Tony D

No, I have never sketched cartoons on the wellhead porta-potty little dumplings happily in mid-frolic around a big oily splotch putting a caption below it "Pipefitter Biscuits dancing for joy in finding a huge puddle of gravy on the rig..." I would never do that. But I would make a mental note of whomever did it and remember it clearly now 26+ years after seeing it out in Bakersfield while doing an Ajax Overhaul! "We all Oil Field Trash!"

I thought there was a definite answer already...what have you added? I'm a bit confused. What you posted adds nothing to the discussion and I'm having trouble finding relevance in any of the tests you did or what they supposedly show. If an FPR fails, it fails opens dropping fuel pressure through the bypass line. If your return line becomes obstructed, full fuel pressure will be dependent on float bowl inlet orifice will be present...(assuming the FPR can not bypass and therefor orifice size becomes the pressure regulation mechanism. In a Holly Red that would be maybe 12-14 psi before its internal bypass opens... On a stock EFI pump that's maybe 15-17psi once your floats sink (it may have been 8-9psi as this was a condition I saw on my triple when I bought a car)... It will NEVER get to the 60psi of the EFI Pump Internal Bypass Valve because of the floats sinking.. Either will sink your floats, flood the bowl, and dump gas into your carb throat. Your fears are totally unfounded. Nothing will be damaged in the carb.

Wow, seeing it all assembled like that...that stock water outlet will be reeeeeeally close to the distributor (but above it slightly, right?) That is close! Also, there is a translation error in that head torquing procedure. The English equivalent of what the Japanese characters are roughly translated at best. There is a phrase in Japanese that means "The same, but different" and UNIVERSALLY is translated as "The Same"... Which, is NOT literally what it means. It should be translated into 'similar' but it's FAR more complex a meaning. In all the time in Japan I witnessed the torquing done COLD, and after warmup and COOLDOWN. The torquing is to be done in an 'equalized state' and the kanas say to warm it up and retorque in equalized state. Meaning stone cold (or in the case of VW 122C which is Tuteonically precise but old VW Mechanics will chide you as being TOTALLY WRONG because the valve lash is way too tight compared to stone cold setting as called for originally and for about the first 40 or 50 years the engines were in production when the change came in (to accomodate Americans who were upset they couldn't drive in for a valve adjustment and were upset they had to leave their car overnight...) But hey, they were perfectly willing to pay the 3 hour flat rate change for cooldown waiting on the service rate change... Imagine that, a German engineer with an MBA...

^^^"Embedment" is the term. Generally from the head gasket compressing, but fretting of the soft metals can do it as well. Some L-Heads frequently torn down will have hardened steel inserts under the head bolts. They are shrunk--pressed into the head and become a permanent part. Stops the embedment phenomenon cold. A properly sized diameter hardened washer under the bolt or nut head will similarly stop the phenomenon.

What's wrong with a FelPro? Why MLS? What are you trying to compensate for that the standard gaskets fall short doing?

^^^^^^People laugh that JeffP has over $75,000 in his S130 (mind you that was BEFORE I started "suggesting solutions that cost him $2,000 every time we talked) but Derek exactly captures what people who ACTUALLY TRACK THEIR COSTS already know... And it's what JeffP knows for sure... It sucks when you pay money and it's not what you thought it would be. And it's a prime reason why a lot of the early development concepts were offline. A lot of background noise can be generated and sidetrack a concept. As stated, there was a desire to make something that could be done at someone's shop if they had access to BASIC machines, or a shop with complex stuff. People will hopefully appreciate exactly how exotic a component set they can buy RIGHT OFF THE SHELF if they so choose...stuff that makes an OSG head look "old technology" in the extreme. It was not the intent, but using modern technology to best advantage was a heavy design consideration. Anybody who has ever lamented being able to find CNC heads, off the shelf titanium pieces, valves people actually STOCK... I think the only thing we could have done to keep performance options more open would to be to use SBC Parts (Derek, about those altered Corvair 140 Head Castings we discussed some time ago...)

People fail to understand what "development" really means. I'm sure if they're used to the stuff Microsoft churns out they figure castings warping, chains breaking, maybe a head that won't lay down flat after a few heat cycles due to uneven heating is acceptable and a field patch is fine.... But that doesn't work on mechanical devices. For all the thought and theory that has gone into it to this point, there are a LOT of assumptions made that have to be tested. This is literally a "proof of concept" in design parlance. It says "yeah it can be done", what we learn on this head will be critical for V2 which will have a sore, miserable life as "test mule".... If it's properly monitored, and changes implemented that should get a product that most people will accept as a starting point. Due to geographic separation of the principals, getting a head to put on an engine for a 200-hour dyno run just isn't going to happen. Even 5-minute WOT Peak Torque Pulls aren't possible. That will be left to those who buy the heads and test prior to implementing their vision of what the ultimate L-Series will entail. I can say were we three in AZ, NV, and CA, we would undoubtedly have a few meetings and dyno pulls to do testing. But with FL, NV, ROP/SEA being the physical location, getting together for a dyno run will be difficult. I have been invited to assist during the Dyno-Tuning in Australia of a 3.4 Liter OSG head, and from that, feedback will be forthcoming to aid in any redesign or practical alteration on this head.

Yes, considerable thought went into which head to steal design and configuration from... This could have been considerably more difficult using a "purist" approach. Recognizing good design practices and using them pays off down the road.

Oh Cool, Kidney Surgery. I can honestly said "I chose to cut out a kidney than buy this head right at this very second..."

I know people, who know things... I actually am involved in a 3.0 build here in the PI. Imagine that, I found probably one of three S30's in a 3 to 4 hour driving radius, and the guy wants help with the engine. It's already turning into a Mini-JeffP: "Every time we talk, you make me spend money!"

He is, indeed. It's pretty well known. Read Tony A to Z's notes on driving the car at Riverside. By "beat the world" though, I was really talking 10 years earlier in places like Kenya, Acropolis, and Monte-Carlo. When the East African Safari was put back to the original rules "nobody but the driver and navigator touch the car between maintenance stages" the 240 jumped back into the lead. It works, is rugged, and that's what you need. The difference in power will merely be at which boost level it occurs at, but with an L30 making 750 to the rear wheels below 20psi you start getting into the "useable horsepower" question. At which point you do the Tony A to Z: crank it in to get the lead you need, then back it off and just cruise to the finish line...

Hey! There are other guys who will help with that! But of course, my application is of course Turbo. They didn't hang "Turbotony" on me back in the 80's because I was singing Wango Tango verses....

Well, that one topped $5.5K by just a tad ($20K)...

To be blunt, Nissan correctly assessed market conditions in the USA and realized that outside of the turnabout on emissions, the US Service Network was not set up nor capable to service the engine. Toyota nixed their DOHC 1600 for similar reasons. There were problems with 2 carbs like the simple SU being properly tuned, three? HAH! Not a chance! Remember, the triple Mikuni 44's fit so well, and had such a nice manifold because Nissan ran them as a production option in the 240Z Sports (165hp) with the SU's as a downmarket stripper version...all that went away for the same reasons. They did have a crossflow (LY) head which made a marginal amount of power more than the non-crossflow head. In the end the added complexity was not necessary, nor was it supportable in the USA Dealership network due to a serious lack of skills. Learn well the lesson of the 2000GT: Add Complexity, Add Cost, and kill the product. The head beat the world. It was in no way "severely let down" by that head design, which made over 1100HP in Turbocharged Form... Knocking it for it's design is really, really foolish. Especially in light of the fact that the valvetrain on this new head was designed 50 years later, from a company with that much time building F1 Engines.

Air movement at any given rpm for combustion is twice that of a four stroke. To size the carb right you need almost twice the carb size on any two,stroke as compared to comparable four stroke and vice versa. Sachs 292 runs fine on a Tillotson HR, a Briggs and Stratton 356cc Lawn Mower engine....notsomuch. But an XR500 one lunger? Back up to HR Size again. Carbs are sized based on air movement.

^^^^why don't you download the damn list 4 posts up and answer your own question? I did and the answer is...

^^^ In fact, I have. Have you heard an L-Series SIX that high up? Mowhahahaha! Corky Bell did a great disservice to builders trying to convince people you didn't need to do anything but slap a turbo on and bang boost to it. For those who want a 'stock engine power curve' just more of it...that works great. If you are bored by a stock L28ET power delivery peaking at 5,300 and prefer the L24 going on a bit higher, or a cammed smaller L24 that pulled to 7,000 then why not turbo THAT profile cam and keep that same rush up top? It makes for quite a different ride than most (_TZ_) Turbo Z's in the USA which I likened to being in a Big Block Vette. Not the feel I had in my VW's, most DEFINITELY not the feel I got in the Turbo Cars I was in while stationed in Japan. 300HP under boost on a stock L28 cranking 18+ psi, and 300HP under boost at 6psi and 7,500 are two VERY different beasts indeed, needing different gearing and driving style.

Most people "in the USA"...

Most of these flat-slides have a power-valve setup (you know, like the hated Flat-Tops had to handle WOT enrichment....) Flat-Slides usually do, it's not all needle taper. You don't really need it as long as there is a functioning power enrichment setup and you sized the carbs right for the velocity... The Mikuni HS40 (which I think these are) does have an accelerator pump for really low-speed, with no power valve. They're two-stroke carbs with a strong inlet pulse so they work well on individual runner engine setups...though piston size is usually 2X of the 2-stroke version to get comparable performance in terms of response. http://www.mikuni.com/pdf/hs40_manual.pdf

But I don't think we need a large A/R necessarily. I've seen a lot of guys give up a lot of bottom end going with a Big A/R because they thought they needed it...then shift at 7,200! Argh... You get the right wheel cut, that AR will move air into the head. You may not make much boost....but go do a pressure-flow test on that runner flowing 310 CFM at -13.5 psi and see what kind of flow it takes passing through it to get up to +3psi even. I think some slip issues will start occurring with the turbine wheel not able to drive the compressor section at lower speeds. Which will be sad.... and THAT is where the VNT comes into play!

You like camshaft lag? Give me a Turbo any day for immediate throttle response!

Actually, I preferred the 73's over the 74's as they have a larger float bowl capacity. Like many things these days, it's just not posted on the interwebs because of the misinterpretation of context that most reading online seem to have. Kind of like this comment: "I get the criticism, but you should consider the design intent of this kind of project-to go out and do something different." That being posted right after the 'why build at all' which is a false exaggeration. People adding nothing to the thread but butthurt makes a lot of this stuff go underground. It's not worth the vomit that is induced and splashes everywhere. In fact, I saw someone rail extensively that the DOHC Head Project currently underway because the detractor couldn't understand no compromises performance, "couldn't justify the cost" yet denied he was budget-constrained. The dearth of intellectual dishonesty online and creeping into even this forum is saddening. That it's not making any sense, that it doesn't make any sense many times is more the point of the exercise than anything else. So what? His car, his build. You said your detractive piece now either cork it or advance the project towards it's stated goals. If I can do it, so can everybody else.

"Problem with these turbos is that they generally don't make them with ARs below .96, and that's with a T4 housing. " Well, then again three years ago there wasn't an alternative DOHC Head Casting available for an L-Series outside Japan, either... I mean, it can't be any more difficult a modeling and casting exercise, and there are plenty of places with 5-axis mills to do the finish machining... Mowhahahaha!

Turbo work most people do is oversized on the A/R for the hot side anyways. I think you will be able to use quite a bit smaller scroll and get very good spool from it. I don't think it will need to go to 6K to spool. The flow / lift numbers are staggering. Were this head to go onto an existing build (which I think this is what was being talked about) the numbers you would see on the intake side would plummet from the better flow, and the spool would not change. The flow through the engine would accomodate the power without the ills seen when you make big boost numbers to reach the same HP levels. It's as I told JeffP (just for me, let's do one pull at 8 psi first, and see where the cam peaks...) Well, he still doesn't know because he got greedy right away and ran 17 or 20 something and found out the turbo went into stonewall...when it went into stonewall (rpms) was based on pressure. And as would be expected the HP remained the same. Just progressively lower rpms as the boost was wicked up. More people should really check their exhaust pressures and see if they are losing power under the curve by thinking they need a humongo A/R on the exhaust side. What this does open up, though is some turbines with PWM Variable Vanes and Nozzle Rings.... This engine now will pull the rpms to where you could exploit a 1.06 A/R diesel turbo on the top end, and use the VNT to choke down for lower rpm boost assist... Tranzilla comes to mind immediately. And, for those drag boys...juiceboxes... they're quick... even with turbos!

"Tip In Response is somewhat touchy."