Tony D
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Posts posted by Tony D
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You don't need to study turbos to survive the two weeks.
I'd suggest 'Operational Fundamentals of the AK47' as more appropriate reading!
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"Supposedly Cursed History"?
It is cursed. It's the Devil Z. You never listened to Buddy Hackett's character in "Herbie the Love Bug" did you?
And yeah, cars like that do exist in Japanese junkyards (all the goodies there, just waiting for a savior...)
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irregardless of your feelings...
more education suposably will make it all better...
it's prolly never going to change...
(Multiple Periods Normally Indicate an Incomplete Thought, the verbal equivalent of stopping in mid sentence and inviting someone else complete the thought or phrase, usually an obvious conclusion or sometimes not-so-obvious. Example: "Well, when I got there and saw him with that sheep, I thought 'man where did he get those boots'...")
Yes, I had fun typing this...
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I would not put Corvette LS9 Engines, Honda Engines, or any other Engine is this discussion on boost and L28's. They are radically different combustion chamber designs.
Six Shooter must have missed my threads in other posts regarding flow through the engine where I used the example of a car making 300HP at 8psi instead of boosting it to the stratosphere on a stock head to make the same horsepower.
I think the off-boost drivability is a red herring. If your car is ported for the flow (even with say a 7.4CR), even before boost threshold the compressor will be putting in air and making power well above an N/A setup running 8.5, 9, or higher SCR. Even with a boosted engine, the 1, 1.5, or higher) boost in the SCR may return slightly better power, but not significant power at these 'off boost' areas. I think this is what JGK is getting at...
The combustion chamber design of the L28 ain't the greatest. There are things you need to do to decrease it's tendency to knock. If you don't, then things break.
Sure Cam Timing and valve events will affect it.
Sure flowing more will decrease the boost needed.
But at the end of the day, if you have a knock problem, and it won't go away then you are left with the old standbys of 'the 60's: retard timing, lower SCR, or change your cam'
riscard is getting to it saying 'FASTBURN'. Redesign of the C Chamber will really pay dividends. But this starts at $1500 on most heads. And if that design doesn't work...you are out another $1500 for the next design.
Putting it back to retard timing, lower SCR, or change your cam...
I'll admit I've run some boost numbers on my setup (Non US Market 1977 L28 with an N42 Head) without an intercooler that people said is impossible. But when BUILDING an engine...choices have to be made. And most people will not spend the $$$ for a head combustion chamber rework, or pay for total custom pistons to promote proper burn...but with a sub-standard combustion chamber to begin with, it will still be sub-optimal.
JeffP did some experiments with his setup, and it shows some interesting variances. KTM's build was X HP with a stock head. Jeff made close to 75-80 hp more at slightly lower boost pressures because of his cam and better flowing head. But both were at a detonation point. Comparing JeffP and KTM's dyno pulls will illustrate the difference between flow built into the engine. JeffP's 3.0 stroker with an 8.5:1 CR of course has more power, but that is some stroker advantage there... but down low the difference in power 'off boost' or at 'low boost' can be explained more from Stroker Advantage than 8.5CR versus 7.4 CR. If only I had my old dyno curves for a 8.8:1 curve on a stock engine...that might illustrate it better for this discussion.
Raising the compression ratio in either of these engines would NOT make detonation any better. And likely this is the situation in this case as well. Eventually BMEP of the cylinder will be to a point where detonation becomes a problem with the available fuel.
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Actually....I'm tight on time and flying back straight to SoCal may not even happen. I MAY have to ship the larger items and make the company pay for my flight to Europe. I have tickets bought for 22 September to attend Spa 6 hours with my family...and it would be nice if work didn't make me miss my 'free ride' there again this year. Last year I was working in Spain...so close...driving distance...but so far when the customer won't release you. And to top it all off, I missed the Nugent Concert in Amsterdam, and Zaragoza Spain because I ended up leaving too early. Now I see no Nugent Concerts at all, not even while I was in Michigan. Dammint!
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Yes, swapping the front tunnel housing form an RB Tranny for an L-Series tranny, same as the KA swap.
The earlier trannies did not have the larger bearing or shift rods. I'm talking 84 models. Seems to me those still had the earlier shifter linkage like the L Boxes. Later units had the better linkages like the KA Trannies.
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You blokes got a good head there...I wish I had a few to prove this to unbelievers.
And that's all the further I can go on this at the current time!
Well, looks like I will be in a position to stock up and get 'a few' of those O5L heads... I'm leaving for the Airport in 12 hours for a flight to Sydney.
OzConnection...you have e-mail! Now to comb the site for other OZ connections, I may have to drink beer with some of you guys. I only wish I had more prep time to load up on 'that which is a beech to get down under' and pack it in my baggage for personal delivery!
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Along the lines of the 'stayrod' the LD28 has a mount that incorporates a hydraulic dampner to quell engine vibrations. It's on the side that never breaks (unless you really are geared towards using a LOT of engine breaking ability!)... A similar setup on the tension side would have similar results, and knock down vibration as well.
Good Information on the poly mount! With the old Corvairs, you would put a bolt through the motor mount with a locknut to hold it together, keeping the soft rubber characteristics, limiting the torquover of the engine when launching, and keeping the engine from falling oiut of the bottom of the car should the mount fail (they did that regularly on the 60-64 models before GM came up with a throughbolt fix of their own much later!)
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On all this, there is one consideration to be remembered:
05L heads are in essence a 'blank slate' for just about any engine you would build.
You can ALWAYS remove material. With an 05L, you aren't welding a head for higher compression, you already have a small chamber---which you can always reshape bigger.
You got small ports...which you can always make bigger.
You got small valves...which you can always make bigger.
When you rationally and dispationately analyze a full-on race build, you will amost always weld up the combution chambers, hog the intake ports, and put in large valve seats. With an 05L, you won't weld that head, meaning you aren't decking the head, meaning you aren't altering the cam-to-crank distance for longest chain life...
You will do these things regardless, and the 05L is something that doens't require any welding, and the attendant work and costs involved. I would posit for a full-on build, it would likely be cheaper to build an 05L than any other head out there. That welding/straightening/decking adds expense to the build that otherwise isn't needed when using one of these heads.
You blokes got a good head there...I wish I had a few to prove this to unbelievers.
And that's all the further I can go on this at the current time!
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87 octane.... ouch. You may not be able to pull enough timing to remove the ping unless you run premium. 20 deg btdc or below on boost just kills an L28's ability to rev worth a darn.
Yeah, it seems O.K. at 18 right now. It really is extreme heat, No Intercooler and running with air filter inlet temperatures going to Palm Springs in the 150F+ range! Remember, it is the WIFE's car...she rarely runs it over 5500 anyway. If it was mine...it would be a different story. Then again, I won't carp about running 91 all the time, either!
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Watch out chaning from two squirts to one...you can get terrible drivability from that! Mine wouldn't even run that way (single squirt) due to the FPR not being able to regulate pressure consistently due to the large drop in fuel rail pressure. An accumulator is a must if you go that injection route!
You always need bigger injectors than you think you do. My wifes' car has 440 supra injectors on it!
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No photos for me... >:^(
Damn computer. I'll look on my kids with the new big LCD screen, he's hardwired to the router and not experiencing the issues I have of late on the work laptop...
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I might be totally wrong but I'm a...
DANCIN' FOOOO-OO-OO-OO-OOL
I am so glad someone picked up the correct and exact phrase I was thinking about when I put that in there! "Disco Boy" would be the 'fart joke' Simpsons reference, but this indeed is the deeper thinking viewers here!
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DOT 'Certified'? What is the FMVSS section they used for hte certification?
Sometimes newer isn' t better. Especially when you are shopping low-buck options.
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Looks like an old Dutch Number Plate...but I could be wrong, it may be UK. Need to see the back to know with that vinatage with my knowledge of the Motor Law.
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Where are you measuring fuel pressure, before or after the fuel filter?
With a T or deadheaded?
What happens when you pump from a clean bucket of fuel?
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Tomei is a high quality engine parts company that has been in the L-Engine Business for... well, since before I went to Japan and came back!
I have one of their ultra-light CR-Mo flywheels, as well as their super adjustable cam timing gear. FAR better gear than the HKS IMO.
Many times you can get the stuff through Japan EMS post for a reasonable price through an E-Bay Auction out of Australia.
I think JeffP just bought a whole buttload of Tomei Parts through the US Distributor. Couple of cam gears, etc...
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Holy CRAP!
A 2mm height difference from a bent rod is hellacious!
I was scrapping Superior Rods with 0.002" twist in them...and that was on a 10" bore, 10 1/2" stroke engine (think rod the size of your leg!)
Amazing what they will take and just keep on truckin!
I WANT PHOTOS! I'm sure a lot of other people are curious to see this one as well.
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Now I KNOW I need those half-glasses Grandpas wear! I can see the wall (floor) fine, but those hoses are nothing but a blur...
WOAH!
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I would agree that 9:1 will net you nothing appreciable, and likely will only aggravate the horsepower problems with inability to tune for anything on pump gas.
Dropping to 7.5 will not cost you that much 'off boost' drivability if the car is flowed and cammed properly...you will always have 2-3psi of boost on hand no matter what rpm you are at, so even below boost threshold the 7.5 will act like a higher compression motor because of the boost down there that is always available.
Sure, an 8.5:1 will give you 'more' off boost...but it's marginal. And if you are having timing issues then lower compression solves a lot of that criticality when under higher boost pressures.
Hell, I'm finding detonation at 10psi on my wife's ride now (115 Ambient) running 87 octane pump gas. She's carping about having to run 91... So it's back to the drawing board to pull more timing. Soon my kid will be able to drive the car, and I can trim the curves while underway.
And that one is 7.5:1! But hey, what can I say, 87 octane fuel is cheap! LOL
Good Luck!
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Strange that nobody has mentioned what nissan did in the later L28s.
They used a dual port barb on the rear of the head with an extra nipple facing forward and add a T fitting into the middle of the long hose.
It is a bypass that does the "looping" while allowing heater core to be part of the system.....but in parallel of the looping.
It is my guess that nissan wanted the "loopback" effect when the car was started cold so the temperature would stay consistent throughout the engine as it warmed up before the thermostat opened and then the thermostatic piece in the T fitting would stop the "looping"......at least until you turned on the heater.
Either way.....most every one i've seen was melted internally into a plastic blob.
Er....kinda! That is a pressure relief valve for idiots who rev the hell out of their engines cold, BEFORE the thermostat is opened. It pops open and allows bypass to the front of the pump to prevent cavitation. SEVERE cavitation. The thermostat is spring loaded to open under extreme pressure, but it didn't stop cavitation in the pump. The purpose of that 't' is to allow bypass under these severe cases of abuse. At the same time, this LOOP makes the car warm up quicker due to the faster recirculation of massive ammounts of coolant straight back to the inlet of the pump. Kind of like the AMOT 'bypass to cooler' setup used on some race cars...
For an example, I'd say it was like the guy with the gold chain who's late for the disco date in New Jersey, and jumps out of the window so his mother doesn't know he's going out again. All suited up in black with his gold chain (you know, like the guy in the AD!) He jumps into his beyotchin' ZX at 10 degrees in February, fires it up and ROARS off to the turnpike without any warmpup whatsoever.
That little poppett blows open and gives a full 5/8" recirc to really heat that baby up fast under those conditions. Not only does it get you heat in the cabin quicker by making a LOOP, but it prevents cavitation in the pump during that brief period when insufficient flow for the pump's rpm is extant.
This is explained in the valve function description in some Nissan Manual somewhere. When I read it, it was like "Oh, THAT is what that thing is for!" The visual of Disco Boy was added to help people understand what is going on in some people's heads (insert Frank Zappa Soundtrack Here...)
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1:1 is what you want.
Get bigger injectors, or bias (increase the spring pressure) the FPR for higher fuel pressure at idle to make the injectors you have deliver incrementally more fuel to make up the difference.
At 25 psi, even in an L24, I would expect a 4 bar static pressure setting to get fueling correct at that output level.
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"Rough" is a terribly subjective term.
When people dealing with mechanical seals lapping start talking about a 'rough' surface, it's a couple of heliup light bands of surface irregularity.
On an aluminum head, like Bryan mentions (insert machinist call out mark) 125 is good general number to the composition grabs. A metal gasket may need something finer, but that is dependent on the gasket manufacturer's recommendations and what sealant they have on the laminate shimpacks.
There are all sorts of things you can do to keep that gasket from walking. But when it comes down to it, the gasket manufacturer's recommendations rule the day.
If you weren't having a problem with it in 400 miles, likely nothing is wrong with the surface finish.
Then again, saying that doesn't get a $100 planing job out of you, either...
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Few mm would be a rod from another engine, as stated. Or a piston with the wrong pin height.
In either case, it's 'wrong component in engine'...
Off to Sydney Australia!
in Non Tech Board
Posted
Well, not to be Outdone by Challenger, I'm off for a month to Sydney Australia.
Any of you Aussie Blokes in the region (or not so much in the region...) send me a PM and maybe we can arrange a meeting on some of my time off during this little interval.
I'm arriving Thursday the 13th into Sydney Airport, 0630. I'm sure my local distribution contacts will want to beer me up for some period of time, but I'm not adverse to putting off their free beer for mutually split beer costs!
During the week I am told I will be out at Dora Creek (?) at some Energy Facility. But from what I'm understanding, the weekends may be fairly free.