Water flow through the L series heads

Engine, Transmission and related drivetrain.
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bertvorgon
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Re: Water flow through the L series heads

Post by bertvorgon » 03 Mar 2018 10:51

It was in talking to one of Don's crew members that I started to put in some of the gauges I have. Only way to know what was going on. They had so many sensors on that car.

As I progressed to the hillclimbs I wanted to see what my actual discharge temperatures was going into the motor. Slaloms were no biggy as there was never any real full throttle over time. I put an air temp gauge into my air box, which at the top of Knox, after a 2:02 run showed 350+ F. ! Time for the inter-cooler. The next year at the top of the hill the temp was down to about 135 F. I basically picked up 22 HP by the temp drop and the engine just felt way more responsive in the mid to top RPM. I then did a test by having I think Byron spray cold water on the inter-cooler while in pre grid. This kept the inter-cooler at ambient or slightly below, instead of massive heat soak before a run. This test prompted my inter-cooler spray system, where I could fill the washer bottle with ice water and manually keep the inter-cooler soaked, even sitting on the line. I did get into trouble once as the start line guy thought I had a water leak, as I was pouring a ton of water on the cooler sitting there and of course it dripped onto the pavement.

Keeping things cool across the board just helps too with preventing detonation, which this thread is basically about.
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

Keith Law
1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
1968 Vintage 3HP Mini Bike
1971 Vintage 13' BOLER trailer

510rob
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Re: Water flow through the L series heads

Post by 510rob » 03 Mar 2018 14:01

Some picture of that engine, either in Keith's collection of photos, or in the Honsowetz book, shows another angle of the mess of intake bits-n-bobs that reveals a curious trick they employed that would have been very high-tech for their time. There are secondary injectors mounted to the bottom-side of each intake runner, pointed 'backwards' at the plenum...

Chickenman
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Re: Water flow through the L series heads

Post by Chickenman » 03 Mar 2018 15:49

bertvorgon wrote:It was in talking to one of Don's crew members that I started to put in some of the gauges I have. Only way to know what was going on. They had so many sensors on that car.

As I progressed to the hillclimbs I wanted to see what my actual discharge temperatures was going into the motor. Slaloms were no biggy as there was never any real full throttle over time. I put an air temp gauge into my air box, which at the top of Knox, after a 2:02 run showed 350+ F. ! Time for the inter-cooler. The next year at the top of the hill the temp was down to about 135 F. I basically picked up 22 HP by the temp drop and the engine just felt way more responsive in the mid to top RPM. I then did a test by having I think Byron spray cold water on the inter-cooler while in pre grid. This kept the inter-cooler at ambient or slightly below, instead of massive heat soak before a run. This test prompted my inter-cooler spray system, where I could fill the washer bottle with ice water and manually keep the inter-cooler soaked, even sitting on the line. I did get into trouble once as the start line guy thought I had a water leak, as I was pouring a ton of water on the cooler sitting there and of course it dripped onto the pavement.

Keeping things cool across the board just helps too with preventing detonation, which this thread is basically about.
Yeah... a lot of guys use CO2 sprayers on Drag Cars. They leave the line typically with Intercooler Temps below 0 C.

I used Water sprayers on the Blue Camaro when I still had the Tiny GM Metric 10.5" front brakes in 2003 to get my Road Racing license back. GM W/wash tank i about 2 gallons. Hooked W/Wash motor up to horn button. Used Garden Irrigation " Fan Misters " in brake ducting. Worked slick.

I did tell the Starter and Chief Steward that I was using water sprayers and not to Black Flag me if they saw " Smoke " coming out of the brakes, as it was actually just Steam. Sure enough.... I got called in any ways.

Apparently one of the Turn Marshals panicked when they saw " Fire " from my brakes. Apparently they had never seen rotors glowing at over 1,000 F at high noon before. The Hawk Blues also lit up like Halloween Sparklers when you got the Rotor temps high enough. Poor 10.5" rotors took a beating..

The Red rotor temp paint was turned a lovely shade of White. I think the Red Temp triggers at 1,200 F. Never lost the Brakes though.....

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