katman

Well lessee, P30-0032's (revalved 70/30) were used on the ERadatz/Kemp Heuman EP 240Z that came in second at the RunOff's one year with Grayson Upchurch driving. Seemed to stick pretty good. Springs were in the 400 lb/in range. But that's revalved. Stock they fit a VM rabbit or something like that. I missed the last 10 or so pages of this thread, are you needing the shortened aspect of the P30-0032's? 'Cause Bilstein makes a shock for the stock strut.

Robinson Racing Enterprises in the Cumming area.

Cheap was the only design requirement he mentioned. Actually 2 coils off stock 240 springs only takes you to about 107F/130R. Now hack about 2.5 turns off a 280Z 2+2 rear and you're up to 180. Yee haa.

Besides the fact that just about every letter of the alphabet has been on the back of stock Z cams, The alleged "A" grind, if its old, could be either an L24 cam (externally oiled) or from an L28 (internally oiled). If you buy one new it will be internally oiled.

Uh, cut the springs about 2 turns?

Alas, one of Murphy's Laws.....

Wow, that's scary close to the custom "Tri-Y' header we came up with for our ITS L24 race engine, 'cept our pipe lengths were a little more equal so it wasn't as simple as that layout. Sucked below 4500 rpm, but nothing else could touch it above that. Wouldn't run it on the street but it was the cat's meow for racing.

Nyet. Well the bottom of the tire bulges from weight, but top and bottom pull over in the direction of force when cornering (bottom deflects more of course). I've seen tires rub the strut or spring perch with twice that clearance. I like to see the thickness of an index finger, 'bout 10-12 mm. YMMV.

Dunno, but its easy enough to measure the lobe with calipers, then measure the base circle and subtract. That gives you lobe lift, then multiply by rocker ratio (1.5 probably) to get valve lift.

ooooh, very pretty. Doesn't look like its anything close to equal length tubes, and to say it should be good for any size Z motor is an indication you really don't understand headers. Nice feature to have the tubes all stick straight out from the head, but makes the intake routing rather difficult. Or are those pipes bent down immediately at the flange? Ouch. There are no hp specs for headers, and if there were they'd all be lying. Headers have to be one of the most BS laden aftermarket performance parts there are. For a stroker motor with a medium cam the Nismo Comp 1-5/8 headers is probably the best choice IMHO. A Stahl, at twice the price, could draw out a few more ponies. Rebello's headers used to just be a stepped copy of the Nismo Comp headers, and in our dyno tests actually made less hp. Stahl and the Comp headers are probably the only real header people with any significant development on the Nissan L series motors. Everything else is just an aftermarket "built to a price and fitment" header.

Theoretically it doesn't matter which is up, but cone side down has better karma.

We tried a crank scraper during our ITS L24 engine program and lost a hp or two. I know that flies in the face of all V8 experience, but on a real SAE engine dyno with real anal retentitive people doing the testing, that's what we measured. To do a crank scraper right you have to get within .050 or so of the crank, the scraper has to be stiff as hell so it doesn't bend, it has to be angled properly, and it has to be able to shed the oil that its scraping. Although we put a pretty fair amount of time in engineering the thing I think we didn't have enough vent in it to shed the oil (adding holes makes it weaker and just bend out of the way of the crank, so tough engineering problem there). For me, I would be very skeptical of anybody else's parts just because I know what it takes to really make that work on a Z block. Although some of these aftermarket scrapers look really good, I wouldn't bother. That is, unless you're racing at the front in ITS and need an extra hp within a very constraining set of rules. For the street, where there are no rules , there's more reliable ways to get more hp. IMHO.

Last time I looked an N42 was OHC and didn't have any lifters.

"Solid Lifter" Ha. Idiot.

M1 Carbine. That count?

What JohnC says. Start with the basics. Could be lots of things. And I'd start with a leak down check.... BTW, SM needles are seldom the answer. For anything.

We used Tilton spherical bearings to eliminate the binding issue (caused by poly bushings or additional caster) on the IT cars, and I would have liked to section the control arm and add another 3/4 inch to get more camber (got to be careful you don't run out of tie rod thread!), but we were also limited by the rules on how much track we could run (contact patch could not extend outboard of the fender lip. Instead we did funny things with the strut to get more camber (the rules were more permissive there) since even with camber plates you couldn't get the 3.5-4 degrees a radial Hoosier likes without bending the strut and/or other more creative things. I don't really see anything wrong with what he's done either.

Actually the people that whine about threads exposed to cyclic tension loads (myself included) that are also a single load path strucutre are proly more concerned with unnoticed fatigue cracking than they are with one time overloads. A 3/4-16 will probably last forever, even with the approporiate notch factors applied to realistic loads. That said, it makes folks like me and Jon cringe because its ingrained into engineer types that you just don't do stuff like that. The sheet metal control arm is what we'd call more damage tolerant, and a lot of those old Z parts weren't just welded up sheet metal, they were welded up sheet metal that had been normalized, stress relieved, and heat treated afterwards. Really, I just don't understand this fascination with adjustable control arms. Camber plates are a much better way to do that and in 15 years of racing Z's I never found the need for adjustable front control arms. Rears are a slightly different story because of the need to adjust toe, but on the front???? To each his own. Nice work anyway.

Most shops don't bother adjusting the valves, they'll leave the rocker pivots low so the head can be transported without worry about bending the valves. You probably have no valve lift. Setting the valve lash is a post build, pre startup operation usually. You need a factory service manual before you go any further.

The air injection adds oxygen to the exhaust to help complete the burn and lower the pollutants. The tube is close to the exhaust valve to make sure it's catching hot flame. If you haven't seen this before you must be a young whippersnapper.

I that an aftermarket timing set? I've seen them with mismarked crank sprockets. When you're at TDC on #1 according to your distributor and timing marks on the harmonic balancer, where's the cam sprocket notch relative to the tick mark on the cam retainer plate? And where are the cam lobes for #1 pointed?

Momo Prototipo has the more classic look. Gotta run it with Panasport wheels. Anything else is ghetto... http://www.pelicanparts.com/catalog/shopcart/911M/POR_911M_UPrc91_pg9.htm

They both suck. Sorry couldn't resist. If you're putting them on a relatively stock motor there won't be 2 hp difference between them, or practically any other off-the-shelf header. What's your application?

Plus flat paints tend to increase the probability of corrosion forming underneath. Z's don't need another reason to rust.

Tire temps - totally agree, Hoosiers like a little camber thrust. Small changes in roll center make a big difference [in front/rear balance, and hence front to back spring ratios and sway bar choices] - absolutely true. 1/4 toe, Jon and I will continue to respectfully disagree on this by about 1/16, but what's a 16th among friends? Stiffer springs and no rear bar- agrees with my road race experience on mostly southeast tracks. However, IMHO we want as much spring as the bumps and shocks will allow, with about 400 being the upper limit for a series 1 chassis with front strut bar but no cage forward of the firewall (ITS spec, basically). Beyond 400 we started going backwards, although possible to go higher in an EP car where the cage can go forward of the firewall. Up above 200-250 and you're beyond the capability of almost all off-the-shelf shocks, and "twitchyness", skating, and other unwanted hair trigger responses are likely. Again, IMHO, roll bars are for trim only, and you only need one so save the weght, UNLESS you are spring limited because of bumps/shocks/street ride desires so you use two big bars to limit roll whilst maintaining some resemblence of kidney health.