jmortensen

I would only listen to people who have ACTUALLY TRIED what they're talking about. If they've only ever replaced or resurfaced the rocker arms, then they haven't tried NOT replacing or resurfacing them. I've only tried NOT replacing or resurfacing them, and as I said, in 10+ camshafts installed that way I haven't seen a single cam or rocker failure. Send your $200 to me, and I will give your rockers and cam an internet blessing. Since you'll get the same result from either expenditure of your $200 in my experience, I think giving it to me would be more useful (to me). Ask them when the last time they changed a cam and didn't change the rockers was. Might be worth a check to see if they make any money selling you rockers too. Why is Bryan Little suddenly such an authority? What qualifications does he have to be the person who says yea or nay? I agree that his site is useful and I've pointed many people to it myself, but that doesn't mean that he should be the arbiter of right and wrong. As I recall his site has quite a few (small) errors. Except if you're me or one of my friends. Then our special camshaft mind meld techniques will magically prevent this damage. It is possible to measure the lash at the pad instead of between the rocker arm and camshaft. Discussed in some depth on the link I posted earlier to Paul Ruschman's writeup at Hybrid Z. Part of doing a valve job correctly is ensuring that the valves are all the same height in the head. Some places don't do this, but that's because they've done the job wrong. Checking the wipe pattern on every lobe ensures that you won't have a problem here.

You'll need springs, Schneider springs and retainers are fine, but some others have a LOT of seat pressure, so look out for that. I wish I could recall the "acceptable" seat pressures, but I do remember that when I installed the Schneider springs and retainers my machinist checked the open and closed pressures and made sure they weren't excessive. Hybrid Z has a good thread about shorter seals here: http://forums.hybridz.org/showthread.php?t=90825 Plenty of room for any sane cam size with those seals installed.

Sorry, Diseazed. I guess I'm a little sensitive on this topic. Mostly I get a little uptight at the "internet imperatives". Examples include: Anything bigger than a mild cam will have absolutely no low end at all and will make the car slower. You ABSOLUTELY POSITIVELY MUST change the rockers or resurface them or the cam will self destruct. Finding the right size lash pad is next to impossible. You must have at least 10:1 compression to run a cam that is significantly larger than stock. It's really easy to go with too much cam, so stay conservative. There's more but those are the usual myths that I find myself getting annoyed with. If you've done the work yourself you should know that it's not rocket science. Just takes some time to understand the fundamentals of what you're doing and the patience to get it right before you start driving the car with the new cam. Probably the one that annoys me the most is the "don't go too big" myth. I don't think I've EVER seen a post from somebody saying: "My cam is too big", but you see hundreds warning not to get too large a cam. I fell victim to this one myself and spent time and $$$ installing a barely larger than stock cam and then really felt like I was taking a risk getting my second aftermarket cam at .490/280 and it was a night and day difference. I had listened to the "conventional wisdom" to my own deficit. As I said, I've run my rockers on 3 cams, no resurfacing between them, and my friend used to install cams on all of our little group of Datsun guys cars and a couple Toyotas too. None of us EVER changed the rockers out or resurfaced them, and nobody EVER had a rocker failure or a lobe go flat. Most of the cars were autoxed, and all of them were either L series or 22RE's or 20R's. My feeling is that most of the warnings you hear related to the rockers have to do with Schneider cams. If you look up "cam lobe failure" here or at Hybrid Z I think you'll be hard pressed to find one that isn't a Schneider. To me this is reminiscent of the Fel-Pro gasket deal, where Fel-Pro proponents generally seem to think that Fel-Pro gaskets are the best, and also that L6 engines are prone to head gasket issues. That's my take on it anyway...

Diseazd, for a guy who (apparently) doesn't do his own work you sure make a lot of absolute statements. In my experience with probably 10+ reground camshafts between myself and my friends with Zs and 510s, it is NOT necessary to change the rockers. Installation is really not that hard either. Just requires that you keep checking until you get it right. Lash pads can be dealt with in a couple ways. 1. Follow the link that I posted and it shows you how to cut up a feeler gauge to test different lash pad thicknesses. Then buy the right pads the first time. 2. Buy one of a bunch of different thickness pads, then use them to test and buy 5 more of the right ones for the intake and 5 more for the exhaust. That said I would say that the hp numbers quoted are pretty close to correct, as judged with the butt dyno.

Changing the cam does make a difference if you get the right cam. My car with the wimpy cam would get to the 6800 rpm redline, but barely and there wasn't much point. When I went to the bigger cam it would smack the redline. With Mikunis it would slam against it. The SU's and the big cam were the best perfoming combo I had. I could have done better with the Mikunis but really had diff gears that were too tall. The Mikunis wanted 4.11s or 4.44s for autoxing, not 3.70s. Getting the valvetrain geometry right is not hard but takes time. Timing the cam is more difficult, but still is mostly about taking the time to do it, not about learning new skills. I think there is info on both here: http://forums.hybridz.org/showthread.php?t=111523

Tongue in WHAT?!? I hope he went out with a smile on his face. Kinda sounds like it...

Yes..

It's tough to say how a cam will work. If it's the MSA Stage III I think its USUALLY too small and gives fairly crappy results. Then again, there's Jeff's car over at Hybrid Z: http://forums.hybridz.org/showthread.php?t=145256 How he's getting that result with that camshaft I'll never know. I do know several people who bought it and then took it off because it sucked. One thing that I can say is that a cam should be just one component in a larger system. I ran that .490/280 on my relatively stock L28 (8.5:1 compression) and it ran great. I wouldn't be afraid of more cam with a stock motor.

I've used my rockers on 3 cams, no problems. I'd go bigger than that cam you're looking at, but if you do you run into issues like valve spring coil bind and retainers hitting stem seals. These are not insurmountable obstacles, but it will take a little doing to get around them. I think its worth the effort. I started with a high lift low duration cam and then went bigger to a .490/280. The first cam made a little different noise at idle and gained me a couple mpg but was not at all what I was looking for. The second one rocked.

Same here. I was a Newcastle guy for a while, then Bass, kind of into the ambers, then I suddenly snapped into Miller Lite mode and have been there for a couple years now. I still enjoy the micros when I go out, but I keep it simple at home for the most part. Been digging the ciders too lately. A good dry apple or pear cider is a wonderful thing.

No. It's right there. You could copy and paste, or just write Jon if that's easier. You CAN adjust them, but you SHOULDN'T. The numbers are stamped on the pilots. Buy the How to Modify Your Nissan/Datsun OHC Engine by Honsowetz. It has a good although brief section on tuning Mikunis, has mathematical formulas to figure out where to start with jetting. You can also download the Mikuni tuning manual from Hybrid Z: http://forums.hybridz.org/showthread.php?t=122217 I would also suggest installing an O2 sensor and either a gauge or a voltmeter to read it. You can go crazy with a wideband if you want, I had pretty good luck with a $30 narrowband Bosch O2 and a $6 voltmeter. I've heard several people who bought the Autometer A/F mixture gauge say the sensor that comes with it is crap. The gauge works fine when you put a decent sensor in it though, apparently. With an O2 installed you're no longer guessing, trying to read plugs (which just about everybody does wrong, including me), or smelling the exhaust. You will KNOW what is happening with the O2. It's really worth the hassle to install one. My take on Mikuni tuning is that it is mostly about the pilot jet. If you have a stumble when you punch it, pilot jet (and venturis). If you're getting bad mileage, pilot jet, if you are running lean at cruise, pilot jet. For whatever reason it just doesn't seem to be that hard to get these things to run good at WOT. It's getting the right pilot for cruising around town and getting rid of the stumble going from cruise to WOT that seems to be the problem. You almost never want to mess with the pump nozzles, and main air and fuel are easy to dial in with the O2 sensor.

Are you answering the question from today or 2004?

Turn them all in until they hit the stops (gently, don't mash them into the stops). Then back them all out 1.5 turns. You're now adjusted. If it's too lean, get a bigger pilot jet. Too rich, get a smaller pilot jet. Some people go 1.25 turns with the above method. Either way, the idea is that the pilot has a function over a fairly large rpm range and cranking the screw open to change the performance at idle leaves you with a lean spot a bit higher up.

No, I never used the front camber bushings. I am talking about the rears. You take the large 24mm bolt, back it off maybe 8 turns or so, and that will give you room for a wrench or a pair of channel locks. It's been a while, but I think a wrench is a PITA because you have limited room to move in there.

I never owned the actual tool. I used to back off the big 24mm bolt in the end of the arm and grab the bushing with channel locks. Yes, they did end up digging in and messing up the corners of the bushing, but channel locks moved the bushings without too much trouble.

Loosen the clamps, rotate the bushings, tighten the clamps. If the car is on an alignment rack, the mechanic should be able to crawl under the car, loosen the clamps and adjust without too much trouble. When I was working as a mechanic I used to adjust my camber bushings before every autox, just trying out different toe settings, etc. DO NOT GREASE between the bushing and clamp. These things have a bit of a tendency to move on their own, so you don't want to facilitate that movement. Example: http://www.classiczcars.com/forums/showthread.php?t=34306 Some guys use set screws to hold the bushings so that they cannot turn, but that only works if you know where you want your alignment to be permanently. If you're playing around trying to find what you like best you don't want to install set screws. I've also seen it suggested that you put some emery cloth between the clamp and the bushing to provide more friction and make it harder for the bushing to rotate on its own. They used that emery cloth that has perforations in it and is more like a mesh than a sheet of sandpaper. Sorry, don't know the technical name for that stuff.

Right. There are pull masters too, but again, that's not the problem...

There is such a thing as a "pull cylinder" but I don't think you'd be likely to find one that bolts up right. That would be a pretty incredible piece of luck... http://www.wilwood.com/Products/006-MasterCylinders/011-SC/index.asp

The point of my post was not to insult your exhaust system, sorry if it read that way. That said, there are other options to the ones you've listed there. Tow the car someplace. Don't have AAA, a tow vehicle, or a trailer or dolly? Rent the truck and dolly. And I've never seen an exhaust shop that wouldn't allow you to drop the car off in the morning and pick it up in the evening or the next day. More options being better reminds me of Dennis Miller's old bit about the 1/2 off sale on short sleeve suits. "If they really want to screw you, they'll give you three of these things!" Give me less but better quality options vs a myriad of crap. YMMV.

What is the goal of the Datsun hobby? If the goal is to have a fun to drive car, there is no reason why V8's or SR20DET's or 1JZ's shouldn't be used. They certainly won't make these cars less fun to drive. I can't wait to get my all aluminum 5.3L V8 installed. Trying for a total weight of ~2250 lbs... Should haul arse! By the way, nice choice--I liked that GTO the first time I saw it and the later ones with the LS2 are even better. I wonder how hard it will be to find parts for it 10 years down the line though... are they directly compatible with the Holden stuff in AU?

Guessing here, but he's probably seen custom L28 pistons on L24 rods. You can put these in an L28 block with the L28 crank. The purpose is to get a better rod/stroke ratio, and I think it's a pretty common upgrade for racers. The custom pistons have the wrist pin higher in the piston to allow for the stroke difference at the crank so that the pistons don't come out of the bores (more than usual). Here is an example: http://www.arizonazcar.com/piston.html

I guess I just don't see the problem. I think the reduction in ill fitting aftermarket exhaust systems is not terribly problematic. My guess is that those that don't build their own exhaust are going to the local muffler shop and having it done there. It doesn't mean that there aren't any Z's left, it means that people who need exhaust systems aren't buying the crap that gets sold from catalogs. Having seen most of them, I'm thoroughly unwhelmed. DIY is still the best option on a cost/performance basis IMO. I bought a Super Turbo muffler from JC Whitney on sale for $25 along with some 180 degree mandrel bends then went down to the local muffler shop and got a couple sticks of 2.5" aluminized tubing and welded it all up in my driveway. It is the tightest exhaust I've seen, mandrel bent, doesn't rub, but sits about 1/4" off the diff in the rear. Actually, it did rub at first. I had to notch the early transmission crossmember to clear it. I paid less than $150 for the header back (probably 10 years ago now, probably could still build it again for under $200 I'm guessing).

Very nice. Congratulations!

So what did that set you back, and how do you like it so far?