BRAAP

Yeah whatever guys! I bought one of those rear tires for my Honda MB-5, (own two of them, consecutive serial numbers even, true story), just to see how accurate their scaling system really is. As a relatively novice sport bike rider I was able to wear away numbers 1-4 in the first week, 5 by the end of the 2nd week. Took me 2 more weeks of tight 2nd and 3rd gear back road corners around our place to get the Metzeler logo to start wearing. Problem now is my rear rim is showing sign so road rash near the bead!?! Anyone else have the same issue?

You should be able to leave it alone, no trimming so long as the ID of the liner is not blocked by the gasket as you described. Exhaust gasses are flowing out of the ID, not the OD. Hope that helps. Update us when you get it up and running again.

Yeup, and they are the Turbo pistons as well. Note the thinner top ring vs the thicker 2nd ring.

Remove the exhaust port liner?!?! Trust me when I say "leave the liner alone!" Not only are the liners VERY difficult to remove, but you will be taking a large step backward in performance if you do remove them! Search this forum for "removing exhaust liners". The liners are are excellent even for high performance applications, removing the liners is bad advice!

Yes! Square port header with round port head, round port liners line up perfectly with the square port header, done it many times, my personal Z 's and a few customer cars. At the time, I was using a Victor Reinz gasket that is no longer available. Key is to us the square port gasket. Hope that helps, Paul

Yeup, improved lap times after any change is indicative of a change in the right direction.

First off, I do want to thank you for your diligence in researching the answers to your questions and reporting back your findings. You are spot on with your findings, the vacuum reservoir and solenoids are for the factory A/C cars which have vacuum actuated diaphragms under the dash vs the non A/C cable actuated vent doors. You also found correctly the Z car EFI uses an AFM, (Air Flow Meter) not a MAF, (Mass Air Flow sensor), which are not interchangeable physically or descriptively. As for what the staff wants from the membership regarding thread titles, we don't want people guessing in their title nor vagueness, just some effort put forth on the posters part to be more descriptive in their thread title. The title bar allows approx 85 spaces to be used. With some imagination, color, shape, size of part, or some other description can be conjured in less than 85 spaces. This forum has been around since early 2000, as you can imagine the archives are broad and deep and the search engine has always been a resource we hope all members will find useful and use regularly. With such a vast archive we have found that a descriptive title helps filter the unwanted clutter when hundreds of posts pop up for a particular search. Not to put too fine a point on this, but regardless of whether anyone feels every title is searchable or not, we run a tight ship and descriptive thread titles is one the rules here. Brief description of this forum. This forum is dedicated to extreme performance Z cars, a forum for those guys/gals that have moved on beyond stock and simple basic mods and are delving into new uncharted territory where purism is not welcome. We have several rules that are not common on most forums and the staff here take those rules seriously. On this forum one can find Viper powered street Z cars to 200+ MPH Bonnevile Z cars. V-12 powered Ferrari replicas based on the Z platform to some incredible 7 and 8 second drag Z cars using the stock rear suspension and differential. Diesel powered Z cars to electric powered Z cars and the list goes on... that is what this forum is about. We want this to be a forum where hard core performance veterans and newbs gleaning from those veterans sharing their experiences are welcome in a family friendly atmosphere. We all have something we can learn from each other. Hope that helps shed some light on why we are, how we are. By the way, clean looking looking Z you have there.

Ahem....

Here wishing a Happy Birthday to grumpyvette.

VERY nice!

OMG! That is wicked quick!

Sorry, I do not have any more N/A pistons. Differences in the L-28 pistons... The dish; Turbo dish and N/A dish share the same volume and shape. Ring lands; All early pistons, use the same thickness of rings since the early L-series was produced, (2mm thick for the 1st and 2nd rings). Ring lands changed when the flat tops came into existence, (same time as the Turbo came to be). Flat top and Turbo pistons have a thinner top ring, (1.5mm). I am pretty sure that the Turbo pistons also have the ring pack set a little further down the piston to get the rings further away from the combustion heat, but not 100% sure if that is the case with the OE. That is common practice in the performance aftermarket for boosted applications. Hope that helps.

Maybe... I have some new in the box L28ET pistons, might have an old L28 piston or 6 laying about.... I'll go check.

Currently, I do not subscribe to the theory of fewer yet harder pulses being easier on the tire, as it is currently described/proposed. Logic says it should be harsher and more aggressive, not as easy to manage. I'm not saying what is being claimed by these bike magazines, etc are false, but I am a bit skeptical of how they are interpreting the results and what they are attributing those results of improvement to, i.e. smoother application of power, less tire wear etc. Momentum and stored energy from flywheel effect of a heavier crankshaft could be playing a major part in this as could other design changes that affect "how" the power is being produced and those affects could very well be responsible for the smoother power deliver, and somehow the magazine writers could be incorrectly linking those benefits to the revised firing pulses?!?! (HotRod magazines have misinterpreted and spread many a engine-building myth since those magazines became available, as such I am bit gun shy of such claims that don't seem add up 100%). Dual plane cranks by design have MORE mass in the counterweights vs a single plane design due to balancing requirements, i.e. have more polar moment vs a comparable stroke length single plane crank, like a heavier flywheel. Note the massive counterweight cheeks on that dual plane Yamaha crank. That extra flywheel affect alone would help reduce tire wear and ease of power application as it absorbs the firing pulse energy to release it smoother, much like a heavier flywheel does in our cars. The best analogy I can come up with is hitting a nail into a board. Not a very good analogy, its all I got off the top of my head. Liken the traction available from a tire on the road to that of the friction of the nail going into the wood. As the nail is driven deeper, it is "losing" its traction each time, like a tire looses its traction. Granted, this dual plane Yamaha crank is not firing 2 cylinders at the same time, they are still spread apart, just bunching the pairs closer toegether, bang-bang-pause-pause-bang-bang-pause-pause... so technically my analogy is not a direct carry over, but based on my interpretation of how and why the benefits are being proposed, this analogy mostly fits their description. Using a hammer hitting with the same velocity every strike, (same energy being input into the nail) hit it twice simulating two power pulses at a level that just breaks traction and the nail drives slightly deeper with each hit. Now with the nail at the same depth as before, hit it only once but with twice the forced simulating two power pulses delivered at the same time, it will drive the nail deeper than the two smaller blows did, i.e. traction loss was more severe. Again, this analogy is not exactly as the Yamaha dual plane crank delivers it power, but it does follow the "reasoning" as used in the claims being touted by many bike magazines currently. I do want to make it clear that I am not saying they are wrong and that I am right, but until I see more substantial logical supportive evidence showing how and why, I am skeptical of the claimed reasoning behind how those improvements are being had.

Ahhh, a Dual plane crank for a inline 4 cylinder, using the same pin config as the domestic, Japanese, German production V-8's. First and last crank throws are 180 degree out from each other, middle two are 180 degrees out from each other but 90 degrees out from the first and last, i.e. dual/cross plane design. Firing pulses are not evenly spaced, but none are shared at the same time. Firing pulses are spaced/sequenced just like either bank of a V-8 and the dual plane design rids the engine of the 2nd order harmonic inherent in a typical single plane crankshaft, which is why it is so common in V-8s, especially in larger displacements. Smoother running, less vibes. In my DIY crankshaft thread has quite a bit of discussion regarding the second order harmonic and the influences that exaggerate it, that are inherent with single plane crankshafts used in inline and V-8 applications vs dual plane, post #75 & #80 cover it pretty well.

Left= Dished Middle= US Flat-top Right= Euro Flat top, (slight raised circular dome on top).

Very nice, welcome to HybridZ. Good to see an LSx powered Z-32 on the forum. Looking forward to seeing a detailed write up with pics of the build, maybe in the "Members Projects/Z32" section? .. hint hint..

Oh, and keep it civil boys. Many ways to interpret the events taking place, and what dictates or determines what. Ultimately the engineers that design an engine determine the firing order and they have the crankshaft AND camshaft manufactured to give that firing order. Which came first, the crank or the cam? :lmao:

Exactly! These pistons arrive at TDC together in this order; 1-6 2-5 3-4 Note the stagger of the firing order... Exactly how the engineers intended it.

One could feasibly have a custom cam manufactured with a different firing order. It would have to be billet stock as most cam blanks are typically manufactured with the rough shaped lobes already set in sequence, then final ground to a specific lobe profile. With the given crank throw configuration of the L-6 crankshaft, you will be limited to the combination of different firing orders allowed. Because 2 pistons in the L-6 arrive at TDC at the same time, 1-6, 2-5, 3-4, and with 2 complete crankshaft revolutions per cycle, that allows each piston 2 different opportunities to fire. You could have cylinders #1 & #6 swapped with each other, and/or cylinders #2 & #5 swapped with each other, and/or cylinders #3 & #4. Only those swaps or a combination of those swaps would work with the L-6 crankshaft. Now as to why anyone would do that? There are NO benefits to altering the firing of the inline 6 cylinder. It is already optimum with the least compromises. For a V-8, that is a different story. Altering the firing order trades one benefit for another which again does not hold true for the inline 6 cylinder.

That is my interpretation as well.

:lmao:

Nope, it will be fine. Now just go do it already.