madkaw Posted October 8, 2011 Share Posted October 8, 2011 Need a little better sound production of that sick motor- freaking race car you got there! Quote Link to comment Share on other sites More sharing options...
zredbaron Posted November 20, 2011 Author Share Posted November 20, 2011 Seized my new race motor today. Never even got to dyno it or race it. Came back to it after about 8 weeks of storage. Fresh fuel, checked all the fluids, all is well. Turn it over, fires right up, zero oil pressure. I suspected the sender (literally 0, as if the gauge never turned on), and let it idle for about 20-30 seconds. Blipped the throttle to 3k. Just fine, sounded like a champ. Cut the engine off, rechecked everything. Removed oil cap, couldn't tell if it looked normal or not. Seemed normal. I hand-loosened the oil pressure sender (to pull it and see if oil spurted out) and restarted the motor. As I walked around to the sender, it started to have a hard time idling, then stalled. Turns out it seized instead, turns out the sender was working just fine. God, it sucks to have no automotive background and the only learning that takes place is learning what NOT to do... I never dreamed I would have only had about 45 seconds. I would have thought I'd have more warning than that! I won't be able to pull the motor and investigate for several more months, but I'm dying to know: What are my best and worse scenarios? (ie what parts will likely have to be tossed? will any of my block/head internals be salvageable?) God, what a loss.... Quote Link to comment Share on other sites More sharing options...
forchunet Posted November 20, 2011 Share Posted November 20, 2011 As someone who has been lurking in your threads and hoping to catch up with you in Norfolk regarding your Z, your predicament is very unfortunate and I feel your pain. I recently bought my dream 240Z only to be rear ended and then crashing head first into the car ahead of me, a total loss in under 45 minutes of enjoyment also. Best of luck and hopefully the guys here can help you out! Quote Link to comment Share on other sites More sharing options...
PalmettoZ Posted November 20, 2011 Share Posted November 20, 2011 Seized my new race motor today. Never even got to dyno it or race it. Came back to it after about 8 weeks of storage. Fresh fuel, checked all the fluids, all is well. Turn it over, fires right up, zero oil pressure. I suspected the sender (literally 0, as if the gauge never turned on), and let it idle for about 20-30 seconds. Blipped the throttle to 3k. Just fine, sounded like a champ. Cut the engine off, rechecked everything. Removed oil cap, couldn't tell if it looked normal or not. Seemed normal. I hand-loosened the oil pressure sender (to pull it and see if oil spurted out) and restarted the motor. As I walked around to the sender, it started to have a hard time idling, then stalled. Turns out it seized instead, turns out the sender was working just fine. God, it sucks to have no automotive background and the only learning that takes place is learning what NOT to do... I never dreamed I would have only had about 45 seconds. I would have thought I'd have more warning than that! I won't be able to pull the motor and investigate for several more months, but I'm dying to know: What are my best and worse scenarios? (ie what parts will likely have to be tossed? will any of my block/head internals be salvageable?) God, what a loss.... That sucks, no doubt. All that work and then this. You wouldn't think it would have seized up that quickly. My grandmother once had a car that a service station changed that oil in, and forgot to put the new oil in... She actually drove it home before it overheated and seized. If it were me I would first pull the head off and see if the cylinder walls are scratched up and galled. Hopefully not. If they are OK, then it might just be the main and rod bearings that would need replacing. Check that cam too for galling if it ran dry. Of course you need to find out what failed caused the drop in oil pressure, maybe a plug came out of the crankshaft or the block, or the oil pump failed. Many possibilities on that one. Sorry to hear about it, for what its worth I still have a 1975 280 motor that you can have if you want, just need to pick it up. I went V8 and had this one as a spare. I think its an N42. Quote Link to comment Share on other sites More sharing options...
rturbo 930 Posted November 20, 2011 Share Posted November 20, 2011 Damn! That sucks Mark. Hope you get it fixed without too much issue. Quote Link to comment Share on other sites More sharing options...
madkaw Posted November 20, 2011 Share Posted November 20, 2011 THAT SUCKS! Man I am so sorry to hear that news. Hope you get to salvage something from that motor. Try not to get too discouraged, but I know these lessons hurt--bad Quote Link to comment Share on other sites More sharing options...
zredbaron Posted November 21, 2011 Author Share Posted November 21, 2011 Thanks for the sentiments, guys. My master mechanic buddy said he was surprised it lasted 45 seconds. In his words, with tolerances as tight as they were, the moment there isn't cool oil (or no oil at all?), the piston rings turn into files in the side of the block. He expects pretty much everything to be toast, even the valvetrain. In my uneducated mind, I might get lucky on the head side; I had single springs with 25% less seat pressure luckily. Perhaps some of the valvetrain will make it. Also, my crank bearings were low friction coated, the crank was high speed balanced. It stalled under idle, which has got to be less destructive than under load. It was also full of 20W-50 Royal Purple with Synthetic LucasOil Stabilizer. Who knows, I might get lucky and just need a new block and new bearings/pistons/rings? Fingers crossed. (Haha only? That's still a lot!) That said, I've accepted the loss as a full loss to be mentally prepared for any scenario. Really the only thing that isn't fully replaceable is the head, which in theory should be just fine. The rest is just money, and well, money doesn't make me happy... but a nasty L6 does. A kick in the nuts, to be sure, but recoverable. Thanks Scott. It will be awhile before I can investigate, but I'll keep your block in mind... Quote Link to comment Share on other sites More sharing options...
Lazeum Posted November 21, 2011 Share Posted November 21, 2011 That's bad You obviously would have to perform a full root cause analysis to avoid future issues. Could it be a worn out oil pump? clogged oil gallery? oil plug that jumped out? ... I'll keep an eye on your thread. I'm rebuilding mine currently because of oil issue, my head (done by Braap) ended up being in perfect shape. Cam however was shot. Quote Link to comment Share on other sites More sharing options...
zredbaron Posted November 22, 2011 Author Share Posted November 22, 2011 (edited) Who knows. Oil pump was brand new. Sat too long, which led to "something" that won't be discovered until I pull the motor (completely). Sometimes stuff just breaks! I'm going to have a machine shop (TBD) do a full analysis of all parts and advise me as to what needs replacing. Engine internals are beyond my experience and knowledge levels. I find myself wondering if I'll go to ITBs while I'm at it. I was really looking forward to dynoing the motor with the carbs and then seeing the jump to ITBs graphically. I might stubbornly wait just 'cause... The takeaway at the moment is to not ever, ever start a new race motor up unless I'm physically around to start it every other weekend at a minimum. Hell, flying home every other weekend is cheaper! Sigh... Edited November 22, 2011 by zredbaron Quote Link to comment Share on other sites More sharing options...
budgy Posted December 8, 2012 Share Posted December 8, 2012 Hello fellas, terribly sorry if this question is already covered somewhere else (I tried searching). I recently picked up a 240Z with a 3.1 stroker build and triple mikuni carbs. As far as I can tell the head was rebuilt with schneider cams but I really do not know what duration/lift they have (I do have old receipts I should try to pour through). Compression ratio is also unknown. The previous owner was a younger guy, he claimed the car ran like shit on 93 or 91 octane and to just use 87. From what I am reading on the forums and from what I already believed to be true it seems like there would be no downside to running 91 octane gas other than a slightly higher cost. I have never seen anyone on here with a stroker build claim they use less than premium 91 octane fuel. That being said I have only put 87 in since I bought the thing and it has not been driven much at all other than the ride home that was like 800 miles. Car seems to be running great other than having a hard time starting in cold weather (which now that it's in heated storage I will never do again). And sometimes if you try to rag on the car from fairly low RPM's it has a stutter, I am not sure if that's the normal for a car with high lift cams and only single overhead valves or whether it might be caused by simply what I am feeding this thing. Any advice as far as what I should do? Do you need more info in order to give proper advice? Quote Link to comment Share on other sites More sharing options...
NewZed Posted December 8, 2012 Share Posted December 8, 2012 You didn't really ask a clear question unless you're lloking to make it run better at low RPM. I would define fairly low. Quote Link to comment Share on other sites More sharing options...
budgy Posted December 8, 2012 Share Posted December 8, 2012 (edited) Sorry, specifically below 3500RPM its like the car just stutters and feels very digital either on or off, the car might buck back and forth as the power comes on for a moment before it gets cut again. Any other driving has been smooth and throttle response is snappy. I am more so worried if running 87 octane is asking for problems, and if running 91 would be better. Can you think of a reason to not run 91 octane other than cost? Edited December 8, 2012 by budgy Quote Link to comment Share on other sites More sharing options...
JMortensen Posted December 9, 2012 Share Posted December 9, 2012 If it doesn't ping and you can get a decent amount of advance (~35 degrees total) don't use higher octane. I'd suggest that maybe different pilots might help with the low rpm issues. The pilots should be 1.25 to 1.5 turns out (even on all of them) and if the car is lean, then you should go with a larger pilot rather than turning the adjusters out farther. If you have a small cam, you need big pilots. Most people go with the Schneider stage III, which is not big enough for Mikunis IMO. Stage IV is better, but really, I'd opt for a regrind rather than using anything Schneider. You should probably start your own thread or post in one of the Mikuni tuning threads, as this info really doesn't pertain to zredbaron's thread at all. Quote Link to comment Share on other sites More sharing options...
Pyro Posted December 9, 2012 Share Posted December 9, 2012 I had a new oil pump fail on me a few years ago. The lid didn't have enough clearance between the rotors and the extra drag wore the oil worm gear off the crank which also put metal in the oil which ate up the engine bearings. Now, I always disassemble my new oil pumps and check the lid clearance. And since then have found a few new pumps that were too tight from the factory. With a cam that big, I would just lock the mechanical advance in the distributor and set it to 35 degrees at idle. good luck! Quote Link to comment Share on other sites More sharing options...
zredbaron Posted December 9, 2012 Author Share Posted December 9, 2012 (edited) Edited November 9, 2013 by zredbaron Quote Link to comment Share on other sites More sharing options...
Josh280z Posted December 10, 2012 Share Posted December 10, 2012 Dude, sorry to hear about the motor; had to be a shitty sinking feeling. I've had those moments once or twice. Quote Link to comment Share on other sites More sharing options...
budgy Posted December 10, 2012 Share Posted December 10, 2012 Haha sorry to hijack the thread buddy, I will go back to eating my popcorn and reading Thank you Jon for the suggestions. Quote Link to comment Share on other sites More sharing options...
zredbaron Posted November 4, 2013 Author Share Posted November 4, 2013 (edited) Well, it's that time of the decade again... time to bring my race motor back to life. At this point in time, the bottom end spins freely and the camshaft is not yet turning. The head itself appears just fine, valvetrain and camshaft TBD. It's clear the oil pump failed. I know the pump was new, but I can't confirm if I bought the turbo pump or not. Time for some design considerations. I don't wan't an oil system failure to ever cause an engine rebuild again. Shame on me for not priming the system first, but still, I feel an all-out NA motor should have a more robust oil system than OEM. Any recommendations out there for a nice and tidy dry-sump conversion? Also, I'm looking at the Kameari twin idler gear upgrade. Ok, JDM bling, blah blah... this looks like a really nice timing chain design update, and I'm all for minimizing valvetrain friction. ...Thoughts? Any experience with this product out there? http://kameariusa.com/L6_Twin_Idler_Gear.php Edited November 4, 2013 by zredbaron Quote Link to comment Share on other sites More sharing options...
JMortensen Posted November 4, 2013 Share Posted November 4, 2013 There was a long, nasty thread about the Kameari part probably 5 years ago that's probably worth searching for. For my part, suffice it to say that I think it's a great idea because you can mill the head and not worry about shimming the towers up. Quote Link to comment Share on other sites More sharing options...
zredbaron Posted November 4, 2013 Author Share Posted November 4, 2013 (edited) Found several threads on the tensioner and nothing but positive comments and theoretical banter. I'm definitely adding it to my upgrade list for this go-around. Still looking for an oil system. I didn't find much while trying to search for lightweight rocker arms within HybridZ. I found two online, varying between 56-65g per rocker arm (stock is evidently about 75g). Both are pretty much the same absurd price. (My valve spring retainers are already very lightweight, so I figure I might as well take a look.) I don't really ever read any posts about this being a particularly relevant upgrade, but figured I'd ask if anyone has any comments? You know, while I'm at it... Edited November 9, 2013 by zredbaron Quote Link to comment Share on other sites More sharing options...
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