Kennymonster

^lol, odd thread indeed. Just reporting back for purpose of search results in the future: I got it to run well using the proper marks. I did take some measures though to ensure an accurate reading, even with a barebone timing light I think the multiple sparks from the MSD have a way of fudging the reading. - Swapped in a separate wire (of different brand just to rule out the existing wires as issue), routed it away from all the others to prevent any interference - Bolted on the L28 tab with multiple scale marks to double confirm the TDC mark, offset mark, and total advance mark - Set the total advance to ~35, it was a bit more touchy to adjust with the precautions taken above, I can only guess the previously seen '35' was off by few degrees Still getting some exhaust popping but that might just be pilot jet settings, definitely less than before however. The reading I checked before the adjustment showed 2.5 degrees at idle (which would mean only ~20 degrees full advance), to my surprise ran reasonably well but it did struggle at the top end occasionally. Now with the newly set timing, it's pulling strong past 6k in fourth, and I'm a happy man.

Yes it has a single pointer tab (stock l24 style) on the block, and I did verify the (black 0) mark on the pulley as lining up at TDC. Couple of other variables I didn't mention, I'm using an MSD 6al2 for ignition, and taylor wires, I guess that could also do weird things to getting an accurate reading, especially using a dial back light. I'm planning on swapping in a different spark wire for cyl #1 away from all the others, to rule out an interference reading maybe... another possibility I read was that if using the msd with zx dizzy, and I have the green/purple polarity reversed, it could do funky things there as well - though I've had it reversed way back once before and it just made a 50 cal noise when trying to start. The car runs pretty good right now so I'm not convinced if it's just reading incorrectly due to the reasons above, or if it's truly off that much.

I've had no problem in the past setting the ignition timing on few different L6 motors, various 240z/280z style timing marks, etc. so I'm kind of stumped on what's happening. Quick overview: this motor was actually built by another owner, I bought it and had it crated over, dropped it in to replace my dead blow through set up. I was told the specs for it, complete bottom rebuild/head/cam setup to my liking. Crank pulley that came with the motor is a single groove, I can't tell if it's the euro version (the ring portion looks different), and doesn't seem to match any aftermarket pulleys either, so confused here as well. There are multiple grooves / timing marks on the pulley, which look like this: - Big gaps are increments of 10 degrees (verified with 280z timing scale tab), smaller gaps are increments of 5 degrees - I checked for TDC via spark plug on #1 on compression stroke, it was the highest at the black "0" mark on the pulley, farthest to the left if looking from the front - When I go to set the total advance timing at 3k+ rpm, it looks like the above pic.... which shows the supposed 35 degree offset mark based on the established TDC, way off from the timing marker/pointer, it's reading almost 10 degrees full advance which is not correct. Note at this setting, the motor runs very healthy. - I've tried adjusting to the referenced black 35 mark to coincide with the black 0 TDC mark at full advance: loss of power and heard detonation. - The red numbers are what makes more sense to me, as I think the total advance is already correct, but that doesn't jive with what I saw to be TDC (the #1 piston was higher on the stroke on the black 0, vs red 0 mark) I'm just running it as is right now, but would like to find out once and for all what's really going on here.. any feedback is appreciated. Power level is great, also getting a lot of exhaust popping when I let off (though the afr is fine) which I'm not sure is related to the ignition timing or not. Pic of the crank pulley:

What viscosity of oil are you running? If you're running straight 50 weight, going to i.e. 20w50 would probably be a good substitute to having to heat/loosen the oil... but you might already be running something close to that so I digress. As you've said, even though I haven't read too much about the dual cam oiling being an issue, it could very well be amplified with the aggressive setup. I guess no concrete way to figure that out short of swapping in a non drilled cam to see what it does.

Sorry if I missed any details, but at this point did you for sure rule out the cam blanks/materials as the culprit? The measures you're having to take (especially heating up the oil), in my opinion is nearing useless in terms of having a fun car, whether track dedicated or not.

Took about 6 months for my unsupported urethane piece to sag towards the middle, even after bracing, I was always OCD about how much flex it would have under speed. Went the fiberglass route and reinforced it with a steel bar behind it. Unless you run over something head on, I think this actually might be the more durable route, no flex which stretches/damages the paint either.

Nice work! So you ended up keeping the stock lens over it? Hard to tell from the pic. I tried to make it work with the plastic lens.. but it was 1 am in the morning before a race day, with my dash all torn apart. Mine ended up flying across the garage somewhere, been running it without any lens or glass over it for a while now. Works great as long as I don't reach in and touch the needle

MSD is actually great with PDF wiring diagrams and active tech support, if you can't find the wiring on their site, try their forum for a quick response. Their reps are constantly on there answering tech questions.

Wow what an ordeal, sorry to hear your frustrations especially with a rebuilt set up. I was also going to point out the same thing, that the cam core might be the constant here for your issues. Could just be a bad one out of the batch, and not necessarily their entire cam core line up to be blamed. Like you said, if that's the case, tough luck there. I've had 2 different cams successfully swapped on my n42/n47 set up using the same rocker arms, both cams from OEM regrinds, and this was my experience with both. FYI for you to reference and others. Cam #1, OEM cam that came in the motor, regrind with Schneider ($120 for regrind, I think another $200 or so for all hardware) - .460 270/280, used their springs, hats, lash pads - Confirmed with Kevin @ Schneider, that the new rocker arm purchases are in fact redundant, and he was weary of off the shelf arms not knowing their source, and attribute to being inferior metal - Was told to visually inspect and rub fingers over it for smoothness, reuse if checks out - Cold valve adjustment - Used their vaseline type break in compound, rubbed it liberally over the cam lobes, used their break in zinc formula and Vr1 oil - Started it up, revved to 2k, and pulled out of the drive way and went for a cruise at 3k or so for 30 minutes - Used it for over a year without any issues, lobes were shiny when pulled Cam #2, OEM cam regrind (bought a different OEM/stock cam core and sent it in), this time to Isky ($135 for regrind, paid another $130 for correct lash pads) - .490/.480 276/268, kept the schneider springs and hardware - Confirmed with Ron Iskendarian himself on the phone, same advice over the rocker arms, recommended visual/feel inspection and reuse, dismissed 'myths' (his words) about new arms and warned against surfacing services taking too much off the pads - He recommended setting timing/idle so it'll crank up to 2 to 3k upon start, and run it about 20 to 30 min - Cold valve adjustment - Used their vaseline/jelly type break in compound, poured oil over it, cranked it (didn't listen to his idle spec advice, actually bunch of times because the motor had low compression) - Went for a 20 /30 min drive - *The lobes, that were mostly black and bare, were already polished and evenly worn even after this short period. - **Was running Turbo oil pump for higher pressure / blow through turbo set up. Maybe something to look into? It sounds like you were wayyy more meticulous than I, so hopefully you'll get to the bottom of this.

Everyone has to start somewhere, I would do a lot of reading on rising fuel pressure regulator + ignition timing map for L28 turbo set ups. It's always good to have some knowledge on at least the basics, even if you don't do the tuning yourself.

^Basically this. The point is ignition timing is absolutely crucial and can mean the difference between a well running motor, or pre detonating to death in just seconds. All in a matter of few degrees. The boost timing unit was purchased 260 new and MSD 6A was 199 new, however I'd let both go (you need both to work), for 190 + ship. I'd advise seeking fellow z tuners in the area for assistance though, as hands on advice might make more sense than online information for your set up.

When the motor was at its peak, at 19 - 20 degrees under full load @ 10 psi, it seemed to run strong without detonating. I have a higher comp motor but also had a mild cam as well. It was very sensitive to anything more though, ~22 - 25 would ping right away with the full boost / under load. Keep in mind that I had a higher comp NA motor compared to your set up however. Depending on the lb's of boost you're running, you should be able to dial it in something close to 20 base, 37 off boost, and 22 or so @ 10 psi, or slightly more if you're boosting less than 10 psi.

I'm not too familiar with stock EFI system's limitations and what you can add on, but I was using MSD 6A with a boost referenced retard module on my NA turbo set up (it was a carb'd blow through). http://www.summitracing.com/parts/msd-8762 Locking the timing at a fixed amount is probably not the greatest route, might be ok on idle / WOT, but I can't imagine how sluggish 7:8:1 motor would run at partial load / cruise with 20 degrees timing. The retarded timing would increase exhaust temps as well I think. With the MSD boost retard unit, using a zx distributor with 17 degrees centrifugal advance; - I had my idle set at 17 btc - At 3000 rpm (off boost) 34 degrees all in (didn't use vac advance but probably could) - Starting at 2 psi (can set 1 to 5 psi when the timing retard kicks in), I had my MSD dial retard 1.5 degrees per psi (maximum of 15) - So running 10 psi with a FMIC on my 8:7:1 motor, (10 psi x 1.5 = 15 degrees retard from 34), it was at ~19 degrees on WOT @ 10 psi On your motor you could probably afford to do low mid 20's and still be ok, and have around 20 degree BTC which will help start up and off boost response. I'm probably going to sell the MSD unit since I'm reverting back to NA, let me know if you're interested or need more info on the set up and I'd be happy to oblige.

lol you've got to be kidding.. are you really asking for someone to predict the tire trends and supply met a decade from now? It doesn't matter if the newer vehicles are equipped with progressively bigger wheels, even if the mainstream becomes 20" wheels as factory option, it's not like that's going to fit on the s30's. Do you realize how many vehicles on the road now days are running on 17"/18" wheels, especially coming from the z32 scene, no one is worried about diminishing tires sizes (z32's came with 16"s and are 25 yrs old now, most run on 17"/18") If you're on stock body without flares, and are running 7 to 8" width but move up the diameter to 17" / 18", all you're going to find are harsher / stiffer ride by having to compensate with smaller sidewall to keep the overall circumference in check. There's lot more to it then just diameter size, you haven't given information on rest of the wheel specs, or what can fit on your set up. Also I wouldn't get caught up on 'ultra high performance summer' term and label, 300 treadwear on those dunlops are anything but high performance even for street. Since you only shop every 5 years for tires, you're better off dealing with this at that time based on what's out there, than trying to gamble on the impossible.

Again, more hypotheticals vs. real world applications. Even with rotational mass, for most people here the weight of the wheel between an 8" to 9" is not going to perform worse to a point where you're noticing a difference. On my current set of BFG Rivals, and I would bet any microscopic/measurable loss in bead seating is offset by the stiffer sidewall, compared to non performance tires. Also 225/50/15 only typically comes in either 300+ tw (passable for street/cruise conditions at most), or R compound/ slicks. My point is following the text book guide on tires size/wheel width isn't always the best or suitable option. Going back to the OP's concern, I think worrying about tire sizes phasing out in 17's is silly. There are lot of combinations for 15/16's that you can make work, we're not the only ones running these diameters. With Miatas, BMW e30's, and the growing vintage scene, I just don't see this as a problem.