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

[Hipster]

What a video! I actually get goosebumps listening to him wind
out that 9000rpm SBC and speedshifting with authority. That's
gotta be the best 19 seconds in all of YouTube. :0)

One of the reasons I always had this guy on a motorhead pedestal is that
he went into every single nook & cranny looking for a performance advantage
over his competition. Check this out -- after watching him rowing through the
gears here's a short blurb (from a '68 Car Craft article) on how he modified
his transmission to give him the ability to reliably shift like that:

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How cool is that?

And right around the time I was in high school I discovered
his new book titled "The Chevrolet Racing Engine", and I read
that over and over. Some stuff (like cleanliness) I got on the first
pass, but there was a lot that I didn't fully comprehend for a long time.
(Longer than I care to admit in public. :0)

But man he made me think. Pretty much single-handedly turned
me into a lifelong student of internal combustion. What a gift
he gave to a perfect stranger he never met. (!)

How to make 2hp/ci using '75-era technology

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I recently reread my worn copy of this book, and I was
impressed by how much information he was able to convey
using clear & concise problem descriptions, setting up the
solutions he had devised. When he talked about how
he was combating several degrees worth of spark scatter
issues because the camshaft was winding up and releasing
(front to back torsional twist) because of the super stiff
valve springs they were running? My mind was blown.

****

Anyway, thanks for sharing that video, which triggered
this particular trip down memory lane. And I'm glad
you enjoyed some of the tall tales of my misspent youth.

Fun stuff!

Cheers --

Got into something similar with Harley transmissions, deburring gears and light polishing makes them silky smooth in normal operation and they drop in gear under load better, an company named Andrews makes back cut gear sets etc. unrelated but seems to follow some of the same principles. Just making sure everything is proper.

 

[Sean Buick 76]

very cool thread I enjoyed reading it all!

 

[Road Trip]

-- When the Squish/Quench Zone becomes the Crunch Zone --

Recently there have been a couple of posts elsewhere in this forum focused
on what happens if the engine accidentally ingests a foreign object? These
posts reminded me of an old project back in the mid-'90s where a buddy
bought a basket case with low mechanical expectations & I offered to help
out with the drivetrain.

The motor was obviously seized tight and couldn't be turned over with a
breaker bar. A price was agreed upon, and the basket case (in the form
of a '68 Corvette in need of a full restoration) with the factory 390hp 427/4-speed
subsequently became one of the more interesting yard art installations in the neighborhood.

Silent as the monolith in the movie 2001, my hope was to get the big block
to belt out it's 7-liter siren song once again.

****

Today I was able to unearth some old project pics, and here's one taken
of this 427 that will help to explain the title of this reply:

Witness marks left behind when a spark plug ground electrode is broken off at speed. (Gomer sez: 'Surprise Surprise Surprise' :0)

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6000 rpm = 100 revs/second. How long did this ground electrode bounce around, pin ball machine style, before
it was finally ejected out through the open exhaust valve and into the muffler?

What I find interesting about this picture is that it becomes obvious from the carbon
that the PO must have replaced the spark plug & continued to drive the vehicle. And
if you look at how close the piston top is to the block deck, the connecting rod is still
standing tall. Looks like the weakest link is confirmed to be the forged aluminum
factory pop-up pistons.

BBC engines are famous for being able to take a licking and keep on ticking.

But sharp-eyed readers will see an even worse problem in the lower lefthand
corner of the photo above.. You see, if the PO runs straight water in the cooling system
and the temps fall below freezing, Mother Nature's frozen water is even stronger
than the General's finest engine design.

The punch line? If the engine was just seized, we could have brought it back to life.

But this engine was truly frozen. Unless you need a really interesting base for a glass
coffee table, then at this point the only other duty that this block would be suitable for
is (with the help of a chain) to prevent a boat from floating away from your dock.

What can I say? You can bring most of them back...but not all. But taking the glass is
half full perspective, at least you can get some pretty cool pictures of the carnage.
The hard part? Finding others who also share my appreciation for this mechanical entropy.

The takeaway? Pay attention to the antifreeze level in your GMT400. A big block is a
terrible thing to waste.

As always, thanks for visiting my tiny performance art installation on the interwebs.

More to follow.

Cheers --

 

[Hipster]

The gearhead opera . I never had an issue with the two sidedraft Webers in the 2002. Stayed in tune great once balanced. But boy they sang a wonderful duet. Was never lucky enough to hear them live on anything else. I was lucky enough however to have a short ride in a 427 sideoiler clone.... goodness me but that was something to remember. Da Grump. I could watch this short video over and over. Thanks for sharing such a great compilation.

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Lol, just a casual Sunday drive.

 

[Road Trip]

Big Block Senseless Beauty Appreciation Society

During a recent discussion of the difference in the sounds of cast iron exhaust
manifolds vs OEM (or similar quality) headers, this somehow reminded me of
what I thought was one of the most beautiful cast iron exhaust manifolds ever
created. And thanks to the big block heritage, this has at least a familial tie
to the GMT400 engine bays.

Check out this portrait style photo of the Chevrolet 427ci Mark II "Mystery Motor":

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(credit: Mickey Thompson's Z06 Corvette Mystery Motor Stingray article)

This pretty much covers all the bases. And that cast iron exhaust manifold rises up to the Senseless Beauty threshold.

Much ink has already been spilled about the Mystery Motors in racing, so I won't go into detail here. But I recently happened
across the nicest photo I've ever seen of one, so I thought I'd share the wealth for all the other BBC enthusiasts in here.

Check out the attached photos for more goodness. There's a David Kimble cutaway plus a couple of photos from back
in the day.

Pretty amazing what we could accomplish when the talent was unleashed and allowed to swing for the fences.

And to think that you can buy an entire chore truck for $3K and have a decent-running descendent of the
above sitting in the engine bay. The GMT400 platform has some stout heritage in it's roots.

Enjoy --