Tony D

I coated the cc and piston crowns at the stationary powerplant I worked at, because I had money in the budget and was curious. Decreased engine fuel requirements a noticable amount, and was still there, 8,000+ hours later. Matter of fact, I ran that engine for 24,000 hours without a valve job, and taking valve recession readings on the 1000 hour valve adjustments got the OEM interested in doing that kind of coating from the factory. Only drawback was there was no way to clean off anything deposited in the field, had to go to a walnut shell blaster (this was 1990's) but that probably wouldn't be an issue now, the stuff is readily available. Noticed some oil temperature reduction on some of the 'splashback immersion probes' in the oil system as well, so the heat was staying in the combustion chamber...on an automotive engine that would translate to quicker spool. In my application it translated to the wastegate being open more...hey, you know you're running a Turbo when the wastegate is 125mm, and the exhaust pipe is 24" before your catalyst, and 36" afterwards, going into the muffler! LOL Natural Gas Lean-Burn engine running 22:1 AFR with rock steady 1100 degree EGT, 24/7/365 @ 22 PSI Manifold Pressure, 10"Bore 10.5" Stroke, V16... Not necessarily applicable, but the N/A version of the same engine ran EGTs in the 800's.

Is there any other?

Are those Raised White Letters I see on the tires? Holder back of information! LOL Nice setup. Now, for that electric 3" cut-out pipe and a stubbie exhaust out the passenger's side behind the wheel....or the driver's side....as long as it's straight out from the turbo it sounds so....nice! LOL

With a metal head gasket, no o-rings, and 8.39psi of boost on the dyno, without ANY detonation being heard, JeffP sunk five sets of ring lands on his expensive forged-piston 3.0L. With a Metal Head Gasket, or an O-Ring, you can make pistons go away, and never even hear it! Hence my suggestion to everyone when they get a Standalone "just learn to tune it on a stock engine" before they start putting money into parts. A blown stock L28ET makes a great donor core for your big-dollar buildup. With another $450 and a junkyard motor you're back on the road learning! Coincidentally, I did see a guy blow his megabuck motor on a dyno, go out and buy a 160K mile ZXT engine from the JY...reinstall it with all the other engine's externals, and then 'just because' ran some dyno pulls on it just to see what it would do. 450HP at the rear wheels, everybody looked at each other, then they turned the boost down and said "Let's just be conservative till the other engine is finished"...He's the guy that told ME to build up the externals first, learn to tune, and once you have the formula down, build your big$$$ engine last, as everything external will still bolt right on! It's not my original thought, and it just made enough sense to me that I parrot it as well!

The key to the AFM Readings is it doesn't go to 'infinity or zero'. Jumping around may make the ECU go intermittently up or down, but only in a very steady state condition---like right at highway cruise. My 75 does that, right at cruise the engine will 'shut off-turn on-shut off' if I approach an open spot in the AFM Trace reeeeealllly slowly on the open road. I can do it free rev by bringing it up slowly as well...right about 2275rpm it will go into an oscillation because the wiper arm has worn through the resistive trace right at that point and when the ECU sees 'zero' it shuts off pulsewidth. Conversely is can go 'full fuel' going to the other extreme. But unless I am cruising very conciously at that speed, it won't do it. The car runs so damned well otherwise, I simply sped up 3mph at cruise, and it never effects the car. So even with an 'open' in the sweep, the car will be functional unless the AFM flap is held right at the trouble point. Usually it's sweeping so fast it's more of an averaging thing. The ECU in the car is like 8mhz, while even most cheap DVOM's are 100mhz in scan time, so many times while you may 'see something' on your meter, in practical terms the stock brain will not register it at all becasue it's so much slower. The important thing is 'not zero or infinity' on the tests. A Diagnostician gave me a tip that has panned out well: If you have a FLuke with Min/Max/Record, hook up piercing probes in the lines you want to test, start the car, turn the meter on and set it up for Min/Max/Record, and just go for a drive. On many of these components, a "Zero" or "Infinity" reading is out-of-range and indicates a failed component. After your drive, before you shut the car off, take the meter out of the Min/Max/Record mode and recall those values. If you see "Zero" or "Infinity" you have a bad component, period. Replace it. The 100MHZ Scan rate of the Fluke 87 is faster than all of the Stock ECUs out there (was at the time at least) and will pick up very small defects. While my example above of my AFM is technically a component that I know 'is bad' and should be replaced...this kind of test will reveal an 'intermittent non repeating failure' while driving the car that may not show up during bench testing. When I did the test on my AFM it indeed 'failed' by showing the "Open" (Infinity) reading, but the car did not buck or stall at the time because I swept across it so fast the ECU didn't pick the glitch up that time. The Fluke recorded it, though.

When I was in Liverpool last year, it was 99p/litre for diesel. Gave my 'driver' 60 L for his Mitsu SUV for taking me on a pilgrimage to Wrexham... Couldn't be in the area without visiting 'The Demon'! LOL

O-Ringing in this case would have resulted in blown pistons, ring lands, or skirts, instead of a $60 Gasket! Get your tuning down on as stock a setup as possible so you only break things like a cheap head gasket. After you get it tuned, then put your money into the block.

I've always installed the Turbo Oil Pump/Drive Spindle as a unit. The dot and marking on the pump will mae it lline up when it goes up into mesh with the crankshaft gear. The only time I don't do it that way is when it's in a running engine and I'm inspecting the oil pump. In that case, I pull the distributor cap, put a big rubber band around the rotor to hold tension on the gearmesh so the spindle won't drop, and I pull the pump. Make note of theangle the slot in the pump drive is at, and get it close before reinstallation. To then install the pump, then stuff it up there and give a twist each way till it seats, then in go the bolts and torque it down. Mind this: don't be pushing up with all your might putting that oil pump in there, push it up gingerly till you fee it hit, then give a slight rotation to get the drive tang on the spindle to fall into place. If you are pushing up too hard, friction will simply turn the pump drive shaft, and you will never get it to line up! Usually, a 15 degree twist one way or the other lets it seat fully, then turn it back so the bolts line up and have at it. Good Luck, let us know how it goes.

Yes, with a stock cam and setup that is about right, depending on altitude. I don't figure much elevation in the UK... I am at about 700-1000 ft above sea level to get the 35 kpa at idle. Our Bonneville Car, on the other hand, idles around 55-60 kpa...a bit more cam there! LOL That one uses an alpha-n map 'blend' software mix to get it off-idle smoothly as with MAP based only, and all the throttle area we have, a simpl cracking of the throttle will flood the engine as it immediately goes to 100! Timing is usually 1 psi per pound of boost on the gauge. Some places more, some places less. All depends on what you find when tuning, and hte octane available where you live/drive. For reference the old Corvairs ran 24 total advance at 5-7 psi, and my old N/A distributor was set to run around that same point at 10psi. So it is possible you can run a lot more advance below 10psi than you think, and then start retarding the spark above that point. All depends on what you find. The Megasquirt Stickie on the board has a bunch of maps on it that you can take a look at to get an idea what other people are doing---that will reveal many similarities especially if you lay it all out on graph paper and write the bins in to correspond to your kpa readings...you will see the scaling makes more of a difference than each individual engine does. For a stock setup they are all pretty much about the same.

Don't get me started... That refill information is good to know, I will have to look into a refill on some 'empty' Halon units I just couldn't bear to chuck since they were so nice looking. EVTech makes a good point about the AFFF in that you can buy 'refill' kits from some vendors. There was one up at ElMirage campaining for acceptance by the SCTA to allow his system as a legal approved system. Uses a CO2 cannister like the old Ansul Extinguishers have used for years. You simply fill up the cannister with water and add the packet of chemicals, and it's a 'pull to charge, push to discharge' kind of setup. Makes the AFFF right there as it's dispensed. I like AFFF since seeing it used on Aircraft Fires in the USAF. For the footwell I'd prefer it since I was phosgened by Halon during a tent-burning incident at FOL in Korea one winter.... Don't even ask! Thankfully I was sober enough to get the rest of the guys up and out before things went really bad!

Shaker Coils, self-igniting and great for practical jokes involving doorknobs and metal chairs! That setup isn't the greatest for 'spark timing consistency'! LOL They used individual coils for the same reason they do nowadays: They couldn't find wire thin enough to wind the coil for enough voltage and still have a fast enough rise time to full saturation for consistent firing. Now the engines rev so high the time they have to charge a single coil (because they CAN get thin wire now...) is limited, and they start getting insufficient charge time above, say, 7500rpms on a 6 cylinder. Same end result, multiple coils, different reasons why they couldn't reach saturation. Those shakers will jolt the hell out of you when you grab the knob!

Not necessarily a steam barrier, but it can work itself up into that eventually, yes. The barrier layer of the fluid/metal interface zone if undisturbed can act as an insulator. Turbulating it allows cooler water from the 'center of the flow' to contact the highest heat area and take the heat away. Think of a metal pipe, with a blowtorch on the outside heating it. The coolest water is in the center of the pipe. If the walls of the pipe are smooth, the water passing over the smooth piping will boil continually at the point where the torch is applied, while the center of the water really doesn't change temperature. Now add bumps to the inside of the pipe---like a sand cast iron pipe instead of a DOM Piece of tubing. When you do a thermal profile, the center of the pipe is still the coldest, but the 'hot portion' of barrier flow along the pipe itself extends further into the center of the flow. This is a result of more surface area...but even if this was held constant, the turbulation of the flow at the pipe-water surface would promote that heat-transfer further into the center of the pipe's water flow.

I haven't bought or even looked at one since the early 90's. At the time the Cartech unit and several HKS bypass valves were avaliable that functioned really well. I have been told the Cartech unit from BEGI is no longer available, which is sad it was a really good one. My HKS unit from the mid 80's has a 50mm orifice and nice flow design...when you consider my boost piping is around 2.5", that orifice will take much of the flow directly. From what I have seen the emphasis seems to be on smaller, smaller, smaller, and I see that as a problem. The flow speeds through that orifice not only make noise...they cas get downright turbulent and that hurts their flow ability. For me on the BOV, bigger is better. It has to be able to flow a lot of air and relieve the plenum pressure with decent resolution without going overboard. They all may be 'well designed' but I think they are being misapplied---most of this stuff looks to be for small four cylinder applications and not suited to flow the air required for bigger engines. I think maybe the Vortech stuff for the V8 Superchargers may hold promise, but I haven't looked too closely at them. I think the problem is in application, more than design engineering. Turthfully I haven't looked in years since I'm happy with the few I bought back then. A Bell (Cartech), Two HKS units, Two SK's from their turbosystems, and one that I have no idea who made it, but I bought it in Japan in 1987 or 88 at a speed shop. It was supposed to be good for bypass on twin applications to 600ps...though is only slightly bigger than the HKS unit on my Type 2 Surge Tank.

A turbulence can help disrupt a barrier that will form right at the surface of the metal/fluid contact area. This barrier can act as an insulator, and keep heat from transferring efficiently. A slight turbulence keeps this barrier from forming, and causing bigger problems. Check out the Grape Ape Racing explanation of what happens when boiling occurs on the metal surface precipitating overheating, and you will be able to follow it better I think.

Was this one a 3 hour start-to-finish engine swap operation as well? LOL

"BOV should be closed under boost. " This is the common misconception! Not necessarily! The BOV shuold move almost in a mirror image of the throttle plate. If you keep 20psi in the plenum, and through throttle modulation you only have 3-4 psi in the inlet between the T/V and the Intake Valve...something is wrong with your BOV setup and you are slowing the wheel and affecting turbo response. In this instance, when you go WOT, you will notice a dip in plenum pressure before it regains to 20psi. This should not happen and won't if your BOV is set up correctly. If the BOV was relieving mass flow at partial throttle, under the same scenario, the turbine would be up to full speed, and delivering full mass-flow for the engine needs, the BOV would simply be diverting the overage during a partial-throttle condition. In this setup, when you went to WOT, there would be NO dip in boost pressure noted in the plenum, nor the resultant 'lag' associated with a lower pressure in the inlet plenum. People think the BOV is either and 'all or nothing' proposition, and it's simply not the case. A majority of people set it up that way through ignorance of the things proper function...but when you lift the throttle even slightly the BOV will crack and divert pressure not being needed by the engine to the vent line---allowing the turbine to remain totally spooled and providing full mass flow. Sure, once you got WOT, it will shut. And if you drop throttle completely it will dump pressure from the plenum like most people do. It's the partial-throttle response that gets buggered up when people set the thing to respond. Just because the manifold is 'on boost' does NOT mean the BOV is totally closed! Perhaps at WOT that is true, but any other time all bets are off. If you are not at WOT, there is no reason to have full pressure in the inlet plenum, and ideally under the perfecct setup the turbo would be fully spooled for full boost, the BOV venting the excess overboard, and throttle plate pre and post probes will show the same boost pressure. If you think about that setup, that is a no-lag situation, but because people are so misinformed about how a BOV should be working, and the common fad is to set it up for 'noise production' instead of finesse in a corner for throttle modulation you get a lot of junk setups out there that don't function nearly as well as they should. There are some systems currently on vehicles...and dammit I can't say why/how I know this, but commercially it should be available some time in the not-to-distant-future, that will let a BOV be controlled on a similar loop like the Wastegate. In fact, the BOV and the Wastegate will be tied together in a common controller, with an input from the TPS. With total electronic control of these items through either stepper motors or pneumatically controlled solenoids the boost response will be amazing for people accustomed to the 'Whizz-Woosh-Boom" style of BOV Actuation popular today. A BOV should sound like a big guy sighing when you feather the throttle, if it doesn't it's set to harsh and you are loosing turbine speed and tip-in boost response...you're opening way too late, and dumping way too much.

Boost is a manifestation of restriction to flow. If you have 100KPa in the manifold, you are WOT, and running an efficient air pump. Generally, because of the way carburettors work, there has to be at least 4-5" Hg Vacuum in there at WOT, at maximum RPM...but BEFORE that point you will register 0"...it's not until the engine starts flowing more than the manifold supports will you notice the restriction...Many times the engines are flowed to be at peak torque. WOT max RPM is not really given that much consideration in most passenger vehicle manifold designs. Peak Torque is where it's optimized. Like WizB said, it's semantics. I run 35kpa at idle, and don't start pulling timing until I'm ABOVE 100. Usually 1 degree per psi from a total of 38 when at high cruise. Say 3500rpm and 30-40 map. Were I at WOT at that same rpm, and running 10psi, my timing would be around 28 degrees, and closer to 18-20 at 20psi. Don't worry too much about what Mr. Bell has to say, there is some dispute to some of his contentions, and his book is using dated technology. He is not, as contended by some, Gawd...

"They don't dump intake manifold pressure, that's what the throttle does. Just gives the turbo somewere to move the air so it doesn't surge when the volume isn't used my the engine. " That is only part of the equation on the dump valve, it is more to prevent the turine wheel from slowing down out of peak efficiency range, and 'surge/stall' are interchangable terms when referring to centrifugal compressors. There is a minimum mass flow of air that a compressor must flow in order to have stable operation. If you fall below this point, you will stall/surge the compressor. The airflow delaminates from the blades, and the airflow reverses instantaneously. Otherwise, I agree on everthing said by Clifton in the last post. Things people attribute to 'turbos' are totally accepted in an N/A car. "Coming on the cam" is one of them. You just drive in the power bump region. Same for a turbo, you drive above boost threshold rpm (usually around 3000rpm, no biggie) and the problem becomes on where to put the excess air than waiting for it to 'come on boost'. Driving a non-BOV equipped car that runs high boost will reveal some really strange things, like 3-4psi at small throttle openings, going instantly to say 20 psi at WOT. It modulates just like the power delivery of an N/A car when driven like a hot-cammed N/A car. It's just that people get lazy with their driving and expect the turbo torque to pull them out of everything no matter what the RPM, and they pick the wrong gear entering a corner, so at exit and throttle roll-on they are below boost threshold...and then the dreaded non-linear power delivery comes on. Incidentally, if you cam and match your components correctly, even then this won't happen! Your car will drive like a N/A monster of MUCH larger displacement, but usually the components are so poorly matched to the application you get a non-linear bump because 'strapping a turbo onto it for more power' screws up the dynamics of even a stock cam.

If your plans run on for a SBC in the future, figure out which transmission you got installed, early or late 5 speed. If you have an early 5 speed, change to a 3.9 differential, and save your 3.36 for the V8. If you have a late 5 speed, change to at least a 4.11 or 4.37 differential. I have several 2+2's and none of them is geared lower than 3.7. The turbo car has a 3.7, the 2 N/A 2+2's I have have either a 3.9 or 4.11 in them. The one n/a with a 3.9 in it, and early 5 speed returns around 22mpg towing a trailer that weighs 800#, with 750# of passenger weight in it. Just remember these engines were meant to REV, I will pass people in THIRD GEAR at 65mph (and this is with an L28) tach out to 5300 or thereabouts and upshift. Thing will cruise all day long, 24/7 (and that is no boast, my wife and I drive in shifts on cross-country jaunts, so the car runs tank full to tank empty, stops for 20 minutes for gas up and dumping of fluids, and then goes again till it's repeated...) and return that kind of mileage. With an L26 it should be little diffrerent. I have a 260Z coupe with a 3.7 and a late 5 speed...I got as high as 27mpg going through Wisconsin one vacation, keeping speeds down. The worst I got on that trip was the 1100 miles from Oglalla NE to Grand Rapids MI...where it had a triple digit average speed and STILL returned 19.5mpg! Steady State cruise can get you great mileage. And 19mpg at 100+mph average speed is phenomenal in my books! This doesn't give you any power, but lets you put the power you have to better use. If you are looking for something that plants you in the seat when trying to pass someone in fifth gear at 70mph...none of these engines will do that. Just downshaft to third, and plant that foot. Fourth and Fifth just aren't acceleration gears in the N/A cars, compared with turbo and lager displacement vehicles.

I GOT to send this thread to my Toyota Buddy! LOL This will drive him up the wall! I donated a 66 Toyota Corona to the Toyota Museum because it sat in my back yard waiting for him to come get it...and I had taken a couple trips out there measuring the engine bay for a VG30T from a Z31! When I started cruising Summit for narrowed 9" rearends I figured better off to send it on to the museum (it was REALLY nice) than for me to rape it and turn it into a FunnyCar style VG Dragger! I need a dedicated Drage Corona like I need another hold in the head! LOL I know the later Celicas had longer noses to accomodate the 5M engines in the first "XX" Celicas (Supra here in the USA), I have seen L28's in Sunny's so anything is possible. The Japanese would take two Suzuki Alto Radiators and put them on either side of the engine with electric fans to cool it, and tubing linking them. With that, anything that fits behind the grillework is suitable!

Got to look a bit closer there, gearheadstick's detonation issue is on the last three cylinders at least! not just 5&6, you can see 4 was also on the way out. You don't hear it all the time, guys. And like the old adage goes, once you'ver heard it, it's too late!

"As for lag, if the only way you use the throttle is to mash it to the floor at the start of the run and to let off again at the end of a quarter mile, then you guys are right. Once the turbo spools up and the motor is at full power than that extra length of pipe probably doesn't matter. But if you actually try to use the throttle and engine power to negotiate the car through a turn, then I simply cannot believe that increasing the volume of the intake plumbing by an amount almost equal to the engine displacement won't be noticeable. Think of the intake plumbing as a storage reservoir on an air compressor. The larger it is, the longer it is going to take to pressurize, the more stored energy it will contain, and thus the longer it is going to take to depressurize. None of those things will contribute positively to throttle response." I will have to disagree only from the point that the way most kids have their BOV's setup today...to make noise, and not function properly, then you might have a point. But for a properly operating compressor bypass valve that lifts and allows the compressor to keep up at speed and constant flow, as soon as the throttle would be changed the bypass will close and pressurization will immediately happen. A compressor bypass will keep the turbo flowing at peak flow, making form linear power delivery when modulating underboost. It's not an 'all or nothing' proposition, the BOV doesn't drop that intake line to even atmospheric pressure unless the engine is drop-throttle closed for a considerable amount of time. Under throttle modulation on-boost it will be some middle ground where the engine may be seeing slight vacuum between the throttle plates and engine intake valve, but the plenum will still have pressure in it. It's a wierd phenomenon, the compressor bypass valve should lift fully and relieve pressure in the piping, but at the same time it will relieve load on the compressor section by allowing N/A operation directly shunting the compressor section allowing it re respeed in almost a vacuum. The setup on the HKS Type 2 Surge Tank did this pretty well---basically once you're on-boost, modulation is occurring without a drop in turbine/compressor speed, you dump your excess overboard and keep the wastegate closed to allow for instant response. With the "Fast and Furious" BOV's dumping 'hard' you semi-stall the compressor for auditory effect, and then since it dumps overboard, and not to the compressor inlet (speeding up the wheel) you loose response. A lot of myths surrounding Turbo Operation come from people running horribly designed systems (even though they make copious amounts of power!) The contention about Mass-Flow is really at the crux of it. In a properly operating compressor bypass system, the mass flow through the compressor will remain constant under lift-throttle with the excess being vented overboard, and being immediately available for use when the throttle position changes open again. Pop's contention is based on the F-N-F style dump, where the compressor is stalled, all pressure in the intake piping is dropped off, and then the turbine is then called upon to speed back up to the prpoer operational point on its mass-flow chart and then start delivering through the piping again. It's a problem of blowoff design, rather than piping system design that solves the issue. This can be seen every day at any air separation plant using cryogenic distallation columns. The cold box must have an uninterrupted mass-flow through the columns or things get all out of whack. The solution to keep the colums balanced is to run the excess air out a bypass that will open instantaneously on switch from "Column A" to "Column B" allowing for constant mass-flow to the point of use, even though the switchvalve operation momentarily stops flow thorugh the column. You watch the Turbocompander's tachometer during these events and the thing stays very steady...a function of the same mass flow being pushed through it. If anything, the Capacitance of a larger piping system makes drop-throttle control of mass-flow through the system easier as you can use a slower opening blowoff, with a much more sensitive closing ramp!

RB20 was a stock option in the Z31 Chassis, no reason that the similarly sized L28 wouldn't fit. The L28 was a common swap in the 'early days' of the VG for Drag Racers that wanted to run the current body, but with proven technology.

I think JeffP has run stragiht Etheylene-Glycol in his engine since new, and the head looks like new, no corrosion whatsoever. The boiling point of E-G is up there in the same area as the stated values of the Evans stuff, I wonder what the thermal transfer properties are in comparison?