BRAAP

Continue on with your build. You won’t have any issues. The Flat Top L-28 pistons pop up out of thebore .020”-.025”, and with a stock Nissan or Felpro head gasket, the squish with a matching head is then PERFECT! Though you wouldn’t want it any closer than that. Your pistons will NOT contact the head or valves, (unless you don’t time the cam properly). Hope that helps, Paul

Ahh… The miniature engines.. So Ron, are we going to again this year? It's still in Portland right? Here are some more pics of those miniature engines… I have video in VHSc of the Rotary and Blown V-8 running… BTW, they use automotive heater cores for radiators...

In short, if your cooling system is up to par, then you could run the thermostat that your particular set up is “tuned” to and it should work under all conditions, i.e. no need to change it out other than for routine maintenance. FWIW, All my custom engines that leave our shop, (keep in mind that all these engines are built with performance in mind, not mileage and emissions), and as such, I prefer to run the 160 degree Thermostat, and whatever you do when buying a thermostat, don’t skimp on quality. Over the past few years, I have run into NUMEROUS medium quality thermostats that were bad, i.e. either were very inconsistent varying engine temps, stayed open, or didn’t want to open fully. It has been my experience playing with, and performance-tuning engines, with performance as the primary goal, that cold water and hot oil has allowed the engine to run stronger. Smokey Yunick also supports that theory for making power. Take that for its worth. Keep in mind, that if you do change the thermostat to a different heat range, especially if you go to a drastic change, you might want to retune your AFR’s and ignition timing to compensate for the different thermal environment within the combustion chambers. Your target AFR range shouldn't change, but if left untuned, the actual AFRs will be different, at least slightly. Hope that helps, Paul Ruschman

Maybe this will help fuel your desire of an RB powered Z car… Here is a ’77 280 with a Mopar 440 and manual shift bodied TF 727…. Sold it to a gentleman in Louisiana.

AWESOME drift angles… great video. COOL car, congrats on your purchase. I wanna ride! Power-on over steer RULES!!!! (wrong wheel drive pull toys, need not apply… )

Linky no worky...

AHHhh... Roger that. Very nice.. Thank you for sharing.

There is a carbureted Nitrous SBC Z-32 here and an MS EFI Twin turbo SBC Z-32 here as well. The Nitrous SBC Z-32 photo album http://album.hybridz.org/showgallery...0&ppuser=20240 The Nitrous Z-32 thread. http://forums.hybridz.org/showthread.php?t=118470 The Twine Turbo SBC… http://forums.hybridz.org/showthread.php?t=110873 We are also planning to V-8 a Z-32, possibly my ’93 N/A car. I just brought home a ’90 N/A shell this last Thursday for mocking up the mounts… The mock up shell.. The V-8 recipient...

VG30E boosted TT; Good torque, not known for high RPM breathing in N/A or boosted trim without going to some great extremes. SR20DE with a hair dryer; set up for similar power levels as the VG30ETT, the SR will be a little more peaky in how it delivers its power, but the SR will breathe that boost more efficiently. Also, the SR should be a tad lighter. Hmmm…. I think you better say what those other engines are…

Nope, these are N/A. 1 fast Z’s very impressive high 12 second street driven 280 Z and the build ups I quoted are all N/A! Not Turbo.

Matt, Well I’m sure that as soon as you noticed that I posted that you know which way I’m going to steer you. EDIS!!!!! Pinpoint timing at all RPM and MAP points, no dizzy cap and rotor, etc… Timing map…

Here ya go. 2 separate projects that both Ron Tyler and myself are involved in. (Me the engine builder/head work and modified OE intake. Ron, EMS and scratch built intake manifold) Both are custom N/A L-28s, stand alone EFI, 6 coil DIS ignition. One is N-42/N-42 getting mild cam and custom scratch built intake and is getting close to initial start up. The other is a F-54/P-79 combo that just left the shop running at about 95% of optimum tune, (just passed tail pipe smog this week), running a cosmetically enhanced OE N-42 intake stock cam and runs much harder now than it did when it came in with the OE EFI and dizzy ign. Custom N-42/N-42 project… http://forums.hybridz.org/showthread.php?t=117607 Custom F-54/P-79 project… http://forums.hybridz.org/showthread.php?t=119783

The drop in compression will have such a minimal impact on performance vs if it had the flat tops, you probably wouldn’t even be able to feel the difference set of the pants, from that little bit of compression ratio difference. Bolt on your carbs and exhaust, just run regular unleaded, set the ignition timing a little aggressive, say 40 degrees total mechanical advance, and this low compression 400CC larger engine will pull harder than the L-24 hands down. FWIW, the OE Turbo cams have a wider lobe separation than the N/A cams. If you also install a stock N/A cam, it will give you little more mid range punch that you will feel seat of the pants over the flatter power band that the turbo cam would deliver in your N/A Turbo long block application. Have fun…

Garrett, Uhh.. well…. This is bit of a gray area. I choose to error on the conservative side and blanket statement this by just saying no. In general, what you are saying is true. For a particular engine type and displacement, all else being equal, cam, displacement, etc, and IF the two engines had similar leakage rates with the piston throughout its travel in the cylinder, (not just from a leak down test which only measures leakage with piston at the top of the bore), then yes, a higher cranking compression would indicate a higher compression ratio engine. Also keep in mind, the faster you crank the engine, the cranking compression will most likely be higher as there is less time for “leakage” to occur during the cranking cycle. (the Nisan gear reduction starters spin the engine slower than the older heavy bulky starters, so just swapping starters will result in different cranking compression numbers)… i.e. If you slowly hand crank a tightly sealed engine over by hand, you may never build up even 75 PSI, but if you install a good fast starter on it, hold open the throttle valve open, and attach a fully charged strong battery, you could easily hit 180-200 PSI cranking compression. A big cam on a high compression engine should have comparable cranking compression to a small cammed low compression engine of the same displacement, (this is if the compression ratio matches the cam specs that is.) In short, there are too many variables that would take way more time to isolate, verify and account for within any particular cylinder of any particular engine than it would be just verify casting numbers, remove the head, verify bore, stroke, piston dish, and cylinder head volume and calculate it out exactly. The room for error has just been removed, so to speak, by calculating the volume, not allowing leakages to skew the math… . (if that made any sense?...)

To verify a stuck open valve, pull the valve cover, and rotate the engine through at least 2 complete crankshaft revolutions. While you are rotating the crank, visually verify that all the valves of the affected cylinders are indeed opening up with cam and then closing as well. You may notice just by looking at them, that one of the valves is will appear to be somewhat open when the cam lobe is not in contact with the valve, that will be dead giveaway. If it is indeed a stuck valve, it could be a bent valve due to contact with a piston due to a broken valve spring or some other reason. If that is the case, the head will have to come apart for repair. If it is just a sticky valve and not a bent valve, more than likely it is due to rust between the valve stem and valve guide. Being as I am a perfectionist and if there is ANY reason why any internal part of an engine isn’t functioning even remotely as it should, I always stress that the engine or at lest the offending component should come apart for thorough investigation as to WHY, then make sure measures are taken to prevent that WHY from happening again, and the engine or the offended component, properly machined/rebuilt before returning it to service. Personally, that is the only way I would personally handle this situation for any of my customers or my own personal projects. For those among you that are into the quick and dirty no initial cost fix, (consider this only temporary), if it is a stuck valve, you can remove the rocker and lash pad of the offending valve. Then be absolutely sure that the piston for that valve is at BDC. Now using a soft blunt drift, such as brass or aluminum, take a hammer and tap on the end of the valve stem, (be sure you are perfectly straight up and down to the valve stem so not to impose too much side loading on the valve stem and guide). The valve should bounce and hopefully come to the closed position. Then verify that it doesn’t stick open again during crank shaft rotation. If it continues to stick further and further open, then just remove the head and fix it properly, i.e. take it to a competent machinist, which generally isn’t the cheapest one in the phone book, unless it s friend pulling a favor for you. Good luck, Paul

Yes, it is possible to have 0 PSI cranking compression Lets say a piston rod broke so the piston doesn’t move up and down the cylinder, or a valve is stuck open so the cylinder isn’t sealed for the piston to build any pressure, etc. If you are referring to using cranking compression to calculate static compression ratio. That is virtually impossible! It is though an indicator of dynamic compression ratio, but in no way can it be used to figure out static compression ratio. Too many variables such as cylinder leakage via the valves and rings as the piston travels up the bore, and of course the real biggee is that the intake valve doesn’t fully close till the piston is some point up the compression stroke, (after BDC). Hope that helps,

Just as Grumpy says, don’t buy Chinese. When I started shopping for a lift, after a bit of research, I narrowed down my choices to Bend Pak and Mohawk. Bang for the buck with quality and reliability as major determining factors, Bend Pak and Mohawk were definitely at the top of the list. Bend Pak 4 post lifts; http://www.bendpak.com/default.isg?cPath=214 Bend Pak Parking lifts; http://www.bendpak.com/default.isg?cPath=358 Bend Pak 2 post; http://www.bendpak.com/default.isg?cPath=216 Mohawk 4 post; http://www.mohawklifts.com/consumer/4post.php Mohawk 2 post; http://www.mohawklifts.com/consumer/2post.php

Very cool. Keep us posted as you progress over the next month.. I take it your custom L-series will be Mega Squirt controlled? Take care, Paul

Dustin, I have an '85 N/A parts car. It is complete other than auto tranny.

Stevo, Yes, you are absolutely right. The P-79 intake port does have “slight” D shape where as the P-90 is pretty much non existent, but you can just barely see a small flat on the inboards port wall. The Maxima N-47 has a VERY Pronounced D intake port, WAY more than pronounced than any of the other late heads. As for the cast step in the exhaust port, I am not totally sure, and the only explanation I can offer is that it is there for valve guide support and to help carry heat away from the exhaust valve as it is closer to the valve head. Here are a couple pics of a P-90a head that we built for a hybrid member across the pond. To save you some searching, here are a few good L-series head threads… Lots of good “meat” to chew on in regards to L-heads… http://forums.hybridz.org/showthread.php?t=104420 More good meat to chew.. http://forums.hybridz.org/showthread.php?t=105653 L-head mods, DIY http://forums.hybridz.org/showthread.php?t=110269

Yes, the P-79 is very close to the P-90 in port design and EXACT in chamber design, with exhaust ports being the prominent difference between the two. In regards to the exhaust liners, you can spend the multitude of hours removing them, but if mega exhaust flow is your goal, you would be much better served just finding a P-90 head and porting the exhaust port by removing the step in the roof. Trust me on this. For mild to hot street applications, the round exhaust ports with the liners intact are more than adequate and offer great flow. Just blend that sharp edge from the back side of the valve seat to the liner using a die grinder or dremel tool. If you want to really make it worth your while, you need to unshroud the valves as well. I wont go into details in this post, but if you perform a search, the details and pics are here on this forum… hint (BRAAP has posted pics with the how and where to remove material… )

EXACTLY!!! Thank you Tony D. for your eloquent description of BOOST! PERFECT! I was just talking to Garret Maddox today on the phone, and in our discussion, this topic came up, but we only brushed on it lightly. Garrett is definitely on track with boost vs. power being produced. So many people view boost pressure on the same plane as power produced. That is a very incorrect view of boost. Boost pressure when viewed as an indicator of power, should only be viewed as a very general indication of power produced in a particular model of power plant, nothing more. In reality, boost pressure really only indicates the intake air flow restriction as Tony D. described above. For example, you can have two L-28 engines, both producing 20 PSI of boost Turbo charged, but both engines producing totally different HP numbers. Lets say one is producing 400 HP, the other is producing 500 HP. This is NOT an unrealistic scenario. The one producing 500 HP on only 20 psi is obviously making better use of the 20 PSI as it is breathing more CFM than the 400 HP version. In short, what Tony is saying, (if I'm not stating exactly what you said Tony, don't hesitate to correct my interpretation), is that you can have all the boost pressure in the world, as interpreted on your boost gauge connected to your intake manifold plenum. But if that boost pressure isn’t getting into the cylinders, you are just building pressure in your manifold, not power at the crank. If that is still unclear, then think of it this way. If you welded your intake valves shut, a turbo could produce ungodly BOOST pressure, but being as NONE of that air is getting in the cylinders, NO power is being produced, i.e. 50 lbs of boost, and ZERO horse power! SAVVY?

The “Smart car” turbo just might be THE ticket for your application. This little turbo is factory installed on a 700 CC three cylinder producing 61 HP. This would be an AWESOME Turbo for a small displacement single cylinder engine and these turbos are readily available. Here is one of those turbos for sale... http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=170094280448 I have personally purchased a HUGE by LARGE Turbo from this eBayer, he is straight up and honest. Here is the spec page on the car and engine this tiny turbo comes from.. http://www.smartcar101.com/specs.htm

LMAO… Umm.. Well based on that not so vague description of what is happening, I can personally list at least 100+ reasons of what could be causing your problem, but I’m sure that huge long list of “what ifs” will do you about as much good as your detailed description does for us in our wanting to help you… You NEED to give us a LOT more information than just, “the engine cuts off”, whatever the term “cuts off” means as it can be interpreted in several different ways…

Just curious as why so much interest in this car? If it is a true black pearl car, then what?