JMortensen

What Pop said... Jon

Couple of problems you might encounter: The stock coils will bind with a "true" .490 lift cam. If you get aftermarket springs, you may run into a situation that I encountered with Schneider springs and retainers. The retainer just barely hit the valve stem seal at full lift. The retainers were turned down in a lathe to fix, my machinist said that he didn't feel comfortable with anything less than .050" space between the bottom of the retainer and the stem seal so they were cut down to allow .075 IIRC. Neither Schneider nor MSA says anything about this. Not sure if they are simply not aware, or if they are choosing to ignore the problem When I originally built my first engine with this cam, I went to a sh!tbag crook of a machinist who "made" the stock springs and retainers work by cutting the valves a LOT. This led to having 0 margin on the valves, and they warped due to the heat of combustion. This had another negative effect, because when I cc'd the chambers during the 2nd build there was a 4cc difference between the same chamber with the new valve vs the old valve. So the original farkwad also cost me some compression with his crappy work as well. Did I mention that I paid this crook for new valve springs and retainers??? On the second build I had to purchase new valves and springs and retainers to fix, and since the valves sat much lower in the head, new lash pads were also necessary. Not that tough to figure out, but unless you have a big supply of lash pads you pretty much just have to experiment until you get it right. My advice is find a "good" machinist to do the work, preferably someone who has dealt with the L series engines in the past. My situation was the exception rather than the rule (I don't think most machinists are crooks) but I thought I'd throw that out there for your benefit. EDIT--All of the above happened with an E31 head with 280 valves, so I think that everything above correlates to your P90. Jon

Anyone else see this show? It was about a 12 hr endurance race at the Point. Very cool. They talked briefly with a Z racer, can't remember his name, but he had qualified 4th overall! Lots of on track shots of the Z, but they focused on a 944T, which qualified 3rd and ended up 12th overall after having some brake issues (the turbo was boiling the fluid in the master cylinder!) and the intake boot pop off during the race. Anyhow, I enjoyed watching it and wanted to let everyone know, because no doubt it will be in re-runs for the next year and a half, like everything else on Speed. Jon

Yep. I think you're right Drax. The one thing I'll point out is that Norm's SU's are not stock. I don't think much over 200hp at the crank is possible with stock SU's. Jon

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Triple TB's are awesome. You can run a 50mm and still get decent low end. Seen 2 Z's with triple TWM's, both REALLY haul @ss. Sound is exactly the same as triple carbs, because you have the same open hole from the air horn to the valve, so you get the same noise. Easier to tune or have tuned too, seems like there are more programmable FI experts than triple carb experts these days... Jon

Anyone know the answer regarding the Schneider retainers? Jon

Well I think the actual rubber engine mounts are the same for the engine, but not the tranny. But I asked if I was remembering correctly because it has been 5 years or so since I've pulled a tranny from a ZX. I think I'm right because I remember it being much easier than a Z... Jon

The tranny mount is different, IIRC. The Z has basically a flat bar which attaches on either side of the floorpan straddling the tranny tunnel. IIRC, the ZX has a much shorter crossmember which hooks into to brackets up inside the tunnel. Or have I killed too many brain cells since I was last under a ZX??? Jon

Wouldn't the duration determine whether or not you need the reliefs, not the lift? EDIT--Dan, did you have to turn your spring retainers down on a lathe so that they didn't hit the stem seals? I recall that you have Schneider springs and retainers, and I had to have mine turned even with my .490 lift cam. Also, did you cut the spring seats flush with the head, or was that not necessary? Jon

I have an ITG filter that fits your description John (black foam, red plastic). Never heard of an ITB filter, and when someone says ITB I think individual throttle bodies, but that may not be correct either... Jon

Why is this guy driving around with a cam under the dash??? Jon

Bastaad was right. That is the cheapest easiest way to get 200 hp to the wheels. Pretty much any V8 that is not from the smog era will get you there, and you won't be pushing the engine nearly as hard to get it. Jon

I thought John's car made 285 at the wheels... John??? I think if he did all that he stated up front and just slapped on an shaved P90 he'd probably have met his 200 whp goal. EDIT--Bastaad's results were probably mostly due to the carbs. Bastaad, I can't tell you how much faster my car is on the track with the Mikunis. It was a HUGE difference, then I tuned them!!! Jon

I think individual throttle bodies, aftermarket fuel injection, cam and header and full exhaust would net a lot more than 10 hp. Maybe I read his original thread wrong, or maybe Mike and John did, but I don't know how you guys can see that as a 10 hp increase. I don't think the pulleys and the electric fan are going to be a noticeable difference to the butt dyno, but you'd probably see a couple hp on a real dyno from those things. Maybe JohnC didn't read your original post... The things that are missing from his engine build ideas (in loose terms) are compression and headwork. The stock compression on your NA L28 is something like 8.5:1. Put a small chamber head on there with the rest of that to get 10.5:1 and you might be closer to your goals, but I don't think the 2 compression points (or even 4 points) gets you to 300 hp. Mike, I think that the hard part is NOT getting the first 85% of your hp increase, its getting the last 15%. There is a huge law of diminishing returns with the L series, and if you spend 20 grand on an engine you might get 20 more hp than they guy who spends $8K. And that last 15% takes you from an engine that can run pump gas to a finicky race gas eating tempermental bitch of an engine too. Look again at Dan's dyno chart. Runs on pump gas, 235 hp to the wheel. JohnC's going to hate this, but use the 15% rule, that's 270hp (it's just an example John ). Reduce that for the 2.8 vs 3.1 engine size, and you're now at 243hp. Back to Dan's motor again, it's that last 35 hp to get from Dan's engine to JohnC's engine that costs the huge $$$. Dan also says that his carbs aren't tuned to perfection. It would be a lot easier to tune ITB's with a programmable FI setup... so there is more hp there too. I DO agree that a high hp L motor is wasted in a ZX 2+2. Get a V8 if you want serious power without serious $$$. Jon

JohnB, if you've got a 4.44 rear gear, why are you trying to find a cam that works at 2500 rpm? Seems like you could get a cam that doesn't start til 3500 or 4k and still keep it in the revs with that diff. Or were you asking rhetorically? If you find that cam, BTW, let me know... Jon

The problem with using the front rotor in the rear is that it is meant to bolt to the back of the hub, so the center hole would need to be opened up and the lug holes drilled. Before going to all that trouble, you could just get a rotor that fits the lug pattern and the pilot on the rear hub, that way when you swap a rotor you don't have such a big job to do. I don't know about you guys, but I like to be able to buy the parts that have to be replaced regularly off the shelf. Vashon--that's Terry's car (BlueOvalZ). He found that the 280ZX front caliper bolted to the Maxima rear caliper bracket with a later Maxima front (vented) disc. Too much bias, so I think he switched to Cressida calipers which I think are the same as Supra calipers. Jon

If it's going to be RATM then its suggest "Know your Enemy" and whenever it says "know your enemy" the video could cut to a Honda or a Mousetang. Jon

No. The front stuff doesn't even come close to bolting on in the rear. Look at http://http:www.modern-motorsports.com or http://www.arizonazcar.com for some ideas for rear disc. Jon

We all like Tools right? How about some Tool? Jon

I'm in a similar situation to Tim. I've got 7 cd's full of autox footage taken straight from a professional TV quality DV camera and a small camcorder in the car, but no way to cut it down. Any suggestions other than buy a $1000 dollar piece of software to do it? I once tried QuickTime Pro at a friend's house using the Sorenson compressor dealy. It worked but then the cones at the autox started to show up like you were seeing double, and I'm not a big fan of .mov's anyway. Probably a built in "feature" of Windows, but QT takes forever to load, even on my new PC. Damn Microsoft BS!!! Jon

Dan--fair enough. I think you can run such high compression on 93 because your cam selection is correct for your combo. I certainly can't argue with what you've accomplished, and since I've never dynoed my Z I can't really offer up a counter argument, although I have a suspicion that I might be pretty close to JohnC's "max" on an E31 headed L series, and my engine is not really all that special. I'm just trying to give Mark another viewpoint on the heads... not trying to take away from your accomplishments. Jon

You'll DEFINITELY need to experiment, but I bet that Sunbelt has a tuning area in the shop where they could dial it in for you if you don't want to do it yourself. It is an art, but if you know what you're doing it is far from impossible. Mikuni parts are getting hard to come by but Mikunis are IMO easier to tune, so if you are thinking of switching your carbs for something bigger you might want to take that into consideration. Webers are harder to tune and keep in tune, but most people think that you can get more hp with properly tuned Webers. Jon

Good point, but IIRC Dan has flat tops. Jon

Dan I can't help but think that your carbs should be plenty big for 8K on a 3.1. In looking at your previous dyno charts, I think your spark starts getting irratic above 6.5K. I agree that 45's would be a better choice for Mark, but I don't think you've run out of carb. Could be the limitation of the gears on the dizzy drive. Maybe yours are worn??? I know the Pertronix unit only has one sensor, maybe the ZX dizzy style where 6 triggers line up to send the pulse would be better... I don't know. I know you don't believe in the importance of quench Dan, but for Mark's benefit, there is a large contingent of engine builders who will tell you that the piston needs to be close to the flat quench areas of the head to help combat detonation. If you stick a thick headgasket in there you keep the piston farther away from the quench areas basically rendering it useless. I have heard .035-.045 and I've heard .035-.060. This is why the P90 or the E31 would theoretically have an edge over a N42. On the other hand, if JohnC is getting 305 hp out of an N42, Sunbelt must be doing something right... Jon