Tony D

The face is blue, which indicated overheating, likely due to either lubrication breakdown, or lack of oil. This would have me looking closely at the lubrication at that lobe before jumping to Schneider. It is also possible that ZDDP not being added to the oil is a culprit as well. Is this a "CWC" or "JAPAN" blank? Talking with some cam people, they tell me that the CWC actually is metallurgically a 'better' cam stock, than the Nissan blanks but for some reason the CWC's seem prone to failure with todays oils lacking the high Zinc content. For the record, I've seen multiple cam lobe failures on Nissan Cams (stock) as well, almost always due to plugged lube spray holes. Bummer, good luck on the re-cam.

Oh, and a comment on the venturi sizing stated in the Weber Example above for an L28... It's stated 'bigger carbs' may make more power. Change your venturi from a 34 to a 36. A 34 is NOT a 'top end' venturi...this goes to the other comment about poor tuning I suppose. A 34 venturi in a 45 DCOE is a mild street setup, and not for max power. Then again, running a 12.4 AFR everywhere isn't exactly how you get maximum power either. But it will give you pops, growls, and snarls if that's your thing! (Hint: Try pulling fuel after peak torque to around 13.8 AFR instead...you're WAY richer than you need to be on the top if you are serious about getting power at higher RPMS...maybe that's why it's feels all-in so early!) If you are talking about bigger carbs being 50's...you need to maximize airflow through what you got first. If you are talking about bigger carbs being 45's...you aren't set up for power, period. The carbs are the limiting factor, not your cam! AIRFLOW makes power, and small venturis and small throttle plates just won't cut it. I ran 44PHH Mikunis with 32mm Chokes on my L20A in Japan, and the power would come up high and pull like crazy with a surprisingly small camshaft profile. Many people would be shocked to see how 'small' our cam profiles are for the above power examples. I've seen people on here with street engines that have cams with more aggressive specifications than what we are running in competition, AND making considerably less horsepower.

Oh Christ! Try THESE numbers for 'runs and doesn't blow apart guidelines' (and we haven't actually floated a damn valve yet): 12,500 for an L20A 9750 for an L28 8700 for a VO7 Stroked L29 And in EVERY case above, we stopped because either the tachometer didn't log higher or we were plenty past the power peak that we've determined further increase would be pointless other than to know we just need a bigger cam or more boost to make even more power at the higher rpms. 8K with an L24 isn't even getting STARTED as far a 'maximum allowable RPM's'! (Do a little linear interpolation between displacements...) You're selling yourself WAAAAY short with THAT assumption for SURE! And guess what? An L20A running 9750 rpms IS NOT going to give a comparable proportional HP as the L28 running 9750 (or for that matter the L28 turning 8250...even if you take the L20A to 12,500 trying to make up porportional RPMs through some theoretical increase in RPMS to compensate for displacement....) If you have forged pistons...you have (from what I've seen) really no practical upper RPM Limit. If you have cast pistons, your upper limit is around 7000 rpms. Run them at 8K and you are going to get an engine that "Sounds like icecubes in a blender" at idle before not to long--if not worse. The cam determines how and where you will make the power. The pistons will determine if you can run to that point or not. Arguments for larger cams that provide more 'power under the curve' being used in Cast-Piston engines do have a valid argument for their employment. BUT if the engine revs so willingly with that big cam in there, I've not seen ONE person who doesn't try to see when it stops pulling. And the engine goes 'boom'...either spectacularly, or 'ice cubes in a blender' kind of way. Almost 100% of the Internet Commentary about 'RPM Limitations of the Datsun L-Series Engine' is pure, unadulterated BULLSHITE! There is no other way to put it. It's bad information. I've personally seen this myself. On the dyno, on the track, on two continents. You don't need forged pistons OR 7500 to get 200 N/A horsepower out of an L28. Likely not out of an L24. If you need a couple of hundred rpms at a particular track, you gear for it. If you are in serious competition, 7500 IS NOT a limit on a built-up L Series Engine. The much-vaunted Crank Harmonics issue is a holdover from the early L24 noncounterweighted cranks. While a harmonic DOES indeed exist there, it is easily squelched sufficiently with a proper damper, and the knowledge that ANY harmonic is adequately worked THROUGH by not DWELLING on the precise speed where the crank resonates. Pass through it and you're up there quite high before the crank hits a second critical speed. And yes, they can operate there all day long, though parts do take a pounding. Which brings us full circle that you don't NEED High RPMS to get most horsepower goals. 320 at the rear wheels on a 0.040" overbored L28 is achievable (in our case) at 8250 RPMs in a dedicated race vehicle. Rebello is making far more than that at far lower RPMs with his Stroker 3.0's for similar competition. Can we kill the maximum RPM myth here and now? PUH-LEEZE?!?!?!? As for Weber Service---I will agree. At WOT you will see great power from them. In our case, it was simple economics that the cost of 55 DCOE's with their special manifold were cost-comparable with a set of 45mm ITB's. It came down to 'what will be more versatile long-term?' The 45mm ITB's work great on our 2 Liter. They work great on the 2.8. If we had sold our 45's to get the 55's (which was the plan) we would have had to go out and buy another set of DEDICATED carburettors for the small engine. Our power production was smooth and the dyno chart looked like someone drew a fashionable eyebrow with a felt pen when running the Webers. I'm sure with 55's the curve would have been similar in format (nice even curve) rather than the somewhat digital jerky interpolation with the EFI. But comparing 45mm Carbs to 45mm ITB's the EFI gave 17 more HP at the Carbs power peak of 7500, and 40 more HP at an elevated RPM range of 8250. Nothing else changed, direct swap from Weber 45's to ITB's and Electramotive TEC2. No different cam, nothing. It made more power everywhere. Even with the 'strange dip' in the Dyno Curves we are still trying to figure out lo these 6 years later, and present in two different EFI systems...the EFI is still making more than the carbs did at those points...and even more elsewhere. We liked our Webers, it was just too damned expensive for a set of carbs that couldn't be used on ANYTHING else.

My SOP is to pull out all P.O. wiring. Restore all wiring to it's proper factory location per FSM and Schematic...and know what? It's worked flawlessly EVERY time! My first step would be to REMOVE ANYTHING NOT STOCK. It can only cause problems. If there isn't an OBVIOUS function to a wire ADDED to a system which worked when new...(like a burned wire that is clipped and lagged) remove it, you don't need it. As for Hazard Switch---that kills your blinkers for sure (hazard AND turn signals.) Headlights---for that matter most lights: Common Big Ground Wire under the steering column. Easily disconnected and many seemingly unrelated things won't work unless it's connected. After that, bulbs, bad local grounds, etc... But my guess would be the above fixes most all of it.

The best bet is that someone screwed up the timing chain install and on first crank-over the pistons hit the valves. It wasn't due to shaving or excessive lift...it was because the timing was off. That would be my bet.

If you are driving at 1800 rpms in a Z-Car in ANY gear other than first moving from a stoplight or rolling to a stoplight (?) you need to go back to driving school! This isn't a Chevy, don't drive it like one! You want bottom end grunt and want to drive it like a Diesel Jetta, install a turbo. NONE of these engines has anything below 3000 rpms, don't make it something it was never meant to be. You want an industrial refrigeration engine, install a Toyota 18R...

Man, look harder! Crown had a turbo kit for an L24 that used a Corvair Turbocharger!!! Curiously, the link between Datsun and Corvair continued later into the 70's when it became common for guys to take the EFI system from a 280Z and install it on a Corvair Engine "for the smoothest running, best cold-starting Corvair you will ever drive!" People have been turbocharging L24's from day one...it's hardly original.

Coming from Aircargo, we all know ratchet tie-downs are the only proper way to secure anything. They work as tow straps on cars. And the little ones you get at Home Depot...yes, they will work as great battery holder-inners: GUILTY! But bungees? My dirty confession is now out there for everyone, I feel so much better!

You said 'Didactically'!!!

If the turbos aren't doing anything, then they aren't inter OR aftercoolers, they are inlet ducting... Without multiple stages of compression, there is no inter, or after-cooling occuring! Being pedantic...

couple of larger ones is easier and less trouble prone. Shoot in at a 5 degree angle to wet a wall down inside the SU someplace to initiate a tau layer, and the rest is golden... Mitsubishi Starion Turbo TBI injectors are 'short pattern' Bosch type, the same style of holder the Ford 5.0 HO TBI used in 84 or so will position them like you need, and give you a decent template to work from Because the mitsus are so short, they fit in the stock air cleaner nicely! Not that I have given this any thought...

It is not running 0:1, the Jake uses compression bled off to slow the engine-watching the PV curve will show the rise and bleed off of pressure---if no pressure is built, no negative horsepower can be put to the drivetrain. It has to do work to functionally slow the engine through compression braking. The Jake brake allows 'flow' which raises the compressive load more than simply running a against a closed exhaust valve, or other such device. The same function as an exhaust brake, but more controllable and with variable volume comes the ability to modulate when the exhaust brake doesn't really have. In these cases (exhaust and jake brake), BTW, the Turbos are not producing any boost, the intercoolers are doing nothing but recovering from heat soak...

If it's cooling the exhaust after coming out of the jake brake---the jake brake turns the engine from simple power piston to PURE COMPRESSOR (thanks for making my point for me, original stirrer of the pot!) The engine IS a compressor! The diesel is a point of compression before injection of the fuel---the ONLY function that differs on Jake-Brake is that fuel is stopped, and the outlet of the exhaust is restricted to let the engine build to a set pressure before the brake allows it to blow off. The MECHANICAL function of the pistons doesn't change with the removal of fuel (which has been my point all along)--the engine isn't point of use! It's just subsequent compression. As for stage sizing, it's all in the relevant engineering manuals. It's mass flow in and pressure ratio starting at point of power production with desired horsepower goal, and working backwards so as not to exceed roughly (in the old days) 2.5:1 CR per stage. Remember, with proper staging in the 2.5 range, it doesn't take much to get 8.6 bar out of two or three stages. and 40 bar out of four!

There are kits to put GM TBI injectors in your SU's and it is a simple matter to put a spacer behind the SU's with a pair of forward firing Bosch-Style injector (a pair of 550's would handle what...200HP?) (Or put them underneath, I don't care)... Patton Machine makes some nice stuff for what you got!

That dome screams small chamber ITB run to 8500 when I see it... Don't know about anybody else, but that's what I personally see...

I'm continually amazed by people who buy a car, then on the way home drop the battery due to bungee cord failure. It's not that it happens so often, but that these guys actually blame the previous owner. Sorry guys, look in the mirror. If it failed, it failed because of your inaction, not their prior attempts to secure it. Who doesn't look under the hood when buying a car? <EDIT>And for the record, I don't use ANY bungee cords in the back of ANY truck I own!<EDIT>

mcmaster carr is your friend...

A waste-gate is only needed if the turbocharger is undersized... The original Corvair used inlet restriction and outlet restriction to keep the turbo boost level in check very effectively without the complexity of a (then) unreliable mechanical bypass flapper. Take the stock carburettor off a Corvair, put on a 2" SU and you got 21psi of boost and not a bit more. Keep the stock carburettor on the Corvair, get a rusty exhaust pipe and drop that special 'turbo muffler' and you found your boost gauge pegged and you detonated to death on a cold February morning...feeling that rush of power and wondering what all that racket was out back. Now, put that 4150 Holley on the front end, a straight pipe at the back end, and mate the first generation turbine with the late model 180 Compressor section... WOO HOO! Then about 28psi and more than enough fuel to make that buggy HAUL! But remember, Turbocharging and Hybridizing is new technology... The Corvair used a combination of exhaust backpressure and inlet restriction. Most diesels have the same turbocharger response curve, and they aren't really governed like a petrol engine is either. Less fuel directly means less throttle position in a diesel since you aren't moving a throttle plate but a fuel injection plunger control of some sort. When you lift the throttle on a diesel, you inject less gas and have less energy to spin the wheel. But even injecting all the gas you can, the turbo is sized that it will only spin so fast given the heat/flow input (same as the old corvairs)... I worked on constant speed diesels and natural gas engines, and its' very similar to long haul trucks in that load actually controls the turbocharger speed. Our engines had wastegates. But wastegate position was dependent on load on the engine. At 900rpms, and no load, the WG is 100% open. But put load on it and you see it close. Some would be 25% open at 100% load, others with different turbochargers (Elliott ET18 vs Cooper 18 for instance) would be 0% open. One turbo would make 17.5psig at full load, the other 24psig. EGT's would be the same, wastegate positions were different, turbocharger speeds were different. Engine horsepower as gauged by instantaneous KW meters was identical, as was inlet fuel flow conditions (neat what you can measure when nothing is spared in metrology!) Long and short of it, if you have designed the turbo to work without a wastegate you don't need one. For most AUTOMOTIVE applications which work at PARTIAL throttle (watch that trucker drive in the lower gears...) an undersized turbine wheel will result in boost coming on fast and giving power earlier for a more broad useful power band...which goes to what JC said: they don't operate over very much of an RPM range, so they come on when they come on, and they are limited by the size of the turbine wheel and compressor as to what they can do... 5am time to go to bed!

I'm not jumping down anybody's throat here. This is a specific terminology based on application. This is what SleeperZ is reinforcing, and is what I've said all along. The basic crux of it is that the engine IS a final stage of compression, and therefore intercoolers are used throughout, what you would call an 'aftercooler' from a laymans point of view may be what you think is correct, but from an engineering standpoint it is not---it's simply another form of INTERcooling to another subsequent stage of compression (the engine at X:1 Compression Ratio at a minimum.) That has been my stance from the beginning. The design criteria for an aftercooler are quite different from an intercooler... There is no trolling here on my part. I was unaware that we were restricting our discussions to only TWO stages as well. It's not uncommon on Diesels to have four turbos to make 200+ manifold boost. So what then? Intercooler aftercooler 1, aftercooler 2, aftercooler 3? No. Intercooler 1, 2, 3, 4... Aftercoolers deal with air going to free field, not being compressed further, but used. An engine is a compressor, same as any supercharging device. I deal with this daily, our equipment has TWO intercoolers and ONE aftercooler. Their construction is identical---the ONLY difference is the one off the third stage is not going to another compression stage, it's going to be used like bleed air to power accessories or perform work. NOW, on the exact same machine but packaged to a BOOSTER COMPRESSOR for hiking the pressure from 8.6 bar to 40+ bar in two more stages of subsequent compression in another compressor downstream...want to know what all the MANUALS and PARTS listings call that third cavity? It AIN'T "AFTERCOOLER".... Viewed as a PACKAGE it has now simply become another intercooler as it's no longer final compression stage, it's now just another in the train. Same part number, same position on the machine, different package. I've said all along, the difference (and this is mainly a problem with American Terminology) is use of the air after it's been cooled. If it goes to another compression stage: Intercooler. If it goes to do work: Aftercooler. This is another one of those things where in America only, the terms become an issue. I'm not trolling to 'get the last word in'---this is my job and it bugs me when people slaughter the terminology haphazardly and don't even admit the intellectual argument for use of the proper terminology. I'll meet you half way Howler Monkey: the day an engine runs on a O:1 Compression ratio, I will concede that the second (or last) cooler in the train can be called an 'aftercooler' but until such time as engines are operating on no compression ratio internal to their mechanical configuration...they are properly called 'intercoolers'! Pedantic? Yeah. Because it's the right thing to do.

Stock pumps stall at 60psi, and the stock lines result in more pressure drop. I don't know about that math, either---as the FPR would then have to utilize a static pressure of 'zero' to get only 64 psi and that won't run the car at all. 36 starting point, 6:1 (or 8:1) always meant to me 6psi fuel pressure rise for 1psi in boost so starting at static an -9psi (about 18"HG) you would think it doesn't mean subtracting but rather only affecting fuel pressure on-boost. So with your base fuel pressure (36psi) and a 6:1, I would expect at 6psi boost to have 72psi (6X6=36, 36+base of 36=72psi) This has always been how they worked for me, and even a 6:1 will overtax the stock pump. They work great on VW pumps for CIS which can stand well over 100psi, and you simply run two or three for the power you want to make (or at least that's what I always did) and you will never run lean. But running 60psi at the rail on a stock pump is almost guaranteeing there is a shortfall in flow due to the internal bypass lifting due to line drop. All that being said, two stock pumps on a Megasquirt will run 550's just fine at stock pressures with stock FPR's...

Nope---there is a TOOL that comes in the SU TOOL KIT that has a gauge, as well as a little 'L-Shaped' rod that goes into the dome to indicate PRECISELY the height of the SU Suction Piston when the engine is running under load. From those notations, you can then transcribe to the needle from interpolated height where you need a thinner needle, or a thicker needle and make the adjustments accordingly. Always work from a LEAN situation into RICH. Why? Because you can always make a rod THINNNER, but if you make it too thin (go rich) then you have to start the whole damn thing over! Actually silver solder makes for quick work if you 'oops'... then you can turn a needle from final dimensions afterwards. And yes, 1979, for a MONTH sitting backwards watching needle station positions with detonation stethescope on and yelling orders to the driver as to throttle position change and brake application to this day makes me LAUGH my ARSE off everytime someone posts 'carbs are easier to work with'! Like Xnke, I JUMPED at the ability to "shift, arrow up....shift arrow down" and simply watch an AFR gauge. As to "adjust the needle up or down" that works if EVERY station is off the same amount. This is usually not the issue. You have needles that work CLOSELY, but generally each car needs some more fuel here, a little less there. A rolling road and AFR meter is about the only way to see it. You will be amazed at how much better your car drives when you go do the needles like that! But for me: "Shift, control arrow up....Shift, control arrow down" FOREVER MORE! I'm NEVER going back!!! Oh, and you can use the rods to check suction dome synch as well like this: On a Single-SU setup like I was tuning, it was more important to know station height...if there were TWO on there... EGADS!!! AH, this IS how you guys are doing your SU's on the car, right? I mean, you don't depend SOLELY on the FSM as the total performance guide to SU performance, right? I mean, these things were around for DECADES before Japan picked up on them... there IS more than one way to performance tune them...but really all the good shops seem to congregate around the original tooling for some reason. Perhaps because it works?

Methinks Xnke picked my primary reasoning, with Noddle hitting on the second valid reason for posting... When I can get a 1971 Vintage SU set on a 1977 Non-USA L28 with Headers and pumping AIR into ONE primary tube to pass to 1983 emissions standards...the issue isn't the standards you have to pass...it's the people building and tuning the engines! Will my Bonneville Engine 'pass emissions'? It has 'a cam', and 14.75:1 CR---likely not... But c'mon vague specs and grasping questions all deserve the same reply: " " Simply from the fact that it's like asking "What?" What what? What who? What where? What WHAT? It's a Non-Sequitur

I wouldn't jump at stainless steel...

12psi will be too low for decent atomization. About the lowest you can go with Bosch stuff is 20psi and then it's pretty dribbly.

"I understand the idea of living in this area you receive a larger salary and have “everything†available to you but I am starting to believe it just isn’t worth it." No Kidding...I've been entertaining the Third World as my alternative place of living... Hell, your property taxes are 7X what mine are in SoCal for 2.5 Acres!!!!!