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inline6

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Posts posted by inline6

  1. I rebuilt my late model 280ZX transmission a few years back.  But, even with a new rear seal, I had a slight leak there.  I don't recall if it was there before I rebuilt the trans or only after...  

     

    I've driven the car rarely in the last several years, primarily a couple of track events, so the slight leak coming from the rear transmission seal was an annoyance, but not something I had to deal with on a daily basis.  At first, I thought I damaged the new seal I put in when I rebuilt the transmission.  But, I replaced that with another new one (which seemed to help briefly) but I noticed after the next track event, I still had some leakage.  I began to suspect that my driveshaft yoke was too small in diameter.  I bought it many years ago from Inland Empire Driveline.  Even though I never had an issue in running it for years, I thought maybe it was machined to like the smaller end of acceptable tolerance range, and maybe it had worn some over the years, allowing fluid to start leaking.   

     

    With the car back on the road recently I noticed that after every drive, it was leaking noticeably. I decided to devote some time to finding the issue. 

     

    I pulled the driveshaft out to measure the OD of the yoke and compare that to a spare factory driveshaft yoke.  I measured both with calipers and was surprised to see that they were the same measurement.  Ruling out an undersized yoke as the problem, I re-installed the driveshaft and pushed upwards on the driveshaft yoke.  I could see noticeable deflection in that direction and it appeared that the oil seal lip came out of contact with the OD of the yoke tube. Pulling down, I could see a rather large amount of deflection as well.

     

    I have a spare FS5W71B, so I pulled the rear seal and looked at what was behind.  Here are a couple of pics:

     

    post-4218-0-02438100-1376848842_thumb.jpg

     

    post-4218-0-66531600-1376848844_thumb.jpg

     

    There is a sleeve which is press fit into the tail section of the transmission case.  This one is showing some wear, but I suspect the one that is in the car right now is much worse.  I'm guessing that with the amount of movement the transmission output shaft/driveshaft yoke is being allowed, it not only allows the seal lips to come out of contact with the yoke tube, but I am eating up rear main seals quicker...

     

    With these transmissions (of this vintage) likely to have lots of miles on them at this point, I wanted to make everyone aware of what I found.  Also, anyone have any ideas for best way to repair?  I can't find the sleeve on the microfiche... It doesn't look to be a part I can buy new from Nissan.  

     

    Garrett

  2. Megacycle was able to source it.  They initially said they would have to try to track one down and in a conversation weeks later (they were waiting for info from the guy that used to run Integral Cams to locate the master), said they had a few on hand.  

     

    Oil lubrication hole location was discussed in this thread earlier.  Just wanted to mention that I asked Megacycle to drill them in more optimal locations, but the cam blank came with those already drilled.  

  3. Just a little update...

     

    The two people I've talked to at MegacycleCams seem to be really knowledgeable.  Both were familiar with Estas blanks.  They told me that I shouldn't have nitrided the Estas blank because they are "chill cast" as is, which makes them harder than other cam blanks.  We discussed how I came to nitride that cam.  We talked about CWC blanks which they said are definitely "softer".  Additionally, we discussed the oil I am using - Mobile One.  They said that Mobile One is a poor choice for my application - "a rubbing surface rocker".  In fact, they said they see more cam failures from use of Mobile One than any other oil, but I'm betting a lot of that has to do with it's percent of market share - it clearly has a large part of the full synthetic market.  They brought up the lack of Zinc in modern oils being a problem especially in my application and basically, to keep it simple, said I should use RedLine or Motul... though they mentioned a couple of other oils that are also good for rubbing surface rocker applications.  

     

    Unfortunately, they don't have a 100% of the masters from Integral Cams - they don't have the one for my cam.  They are in contact with the former owner of that business and believe they can get the cam profile info - the design specifications from him in the next week or two.  They plan on making a new master.  This should be good news for anyone that would like to have this "Kinetic Sunbelt" cam grind.  

     

    They talked about spray welding on the lobes to create the hardest lobe possible, but I don't want to go into uncharted territory again.  I told them that I just want them to use an Estas blank, and I'll forego the nitriding this time.  Time will tell if they can make it happen for me.

     

    Additionally, I believe I have tracked down the valve springs that are used with the cam.  "1W901" was on the Kinetic Sunbelt invoice.  A little searching on the internet brought me to this Nissan part number: 

    13203-1W901

     

    Looks like my springs may be outer valve springs from what looks to be like several different VG engines.  They are $4.89 each at NissanPartsZone.com.  I will check that out further at some point down the road, probably by buying one and checking to see if the specs on it match what we put in my engine.

     

    G

  4. As I said, Kinetic is no longer sourcing these cams.  Did some searching...  Found the paperwork that came with the cam.  The cam manufacturer was Integral Cams.  The are no longer in business.  However, I found online that Megacycle Cams bought all of their "masters" - this means they should have what they need to make me another one.  Called Megacycle today, and they confirmed this.  So, now I'm going to pull the cam out of the head and send both that cam and a stock cam to them along with all the documentation I have on the "z-car l-series datsun E30 race cam #2" as it is named.  I'd like to get another cam made from an Estas core, but might get a regrind from the stock cam.  We'll see.  

  5. Saw this comment and remembered being surprised about the holes in my factory "F" cam.  Nissan cams have their holes in a wide range of locations.

     

     Looks like "anywhere but a wear surface" was the Nissan spec.  They might have been cutting it close for manufacturing savings too, some seem to be on the start of the ramp.  Appears to be sets of three holes on the drilling machine for the ends, and ones and twos for the remaining six in the middle.

     

    Just one of those interesting realities.

     

    Indeed.  It clearly didn't matter for the stock valve train, but it becomes an issue at some point with higher lift cams, higher lb valve springs, etc.

  6. Checked with Sunbelt about a replacement cam.  They are "no longer sourcing these cams".  I pulled out my paperwork and see that the cam was manufactured by Integral Cams, who have since gone out of business.  Found a post online that said http://www.megacyclecams.com bought all the cam designs.  I guess I'll give them a call on Monday, but I was thinking, I have the old cam and some pretty good documentation on it...  Would it be possible to send it off to someone and get back an identical replacement?

     

    Garrett

  7. 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 nitridedHe 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:

    1. 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.
  8. Why the nitriding anyways, if you dont mind the question? I have worked on many high performance engines and even some race cars, and 1 funny car. I have seen special coatings used on pistons, even the inside of the block, but never on the cam, ever.

    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.  

  9. 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.   :sour:  

  10. I can do the welding and straightening for you if you can't find someone. I have done it a number of times

    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.  

  11. 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

  12. 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.   :)

     

     

     

    post-4218-0-92296200-1354579905_thumb.jp

     

    http://forums.hybridz.org/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=45861

     

     

    post-4218-0-10910900-1354579905_thumb.jp

     

    http://forums.hybridz.org/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=45860

  13. 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?

  14. On a side note, when I finished my engine assembly, I used a modified distributor shaft and a drill to pre-prime the oil pump and galley before initial engine start. Always a good idea!!

     

    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.

  15. Did you prime the engine? If not, I think this is what caused the damage. Most likely it happen after running dry the first few seconds after startup.

     

    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.

  16. 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. 

  17. What I know I have done right is primed the motor, have proper valve lash, and used ZDDP. 

     

    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

  18. People have no idea how long the rockers have no oil on them on start up ,when the engine starts get the rpm up and make shore the timing is right then hold the rpm at 3000 to get the oil flow up to the cam , this is not a good time to start and stop the engine , try keep it running for 15 min at a good rpm 

     

    Since, I thought it was necessary for the cam break in, on first start, I ran my engine for 20 minutes at 2000 RPM. 

     

    We used an old fire extinguisher filled with oil to "pre charge" the lube system before first crank. You blast in the oil at 125psi (or whatever your shop compressor can pump air to I suppose) until your sump is full, then go to it. A check valve in the charge line allows you to immediately start the engine without physical disconnection... If you have some HK Hydraulic Disconnects you can pull it immediately after firing up.

     

    It sprays from the bar or the cam pretty quickly this way. Everything is flooded before start.

     

    My engine builder offered to send me such a setup, but being ignorant, I thought it was unnecessary.  C'est la vie.

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