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Spockie-Tech
Site Admin
Joined: 31 May 2004
Posts: 3160
Location: Melbourne, Australia
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Both of those, while interesting, are lousy videos.
The BMW vales werent filmed with a high-enough rame-rate camera, causing the video to show anti-aliasing/strobing effects, which lead to a bunch of n00b commentorss to start crapping on about valve float, (which it clearly isnt doing if you understand video frames and beat notes) ..
it just *looks like it is*, due to the beating between the movement and frame rate. More video/sampling-rate aware people can see the beating that fades in and out as the movement and video frame rate go in and out of sync.
They should have shot it with a high frame rate camera, or at least put in an explanation of why what people think they're seeing isnt so.
The second one is the same 2/3 of the 4-stroke cycle looped over and over again, with the last 1/3 exhaust stroke completely missing and just cut out and the ends spliced, which ruins its use as a suitable visualisation of what the inside of an engine really does.. trying to show that to someone who didnt already know what happens in there would just confuse them..
So while sort-of-interesting, a big FAIL to both of those videos as far as I am concerned. hmph (grump grump  )
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Fri Nov 19, 2010 12:33 pm |
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Spockie-Tech
Site Admin
Joined: 31 May 2004
Posts: 3160
Location: Melbourne, Australia
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quote:
Originally posted by Valen:
To be fair that was a very worked older engine, against a slightly warmed stock.
yes, "very" worked.. a mild cam, some extractors and triple webers.. omg, worked to the max !
not to mention that video was the 1971 *3* speed Manual E38.
The 1972 E49 has a bit bigger a cam, some bigger jets, and a 4 speed man. Worked to max huh ? 
quote:
and the xr6 has A/C, cruise control and a back seat ;-P
Cruise control and a back seat you can keep.. who wants rug rats in the back and a sleeping driver at the wheel of a sports car ? Buy a Station Wagon for the family man if thats how you wanna roll..
A/C is nice, which is why I'm retrofitting it to my Charger for those summer day tours
quote:
1/4mile times haven't really improved in the falcon range too much.
Exactly. 30 years of "Progress" with lightweight components, EFI, computer controlled everything, half the car is plastic, modern tyres and suspension, and the low-tech, 3 speed, normally aspirated, carb'ed old dog can still kick its wimpy hi-tech turbo ass.
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Tue Nov 23, 2010 4:07 pm |
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DumHed
Experienced Roboteer
Joined: 29 Jun 2004
Posts: 1219
Location: Sydney
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quote:
Originally posted by Spockie-Tech:
yes, "very" worked.. a mild cam, some extractors and triple webers.. omg, worked to the max !
doesn't seem to be a mild cam, with solid lifters. Forged pistons, ported head. Balanced for higher revs, etc
Triple webbers are are fairly serious upgrade, dollars wise especially!
They've definitely spent a bit of cash on that engine.
The 265 Hemi is a really nice engine though, really responsive, pretty good on fuel. Way ahead of the other local offerings of the time.
In normal standard form though they were about 160hp, from 4.3L.
A Datsun 260Z from the same era had 160hp from 2.6L
They're very different engines, from very different cars. A friend used to have a Charger when I had a 260Z.
The zed loved to rev, and the car handled really well with its proper independent suspension and lighter weight.
The Charger had massive torque down low, and was great fun to accelerate hard in, but it really didn't like to corner... or stop. The gearbox was also painfully slow to shift which made the awesome acceleration between shifts a bit frustrating
quote:
who wants rug rats in the back and a sleeping driver at the wheel of a sports car ?
A Charger is hardly a sports car
It's a muscle car / performance car, etc but it's all about power, not precision!
quote:
Exactly. 30 years of "Progress" with lightweight components, EFI, computer controlled everything, half the car is plastic, modern tyres and suspension, and the low-tech, 3 speed, normally aspirated, carb'ed old dog can still kick its wimpy hi-tech turbo ass.
The main difference is comfort and safety. Car are way heavier now, so they need all the extra power to give similar performance.
The problem is that people want to be able to drive around in airtight silence and be able to run into anyone and anything and walk away...
There are not many real drivers' cars left any more...
There is a sweet spot though for performance vs over complexity, which seems to be in the early 90's.
Unless you're talking about very expensive cars, where some of the new ones are very quick around a track - even with a lot of weight - it's MUCH cheaper to get a 90's sports car to do good lap times than it is to do the same in a 70's car.
I'm about to have a very light weight 260Z on the track, but I very much doubt it'll be anywhere near as quick as my Silvia was - even with more money spent on it.
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Tue Nov 23, 2010 6:09 pm |
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Spockie-Tech
Site Admin
Joined: 31 May 2004
Posts: 3160
Location: Melbourne, Australia
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quote:
Originally posted by Valen:
@Spockie-Tech
no, but 30 years of advances have whats more, my missus wanted me to get the car say that about your big boy toy ;-P
Heh, you dont know my lady, do you ?  I *can* say that.. She *encouraged* me to embark on the current major rebuild of my boy-toy after it sat in the paddock for a few years (after being crashed into by someone).
Maybe the average missus prefers a modern troop-mover to a boy-toy, but Mel isnt your average woman..
She drives another 70's classic.. This is her Targa-Top 280z
@dumhed. Ok, a nice balanced view, but thats not how rev-heads are supposed to rah-rah at each other..
According to the details for that vid, its an original-spec E38, which *is* a mild cam. I had an E38 cam in my Hemi for a while, and they are nothing wild.. The E49 is a bit lumpy, but the E38 is a very streetable cam.
Forged Pistons, balancing etc do nothing for the power output, just reliability and the original E38 made 280Hp back in the 70's, with the E49 making 300.. I have Dyno sheets for my Hemi in E38 spec (without the triple webers, a 4 barrel at the time) making 280hp.
And those 1/4 times for that rebuilt E38 are identical to what the factory cars made back then, so theres nothing particularly "worked" on that video compared to the original car.. thats what they *really* were like, which is why they held the fastest-accelerating australian production car record for decades.
Agreed, they are more of power/muscle car than a "sports car", but as long as the road isnt too bumpy (which tends to throw the torsion bar and leaf suspension around a bit), you might be surprised at how well they do handle when driven hard. In New Zealand, they dominated every race they were entered in due to their handling and power.
As for a 260-Z vs a Silva.. The Silvia probably is more cost-effective in terms of $ vs lap times, but park the two side by side and guess which one will get more appreciative looks, and which one you would rather driving ?
Of course to some people, they're all just shaped metal boxes with wheels, but its all just doof-doof-doof to some people too..
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Sat Nov 27, 2010 8:38 pm |
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Spockie-Tech
Site Admin
Joined: 31 May 2004
Posts: 3160
Location: Melbourne, Australia
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Ive been in Silvia's.. they give too much of that "new car" feeling.
A sort of plastic cocoon feeling.. no doubt they handle well, but as an article I read put it, newish cars are like having sex with a condom on. If you can't feel the metal vibrating under your skin because of the plastic layer, its just not the same..
The Solid Cam in that video is probably because Hydraulic Cammed Hemis have an annoying habit of intermittently developing lifter-clack that comes and goes at random.. (I think its caused by the cam moving around a bit at idle, so mine has a retaining button).
But I put solid lifters in my hemi too.. You adjust them about once a year (or less if you do up the lock nuts properly) and they're fine. My cam is a close-to-E49-spec one, and is no different for being solid than a hydraulic is.
I agree on the 240's.. A friend of mine is restoring one at the moment.. The 240's and 260's are more of raw racer feeling car. The 280's seem more of a refined "Ladys Car", with Air-con, power steering, Auto, and Electric Everything. The Factory Targa-Top is nice in summer though, and it still moves pretty quick for a small 6 being a small car.
The problem is the amount of rust that the 240s developed is insane.. *If* you can find one that isnt a pile of oxide then they usually need a lot of work.. With his, he went to Qld to find a useable one and I still I dont think theres a square meter of the car that hasnt required major repair surgery on it. He had a pile on the floor about a cubic meter in size of rust that had cut out of the car and welded new steel back in.
We were looking forward to having a race to see who could dial in their triple webers better, until I decided to add in a Megasquirt and Nitrous..
I'm keeping the webers as Throttle Bodies and they will be able to run, but after a few baseline tests, I'll probably pull the venturi's out for better airflow.
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Mon Nov 29, 2010 8:31 am |
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