[MWP]

Apologies if this has made the rounds before--I didn't find it in an archive search. Saw it on the internet while (of course) not looking for it, and thought it was pretty interesting.

A fellow figures out that using a small restricted coolant bypass (the steam pipe) in the heads will solve a steam pockets problem without affecting coolant flow, and thus enables reverse-flow cooling for GM's new LT1 engine. GM disassembles his engine overnight, steals the idea, backdates fake documents to deny the theft, won't pay the inventor. Kinda like Ford and the intermittent wiper inventor, as in the movie "Flash of Genius" (2008).

Maybe an old story to others, but new to me--changes how I look at that pipe now!

Did GM steal the innovation that made the LT1 possible? The decade-long legal battle. - Hagerty Media

The skunkworks of the era were built on handshakes and late nights at the track. John Evans had opened his own shop near Lime Rock Park and was a regular brainstormer for GM engineers who flocked to the tracks to see how racers were using their creations.

www.hagerty.com

 

[1slow96]

Also encourages additional coolant circulation at the very back of the motor.
Which tends toward being hotter.

 

[96Lt1civi]

I've seen that one, pretty neat story! Sucks GM completely stole his idea, in the dead of night too like some cat burglar lol.

 

[96 Black]

[snipped]
.
.
Maybe an old story to others, but new to me--changes how I look at that pipe now!

Did GM steal the innovation that made the LT1 possible? The decade-long legal battle. - Hagerty Media

The skunkworks of the era were built on handshakes and late nights at the track. John Evans had opened his own shop near Lime Rock Park and was a regular brainstormer for GM engineers who flocked to the tracks to see how racers were using their creations.

www.hagerty.com

I had never heard of this, and great find. I agree it was a game-changer for us motorheads and upping performance overall in the market. Unfortunately, it didn't change {but only reinforces) my perspectives regarding the company. More appropriately most all meglaton size and mentality corporate culture. Unfortunately.

 

[stonebreaker]

NASCAR mechanics and others have been using steam pipes for years, back in the days when they used stock configuration smallblock heads. By putting a steam line in the head just above the siamesed center two exhaust ports, they increased coolant flow enough to prevent boiling. So while the guy may have come up with the idea on his own, I don't think he was the first.

 

[sherlock9c1]

By putting a steam line in the head just above the siamesed center two exhaust ports, they increased coolant flow enough to prevent boiling.

Steam out, or coolant in?

 

[stonebreaker]

Steam out, or coolant in?

Steam out was what I remember reading, but since we're talking about race cars, I'm sure there are examples of them going both ways.

 

[95wagon]

Yeah , didnt see the head bleeds as a new thing.
I put a pair of AN 3 lines on the back of the heads of the TA - IMSA Camaro I built in 1984 and it wasn't new then!!
Angle of the engine played into it as well as many race cars the crank is level to the ground.

Having to bleed an LT1 , sorry seems like a no brainer, is extra important as the only other path for air to escape its heads is down.
I think ( with no supporting data ) RPM, the turbulence would remove a lot but during low speed , the pockets of air would build and build.
We have one engine that has large pockets in the heads that there is no way to get air out at rest. It MUST be vacuum bled.
It rarely runs at anything less that wot and high rpm and never has cooling issues.
I would surmize these heads would be a complete disaster on a street car

Same as steam holes in siamese blocks.
Big deal in street cars , high RPM race, not so much. This explained to me in the '80s by
Jim Cavallaro (look him up) as his company prepped a couple bowtie blocks for us.
Now that said we have a small bore block here that Katech drilled bleeds between the liners so maybe things have changed again.
It also pumps water to the center 2 exhausts of the bowtie heads.

 

[BALLSS]

I had "heard" GM got its nuts wacked for stealing the reverse flow steam pipe thing..

Cool post OP

 

[1slow96]

There's nothing "reverse flow" about the steam pipe IMO. Drill/tap a pair of heads from an ordinary SBC ,and the steam pipe will behave the exact same way. Likely providing the same benefit of increased coolant circulation for the rear pair of cylinders. Hard to claim inventing steam ,or a pipe... Just another application for rather ordinary item that has been around quite a while.

 

[tayto]

i was under the impression that gm stole the whole reverse flow thing, not just the steam pipe.

 

[1slow96]

Is reversing the flow of coolant that unique an idea that anyone discovering some advantage to doing it in a spacific application be precluded from doing such without paying royalities to one person when the idea may have occurred to litterally hundreds of others from time to time.

 

[stonebreaker]

i was under the impression that gm stole the whole reverse flow thing, not just the steam pipe.

They may or may not have, but the article that was linked said it was the steam pipe itself that was patented.

 

[GoremanX]

i was under the impression that gm stole the whole reverse flow thing, not just the steam pipe.

GM had reverse flow cooling in its arsenal since 1955, when the Pontiac V8 was first launched. Therefore they didn't need to "steal" anything. The reverse flow cooling was dropped in later years when accessories started getting mounted to the front of the engine rather than the top, due to lower hood lines. This presumably blocked some of the required plumbing at the time. But Pontiac developed reverse flow cooling for the exact same reason: to cool the heads first and increase compression ratio with less risk of detonation.

The innovation here wasn't reverse flow cooling, or even the use of a steam pipe. It was the development work that went into figuring out the ideal size and placement of the steam pipe to make reverse flow cooling viable and beneficial in this application. Evans did the work, and based on his story, GM stole the design outright. I don't know how much of his story is true, but having some first hand experience with GM's tactics during those years, I'm inclined to believe it's very likely.