Tony D
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Posts posted by Tony D
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Typically it will be from the Thermostat Housing, and returned to the pump inlet...
In this situation it will act as a cold startup bypass line, speeding warmup in cold weather. After shutdown there will also be somewhat of a thermal siphon through the hot side of the head, back to the cooler inlet side of the pump.
If you return directly to the radiator, you may (depending on line size) experience some longer warmup times due to the engine having to warm the whole system (or even the radiator) as well as the block when starting cold.
What you want is maximum differential pressure during operation. This is afforded by the standard Thermostat Housing, Pump Inlet Scenario. That keeps the turbo cool. Though taking the water source from the bottom of the block, and routing it back to the pump inlet would result in MUCH cooler water being supplied to the turbo, with all the advantages of the Thermostat Outlet...though thermal siphon may not work as well from that location.
I'd feel comfortable taking water source from either place (Thermo or block) and returning to the pump inlet for turbo cooling.
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Remember the Chrysler "Lean Burn" engines of the 70's and early 80's before EFI? Some cases they were 17 and 18:1....
Iron Block, Iron Heads, hardened seats...
Industrial Stationary engines routinely run 22:1 with stochiometric precombustion chambers for consistent ignition. Stellite is your friend in those engines. Stellite Valve Seats, and Valve Faces.
Anybody up for recutting a head to optimize lean burn abilities? You got my attention.
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I think the discussion was about selling options on parts someone said they had, but didn't in all actuality posess.
But what does that have to do with a photograph of flanges that are available for sale (obviously so, since there is a photograph of them)?
I'm missing that connection, if there is one at all.
I'm waiting to see what the "protest" with the SCTA holds for the Bonneville Car, I may be making my own manifold with Turbo Usages much earlier than I had anticipated. So this thread interests me on that level.
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Yep, Float Valve is stuck down, or not sealing.
My 77 Impala would do that after a long run...would pump out of the vent in the center of the carb---would have to jump out and bang on the body to get the float to seat the valve. Bad thing was it was doing thin in 1979...
So 30+ year old SU's are forgiven! LOL
Weigh those floats, make sure they aren't leaking and filling with fuel, causing them to sink. My friend recently replaced two of his floats, as it had failed all around the solder joint at the center of the float. You can boil the floats (brass ones) in hot water....if you see bubbles coming out of the float, you know you got a leak! Sometimes you can solder over the hole you see (do it while it's hot, so the solder will be 'sucked in' as it cools, instead of having air blowing out as you heat the float to solder it!) but you have to be careful not to make the float too heavy, or the bouyancy is affected, and you end up in the same situation you were in with the leak!
Good Luck!
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Summing up what we teach our Technicians:
Surge is the phenomenon of compressor flowpath instantaneously reversing due to the inability of the compressor to continue making pressure at that given flowpoint. Air delaminates from the blades, slips backwards until pressure comes to a point where stable flow in the normal direction can again occur, and then it will repeat.
From there, there are other terms that are used, like 'pumping' whereby the compressor operates in a surge condition continuously. Bad!
Microsurging can occur when ambient conditions make the flows or densities marginal for the conditions...you can not hear it in many cases unless you mic up the compressor housing ultrasonically.
I digress...
"Backspin" or "Pinwheeling" is the phenomenon whereby the turbine is actually driven backward from an air source that has sufficient volume to drive it for a time. This would be very unlikely in a vehicular installation if there was any kind of BOV in the system...mainly because even on lift-throttle the turbine is still getting energy to spin in the correct direction, and that would have to be ovecome as well. In industrial compressors, I have seen failed discharge check valves cause Pinwheeling. But not while the unit is coasting down. It happens after the inertia of the drive is stopped, and then the motive force of stored compressed air starts driving the wheels of the compressor backwards like Turbine Drives...Failure happens almost immediately as the bearings are directional, and speeds come up so fast things just go bad, very bad...quickly.
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What I am stating above is that just because a part meets or exceeds an SFI spec that part may still not be dimensionaly correct.
This is concurrent with what my understanding of several items I have checked upon as well. When spin-testing Turbomachinery Impellers, the dimensional integrity is not determined, it's more of a 'spin to fail' or 'overspeed' mode of testing. As long as what they are checking for passes their criteria, they get their certification.
This is not to say they are making something useless, this sounds more like a bore tolerance mistake---and those things happen. If they make it good, by either reworking it or replacing it with one of dimensionally accurate machining---then it's all good.
The SFI rating regarding Structural Integrity is important to me---Clutches, Flywheels, etc.... Same for a Damper---you don't need a chunk of something flying off doing impromptu bodywork (either vehicular, or personal!) during a run!
Tolerances are always subject to buggering it up. They need to make it good, and I'd say the SFI rating is a 'good insurance' for any part put on the car, and is---as Dragonfly says, not related at all to how it is supposed to fit.
Myself, I may have been tempted to have it finish-ground slighty undersized as I mentioned above. The impellers I work with can have as much as 0.003+" Interference on a 1.5" shaft! Freeze the Shaft, Heat the impeller in a 600F oven, and hope it all goes together without cocking and binding halfway down.
Believe it or not, those parts DO come apart when it's time for overhaul as well. It just takes...er....'effort'! LOL
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Don't get greedy, the VW industrial engines were only rated about 25hp. They were interchangable with Wisconsin MV4HD engines in Military Support Equipment....the Japanese used VW Industrial Engines in their support stuff for the F15, where we used Wisconsins...and later Diesels.
The A-Series Nissan Engines were also rated similarly, and give good service life.
When you get above about 30HP, TurboDiesels rule in things like Small Tractors and Bobcats---generators as well if you want a small package.
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I watch this closely, thanks for the pioneering, guys. I'll need a better ratio for Bonneville, and was thinking of harvesting an Armada Unit as well for those tasty gears!
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Actually, Motorsport Division at Nissan recomended Locktite Green for Damper Bores to make sure there was not any chance of fretting or working the keyway in competition engines.
If you have a turbo engine that you rev to higher revs regularly, I'd be more comfortable with a tight damper that I had to heat to install (along with loctite) than a stock slip fit.
Granted, given the interference fit that was measured in this case, that is dead wrong. But 3 to 8 tenths of a thousandth is acceptable for a 'tight fit' and in some cases even more can be had and easily assembled with slight heating as noted by Dragonfly.
What it came like 'stock' has little to do with it, if you want something that won't rattle around, 'tight' is better then 'line to line'...
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Does anyone want to buy a "reconditioned" OBX unit for $300?
PM ME
I'm heading over to Los Alamitos this evening for rewiring on the Bonneville Car...for the hassle of shipping it, I can pick it up anywhere in the LA Basin. I'll be working in Torrance next week as well.
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"I was hesitant to open up the Quaife, because they don't break and the warranty card says I shouldn't, but I decided to because there hasn't been a picture thread comparing the 2 side by side."
I will bet money, if you reveal the comparison you did, and supply them with the photos....they will
1) Understand
2) Pay you something for the rights to use them as 'examples' when fielding inquiries!
Thanks for a very informative post, and I nominate for "Sticky" as well so people can see for themselves and make the decision based on what they decide they need, or if they actually want to take the time to rebuild new parts so they know they will work...
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That is Fred Sangalang's Car...his project shown at this years' MSA was a mid-engined 240Z that utilized the new Maxima Drivetrain mounted behind the seats...and it had an onboard jacking system so you could rotate the car about it's centerpoint. Really handy if you get into a deadend road and can't three-point....I guess....LOL
As for what parts are what on one of Fred's cars...anybody's guess! It may have started as one thing, but he will rework just about anything to make it fit.
Photos above a great case in point!
Should have seen his '4WDZ' that was mounted on a Bronco 2 Frame! That started out as an innocent comment one day of "Hey Fred, now the only thing you haven't done was make a 4 By 4 Z-Car!"
You gotta watch what you say around him...he WILL make it work! LOL
He will also, if you ask him, tell you exactly what he did in detail on whatever you want to know. Really a great craftsman, who is proud of his work, and more than willing to share what he did to overcome whatever challenge was presented. He is a great guy to talk to at a car show about his car---really nice! If you get the chance at an MSA show, or anywhere else, just ask him, he'll tell you.
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The XS Manifold clearly states it's for an RB20 / RB25, with differentiations on what is different between the two applications.
I bought one of their T3/T3 External Wastegate Adapter Flanges...just because. One day I might use it...or not. For the price....who cares? LOL
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Better to do a pin to pin check from the connection at the MS, and then at any juncture heading back to the sensor, culminating with a sensor resistance check.
If you get a noticable drop in resistance as you work toward the sensor, the connection you just eliminated is your problem.
It's not uncommon for resistance to build up in connections, and cause false readings. Skews them high or low, depending. Unless they are both drawing from the same sensor, likely they will be different---but not that different!
Somewhere you should be able to dig up a resistance-to-temperature curve for the sensors. That will tell you the range you should expect to see during your troubleshooting.
Many times people skip to sensor, when it's a harness connection that is the problem. Doing the pin to pin checks the whole loop first, and then you eliminate pieces as you go towards the sensor.
Good Luck.
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I'm not sure. I know the one Frank is mounting is the one from a Buick 3.8L Engine, so it should have no problem flowing correct amounts of air in his application.
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Yeah, a simple bleeder will provide for a much more 'mushy' coming on of boost. Wastegates typically open at about half full boost, and are open wide by the time full boost arrives---safety concern in OEM applications. Putting the check-ball in there really helps bring the boost on harder. That may be all you need to do to solve the surging...just let it come on a bit softer.
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Interesting Tidbit... Wish there was more delineation on what used what. I've seen both. Learn something new every day---in that case the wiring diagram is totally applicable.
And I have another source of CAS units....
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The Toyota unit is a popular L20B swap for the 510 Guys...expecially if they start playing with the Z22 and Z24 bottom ends! I was in negotiations with someone in OZ to buy his 510 setup that utilized the Toyota SC. He didn't employ the bypass, but said when declutched the rotors freewheeled under engine vacuum, so the pumping losses didn't bother him that much! LOL Fell through when his other buyer came up with money before we determined the shipping costs. Can't fault him, shipping overseas can be a PITA...And things to OZ seem to take forever to get there...coming this way doesn't seem so bad, though. Strange, huh? I digress....
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F1 was Desmodromic in some applications recently.
The DEVAS system uses electro-hydraulic actuation of valves....camless engine, uses Electronics to control opening and closing rates, time at dwell (duration)....with the DEVAS system the need for an inlet throttlebody is negated---all airflow through the engine is controlled solely through valve lift and duration. With infinitely variable valve timing, lift, and duration, this is totally possible.
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SoCal? Anything more concrete? I'm in SoCal, and finding engines isn't as 'braindead easy' as it was 10 years ago, but it's far from hard.
If you are doing a conversion, buy a car that you can see run. If you just want a core, any one is as good as another.
Costs from a junkyard run $250 to $450 including core.
Costs for clapped-out donors run in the same range, up to $1500...
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There are three NIB (New In Box) that I know of, recently acquired by accident, and I advised the buyer NOT to sell or trade them!
In Japan, I have seen LY heads bare sell for $30,000 and UP!
Having had a ride in a car powered by one, 'meh'.... A well done non-crossflow head can make just as much power, and at 1/10th the cost. The fascination with crossflow technology is more emotional than practical in most of these cases.
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Spacecase, be advised he's in New Zeland, and likely will not be using an ECU that is ECCS. The L20ET used EFI components, and did not have computer controlled timing in all cases. The 82-83 ECCS Diagram is not applicable.
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Really depends on the ECU, mate! If the ECU you are using used injector resistors, then you will need them on this setup. If it's an in-chassis modification and you are tweaking the setup using off make injectors, then your harness probably has injector resistors already installed. You will have to do a bit of tracing to find out if you do. It's a silver-grey box---sometimes formatted with 4+2, sometimes one box with 7 wires in the bottom of it---usually near the brake reservoir/booster on LHD vehicles---so on the left side of the chassis (not near your booster, right!)
Resistors normally are "X" Ohm, 3 to 5 watt. Look in the Megasquirt Forum, there is lots of limiting resistor talk there---I would go measure the resistance of my pack but it's late, the lights are all out, and it's time for my beddy bye! I know the stock setup in the Nissans is very close to what the Megasquirt formula figures out.
Timing on the L20ET is usually done via a pneumatic retard module on the dizzy, so if you have one of those, you're set. Set as normal, and make sure when you put pressure to the diaphragm on the dizzy, you can see the idle timing (check with a timing light) retard 1 or 2 degrees per PSI applied. There will be a Limit, around 10 degrees, if you need more retard due to bad fuel you can modify the retard mechanisim to allow more retard by clearancing the stops, or simply convert to Megasquirt and program what number you want! LOL Generally 24 degrees at 10psi is considered normal, if you don't have pressure retard then you may be limited to setting total advance to 24 degrees and living with it (then you buy an MSD Boost Timing Master, so you can run 34 total, and dial in your retard in pounds per psi...then you see the Megasquirt Suggestion above and search for buyers for everything else you already bought! LOL)
Christchurch, huh? Here's a long shot: Do you know a bloke named Kevin Lowe---Registered Compressor Engineer for Comp Air New Zeland? Motors about in a 32 Ford Lowboy Roadster and runs gymkhana...
Like I said, it's a long shot...
Cheers!
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Can't you download the data for storage to an off-ECU device?
I thought SDS had that ability. If it's all resident in the ECU, then you must manually write down everything?
Man, that's a drag!
Good news Bad news -Turbo Surge
in Turbo / Supercharger
Posted
Yeah, using compressed gasses that have a tendency to explode in the manifold may have sufficient force to overcome turbine inertia well above idle speed!
I someplace have nice photos of an impeller that actually had the blades bend backwards enough to score the root of the next closest impeller valley ... before shelling out completely, breaking off, and migrating to the diffuser portion of the scroll, and parts downstream. "Violent Surge" didn't begin to explain it...until the owner admitted he drove into a puddle and immersed the turbine inlet under boost from a stuck throttle. Turbo didn't like to pump water. Oh, that explained it! LOL