Zmanco

No, I'm running 2 12" efans. But my only issue is at speed on the track. The rest of the time I have no issues so fans aren't going to solve my issue. I'm working on sourcing an oil cooler per JohnC's suggestion. That makes the most sense to me.

I've been gradually warming over the L28 in my 73 and have stayed with the stock clutch until now. Basically for street driving the stock clutch is adequate, although now just barely. But as soon as it gets some heat in it, I'll get slippage on hard 1-2 upshifts. I'm not talking about a hot day, but rather doing some exercises at a HPDE that involve agressive launches. I'm going to go with a Centerforce II pressure plate along with their disc. The general concensus on this site was to use a PP with more clamping force and a stock disc, but CF only sells them bundled together. I won't have it installed for a few more weeks so can't comment on it yet. But most people here in our situation (warmed over L28) were happy with its extra torque capacity and yet still found it reasonable for a street driven car. Search on "centerforce" and you can read their thoughts yourself. Edit: just noticed that you've got a Z31 - sorry, my comments are based on an L28 in an S30.

Am I better off going with a kit like this with the cooler mounted in front of the AC condenser? http://store.summitracing.com/partdetail.asp?autofilter=1∂=PRM-10189&N=700+115&autoview=sku I have a $30 off coupon at Summit that expires in a few days so now is the time if I'm going to go this route

So is 215+ for 20 minutes at a time maybe 10 - 15 sessions per year going to make a significant difference in engine life? Alternatively, if I were to add an oil cooler, what about using parts like these? Adapter plate: http://store.summitracing.com/partdetail.asp?autofilter=1∂=PRM-1060&N=700+4294843279+115&autoview=sku Thermostat: http://store.summitracing.com/partdetail.asp?autofilter=1∂=PRM-1060&N=700+4294843279+115&autoview=sku Is 3/8" hose enough or is 1/2" required? Also, could the transmission cooler of the radiator be used to cool engine oil? I'm guessing it can since it would only flow oil when it was hot and less viscous. That would be easier than trying to mount a separate cooler in front of the rad and AC condenser. But if the oil cooler on the rad takes away from capacity to cool the coolant, then that might not be a good idea. Sorry for the many questions, but oil coolers are completely new to me.

As zcarnut said, running with less advance will cause the engine to run hotter which contributes to this. If this is the only reason you retarded the timing, try putting it back. Also, I agree that dumping the clutch to kill the engine is not a good idea. But letting it out just as you would after a stop won't hurt anything. It's not a good long term solution, but until you get it sorted out, I'd prefer that to allowing the engine to run on by itself.

Sounds like you have enough carbon deposits in the head creating hot spots that the engine self ignites (diesels) even after you turn off the ignition. Not surprising with a high compression head and carbs. A simple fix is to turn the engine off with the clutch. Put it in 4th, set the parking brake and step on the service brake (just to be safe) and let the clutch out. It's probably not the long term solution you want, but it's easy and really won't hurt anything. Remember to turn the ignition off afterwards.

Going back to one of my original questions, how have others soft-mounted the Al radiators?

Derek, I think I remember seeing your pictures (it's a little hard to keep all these discussions straight right now). My issue is that I have a 240Z (73) with the bumper in place. The bumper supports are what makes it extra hard to block/channel air. If those weren't there, it would be simpler to build something behind the grill.

Yes, I ran with that and 40/60 anti-freeze/water last weekend. Temps were around 215 on the track.

We're about to have the same discussion covered in this thread http://forums.hybridz.org/showthread.php?t=122197 and that wasn't my intention with this post. I agree that better ducting should help some, but I'm trying to avoid changing the external appearance. The only noticeable mods I've made are the panasport wheels (necessary to fit performance tires and arguably period-correct), and the spook ( which is also period-correct). I'm fortunate that my 73's body, paint, and interior are in pretty good condition. On top of that, I don't have a welder nor welding skills (yet) to build ducting. Like I said earlier, I'm only concerned with improving cooling while on the track. And it may be that what I'm trying to do (build a reasonable track car that otherwise looks stock) is just not possible. But if an aluminum radiator could help flow more air and/or dissipate heat better, then it would fit in with my approach to keeping the car externally stock.

Woldson, I read that thread with great interest even though I'm NA. So far I'm not sure what to do differently in my situation based on that thread. Do you have any thoughts? Challenger, prior to last weekend I agreed with you. But I'm out of things to do (save remove the AC condenser which I don't want to do). My temps are fine all of the time except when running hard on the track. So I'm not too far from where I think I need to be. For example, I ran 40/60 antifreeze/water and added water whetter as well. I suppose I could go 100% water + water whetter, which should help, although I doubt it's going to drop the temp 20 degrees. I've looked at ducting, but not sure how that will help me. There was only one opening into the engine compartment (3" hole to the left of the radiator on the passenger side) which I've closed up. Other than that, the only path for air to get into the engine compartment is through the radiator. The good news is that I never went over 215 F, but I'd feel better with it lower when I'm running that hard for that long. The rest of the time I have no issues.

One idea I have for soft mounting is to enlarge the holes on the rad brackets and fit rubber grommets with an ID that is perhaps 1/4" larger than the mounting bolt. The idea is that this would provide a nominal 1/8" play in any direction as the chassis twists. It also has the benefit of electrically isolating the rad from the chassis. A large flat washer would go on the engine side followed by 2 nuts tightened against each other so that the grommet was under some compression, but not so much that it couldn't move a little. Thoughts?

I'm considering switching to an aluminum radiator to help with cooling at the track. On the street my 4 core copper/brass is just fine, but I was seeing temps of 215 at the track last weekend with ambient temps of 95 F. I have the AC condenser up front and suspect that's part of the problem but don't want to remove it. From what I've read here and elsewhere the more modern Al radiators have less resistance to air flow and while Al is not as good of a heat conductor as copper/brass, the older designs (which is what mine is) are apparently not that efficient. I've already ensured that there are no other major sources of airflow into the engine compartment except through the radiator. I did have some fin damage on the AC condenser which I've since straightened. So I'm leaning towards this unit: http://cgi.ebay.com/ebaymotors/All-Aluminum-1970-75-Datsun-240z-260z-Radiator-110AA_W0QQcmdZViewItemQQcategoryZ33602QQihZ012QQitemZ220259419403QQtcZphoto Has anyone tried it? Also, what about going with a later 75-78 unit which has a larger core? Mine is still in the car and with the AC condenser in place I can't see if going with a deeper core would expose more of it to air flow. I know it would hang down lower, but my spook already hangs low so I'm not worried. Also, what about mounting it? I know I'd need to isolate it to protect against corrosion, but I'm concerned about frame flex and what it would do to the radiator. Has anyone found a simple way to soft mount this type of unit?

Sorry we missed you Ryan, would have been good to have another S30 car there. jt1, it was a Z club event and we had quite a few Z32s, most were tts. There were a bunch of other cars as well including a few newer 911s, a Cayman, a Caterham 7, a full race prepped early 911 (2.7 liter I believe, and very fast!) an LS1 miata and LS2 C5 corvette. The last two were really drag cars (both had automatics with stall speeds >3000 rpm), but gave it a good shot. I'm sure I forgot a few cars. I was quite happy with things (except for the engine temps). The car and I were very much in sync and the little changes I've made have netted the affects I wanted. I think I'm mostly at the point where most improvements are going to come from small changes/adjustments and not from major bolt-ons. All in all a very satisfying day!

http://s88.photobucket.com/albums/k172/dbailin/2008-07 State Patrol Track Day/?action=view&current=2laps.flv Here's 2 laps. This track isn't all the interesting as it's used by the State Patrol to train officers. But it's got a few off camber and undulating turns that are more technical than it first appears. And any track is better than no track...

If you use the stock ignition module to trigger the ECU or MSD and it fails, then yes, "you're stuck". But that's obvious. So did I misunderstand your question?

Track day was great! I've finally found a good combination of tire pressures and illumina strut settings that settled the car over bumps yet left it pretty neutral without excessive understeer. Brakes did well too. I have a major heat issue with the engine temps running 220+ though. I need to read up some more on the ducting ideas of others as I'm pretty sure it's an airflow issue (running a 4 core MSA rad that I bought new). I still have the AC condensor and suspect that's part of the problem. I'll start another thread when I'm ready to ask some intelligent (hopefully) questions. I'm ripping some video off the camcorder as I type. If there's anything of interest I'll post it.

You can run the output of the 82-83 CAS to an MSD 6 box. The wiring to the MSD would be the same as if you used a NA distributor with its VR output. But, if you do that, what is going to control your timing? Basically you would adjust your initial advance by turning the distributor body and then locking it down, and it would never change. I don't think you want to do that. I'm not familiar with the 86' Z31 ECU/MAF combo so can't suggest how to put this all together. If you're going to go with an aftermarket controller, then you'd want to run the CAS into it, and let it control the MSD. That's what I did with Megasquirt. Edit: forgot to mention that you would have to supply power to the CAS. Here's a diagram I found on this site. I think credit should go to Mobythevan, but if I'm mistaken, my apologies to the original creator. It's not for what you described, but if you focus on the upper left you'll see how to wire the CAS.

Paul and Myron, how did you guys think of that? Has it happened to you? You nailed it! Many thanks, no need to hold back tomorrow Daniel

Thanks for the suggestions. I did jack it up (both ends) and crawled around underneath. So far I can't see anything abnormal. Logic says that it's not from the car, but if you saw the color of the metal and the dirt/grease embedded, you'd think it was indeed from the car. And no one else spends time in that side of the garage except the Z and me. And I wish I had custom camber and/or TC parts, but I don't. Like I said, I'm going to drive it and hopefully it's not anything critical.

Well, it's not from the floor jack nor any other tools I've used in the last few days, at least that I can find. I put everything back together and on a local drive cannot find anything abnormal. FWIW, in this picture you can see on the bottom piece where the metal fatigued and that must be how this piece broke free. My wife was suggesting things like window crank mechanism, and while I don't think that's it, I think she's going in the right direction thinking about things that don't carry a lot of load. That bottom piece is very light metal and couldn't carry much load at all. I suppose I'll follow jt1's advice and go to the track and use the first session for a shake down. And yes, Darrel, she thinks I spend too much time on the Z, but there's nothing new in that

I was going to ask that no one say "muffler bearings" since I'd already checked them I'll keep looking in the garage at tools...

Just my luck, I found these parts when I pulled back into the garage just now and I have a track day tomorrow at 7 am. Actually, I noticed the ball bearings before I pulled out to leave and figured they were from my creaper which has lost bearings before. Turns out the creaper isn't missing any, and when I pulled back into the garage I ran over one of the races. I drove about 10 miles on the errand and didn't notice anything wrong. I've been under the car and can't find anything loose or amiss. I thought it might be from the top of the front struts, but after loosening it enough to pull it down a little, the diameter of the race looks to be larger. These are a little over 1.5" across. Also, how would these fall off without whatever went through the center hole preventing it from falling off the car? Anyway, I'm not real happy about the idea of tracking the car without knowing where this came from and will probably miss the day if I can't figure it out. Any and all suggestion are welcome and encouraged!

Pictures are great! Now it's clear to me. BTW, looks like the condoms are provided in the Felpro kit. I'll have to go visit the shop today and see what we can do. If he's already buggered the Viton seals, I'll probably just put a set of the polycarbonate Felpros on it and call it a day. Again, thanks for all the advice and education. I agree, it's important (and fun) to keep learning. Besides driving it, I think the best part of having an early Z for me has been learning about all the subtle issues involved in building something that is better than stock, and yet is still reliable.

Paul, as always, thank you for the very detailed advice for the installation. A few clarifications if you don't mind: - any chance you have a picture of the condom? Many have suggested using them, but I haven't seen a source for them nor even have a clear picture of what they look like. - The process you describe sounds like the seals can easily be damaged. Is this just for the Ford seals, or the polycarbonate as well? The shop that did the machine work wants to reinstall the valves in order to warrant their work. I'm inclined to let them do it unless the L engines are different enough in which case I'll just do it myself.