duragg Posted November 30, 2011 Share Posted November 30, 2011 191.8 wheels. Charts to follow. Benz in front of me made 900. Had 17 inch front Brakes! Tj Quote Link to comment Share on other sites More sharing options...
forchunet Posted November 30, 2011 Author Share Posted November 30, 2011 Wow! Those are great numbers. What did you get for torque? Quote Link to comment Share on other sites More sharing options...
roger280zx Posted November 30, 2011 Share Posted November 30, 2011 You can always use multiple felpro gaskets stacked. I don't remember all of the details on the process, but I remember something about using copper spray between them. A quick search will bring it up I'm sure. Then again, the member doing this was also using emery cloth to bring down the thickness of the piston crown. He did have a motor with a serious kick-ass reputation though. I wish I could remember his screen name! Then again, it isn't a widespread solution, so I'm sure there is some sort of implication with the method. That would be norm (that 12 second S.U. guy). It is a shame he is gone from the forum, but he had a lot of good tech posted here around 2004-2005 IIRC. Stacked $20 headgaskets is the least of his genious contribution, but that engine DID detonate (too much compression). Just search for norm. Quote Link to comment Share on other sites More sharing options...
duragg Posted November 30, 2011 Share Posted November 30, 2011 Raw data is attached. I didn't have interest or the jets with me to play around with it. Ran it twice and called it good. With some tweaking I could probably hit 200 mark. Not bad for a hack.. The dyno guys seemed very happy with the cam which surprised me. How they can tell I don't know. Sorry for the file size. I need to work on the lower end jetting, fix the mid-range, maybe fatten the top a bit with a smaller air corrector. Get some 36mm chokes and start all over... 2011 Dyno N240ZZ.pdf Quote Link to comment Share on other sites More sharing options...
duragg Posted November 30, 2011 Share Posted November 30, 2011 And yes... it did really happen: Quote Link to comment Share on other sites More sharing options...
z-ya Posted November 30, 2011 Share Posted November 30, 2011 Raw data is attached. I didn't have interest or the jets with me to play around with it. Ran it twice and called it good. With some tweaking I could probably hit 200 mark. Not bad for a hack.. The dyno guys seemed very happy with the cam which surprised me. How they can tell I don't know. Sorry for the file size. I need to work on the lower end jetting, fix the mid-range, maybe fatten the top a bit with a smaller air corrector. Get some 36mm chokes and start all over... Very nice numbers! You should ask the dyno guy for a plot that also shows AFR. Looks like the power was starting to drop off around 6800. I'd keep it below 7000 with cast pistons. Quote Link to comment Share on other sites More sharing options...
duragg Posted November 30, 2011 Share Posted November 30, 2011 PDF with dyno charts and AFR is just above one post (3 pages). I keep hearing about cast pistons (ITM +1MM for me) and 7000rpm. What begins to happen to them above 7000. This is one area I am now wishing I hadn't gone the cheap route in afterthought. Tj Quote Link to comment Share on other sites More sharing options...
z-ya Posted November 30, 2011 Share Posted November 30, 2011 (edited) PDF with dyno charts and AFR is just above one post (3 pages). I keep hearing about cast pistons (ITM +1MM for me) and 7000rpm. What begins to happen to them above 7000. This is one area I am now wishing I hadn't gone the cheap route in afterthought. Tj Didn't look at page two. Looks safe on the top end. I ran ITM pistons in my previous race engine and didn't have any issues. I never ran it much more than 6200RPM. It was still running great after 3+ years of events. As you can see, it didn't make any more power over 5800RPM, so I only ran it to 6200RPM where the track conditions required it. This motor was 10:1 CR, N47, mild cam, no head work, and Megasquirt EFI. Forged pistons are less likely to shatter under extreme loads. The higher the RPM and CR, the higher the piston and rod loads. Edited November 30, 2011 by z-ya Quote Link to comment Share on other sites More sharing options...
Lazeum Posted November 30, 2011 Share Posted November 30, 2011 (edited) Nice numbers I'm wondering if it is truly your carbs + chokes that limit the power past 5500 rpm. Could it be the head or the cam instead? I'm being curious since I have to get new chokes on my setup, current 32mm are definitely too small, I'm hesitating between 34 & above. Looking at your AFR curve, if chokes were too small I would have anticipated AFR going on the rich side (no more air) which is no your case. Then regarding your mid range rich spot, we all have it (see post about Weber's around page 14 for AFR from me or Redbaron). With my new head (p79 ported with new cam from Rebello), I did not see it anymore (before the engine failed - lube issue). Edited November 30, 2011 by Lazeum Quote Link to comment Share on other sites More sharing options...
forchunet Posted December 6, 2011 Author Share Posted December 6, 2011 (edited) Update: Found a user online to sell me an LD28 crank, forged ross pistons, as well as 133m rods. I've since pulled the engine out of my wrecked 240z. It took a few days as I had to cut the front frame off as well as the radiator since it was all wedged in their pretty tight. A few surprises from the engine though, It had a brand new centerforce clutch and what looks like one of those 10.8 lbs lightened flywheel. ps. I cant seem to get the flywheel off. It's not a matter of it spinning as you can see I've got the chain to take care of that. Its that I just cant get enough torque to break the bolts loose. Doing all this with a recently broken hand doesnt seem to help. I even bought an electric impact wrench rated at 385lbs of torque and the bolts still wouldn't budge. I may just bring the whole bottom end, flywheel and all, to my machine shop while I get the blocked bored out and have them remove it. Maybe get the flywheel resurfaced while theyre at it. Edited December 6, 2011 by forchunet Quote Link to comment Share on other sites More sharing options...
Leon Posted December 6, 2011 Share Posted December 6, 2011 Use heat to break those flywheel bolts loose, the installer probably used loctite. BTW, from the looks of that flywheel, you bolt in new friction material instead of resurfacing. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted December 6, 2011 Share Posted December 6, 2011 Yeah, that flywheel looks like it has been recently resurfaced already. I've got one of those electric impacts, and it's barely good enough for wheel lugs. I'd use a good 3/4" breaker bar with 3' of gas pipe; it should pop those right off. Quote Link to comment Share on other sites More sharing options...
forchunet Posted December 6, 2011 Author Share Posted December 6, 2011 (edited) Success! Thanks for the pipe tip! Goal is to get it to the machine shop by tomorrow. Edited December 6, 2011 by forchunet Quote Link to comment Share on other sites More sharing options...
Lazeum Posted December 14, 2011 Share Posted December 14, 2011 I was looking for some info when I came back to your thread. You should look for quench definition and distance required to achieve an effective design. Your 2mm head gasket planned might not be a good solution. I've done it on my build not such a long time ago => How to check quench distance? Quote Link to comment Share on other sites More sharing options...
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