Hands-on experiments since the '70s in Performance (GPM) and/or Economy (MPG)

[Road Trip]

In the interest of full transparency, while I have no regrets with any
part of this whole Cobra replica subroutine in my life, it doesn't exactly
reflect my personal style. As a matter of fact, if I were to bid on a
storage locker and hit the jackpot, I would do it all over again, but this
time aesthetically a little more like this one:

"...and at full noise in 3rd, it sticks to the road like paint."

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(credit: consumerguide.com LINK)

And this:

Imagine a time when this car was only worth a normal car...and you could lean against it like this?

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(credit: supercarnostalgia.com -- LINK)

So that's the look that I feel most comfortable with. You know, understated. Faster Than It Appears.
(But as 1/2 owner of the yellow one there's some give & take to be had. No problem, after 10 years I finally got
to make the motor best suit my own sensibilities. The car makes people smile, and if we fire it up at
a car show people come running. Everyone involved walks away happy.

A couple more period photos that I've collected over the years. I first saw
this photo as a youngster, and if I was a pinball machine this was the moment
where I went straight into *TILT*:

Always liked the look of the Torque-Thrust D. Always seen on very capable cars.

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NOTE: There's debate as to whether or not this was staged. (Even if they did, I applaud the effort.)
All I do know is that 9 year old Road Trip was enthralled by the possibilities. Every time I popped a
wheelie on my bike this image was circulating in my noggin.

And then I saw how these guys made it run like that. Man, I want to do that too!

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NOTE: Back in the day, the 427s got all the ink, while the 289s won all the road races.

Back in '00 when we had ordered the kit and were gathering the bits, try as we might we
could not find a restorable side-oiler 427. So, after reading about how the
more balanced 289s won all the races, we decided to use modern technology
(AFR heads on a roller cam block) in order to make iron block/head/intake 427 power
while only paying the aluminum head/intake 289/302 weight penalty. (!)

Sometimes when you can't get what you really want, you end up with a better solution
despite your best efforts to the contrary. :0)

The moral of the story? Parents, pay attention to what your kids are looking at. If asked what
warped my outlook on life, I would reply that I'm a victim of the lure that the Dragginsnake duo
were polluting the car mags with back when I was young and highly impressionable. :0)

Enjoy your toys --

 

[Road Trip]

I know that with this crowd that 'if there aren't pictures it didn't happen.'

Only problem is that the majority of the photos documenting the Cobra
build are marooned on a hard drive in an old decommissioned Windows XP
desktop buried _d e e p_ in a storage unit. Even so, I managed to find the
cam sheet showing what we picked to right our original wrongs.

And as part of the Sunbeam Alpine resurrection effort, I want to make
sure that Erik sees this too.

****

But before I go into the best overall solution, I first must explain how
we were talked into being too greedy, and ended up with something
that only drove best when driven in anger...

So, sitting beside me is a December 2000 MM&FF magazine. On p.167
is a detailed dyno article by Richard Holdener titled "Pulse Width -vs-
Power Valve". (Carbs vs. Computers -- Round 2)

In the article they took a 306ci SBF, put AFR 185cc heads on it, stuffed
a hydraulic roller Comp Cams XE282 cam in it (.565"/575", 232°/242°) ...and
on their dyno, a claimed 454hp @ 6200rpm, naturally-aspirated. No
exotica, something we could mimic, and approximate our goal of getting
close to the 427s of yore without the associated big block FE weight/handling
penalty...plus the octane appetite for near Avgas.

Compared to everything else we had researched back then (back when
64-bit Alpha-powered Altavista was the best tool we had to use) this
was the real-world hot setup. So that's exactly what we did.

Once the car was together, the full throttle behavior was everything we
had hoped. As a matter of fact, the F*rd Motorsports clutch was right
at it's limits, taking a quarter-second or so to grab on full throttle 2-3 upshifts.

On the brand-new World Class T-5, we attempted to forestall cataclysmic
failure from shock loading by filling it with 5W-30 Mobil-1 instead of the
watery thin ATF spec'd. (An old trick we had learned from wailing on
5.0 'stangs back in the day. I'm happy to report that it worked! That
same tranny is still in use 22 years later. (!)

Downstream of all this, the 3.73 posi in the 8.8" diff from the donor
car drew zero attention to itself. (Stock aside from a fresh set of
posi clutches and a F-150 preload spring upgrade.) A far cry from
the rear ends we kept feeding the original '75 Chevy Monza that we
had stuffed a LT-1 style 355" motor as our previous project...but
that's another story for another day.

The good news is that we had managed to generate enough power
that if we went for any more go under the hood we were going to
have to upgrade immediately to a stronger clutch + a TKO tranny (definitely)
and a F*rd 9". (maybe)

The bad news? First of all, we found out exactly why the power peaked
at 6200 in the article and dropped off like a stone immediately
afterwards. The hydraulic roller cam would float like clockwork
at 6200 rpm, even though we had the triple valvesprings on
the AFR heads.

And the other bad news is that we also found out why the dyno
run started at 3000 rpm. Because below that there was a mighty
torque deficit. Not that obvious in a lightweight car in the lower gears,
but the engine simply couldn't carry (overdrive) 5th below 75mph.

Of course, it would come on the cam and do license-losing justice
to 80+. So I told the co-owner to just drive it in 4th when it
was wisest to observe the posted speed limit. "No. The
sidepipes get old while cruising on the highway in 4th on longer
trips."

And I couldn't argue with his logic, for he was right they *did* get
old! Back in the '60s & '70s all we had to work with in our pony cars
were 1:1 top gears, so we just got used to buzzing down the
highway. But by the '00s, thanks to being spoiled by all the OD
vehicles starting in the '80s, this simply wasn't going to cut it.

(Years go by, stuck in this loop. About 10 years, for my
daughters were in college & took financial priority over this
1st-world 'too bigga cam' issue.)

****

Sorry it took so long to set the stage, but after agonizing
over what to do & then having to wait to implement it,
here is the cam that made everything right with the world:

The mechanical computer that unlocked the 6200>7500rpm door. No mo' valve float! :0)

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More lift + Less duration + Solid Roller + Improved Quench + Carb upgrade = Bliss.

Alright. Was going to make all this happen during the off season, but due to deployments
we missed an entire driving season waiting to put it back together.

Well, after what seemed to be a forever wait (Are we there yet? Are we there yet?) ...
the fall day came when we fired it up. A good 90% better behavior, but the original
Holley 4150/60? carb was now the driveability LIMFAC. More research (and a TDY) later,
and with the help of the following carb upgrade, we finally had Q-jet level driveability
on an square-bore intake compatible form factor. (See attached photo for 770cfm Holley 4-bbl.)
(And if any carb guys are reading this, here's a great article where they tested
annular discharge venturis vs. the original dogleg style. LINK)

So imagine a clear, brisk January day, after maybe 18 months of downtime, we put the new
carb on the refreshed/upgraded motor & head out towards the Interstate. The first
thing I noticed was the absolute lack of throttle lag, even at low speeds. At least as
good as a factory HiPo 289 with a much more streetable cam. Goal #1 accomplished!

And also on the way, the car now pulled 5th cleanly at 50+ mph. At 65+ mph highway
speeds, downshifting was purely optional. Goal #2 accomplished!

And then, when I power merged onto an empty interstate, the first time I sent the tach
right of the scale, and the engine was still pulling like a Ducati with the desmodromic
valvetrain, I was complete. Goal #3 accomplished.

****

Before I leave this subject, I'd like to add a statement made by a piston designer named
John Erb about the critical importance of getting the quench correct. And since we
no longer have the super high octane fuels of yesteryear, the following is even more
important than ever:

Be sure to pay close attention to the baseball bat/coffee can analogy. Way better explanation than I ever could attempt!

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(credit: Follow this link)

So Erik, in the spirit of the GMT400 forum, I have now divulged all my secrets to building
a SBF on a mere mortal's budget and then getting to eat a BBF worth of cake afterwards.

And, in the spirit of a timeless classic movie...

I hereby triple dog dare you to revive that Alpine. ;0)

 

[Road Trip]

"Welcome Back My Friends To the Show That Never Ends..."


If you were to ask me if I was satisfied with the current state of
the Cobra, I'd have to reply both yes & no.

Yes, because it does all that we had hoped it would when we decided to
embark on this big adventure back in '00.

No, because I'm really into sound, and I'd love to hear that engine
sing through this setup:

Individual runner chorusing is the sound of an internal combustion choir at full song

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Q: Would it be any faster?

A: Unsure. Maybe once a season when all the stars align, and the baro matches the calibration?

Q: Would it be as reliable as the modern Holley it would replace?

A: I don't think so. There's a lot of fiddly bits. Pretty darn close to herding cats for a results-oriented carb guy.

Q: Why would you do this then?

A: I could easily justify this upgrade on the superior sonic characteristics alone.
And if the engine looked like thus I could declare it my signature SBF creation
& finally leave well enough alone. :0)

Probably will never happen. The guru on these setups (Jim Inglese LINK) gets more
for one of these 4x2 setups than I paid for my entire '99 C2500. Common sense
dictates that if I add value to my needy GMT400 instead of messing around putting
nice-sounding jewelry on top of an already perfectly running toy, the value proposition
is simply way better.

But, it's always nice to have a little something to
dream about while running the blast cab. :0)

 

[Erik the Awful]

289, right? 4.00" bore x 2.87" stroke? A set of beehive valve springs & other
stealth upgrades (modern aluminum heads painted to match the rest of the engine?)
...and that car would be an absolute hoot!

The Alpine had a 1.6L 4-cylinder. Tigers got the Ford 260 - the 289 hadn't come out yet. Mine's probably going to get my old half-bridgeported 12A rotary. It's probably 220 hp with a 9,000 rpm rev limit. I have a lot of other projects to get out of the way first, though.

I have a friend who has a genuine early Cobra that was wadded up on a race track many, many years ago before the prices rocketed up on them. He bought it and has been rebuilding it for about twenty years now. It was wrecked so hard that he had to build a new pedal box. I think he started with pretty much a VIN and a pile of scrap.

 

[Road Trip]

The Alpine had a 1.6L 4-cylinder. Tigers got the Ford 260 - the 289 hadn't come out yet. Mine's probably going to get my old half-bridgeported 12A rotary. It's probably 220 hp with a 9,000 rpm rev limit. I have a lot of other projects to get out of the way first, though.

OK, thanks for the clarification - it's appreciated. Sounds like your Alpine was more like
my 1.8L 4-cylinder Fiat Spider. And I should have known the about the Tigers & the 260?
I must have read about a Tiger owner doing a Day-2 restoration with a HiPo 289 upgrade
and thinking that was a clever choice.

The rotary into the Alpine sounds sweeeet! A 9K beer keg under the hood would be transcendent.
Who needs a white-haired uncle with a red Barchetta when you have that combo ready to rock? :0)

I have a friend who has a genuine early Cobra that was wadded up on a race track many, many years ago before the prices rocketed up on them. He bought it and has been rebuilding it for about twenty years now. It was wrecked so hard that he had to build a new pedal box. I think he started with pretty much a VIN and a pile of scrap.

Truly lucky b@st@rd from this vantage point. (Though having to sort out something that
wadded up feels anything but lucky when you are at the business end of that kind
of project.)

FWIW, I do still remember that after what seemed to be an endless, non-stop
thrash on a then 10-year old $1,000 '75 Monza, we were all so sick & tired of
sequentially locating the next weak link in the vehicle after overpowering it...that
we all took an extended break, licked our wounds, and (I thought) that we had finally
come to our collective senses. :0)

But then, maybe a dozen years later when my same buddy broached the subject of building
a brand new Cobra replica from scratch, I felt that I could no longer hide behind the
excuse that my lifetime quota for road salted rust specs to fall into my eyes
had already been checked...and away we went.

Anyway, I can appreciate your friend's vision. Sounds like he suffers from the same
addiction that we do. And the lesson from all this is one should be very careful of
the people that he/she hangs out with.

Cheers --

 

[Erik the Awful]

Just about five minutes ago I learned that the last year of Tiger production got 289s. You weren't wrong!

 

[Road Trip]

Just about five minutes ago I learned that the last year of Tiger production got 289s. You weren't wrong!

Looks like the '67s came with the 200hp 289. Of course a few owners took it upon
themselves to further upgrade to the high winding 271hp HiPo 289. (I think I read that
the 4-cylinder was rated at 80hp? 3x the power would be easy to feel the difference. (!)

But forget about all that motorhead mumbo-jumbo for a moment. Look at this little beauty.
A '66 in Sherwood Green, minilights, and the current owner has already upgraded from the
260 to a 289:

Check out that hood -- looks to be in better than Day 1 showroom condition. (!)

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(Credit: Here's the LINK to the barnfinds.com article.)

So, if you were to follow that link there's a newer Holley 4-barrel sitting on top
of a cast iron intake, which in turn is bolted to a pair of cast iron heads.
And there's a cast iron flywheel out back.

Imagine putting that motor on a modernized aluminum diet (heads, intake,
flywheel. 100lbs (up high) for a pair of cast iron 289 heads. Switching to
aluminum would cut that in half. (Right at 50lbs per pair!). -15lbs going
from cast iron to aluminum intake. -12 lbs for aluminum flywheel.

Imagine taking 77 lbs off the front end? And that the CG actually improves
because the heads & intake are on top of the short block? Last but not
least, on the last dyno run the 306ci we brewed up was 380hp at the
rear wheels. (Back with bad old roller hydraulic cam artificially limited to 6200rpm.)
NOTE: We have not dyno tested the B&B V2.0 motor discussed earlier, but this
new engine seemingly pulls even harder than before? And definitely higher!

One last thing. The aluminum version of the SBF weighs just over 80 lbs. But the
lightweight thinwall '85+ cast iron roller cam block only weighs 118 pounds.
(Personally verified -- and this is actually a bit lighter than the older '60s-era blocks.)

So, a stealth upgrade to a lighter roller-cam block, throw in a modern lightweight mini starter,
and a total net improvement? You would be flirting with a near 100lb total weight reduction
vs. the old '60s era cast iron 260-289s!

(If I'm not mistaken, we got the 306ci motor to just under 400 lbs fully assembled --
it seems that we were closing in on the goal of getting the motor to a 1hp
delivered for every pound it added to the curb weight of the car?)

****

Of course the wail of the 9K beer keg is a siren song to be sure. And no
doubt you would be well over double the hp while at the same time lighter than the
4 cylinder it's replacing?

But, it's always savvy to have a Plan B in your back pocket just in case Plan A hits
an unforeseen showstopper. (You know, we ain't getting any younger... :0)

Man, that sure would look nice sitting alongside my Indigo Blue metallic
8-lug chore truck! Hey, that old guy sure is living cheerfully in the past --
just look at his vintage fleet! :0)

Sherwood Green Sunbeam, now with extra suds!

 

[Erik the Awful]

But, it's always savvy to have a Plan B in your back pocket just in case Plan A hits
an unforeseen showstopper. (You know, we ain't getting any younger... :0)

My current showstopper is that the stock suspension geometry sucks and Girling brake calipers are non-existent in the US. I have Mustang II control arms, GM metric calipers, and a '78 Corvette master cylinder ready to fix all those problems, but I need to fab a front crossmember, which I haven't done before.

 

[Road Trip]

Alright. Re-reading through some recent posts in a troubleshooting
session, I feel like I'm giving the impression that all I ever strive for
is a perfectly smooth idle. Which is the furthest thing from the truth.

That would be like me implying that all I ever listen to is Windham Hill
artists like Michael Hedges. I do enjoy that calming genre, but there are times
when the situation I find myself in requires a different sonic soundscape.

I've come to realize that I listen all across the musical continuum. And
given that in my old gig I was subjected to random drug testing as
a matter of course, good music became my recreational pharmaceutical
of choice. Well that, and listening to engines intently. :0)

And after a lifetime of listening to engines in all different states of
tune, I find similarities there as well. What does this have to do with
how engines idle? We've already established that a smooth idle is
highly desirable on a stock, emissions-legal DD. And that a
weak/erratic/random idle is obviously undesirable?

****

Choppy brings a little intensity...a good thing. And lopey has a
happy bounce to it. But for me, if the engine has a distinct
polyrhythm to the idle, then I simply fall under the spell of
the aural promise of a good time behind the wheel.

Check out this video. It's something we threw up on YouTube
as a test video. (Think proof of concept version 0.1) As a matter
of fact, the thumping bass of the exhaust was bottoming out
the tiny built-in mic in my camera...so when you hear the pop pop pop
in the soundtrack that's a recording fault, not a feature. :-(

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In this video, the owner is torquing the connecting rod bolt
& installing a piston ring; meanwhile I'm throwing sparks about
halfway through. And on a windows laptop, you can tap the
spacebar while watching the video in order to pause/restart
the video. (Again, this was just an experimental video.)

Note: The tiny speaker in your iphone or laptop won't do this
much justice. A full range home theater works much better.

Bonus video: Here's a video of a drummer demonstrating
the percussive polyrhythm foundation that Tomas Hakke is
laying down underneath one of their band's toe-tapping tunes:

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@1990Z71Swede, what it going on over there in your neck
of the woods? It seems that Sweden's musicians and mechanics
march to the beat of a different drummer?

Music sweet music...

PS: I was working solo, so I was unable to include what it sounds like in
Drive. She's a a bit fast in Neutral, but loaded down in Drive it sounds
twice as good while maybe 20% slower. You know, from the eager
sound in the video to just a lot more attitude. We get a lot of
thumbs up from fellow enthusiasts while waiting at the light.

 

[Road Trip]

So, to be perfectly honest, in order to give the customer who owns the
car above (who's also now a good friend) *both* a snappy street ride AND
the sound track he wanted, I couldn't break the laws of physics...so I cheated.
A little.

When he was trying to describe the sound he wanted, I gave him a homework
assignment to listen to as many vehicles as possible, both in the real world
and in YouTube, and then play for me his favorites.

Meanwhile, I did the same thing. And for a small block, the sound of a factory
L79 (350hp 327ci hydraulic cam) was right in the sweet spot. When you heard
a car with the L79 idle, you just *knew* that fun was in your immediate future!

The good news was that when the owner came back with his favorite, it sounded
much the same. I played him the best restored L79 car I could find ('67 Chevy II,
a beauty of a factory sleeper) ...and he was all in!

****

Comp Cams actually offers a Nostalgia+ version of Chevy's mid-'60s offering.
Original sound track combined with some modern touches for mo' power.

Of course, the cam jockeys in the audience know that putting a cam like this
in a larger displacement 383ci stroker would actually smooth it out & tame the sonic
signature. But given the Turbo 350, slightly looser torque converter, somewhat
tall gearing in the back, and overall weight of the '70 Chevelle, I didn't want to
go any bigger on the cam...even though the customer was very clear about wanting
the car to dance a bit even while sitting still.

****

So here's what I did. FIRST, I made the car idle as smooth as possible and
wrote it all down. Ported vacuum advance. (ie: no vacuum advance at idle.)
Then, fairly tight springs on the centrifugal advance weights in the distributor.
(no centrifugal advance at idle.) And finally, set the idle mixture screws for
highest vacuum/smoothest idle. And the result? Way too smooth.

Now, it was time to methodically deconstruct the smooth idle. I first leaned
out the idle mixture screws until there was an unmistakable chop added.
Maybe 1/2 or 3/4 of a turn each from the max vacuum setting? Now the
needle on the vacuum gauge was bouncing quite a bit.

Next, I moved the vacuum advance hose from ported to intake manifold.
Oh, yes! Now, with the spark timing bouncing around due to the intake
manifold vacuum fluctuations, now we had some quality thumpity thump
thump!

Then I had to slow the idle down a bit, for the vacuum advance at
idle had sped it up. This resulted in a bit dirtier idle. Beauty!

The last part is my secret, but just in case I get hit by the Ring Ding
truck, I don't want this to be a lost trick. It took a little experimentation,
but by trying different spring combos on the centrifugal advance weights,
I finally got the weights to just start oscillating a bit off the stops due
to the existing idle speed fluctuations, which added a little more swing
to the song. (Note: I temporarily put the vacuum advance back to ported
so that I could concentrate on just the centrifugal advance induced
idle instability.) That's right, I was doing the exact opposite of what
you are supposed to do -- it's so much more fun to funk up the idle
instead of trying to smooth it out! :0)

But afterwards I was sure to put the vacuum advance back to the
intake manifold, and this managed to layer one bouncing idle tendency
on top of the other = very confused and a bit nervious.
Better than I could have hoped for!

All in all, it took a couple of hours during an evening tune session in order
to get exactly what I was after, but if you listen to the video carefully you
should be able to pick out at least 2 intertwined rhythms, with a side order
of chop chop for added emphasis.

The neat part? As soon as you crack the throttle & the correctly-jetted
main circuit starts to feed, the engine instantly smooths right out and gets
down to the business of off the line torque production. And the engine purrs
when cruising down the boulevard or the interstate, just like a factory cam.
Which it is!

It's all about having the street torque curve yet still getting to eat your sonic cake too!

Build for 'right now' torque where you really drive...and then, (de)tune your
idle so that it sounds like you built the car for high speed hp at the track!

And if I was talking to a musician, I'd tell him that it wanted to sound like an
upright piano, but instead I gave it more of the feel of a Hammond B3 with all the
stops pulled out. :0)