BRAAP

Sorry to for being slightly off topic here, but do any of those L-series engine calculators take into account that the OE Flat tops pop up out of the cylinder bore .020”-.025”? I always just use my own spread sheet for compression ratio calculations, I have never used those L-series calculators, but have heard them mentioned quite a bit. I was just curious. Paul

First off welcome to HybridZ. So you don’t want an L-28, but what you proposed is essentially building one, well close any how. If you are planning to use the L-26/L-28 crank, over bore the L-24 block 1.5mm, why not just bore it another 1.5mm? Then it would exactly be an L-28. So why bother paying the money for new oversize pistons, machine work to over bore, when you can find a suitable L-28 engine, if it is in good condition, just kiss hone the cylinders, re ring, new bearings etc, and it will be FAR less expensive than this L-27. If money is an issue, don’t spend money on things you may not need. The machinist is going t to charge you to over bore the engine. Those pistons for the over bore cost money. If you want an L-24, leave it an L-24. The ONLY reason I would even consider your proposal is if you wanted to keep a numbers matching block in your car and you wanted more displacement, and you don’t mind throwing money at something that wont get any closer to your goal than what already exists for far less. If are dead set on staying L-24, then leave it an L-24, don’t build an L-27 or L-28 unless you are attached to that particular L-24 block for whatever reason. Mileage and A/C are your requirements. My suggestion is to go find yourself a running L-28 with the EFI and electronic ignition. Bolt that in your car. Install quality ignition components and fine tune the ignition advance. Then fine tune the EFI and 25-30 MPG and 170-190 crank HP is totally realistic. Even the L-24 with the SU carbs is capable of 28+ MPG if you keep your foot out it. L-28 testimony... My personal 280-Z, with a BONE stock L-28 short block, barely over 8;1 compression, (low octane friendly), was getting an honest mile post to mile post 28-30 MPG, (installed dual 2” exhaust vs the previous dual 1 ¾” and mileage dropped from a solid 30 to 28 on the freeway), a little head work, Cyclone header and dual exhaust, finely tuned stock EFI with the stock cam, lightened flywheel, recurved ignition advance, quality plug wires, plugs and coil, cap and rotor. That 2900 lb 280 (2900 lbs with half tank of gas and driver), ran 0-60 MPH in 5.7 seconds, and the 1/4 mile in 14.4 seconds @ 97 MPH.

Ah, air cooled bike engines.. you mean like this 48 cylinder bike?… I think I got these pics from Ron. If he sees them maybe he’ll chime in the details and specifics on this monster..

Team Nissan.. How did you know that I couldn’t resist this thread? I’m no expert, especially in this sort of a project. Entertaining for sure. Immediately, the Hartley came to mind… OOohhhh. I wonder if they could produce a crankcase as one V-16 instead of two separate engines? It would fit nicely under the hood of a Z . Now that twin engine car that Mardukes father drives is WAY FRIGGIN COOL! Maybe he’ll dig up some pics and share more with us? (hint hint..) Back in the ‘90’s there was a gentleman who was a very gifted welder and welded 2 SBC, blocks, cranks, heads etc together, but he took the time to do it in such a way that the block and heads looked as if they were cast as a V-16 SBC. I think HOTROD magazine did a write up on it at one time. Any how, here is that engine today. I guess he built two of them.. http://www.museumofamericanspeed.com/Collections/Engines/AllAlphaE002.shtml Here is a tractor puller with a pair of rotaries linked together. I can’t seem to find the picture of the coupling itself, (buried somewhere on my hard drive), but it essentially is a pair motorcycle sprockets, one on the back of one engine and the other sprocket on the front of the other engine, and a double row chain around them as the coupling. Looks simple and functional. Here is a video of two SBC’s in a Street Rod running..

Just a heads up, The info you gave in regards the Borg Warner T-5 trans is inaccurate. The World Class version of the Borg Warner T-5 was never offered in the 280-ZX and Nissan never received the World Class T-5 in any of its other vehicles. This page explains quickly, how to positively identify a T-5 as World Class or Non World Class. They left out another important difference in the alloy of the gears sets were much improved for the World Class T-5.. http://www.5speeds.com/t5/ As 350datsun eluded to and the route he is going himself, if 5 speed is a necessity, it is far easier to just use the W/C T-5 that came behind a SBC in the first place It would simply bolt up, no special clutch, trans mount is SIMPLE if your read the JTR V-8Z conversion manual, driveshaft with Chev U-joints front AND rear, you’re done. Far less compromise, easier and less expensive and stronger. My W/C T-5 I ran behind my first SBC powered Z came from a ’91 Firebird, shifter came out the stock shifter location, car was plenty fast, tranny never gave me a lick of trouble, car was daily driven, and ran 12.3 @ 113 MPH on cheesy 195 60HR 14” all season tires. If you haven’t already, order the JTR conversion manual. The book is invaluable, to ANYONE doing a V-8 conversion whether it is the JTR set back style, Scarab or their own scratch built concoction. Some items covered worthy of note is calibrating the OE tach for use with the GM V-8 HEI, retaining all the OE gauges, wiring and GM one wire alternator, exhaust, transmission, both automatic and manual trannies, speedo gear chart for calibrating your speedo, driveline info, starter tech, cooling, etc etc etc. http://www.jagsthatrun.com/Pages/Datsun_Z_V-8.html

OOPS! I owe mike88SS a public apology for closing his post without first verifying his original intent. Sorry about that mike88ss. Your thread has been reopened. As for the injector spray pattern in regards to the L-series, (sorry, never really played with the VG engine much), the injector is so close to the port itself and aimed directly at the back side of the valve, the injector notch machined in the head will not be in the way of the spray pattern. In a quick search for Supra 440 injectors, it appears that many other guys ARE using those injectors with no issues. Here is a picture of an L-series cylinder head with an OE intake attached, looking straight down the injector boss port and the back side of the intake valve can be seen. This pictures sort of shows the machined injector notch, untouched port on the left. In this picture you can see the orientation of the injectors. The manifold on the right are the OE injectors, to the left are Ford 4.6 modular O-ring style injectors, (the injectors themselves are just barely protruding out of the manifold, hard to see), with a much wider spray pattern than stock. That intake is up and running with a Wolf EMS, and 6 GM LS-x coils on an L-28 currently.

Way cool. Keep us posted on progress..

Ah yes, Multi valve heads as produced by the OE, with the cams "in the head" are conducive to MORE RPM due to the main fact that the cam shaft is overhead, i.e. less over all valve train mass. (Honda, Toyota, Mazda, Nissan etc are excellent examples of that technology). Now you offered those really cool high flowing heads as a solution to our problem, but at this point, without further information to back up any claims of mega RPM, I’m seeing those heads as a step backwards regarding the valve train issue. On their site in the SBC section, they are claiming 9000+ PRM with their “unique valve gear arrangement”. What is that “unique valve gear arrangement”? Those heads still utilize the “in block camshaft, lifters, and push rods”. Now those same cams and lifters are opening 32 valves instead of 16. Granted, those 32 valves are smaller, but the overall valve train mass would now be greater, which will only exaggerate our “valve train stability/cam flex issue”, right? Maybe they have special unobtanium valve train material that is mega light weight, but I doubt it. Based on your camshaft flex theory, the only real improvement I see that those really cool heads have to offer for this theoretical high RPM V-8 is air flow. At this point, I’m not seeing the mechanical issues such as the valve train stability at such RPM being solved with those heads, unless their “unique valve train gear” uses some different timing gears etc, which we should be able to use with the standard SBC heads and valve train as well, (they claim their heads still utilize the standard cam and lifters). As for the cam flex info, good info, and it all makes sense. I’ve read a bit of Vizards writings, Harvey crane, and few other sources, and cam flex was talked about, but only in regards to how we use the SBC traditionally, not to the that wild dream of mine of 10,000+ RPM . Being as you seem to be well versed in SBC camshaft design/technology/etc, is cam flex totally dependent on RPM only, or is it also influenced by the cam lobes as well, i.e. intensity, amount of lift, also possibly spring pressures, overall valve train mass, etc? Also, If you don’t mind divulging your sources, where are you getting your information? Your answers to my questions leave so many more questions that as a professional performance engine builder myself, it would just be easier for me to read them first hand so I don’t have keep asking you to fill in those holes. TIA, Paul

Well, it shouldn’t sound any different than any other SBC or even BBC. No magical exhaust note differences with a destroked 400. I’ve heard 283’s that sounded JUST like a 454 and vice versa. The exhaust system will a have a lot of influence over how much different it sounds than any other SBC. As for how high it will rev? Depends on how stout you build the bottom and the combination of parts that compliment the RPM the bottom end is capable of revving to. There are 383 strokers turning 7500 RPM, which would sound very much like any other 7500 RPM small block using that same exhaust system and mufflers. Equivalent quality parts for the 377 combo might allow 8000-8250 RPM, but the rest of the parts such a heads, cam etc must compliment that. Being as it is a 3 ¼” stroke, it can safely rev a little further than the 3.48” stroke of the 350 with equivalent pistons and rods. For the ability to rev even higher, use the 3” stroke from the ’68-’69 Chev 302, or maybe the 3.1” stroke of the ’75 Chev 262. In short, what you are really after, is a sound bite of pretty much any SBC with a similar exhaust system and mufflers that you plan to use, revving to the RPM that you plan to build your engine to.

That Turbo, (looks like from a P-38 possibly), is designed like a standard Turbo, asymmetrical, of course much larger. Note that the snail scroll is much wider on one side, OTMs find is symmetrical, at least on the exterior it is symmetrical.

Jessz, Just a heads up. Did you realize that you posted this same exact question twice within minutes of each other? Oh, and you'll find on http://www.Zcar.com and http://www.classiczcars.com all the details about 4 speed to 5 speed swaps. Don't forget to use the search button over there, I have heard those other two forums are real sticklers for not using the SEARCH button. Hope that helps, Paul

Not to mention, where you parked the car, and used the fuse box last. That will help us in our search for your fuse box. JK, If no one else posts those pics, I’ll go out and take some for you.

Same here. JB weld works spectacular in that application. All of the N-42 intakes I have built that were getting painted, I tapped all the big holes for pipe plugs, used brass pipe plugs from Home Desperate, then filled all the little holes and divots in with JB weld. Used it like body filler. On mine, I’ve used AeroVoe Cast iron Gray paint as in the pictures, and also Hammerite Gray. I then drilled and tapped all my vacuum ports in the bottom of the plenum near the rear. My first N-42 intake built with that process still looked like new some 7 years later. The few that we have done to be ceramic coated, all holes were plugged with aluminum bits and welded and all divots were welded. Then lots of time smoothing the manifold much smoother than in these pics as the CermaKrome will show EVERY imperfection. Do NOT use JB weld o rany other non metal filler if you plan to ceramic coat. Here are pics of one of the last N-42 to leave our shop. HybridZ member GearHeadstik is currently running it now.

Heck YES!!!!! Love the foggy… I think we even started a Foggy Burnout thread at one time, that would be a good place to post that video as well. Great foggie, thanks for sharing..

Kevin, Your choice of colors, I’m beginning to like you more and more.. BillZ260, Whenever there is a choice between Red or Blue in regards to car parts, remember "Red" is always faster than "Blue", just ask Ron Tyler…

If it were possible to build such a creature, it would displace 3.34 liters, so torque output would be comparable to other OE performance 2 valve 3.3-3.4L engines, 220-230 ft lbs at the crank, but this fantasy SBC would be revving to 10,000 RPM, so HP would be much better. Lets say peak torque is 230 ft lbs, but at a HP peak of say 9500 RPM, it is producing 200 ft lbs, that is 360 HP even with only 8:1. If we can get the engine to produce that same 200 ft lbs at 10,500 RPM, now it is producing exactly 400 HP N/A! Now with only 8:1, you could easily add say 7-8 lbs of boost from a pair of hair dryers and 450-650 HP would be totally realistic depending on how much RPM the engine will allow. FWIW, the L-28 is only 8.3:1 compression N/A. My first personal ’75 280-weighed in at 2900 lbs, was running only 8.1:1 compression after I finished the chamber work, engine was N/A and ran really strong for what it was. Stock Datsun EFI and stock cam and still had had incredible throttle response, (ran 14.4 @ 97 MPH). Of course there is LOTS of room left if the compression ratio can be bumped up a couple points, but you get the idea. 8:1 will run fine N/A, your just giving up couple percent in HP. As Mark mentioned above, the pushrods and the rest of the valve train of the SBC is not conducive to such RPM’s. Being as the short block is a no-brainer, other than the crank would require some time and eat up a few cutters, I would like to hold onto the possibility of finding away around the valve train issues.

Don’t tell us you lost your fuse box again?!?!?!

Mark, I understand the point you are trying to convey, it is valid and has a little bit of merit, sort of. Thank you for the Push rod info. The valve train is the trick for sure. Though I think the short block can be done for fairly inexpensively, aside from the crank itself. Based on your short block parts summation, I get the impression you didn’t read all the posts pertaining to the theoretical HIGH RPM Small Block Chevy? I honestly feel that there is no doubt in anyone’s mind that to replicate the exhaust note of the Ferrari V-8, (that was purpose of the that theoretically SBC), it wont come cheaply. If it did, more people would have them. Your claim of having to have an exotic parts list just for the SHORT BLOCK, (not talking about heads or valve train), as an engine builder/machinist, I am in strong disagreement with. The intent was to replicate that Ferrari exhaust note as inexpensively as possible, without actually purchasing a Ferrari V-8. Building a DIY single plane crank for the small Block Chevy at a mere 1.75"-2” stroke, (can be done on a lathe which we have, and then final grind the journals as with any other crankshaft and dynamic balance), in theory any how, even with OE cast pistons, and OE rods from other manufactures that already have the desired rod length which again, was all covered in the previous posts regarding that theoretical V-8, would survive as piston velocities are still pretty tame even at 9000 RPM with only 1.75”-2” stroke. As for the ECU thing, if ANYONE is building ANY sort of custom engine for use with EFI, same holds true whether it is the this theoretical high RPM SBC or a mega torque 383, I’m not seeing your point with that one. In regards to the cost of this project, and I quote;

PC Load Letter. This is the wrong thread for a question like that, and that is the wrong question to ask on this forum? Please read the entire page linked below. Items #2, AND #3, AND #4, AND #9. in particular The answer to your question is custom cylinder head work is NOT where you start to in an effort to make power to out run your girlfriends Honda. http://forums.hybridz.org/announcement.php?f=65&a=2

Couldn’t find any section titled "Something to know" The only thing close was section called “In The Know” and in there, no mention of anything valve train related, of course I could’ve just missed it completely.. .

By weaker synchros, are you referring to actually busting them, or they just wear and the shifts become crunchy? Thanks again for input, Paul

Hmm.. NASCAR take out parts.. Nascar typically spins their engines to 8500, for en extended period. We are shooting for 10,500-11,000 max, between 3k-8k jaunting around town, though we’ll be using much less lift, duration, a less aggressive lobe profile vs Nascar, so that just might work. So long as those RPM’s don’t set up some harmonic we are not aware of?…

I have no idea. Maybe something to do with an Indy designation? In several articles it is referred to as the “Indy 35A”.. The "R" designator is another one that seems to have no reference, at least I wasn't able to find anyhow. I'm sure there has to be an Indy racing fan on this fourm that would know?... I did some googling and found that the engine weighs in a feather light 325 lbs and only cost the Indy teams $90,000! I'm sure they are pretty coveted sot he chances of them trickling out the general public will be few and far between. IF they do poop up, the price will most likely be steep.. All were really need is the crank. Rods are within reason budget wise to have built as are pistons. Then just stuff it in a VH block.. http://www.popularmechanics.com/automotive/motorsports/1269261.html?page=2 Here is everything else that I found..

Careless, You to can duplicate this motor easy. eBay baby... Seriously, that is how I built that one. I just bought a bunch of Lego engine parts over a couple months time on eBay.. (Pathetic huh?) You can build it with a dual plane or single plane crank, or switch back and forth.. Bschiltz, Good question. I’m pretty sure you wouldn’t need any sort of surface treatment . Cast chevy cranks are reground all the time without any heat treat applied to the journals. The other issue I haven’t been able to find any info on is a 10,000 RPM valve train for the SBC! (I’ve only causally been searching, no hard core digging YET!) Even with extremely sedate lift values, the lifter, pushrods, rockers are all pretty heavy and going to require a bit of engineering to keep the push rod style valve train “stable” at such RPMs.

Good point Jon. If the manifold gasket surface on the head was prepped using one of those spinning scotch brite pads on and angle die grinder, (metal remover extraordinaire), the surface will have waves big enough to surf and subsequent gasket failure is imminent. If that be the case, the head should be removed and properly surfaced at a machine shop.