BRAAP

Here's mine, quoted from this thread; http://forums.hybridz.org/showthread.php?t=154591 Here's another thread, same topic; http://forums.hybridz.org/showthread.php?t=137027 Hope that helps, Paul

Hmm... We are looking into it.

Brand new ARP head stud kits, L24, L26, L28/ET $250 shipped, $241.97 local pickup. Have a barely used 225mm clutch here; http://forums.hybridz.org/showthread.php?t=156347

Revised… Regarding balancing a single plane V-8 crankshaft, it depends on which style of single plane we are using, (both styles mentioned on page 5, post #83 of this thread). I’ll cover the L-R-R-L first, (I call this style mirror image as the crank pins are a mirror image of each other when viewed in profile). With the mirror image style crank pin layout as used by Ferrari and the crank I just acquired, these are a neutrally balanced crank. Bob weights used on these cranks during balancing will have no affect on this style of 180 degree crankshaft. The same amount of material needed to be removed or added to the crank to bring into balance statically and dynamically will still come out exactly the same whether no bob weights, or any amount of bob weight is used, i.e. neutral balanced. Another way to look at this. When using bob weights on a 180 degree mirror image style crankshaft, you will have 4 bob weights, one on each crank pin. One at each end that cancel out the two in between. The bob weights could be a couple grams, calculated as you would a 90 degree V-8, or a totally arbitrary bob weight, the balance of the crankshaft will not change. The L-R-L-R style is different in that by design has a rocking couple vibration covered on page 1, post #11 of this thread, ("another" 2nd order vibration in addition to the original 2nd order harmonic inherent in 180 degree crankshafts). This amount of this other 2nd order vibration is based on the distance between the 2 adjacent crank pins “and” the amount of mass on those pins. As such, I could see using bob weights on only the front and rear crank pins only to help “reduce” this rocking couple in a dynamic balance. This rocking couple can’t be completely eliminated especially with the 90 degree banks of cylinders and their corresponding piston and rods in motion, but I can see where applying an over or under balance would reduce the rocking couple to some degree. That would explain the larger counter weights on both ends of that style of crank, circled in MAGENTA, below This picture shows the couple force in ORANGE arrows, counter weights in RED, (Text in picture is supposed to read, Rocking couple, Balancing with bob-weights could help "reduce" amount of couple induced vibration, but wont eliminate it.) As for other single plane cranks being available, I don't know of any others, but I am keeping my eyes open and will let you know if I come across any more. I would love to see a few more of these end up on the street and those builds shared on this forum.

SBC cam blanks, (full circumference blanks) are available for custom grinds, it's just a matter of picking a lobe profile for the intake, one for the exhaust, pick the lobe separation angle and have it ground. I'm sure it isn't cheap though it should be less than the crank itself.

Yeah, that is one sexxy crankshaft for sure... I have no idea how it compares to mine in weight, it does appear to be manufactured with less material. I learned from the previous owner today that my single plane crank was manufactured in 2000 and came from the Lingenfelter 358 CID Chevy Pro Stock truck engine program. Previous owner was involved in Pro Stock Truck engine building and recalls John Lingenfelter ran single plane cranks, just not very often. A little more digging on John Lingenfelters Summit sponsored Pro-Stock truck revealed the 358 CID was producing 900+ HP! He later went to a Turbo 2.2L that produced similar HP. I tried finding a video of the truck running a single plane crank but only found it running with the dual plane crank and the Turbo 2.2L. Of all forms of racing with V-8s, in my mind, drag racing would be last venue I thought I'd see a single plane V-8 crank being used. John L. is definitely one of the leading gurus regarding SBC performance, he must have saw something worth while to at least try it.

Pete, I can't argue your measured gains. They are what they are. The only possible solution I can come up with is that other factors are at play, not purely C/R alone. The math doesn’t support such a power increase. At 140 wheel HP, to go from 8:1 up to 10:1, A full 2 point bump in compression, (3 tenths of point more than your bump in C/R) is a 6.5% gain in power, which at 140 WHP is a gain of 9.1 HP, not 20, especially if you retarded the timing by any amount at all. With a 20 HP gain, I believe other factors at play delivering that gain, especially if the ignition timing was also retarded. Courtesy popularhotrodding.com

I agree entirely! As I covered in my first post of this thread, the L-6 head, a 2 valve design who’s chamber design isn't that terrible, but for some reason is hyper sensitive to knock! As you mentioned, an iron head small block Chevy, Ford, or Mopar V-8 can safely run 9.5:1, 9.8:1 and even 10:1 on premium pump gas, aluminum head can run on more point of static compression, so 11:1, (10:1 for Iron heads and 11:1 for aluminum heads really is about the max safe static comp ratio for most production 2 valve heads on premium pump gas). Many other manufactures, Toyota, etc, are also able to realize greater than 10:1 static compression ratios with their aluminum heads without knock! The L-6, for some reason, is very knock sensitive! The Turbo guys are regularly popping head gaskets at 10-12 PSI boost on conservative tunes, with only 7.5:1 compression! That low of static C/R should be able to safely support more boost than that! As I mentioned in my first post in this thread, my theory as to why has it roots in this thread linked below; Again, that is just my theory as to why the L-6 is so sensitive to knock, and the findings of those guys testing in that thread seem to be supporting it. To some degree at least.

I don’t recall the actual dyno figures from the example I quoted above where we dropped the compression ratio and swapped out the aggressive cam for stock one, maybe the owner will chime in? Mikey, you out there? My particular L-28 280 Z, I don’t have any dyno numbers for, but I did weigh it and run it at the strip. 2800 lbs with driver and half tank of gas, ran the ¼ mile in 14.4 @ 97 MPH all day long! Engine was bone stock ’75 dished piston short block. ’78 N-47 head that was my very first attempt at porting heads, included extensive valve unshrouding, dropped the compression ratio down to between 8.0:1-8.1:1. Cam was a stock ’78 cam. Stock ’75 EFI. Lightened flywheel, stock ’75 ignition system and module with Jacobs coil, Jacobs wires and recurved ignition advance that brought full mechanical timing in by 2500 RPM and full mechanical advance was over 44 degrees! Was my daily driver for several years in that configuration. Power to weight ratio, possibly puts that set up in the 160+ hp range? In short, my personal preference is do NOT run any more compression ratio that would force you to retard ignition timing due to knock sensitivity, because you WILL give up more power in retarding the ignition timing, (from the heads ideal), than you gain in compression ration increase.

It better work! I've got... uh... you don't want to know how much time I've invested in this one.. Good luck and keep us posted.

JimConnor, You bring up a very good point regarding harmonic dampers, (are you by chance also an engine builder/machinist?) By design, elastomer dampers are tuned (the suspended mass and the polar moment of that mass along with the elastomer resistance etc.) and are most affective within a particular frequency range. Within that frequency range, they do an excellent job of quelling harmful harmonics that would normally destroy a crankshaft. Using pistons of different weight, different rod length, crankshaft of different material, i.e. steel vs cast, will change what points in the rev range harmonics can and will be present. The OE has gone to great lengths to learn a particular OE engines harmonics frequency and match an appropriate damper to it. With aftermarket pistons, rods, cranks etc, thank goodness for the fluid dampers as they are a good catch all damper. (For this reason, never, never, EVER run a solid hub sans-damper for endurance or street application! Depending on how much time the engine spends in the range where its harmonics are strongest, a busted or at least a cracked crank shaft is par for the course when not using damper, on most any engine!). Elastomer dampers can be more effective within the range they are tuned, but when an internal change has been made and we the home builder have no way to know were the new harmonics are peaking and which elastomer damper would be ideal, the fluid dampers are our next best help in combating destructive harmonics. All this info is what I learned back tine late ‘90s and early 2000’s, I’m sure damper technology has evolved even further. As this applies the single plane V-8 crank, I think more research is in order, find out what NASCAR and the open wheel Lola cars that used these SBC cranks, used for dampers. Apparently someone else was thinking along those same lines. Another manufacturer built this SBC 180 degree crank, 3.290" stroke, fully counter weighted, mains are Chevy small journal @ 2.300”, rod journals are Honda @ 1.888”, 2 piece rear main seal, gorgeous crankshaft. Courtesysbraceparts Courtesysbraceparts

Jeff, Is that what you are after? Got the exact numbers from another more legible '78 service manual.

Did you verify the following for your '78 harness; Before I begin with the '77 ECU conversion, I want to let you know that with a Haynes manual you should be able to wire in a complete ’77 EFI system into your car. I have used the Haynes manual ’75-’77 EFI wring diagrams to install countless ’75, ’76 and ’77 EFI systems into 240’s Z that that were carbureted, and no one taught, told, or showed me anything about it, I had to figure it out my own, the hard way. I was pleasantly surprised by how easily it actually was. So everything I’m giving you is info you can figure out on your own with a little digging in the Haynes manual, which you should have. The '77 and '78 harness should have the wires individually numbered every few inches or so. Peel back the bundle sheath to reveal the numbers on the wires and they should match the diagram below. All the info I am providing here is based on that diagram below. With your ’77 ECU, ’77 EFI harness AND ’77 EFI relay in hand, here is the simple version of how to get it installed in your ’78 car. 1) This approach assumes the fuel pump is controlled separate of the ECU, (as it is in the ’78 car). As such, the wire for the Fuel pump in the ’77 umbilical and the '78 car umbilical is left open, connected to NOTHING, be sure it is protected well so it can not short out to ground in any way. 2) Connect the White/Red from the ’78 car umbilical to the ’77 EFI umbilical, Green #73. 3) Connect the Black/Yellow wire from the ’78 car umbilical to the ’77 EFI umbilical, Green #76. 4) Connect the White/Black wire from ’78 car umbilical to the ’77 EFI umbilical, Green #71. 5) (Leave the Green/Blue alone, connect it to nothing! Protect it so it can not short out against anything!) 6) Connect the Blue wire from the ’78 car umbilical to the ’77 EFI umbilical Black #1. The ’77 EFI has a separate +12v main power wire and separate – ground wire that connect directly to the battery. Be ABSOLUTELY sure you do not cross these wires when you connect them! They are both BLACK wires. a) #70 goes to the +/Positive side of the battery. b) #75 goes to the -/Negative side of the battery! 1) Plug in the EFI relay. 2) Plug in the dropping resistors near clutch master cylinder. 3) Connect all 6 injectors. 4) Connect the Water temp sensor. 5) Connect the AFM. 6) Connect the Air flow regulator. 7) Cold start injector and thermo-time switch are not necessary to have connected. So long as the fuel pump is operational, harness, ECU, and EFI relay are good, spark to the plugs, the engine should run. Hope that helps, Paul Sammy, For your '78 car, IGNORE the Fuel pump wire in this picture! Courtesy of Haynes

Gollum, Thank you. I will more than likely keep the build quite tame/mild, streetable. nothing crazy... The balance shafts would reduce harmonics by only 1/2, personally I wouldn't go through the trouble to build/install them due to the fabrication involved, the added weight and added rotational mass. I'd gladly accept some buzziness for a quicker revving engine. For what it's worth, the rod journals are already small journal, 2.00"

You can replace the '78 harness and ECU with a '77 ECU-harness-EFI relay. Keep in mind, the '78 harness, ECU or relay will not work with the '77 so be sure you have '77 Harness, ECU and '77 relay for the '77 harness, (goes under the dash in the '77) With a few other things that recently came up, give me a day or so and I’ll line out exactly how to tie the ’77 harness into your ’78 car. Hmmm.... Sounds like everything was covered that could be covered, out side of verifying the rest of the harness is correct, i.e. pin-out are going to their proper destination.

I’ll post all the information as I get it, including weight. Got it on a tip from a brand new HBZ member. Thank you Jim for the tip. For bore, I'll go as big as I can realistically afford. Helps with displacement and I am a fan of larger bores for the reduced valve shrouding. Either 4” or 4.125” + any over bore required for the used block, (302/327/350 block or a 400 block). Available/affordable piston-rod combinations may dictate that bore size, most likely 4" due to availability/affordability of over the counter pistons. Heads? Not sure with SB2 heads due to cost and their huge-by-large Nascar power level port volumes. Maybe if a set of untouched SB2 heads with the seats, guides, and valves, fell into my lap, the "as-cast" ports of the SB2 may be small enough for a mild street application. Cost would be the determining factor. Probably will be some standard 23 degree SBC head, Iron Vortec or the late '80's Aluminum Vette would be my first choices. The Gen-II LT1 block and heads are also an option with the 2 piece rear main seal adapter... Ahhh yes…. “the” intake… The stroke is a tad longer than I’d prefer for RPM reasons for off the shelf cast el-cheap-o pistons, though as rare and hard to come by as these cranks are, I’m not going to loose any sleep over it. Probably keep redline to max of 7000-7250 or so. Exhaust note should still be incredible and make acceptable power, 300-350 HP?... May be abit buzzy though, so wil be lookign int as long a rod as possible

Well.... Recently acquired a Bryant 3.240" stroke, single plane SBC (2 piece rear main), crank-shaft, pictured below! More detailed pictures to follow either later in the week or next week.

Don't know if this helps in deciphering which of yours ECU's is '78 or not, but this ECU is for sure a '78 ECU.

Due to the low static compression ratio, you should able run full ignition advance allowing that head to make its peak power, not knock limited. That head shaved .080" with flat tops offers some squish which in itself is a detonation deterrent. How much so, I don't really know. I would like to hear from more people that are running this that set up on premium pump gas and find out if they are still able to run full ignition advance. One thing to point out, with a squish design, due to how the gasses are being "squeezed" out into the smaller open region of the chamber surrounding the spark plug, the gain in efficiency from that allows for less total ignition timing. How much, again, I don't know, but I would venture to guess it will make peak power, (when not knock limited), between 34-40 degrees total ignition advance. Again, just a guess, the gain in efficiency from the flat tops and squish might not be that much of gain. Hope that helps.

If the head was ported or bone stock on an L-28 that is “not” knock limited, it will make more peak power with 38-42 degrees total ignition advance vs 26, 30, or even 32 degrees! Flat top pistons with that open chamber head does not change the efficiency of the burn in the chamber, (still has no squish), as such retarding the timing below 36 degree IS removing available power that head could produce, (if not knock limited due to too much static compression ratio)! If you dropped your compression ratio down to 8.5:1 or so, you could run full ignition advance of 38-42 degrees at WOT above 3500 RPM, you will gain more power than you have now at 26 degrees! If you could find a way to run 36+ degrees of total ignition advance on your current setup with NO rattle, you will see more power, probably in the neighborhood of 7% more than if it was 8.3:1 comp ratio at the same ignition advance. Here is a simple test for anyone to perform on their own to see and feel this first hand, with an L-28 that has low enough static compression to take advantage of the heads ideal full ignition advance with premium pump fuel. The difference is so drastic, even the butt dyno will accurately show the results, back to back dyno runs would also be good. Set total mechanical ignition at 38-42 degrees when above 3500 RPM, (with the vacuum advance disconnected, depending on the dizzy mech advance will be approx 15-20 degrees initial advance at idle), it will run quite well. Then retard the dizzy to a total timing to 26 degrees and drive it around! You will notice a HUGE decline in performance, a loss of far more power due to the ignition retard than that same engine would gain if you added 2 full points of static compression ratio to it alone, if it could still use full ignition advance! Yes, I strongly believe with your 26 degrees of total ignition advance at WOT above 3500 RPM with a stock untouched N-47 head, you “are” leaving power on the table! If you can find a way to get more ignition advance without rattle, you will see more power.

I as many other have noticed with the L-6, it is highly sensitive to detonation. With an aluminum head, it should be able to handle 10.5:1 compression ratio N/A on premium pump with no rattling, (many Chevy, Toyota, and other valve designs do just fine), but far more often than not, the Datsun L-6 will rattle at anything above 9.5:1 comp ratio on prmeium pump gas! Why? I have my theories and I firmly believe it is rooted it eh coolant through the head which this thread address. Again, just my theory... http://forums.hybridz.org/showthread.php?t=125186 Sorry to pick you on ya Pete, but your example is perfect. Too common for the L-6 to have to back off ignition timing due to the compression ratio. I have been preaching for some time that the power lost due to the retarded ignition timing to keep it from rattling is far greater than the power gained by the bump in compression ratio. Gain of maybe 7-10 HP max for the compression ratio bump over the paltry 8.3:1, but over 20+ HP lost in retarded ignition timing! open chamber L-6 heads, (E88, N42, N47), have their optimum non octane limited spark advance in the 38-42 degree range. If you can't get 38 degrees total ignition advance above 3500 RPM at WOT, (N/A), with E-88, N42 or N47 head because it is rattling, you are leaving HP on the table. I'm not saying that 10.4:1 comp ration can't be done successfully and still have adequate ignition advance, it has been done, only by a few with no info on what makes theirs able to run ideal ignition advance without rattling vs the many others that cant run that advance. Most of those combinations rattle and can't run full ideal ignition advance which is leaving power on the table. One specific example I dealt with first hand; In short, I do not endorse L28 builds with flat top pistons and E88, N42 N47 heads for ANY street application unless a thicker head gasket is used to drop the compression down to below 9.7:1 or so. If flat tops are is on your must have list, then I recommend the P79 or P90 head.

Follow Jeff's suggestion regarding the fusible link. (good catch Jeff, I totally missed the individual links.) The EFI main relay may be just fine as the injectors are getting power, but, the fusible link that is for the ECU power side of the relay may be blown, (fusible link is nothing more than fuse). It may have blown when the harness melted. This diagram that I highlighted should help show that little more clearly. As you can see in the pic below, when the EFI main relay energizes, it powers the injectors and the ECU. If the main relay is good, then pin #10 should be getting power when the injectors are getting power. You can use this diagram to verify the harness is correct as well, checking continuity from EFI relay plugs to ECU plug and umbilical plug. Also I was wrong again about your cold start operating correctly. If the engine is running for more than 5-10 seconds on the cold start injector then your cold start injector is getting power when it shouldn't be! Need to find out why!

Thank you for the link. I printed that one out, lied up and taped the 4 sheets together and spent some time tracing. Came up with this now. Few more questions; 1) What year is this car? Is it also a ’78? (only relevant for verifying ignition switch wiring) 2) You mentioned the ignition switch is a switch, not a key. Is that wired into the black/white wire for the ignition switch? First off, I was wrong about the plug under the dash being a 6 connector plug with only 5 wires. It is a 4 connector plug and all 4 being used. I labeled that connector on both the EFI and car side. I call this connector the umbilical as it is the umbilical connection between the car itself and EFI. Lets look closer at it. Car side of the connector; 1) The Blue wire is the RPM signal which comes directly from the ignition module/negative side of coil and tach. 2) The Green wire, (may be Green with blue stripe), will be power coming from the Fuel pump relay. That is the power for the air flow regulator. This wire should have no affect on your injectors not pulsing. 3) White wire with Red stripe, (may be white wire with black stripe), is the ignition on signal to the ECU. When the key is ON, this wire will be +12 volts telling the ECU to turn on. Be sure that wire is hot with the key on and with the key in the start position. 4) Black wire with Yellow stripe is the engine “cranking” signal, comes from the start position of the ignition switch. This tells the ECU the engine is trying to start and will enrichen the fuel as well as activate the cold start system. Verify #3 above goes +12 volt with the ignition on and key in start! That is the wire that turns on the EFI relay! (With your injectors getting power, good chance the EFI rely is energizing, but it is double pole so the other side of it that powers up the ECU could be bad, see below regarding pin #10) With the umbilical plugged back in, unplug the ECU. Verify these values at these pin locations; Pin #10 should be +12 volts when the key is ON AND in start! That is the ECU power wire directly form the EFI relay, (if the EFI relay is being turned on or is good). Based on the fact that injectors are +12v, that is good indication the EFI relay is energizing.) These pins should be earth ground; #5 #16 #17 #35 Be sure it is GOOD ground signal, i.e. no resistance! There will be a group of wire coming from the EFI harness into one eyelet that either attaches to the manifold itself or the fender well. Be sure that that ground connection is good. Also be sure the engine is grounded to the negative battery cable as well as the car body.

I certainly do. I talked with Kurt of Auto Kraft about his oil pan when researching pans for the Z32 and this is the info he gave me; http://www.autokraft.org/products/ Hope that helps, Paul