isn't. G

Someone (like me - ) would be interested in the water pump. When I parted mine out, the injector pump was desired.

Since, I thought it was necessary for the cam break in, on first start, I ran my engine for 20 minutes at 2000 RPM. My engine builder offered to send me such a setup, but being ignorant, I thought it was unnecessary. C'est la vie.

Ok. Well, thanks very much for the info you provided... which you didn't have to, and I appreciate it. I've been talking to my engine builder and thinking about the initial engine start experience a lot. My engine didn't fire immediately, but I was very cognizant of not turning over "too much" as I was told that assembly lube only protects for a bit... then engine oil pressure needs to happen. And yet... So... here is something everyone who builds a L series (or buys a rebuilt one) needs to know - and it is my main takeaway from my unhappy experience. At engine cranking speed, there is not enough oil getting to the cam and rockers... on an L series. Period. Freshly rebuilt motors with dry oil passages? That... times 10! When newly rebuilt, these engines NEED to start quickly. That is, you can not crank newly rebuilt L series engines for extended periods of time... or many short periods of time. If it doesn't start within a few seconds. STOP, and find the problem. Yes, you have to have everything lubed and in my case, everything was... properly. And even though you have everything lubed with the trick-est lube on the planet, if you crank it over many times without it starting - you absolutely are making a mistake - one that may cause cam and rocker failure in a hurry. As MadKaw has discovered, the stock spray bar set up is not ideal. At cranking speed, it is basically doing nothing but waking up from a knap. And, It is sitting on the passenger side of the cam towers with its holes pointing (at best) at the "back side" or the valve closing side of the cam lobe. The loading from the spring and valve while closing is much lighter than on the opening side. Spraying oil onto this side of the cam is not optimal. Spraying oil at the front side, or the opening ramp, which is the high load side is much better. And yet more, if your cam is drilled for internal oiling, check out those oil hole locations on the lobes. Half or more of them are in very sub-optimal locations instead of spraying the pad just before the front side of the lobe comes into contact with the rocker pad. Now, at engine speed - let's just say 3000 RPM for example, the oil coming out of the spray bar and the holes drilled in the cam is coming out big time. There is lots of oil everywhere, and it is getting whipped all around, and in fact is creating a fog of oil inside the valve cover. Though not optimal, as discussed above, at speed, it is adequate. Turning over at starter speed? Not so much. I pulled the rockers and cam from the car today. The silvery stuff on the cam lobes is not the rocker pad material transferring from the pad to the cam. It's very tiny flakes of cam that are now gone... due to lack of lubrication during initial start up. Since the cam is nitrided, and should as a result have a "case" that is hardened beyond .015 - .020", I am going to send it off to have it polished just enough to clean up the lobes (I estimate .001" max). The rocker pads will be resurfaced as well. When I get it all back together, (with lots of lube) I will have my starter fluid ready.

I have been talking to the engine builder and he was saying the spray bar should optimally run on the other side... How much for the spray bar - to the U.S.?

Wow. This is hard for me to believe. So I need a new cam and rockers... or to resurface these rockers... Any chance that because this cam was nitrided, I may be able to polish the lobes and salvage it? I mean, the case of the part is hardened up to 0.65 mm (0.025") in depth during the nitriding process. Maybe after polishing them to mirror finish, I could still use it with the same rockers (once they have been resurfaced, of course)? G

Ok. Good to know, and I feel better about the "internal oiling + spray bar" issue as I am using a known good turbo oil pump. Thanks for the input. If you look at the third rocker picture (going down the page), you might be able to discern the spot where the cam lobe wear spot stops. I looked closely at each rocker and can see that the lobe is not running off of that end. I do note that we could have "cheated" a bit more towards the passenger side and picked up a tad more effective lift, however. Yeah, I hear you on point #2. If I was the test mule for this cam, I never would have gone for it. But, Kinetic used this set up in race winning engines - a long time ago, so there is some history of success here. I will have to check with them though about valve spring life. I am sure since this is a race setup, they wouldn't dream of sticking in a car and running it 50k miles. And I shouldn't dream to either. Probably need to buy a spare set or two now assuming I still can.

Before I removed the one rocker I took a picture of, I checked the valve clearance on a few... 3 to be exact. .25 mm and .30 mm were the feeler gauge sizes. I forget which is for intake and which is for exhaust, but I was just doing a quick check. Two of the clearances I checked were intakes and one was exhaust. The .30 mm fit in one only. The other two accepted the .25 mm gauge. So, seeing the clearances were close, I obviously moved on rather quickly to pulling one of the rockers for examination. No dark areas on my rockers. Heat like you experienced did not occur with this engine. Sorry to hear you have had such major problems. I know that has been difficult to deal with after hoping for a nice experience from the new engine. I had come across the posts about zinc before in the forums, but since my stock cam and valve train (old engine) had been rebuilt in the 90's and run for many ten thousands of miles over the years with absolutely no issues, I really didn't feel the need to invest a lot of time reading about it. Definitely more interested now... My engine builder is pretty top notch, and I know he used cam lube. I just haven't bothered calling him to see which. I found an assembly pic that shows the cam lube... Thanks... I am running a "high capacity" pump which is most likely a 280ZXT pump. I bought it from Malvern Racing - (Datsun Competition dealer) back in the 90's, and ran in my 4 cyl. 510 motor for a long time. For this engine build, we took it apart and modded it a bit for improved flow. Instead of running the high pressure spring, I run with the standard spring and a washer (used as a shim to bump the pressure up just a tad). I'll definitely need to check the spray bar for flow issues. Since all the lobes are looking very consistent with regard to the amount of deposits on them, it would seem my problem is also very consistent. I'll also need to check oil pressure across the engine operation spectrum. Perhaps I don't have enough pressure for 7700 RPM. I don't think that is a problem, but it I have not checked it. The rule of thumb is what 10 psi per 1000 RPM?

For clarity, were you saying this about my cam and rockers or about Lazeum's? I think my cam and rockers are still quite useable though they need some attention. Also, can you explain this part some more, as seeing "a cam do it on the bench before it was started" sounds very interesting. What is "it" and can you explain "and was picking up when turned over setting up the rockers." Picking up what? If you are referring to my pictures and not Lazeums, please let me know.

Oil is Mobil 1 - the full synthetic 10W30 stuff. I would have thought Jim Thompson from Kinetic Motorsports would have raised a concern with regard to getting the camshaft nitrided. I just now sent a note via their contact form asking about the issue, and will see how that goes. I tracked down some of my emails with Kinetic where we discussed the nitriding... Here are some excerpts: "The cam blanks used by our cam grinder have never been "CWC" blanks. Though Kinetic has tried Nitriding and Parkerizing in the past, the fine polish finish on the lobes has worked best for lobe durability. I asked Jim to confirm the cam grinder used the same cam blank (Estas) as usual." And from the same email thread: "That said, as it stands now, I would feel more comfortable with a Nitride treatment, but I don't want to ruin the fine finish on the lobes if that is beneficial. You guys are the experts, just tell me which way I should go. The couple week turn around won't be a problem for me because the car is down for the winter. How should we proceed?" So summarizing: Cam grinder: Kinetic Sunbelt (actually subcontracted) Shaft material - don't know for sure, but cams used by Kinetic Motorsports (cam blank is Estas) Nitriding done on cam only - I am not sure of the type - totally guessing it is ion nitride instead of ammonia gas for less warping No break in lube - just assembly lube - and I can get that info if needed. Oil used - Mobile 1 full synthetic 10W-30 No ZDDP or any other additives.

Took me a minute - Wild Ass Guess... I pulled my documentation from the build. These springs are custom spec'd for the cam. Here are the specs: 7700 RPM max - One spring only on intake and exhaust Intake: Installed at 1.680" with 54 lbf. Open height = 1.130" or .550" lift with 193 lbf. Exhaust: Installed at 1.680" with 54 lbf. Open height = 1.130" or .550" lift with 193 lbf. Actual build notes: Springs - 1.700" - 1.705" = 58 lbf in valve spring checker Seat: 1.710" = 56 lbf Open: 1.160" = 190 lbf (.550" lift) .578" to coil bind - minimum So, is that difference .578" vs. .550" ok, or tight? Valves are Manley stainless, retainers are titanium.