Tony D

Try running a stock L24 or L26 in 110F+ heat on modern fuel before you comment on 'something else is wrong'---that something else is THE FUEL! (REMEMBER: 160F Thermostat as well!) To paraphrase Tom Jefferson: We hold this truth to be self-evident. I'm not in the frigid northwest. I didn't have issues like this with my Corvair or VW in Michigan. I do in the Soutwest USA. Remember this board can cover more climates than your specific area. For some people, putting Methanol Injection on an N/A to simply allow driving of a stock vehicle in stock form at all times of the year is a cheaper alternative than changing a head and suffering performance loss on an already marginal performance engine... That Skib is in Oregon someplace (we can only hope it's not the scorching inland desert area...) notwithstanding, the 'additional costs' of a methanol system are minimal and require no performance compromise whatsoever. I thought that was what building a performance car was about? I've got an engine that was built in the late 80's which WILL NOT run on premium today. It did in 1985. What do I do? Open it up and chuck a $2400 cylinder head to lower compression to allow it to run and sacrifice 10% of the available horsepower? Or spend $350 and be driving in two days.

"I dont see what is hard to understand tho, I try my best to write for people to understand what is confusing?" Let's eat, Grandpa. Let's eat Grandpa. Just an example of one comma omitted, changing the whole complexion of a sentence. Seriously though...learn more about your setup. You're parroting sales terms with absolutely no knowledge of what they mean. Or more importantly, what they mean on your car. If you don't know, then who does? Find out, and get things clarified: "What does that mean, tuned to 10 psi?" is a good question to ask when an owner says "It's got a 17 psig wastegate tuned to 10 psi." Does that mean the wastegate is tuned to only give 10psi. Does that mean the fuel and spark curves are tuned to 10 psi and he gave up so buyer beware if he uses the full 17psi available in the spring? That's what guys are getting at...

I go to the Conex Containers in my back yard...

It's a pilot for positive location of the flywheel. If you aren't balancing the flywheel properly, it can 'waggle'. That pilot they machine there is much like the pilot on a turbocompressor impeller used on the old Elliott PAP Plus (or for that matter, the original PAP introduced in 1964!) There is nothing new here, just proper ENGINEERING applied to a problem someone is seeing. But is it the root cause solution, or band-aiding a symptom?

Mine has never 'stuck' that I can recall. I think this is much ado about a non-starter. What is sticking? A 30+ year old component that is fouled with 30+ years of contaminants passing over it? The people that experience this need to look at the reasons it stuck, and not blanket condemn the device. There IS a reason they are there, and it's been extensively covered in the archives. Grapeape Racing link...

Depends on your spoiler design. The stock BRE/432 whatever you want to call the 'little kick tail' will increase drag to balance the front spoiler and give grip. The same effect can be had by ballasting the rear end of the car. Taking the kick tail off the car gained us 3 mph (140 to 143mph) on the same day at the races, in hotter less dense air (read power lost on the engine). Adding ballast (200#) in the spare tire well regained us traction at speed (half spin at 140 is not fun...) and picked up even more speed. The design of the spoiler is as important as having one there in the first place. Some will give a high drag penalty (the small kick-tail) at the tradeoff of traction. Others, not so much drag but same increase in stability/balance (Rusty Old Datsun style). It pays to experiment.

Is your tachometer accurate? How do you know your 2700 rpms is correct? Do you realize the injectors go from double-pulse per cycle batch-fire to a single massive pulse above 5000 as well? Can cause fuel delivery issues as well...5225 or some bizzare number.

Look at the power under the curve, it's not manifested by peak horsepower gain. It's manifested by more torque down low where a street car is driven. Like I said, I have it installed where my BONE STOCK ENGINE will not run WITHOUT PINGING on premium fuel. The cost of installing the methanol system allows me to run REGULAR fuel (not premium) for daily driving whitout having to retard my spark (and the terrible drop in power of the already gutless L26 in lower rpm driving) and n fact allws me to run 15 degrees initial like I could in the old days when premium fuel was premium fuel. There is no reason to compromise on torque when the methanol/water mix will allow you to run REGULAR pump gas, as well as get increased drivability. I mean, if you want a gutless wonder go for it. But for the cost the economics are hard to argue. In the case of a stock L26 (or in most cases the stock HIGHER compression L24 with an E31 head!!!) it allows you to run the car on regular fuel without retarding timing (performance loss) for a modest investment. On a turbo car, the torque increase down low is massive over simple race gas in the same application. The prejudice against it as an 'improper detonation aid' should vanish as the realization is made the current systems do more than simply blow liquid into the intake in hopes of suppressing detonation through simple chamber cooling. This is a supplemental fueling system which affects both power delivery curve as well as allow usage of more economical fuel for a daily driver. Driving hard I might go through half a gallon a tank. The turbo car uses a lot more. That system shown would likely work fine and is about 2/3 the cost of what the Snow system costs, so that would only improve the economic performance I experienced in terms of payback also realize my economic model was about 2X (conservative) on what real-world consumption really is... During the winter I can scale back on injection as it's not needed as much. Try that with a compression change. IMO dropping compression is a radically complex answer for what likely will be a part-time situation. Getting 100-octane equivalency is not hard with one of these systems and the performance you will get returned will be surprising. If you are making WOT runs and worrying about running out of methanol and giving that warning, then you also have to warn people about clogging a jet on their Mikuinis or Webers. I've seen FAR more detonation to death scenarios from a clogged jet than someone disregarding the low tank level light and then going on a bone-headed run. You will hear it baby ping far before you will do damage. I can't drive my L26 up a grade at more than 1/2 throttle without hearing it ping (even with the header and opened up exhaust now...) If you keep in it after audible pinging, you deserve what you get. I believe that warning is as much a Red Herring as a clogged jet warning for a Mikuini or Weber owner!

In the VW world, Gene Berg would run 7:1 CR's while all others would run 3 points higher. Of course his engines made nearly the same power...but lasted 150K miles. As for wasting money, depends on what your costs are I suppose. If 100 octane is $6 a gallon, then running a full tank is $84. If it costs you $3 for 91 octane, and $5 for a one gallon tankful of Methanol 50/50 wiper fluid (the most common mix) and gets you the same octane performance, or allows even more advance for a cost of $47 a tankful ($37 a tank saved...) That means in 16 tanks you recover the cost of the methanol injection unit. Let me see, I run through two tanks a weekend while home, so in 2 months of driving I get my costs recovered. Being I can drive (potentially) 52 weekends a year. then that means 44 weekends at $37 saved per weekend: $1628 a year versus running racing gas. I need to see how this is defined as 'wasting money'... (Keep in mind I'm inveterately cheap and run 87 all the time, so that means I save 0.20 a gallon over premium which STILL PINGS in my L26, but 87 and washer fluid doesn't... I had it on the Corvair for the same reason---to run REGULAR which didn't ping, versus running Premium which DID STILL PING.)

Did I read that right? Two head gaskets in less than 5 miles? And you're optimistic...indeed you truly are! What kind of torque wrench are you using on the head bolts? When it blows in that short a distance, either insufficient torque (wrong make up or bad wrench) or excessive warpage is where I'd look, costs be damned. Hoping a head gasket will fix a 0.020" warp won't make it so! Good Luck.

constant tuning with an EFI system is like constant tuning with carburettors. Some people can buy a 340 Chrysler and drive it 215,000 miles with Air Cleaner changes and never more than an idle readjustment every couple thousand miles. Other people have the cover off and are in the jets on a weekly basis it seems. Same with triple carbs, I have set the synch and locked my arms in 1985. To this date, other than idle screw checks I have not had to rejet or readjust anything. If you have o2 correction, and the correction tuning parameter set properly, 'fiddling constantly' will not be necessary. If you are, there is something going wrong with the engine. Most new ECUs incorporate long and short term fuel trim to tailor the base tune to the engine. It's why many new car diagnostics start with 'disconnect the battery for 30 seconds to reset the computer'... it sets it back to square one where the car should run, and then let you go from a known starting point. It lets the ECU run on a very poorly maintained engine without skewing outside emissions parameters. This should not be a car on this forum---they are likely overmaintained. There shouldn't be variances that big that would skew a MAP based system enough to change parameters that much (with correction turned on)---now, if you aren't availing yourself of O2 correction...then why bother with EFI?

Batch fire is over 3500 on that ECU, not below.

I don't think I would catagorize 8.5:1 CR as 'high compression'...

3.5 psi at idle, rising equivalent with boost. Webers work at 3.5 psi, and all you need do is run the pressure via a boost-referenced regulator to keep it 3.5 psi above boost. less that that, and you loose float bowl level and run lean, more and you run higher levels and consequently rich. Read Yetterbens' threads on his buildup (start of something awesome) and what he went through with his blow-through DCOE18's. I preferred Mikuini's myself, and went to EFI for the stuff you will read about in Bens' thread. Thing was, I didn't have to change my fuel pump when I went EFI! Just the regulator setting.

Two Words of Advice: Canton Accusump Swore I'd never Autocross my Turbo Shark Car without this!

Indubitably it is, and this is why you have chosen to say 'my theories are all shot full of holes' yet proffer absolutely nothing in response to my query as to exactly what I said was incorrect. Abusive rant? You were the one getting personal, and then coucing is from the 'gee shucks I don't know nuthin man' perplexed commentary. If youre so perplexed, what exactly am I wrong about in this situation? How have I misled the gentleman? If you want to chuck stones in a non-helpful manner I'd suggest you don't. Jumping in a thread to profess ignorance helps nobody. Ron, I did get up on the wrong side of the world. And when I see stupid commentary like this I should take it to PM, but in this case, it's not worth it. I institute a self-ban of a week for my misbehaviour. But idiots need a smacking now and again and you moderators can't have all the fun. That agression can not stand. And as for 'reputation of abusive rants'---get your f-ing forums staright. If you have a hard-on from a forum where i no longer post, and haven't for some time now-you need to leave your bigoted ideas at the door. This ain't there, and what I posted was not abusive nor conceited. If you can't take questions in a mature matter, don't post inflammatory things about someone and then expect not to go challenged. As you have admitted, you have nothing to add---and have not responded to what 'holes' which are applicable. If you are suggesting the guy to go a returnless system, you damn well can state that instead of nebulous commentary and stone-throwing. I'll go to Thailand for a week in exile. So goes my self-expurgation from the forum for my outburst.

We had our first DNS at El Mirage this past weekend. Andy bumped the new extinguisher actuator plunger and, well....there went a $600 charge for nothing. I guess there's later in the year. We got, after all the hemming and hawing, reduced to GT class by the Roadster Contingent. A 2+2 is no longer considered a 'production' vehicle, so we will be unable to better any of our former records. Now Coupes (which were always GT) will compete with 2+2's in the same class. A great step forward in the inclusive environment on the dirt. Nothing like being scared your DOHC Monza has to compete with an aerodynamic brick with a 50 year old Japanese SOHC engine design. Gawd forbid...

L28ET pump since 1985 on HKS Blowthrough and Mikuini 44's.

I know, it's a 5amp PWM circuit that controls that stuff on the Fords. MS has a PWM driver compatible...

Sigh... still fixated on pressure.

Additionally, the loss of fuel pressure to "0" will indicate a leak somewhere---usually the fuel pump check valve. There are check valves that have low open pressures which can be installed in the line to replicate the action of the in-pump check valve. This will aid in the loss of pressure. If you loose pressure, you will have issues. Then again, the three second power-on of the fuel pump (and maybe a light on the dash triggered by a 37psi pressure switch in the rail) before starting will also negate the hard-starting issues that come with 'no fuel pressure' in the rail.

Firstly: Anybody who is putting ANYTHING I have said about a 40 year old system to use in a MODERN returnless system is an idiot. They are two different animals. For someone to actually think ANYTHING I have EVER discussed was meant to apply to a modern system...foolishly stupid is the most polite way I can phrase it. Who the hell would make such a stupid leap of (il)logic? Better put your money where your mouth is with that above comment and show me ONE Thing I have stated which is incorrect, not factual, nor based on firsthand observation on the fuel system beiong discussed in this thread (And I don't recall the car in question having a modern Returnless Fuel System). You think the heat and the fact of a returnless fuel system has ANYTHING to do with it? Do you understand the impetus for a returnless system (EVAP Regulations)? Since you are so up on them, please tell the rest of the forum how they control fuel pressure. Please tell them when the car is off, on these returnless fuel systems, what happens as the fuel injectors heat soak? Edify us as to what happens should the anti-return valve in the fuel system malfunctions due to a small speck of dirt in it, or whatever... NOW.... Understand that the older systems have a return line, and the FPR is part of the issue that CONTRIBUTES to the problem. The fuel pressure is NOT ALLOWED TO RISE and keep the vapor from forming. The FPR releases the hot fuel back to the tank, and eventually as the heat soak goes away, you see a DECREASE (then resultant flash to vapor) of the fuel. Were you to clamp the fuel supply and fuel return line on the car in this post when you shut it off, it would react EXACTLY like a current returnless system, the fuel would NOT turn to vapor. If you are going to throw nebulous B.S. commentary about me not knowing what I'm talking about, you damn well better puke up some specifics and discuss it rather than throwing nebulosities or calling them 'theories'! I don't think you know as much as you think you do. About the new, or old systems. You have the typical attitude of someone who works on new stuff and hasn't a CLUE about any historical problems or perspectives. You may work on the new stuff all day long, but that doesn't mean you know anything at all about what we are discussing here on a nearly 40 year old system. Don't ascribe my 'theories' to a new fuel system, I have NEVER discussed a returnless system, so I have no 'theories' to espouse about it--other than the questions I posited above. I know the answers, the question is do you, Jasper?

sticky vote #2

The Harrison/Delphi V5 series uses a variable swash plate on the pistons, much like hydrostatic pumps. This is old technology, been in play for years in hydraulics. Apparently it has finally trickled down. From what I can see they use a pressure-balancing bellows. So is this the pump you aim to use? Toyota is also using a Variable Displacement unit which may fit in a standard Sanden footprint. If not, then what I stated still stands about accessories, all they do is affect state change, the item doing the work still overcompresses and wastes energy--using a non VDP the selection should be the smallest pump available to compress the medium for most efficient operation with system capacitance sized for anticipated transients.

I have to go with KTM on this one, the height of the pressure plate fingers for proper engagement is what determines the height, and even though there are four collars shown in the photo, generally there are two which will work in all situations. "Short and Long" The difference between the other two of 'medium length' will ONLY matter if you have some funky non-standard clutch assembly which has a thicker build depth on the clutch facing, or when it's very worn and you want to get right to the rivets before having engagement issues. There are actually many more collars that what have been mentioned, each with their own part number, and what it ends up being is fractional millimeters of clutch life at the very end of the discs service life. In most cases, if you have retrofit an adjustable slave ROD, it will not matter one whit unless you get the absolute shortest collar and fit it to the shortest PP assembly (finger height distance-wise). Then the rod may not be long enough, even with the adjustment all the way out for proper disengagement of the clutch. Selecting the wrong collar is not the end of the world, there are different length rods out there to fit to the slave which will acoomodate for this as well, about 5mm different (longer or shorter) on this rod and you will get proper function restored without having to drop the tranny and put in the right height collar. Unfortunately I am too far away right now (Jakarta) to be able to go out with a depth mic and measure the T5 housing, but the PRESSURE PLATE height on an L28ET Diaphragm is exactly the same no matter what tranny is in it. The T5 argument is as simple to resolve as this: measure the engine mounting flange distance to back of throwout collar distance near the input shaft furthest riding point, and compare with the N/A five speed. You will find, in addition to the pivot ball distance (the last adjustable point in the system, fulcrum point) that the combination will be a Nissan Standard Distance. This leaves the installed height of the diaphragm the ONLY factor in determining which length collar to use. Someone stating "N/A 5 Speed" needs to remember these cars are 40 years old, and can have any number of components swapped in the past. That you have an L28 Five speed does not mean it's got an L28 clutch cover and collar in there, especially if it's in an early 240---some people have swapped clutches from their existing L24/26 to their L28 because it was still a good clutch. No reason not to do it, and it works fine. If you get it wrong, alter the rod length. The only time it gets critical is if you get the longer collar and you physically have a 'crush situation' and that should not happen with the Datsun automotive collars. Which is what upsets me about Eric's illustration above... they are giving an irrelevant distance (or have it diagrammed wrong)---the operational / functional distance is from the collar engagement to the bearing face---there is plenty of backspacing to accomodate any collar in any tranny. They also left off 'A' series 5 speed... When you start looking at it from fork to bearing face (the effective working length when pivoted on the fulcrum point) you will find FAR more pertinent information, and 2 or 3mm difference will not make a shite bit of matter. Forklift stuff doesn't count.