602 Water Bypass Lines

[brad hibbard]

602 Water Bypass Lines

We have commonly seen hot water lines connected to the ports below the carburetor on 602 engines. For racing applications this connection is completely WRONG.

The cavity in the 602 manifold below the carb is not attached to the cooling passages and should NOT be plumbed into the cooling system.

The intended use of this cavity is to heat the carburetor for winter time driving in a street application.

For racing application, we strongly recommend removing the pipe plugs to allow air to pass through this cavity.

NOTE: There are appropriate water bypass systems for 602 engines, however for this tech tip segment we wanted to emphasize what is NOT correct.

see the attachment below
Brad
www.race-1.com

[Bmod141]

Brad, this may be a stupid question, but are those passages tied to the exhaust system?If so, wouldn't that be an exhaust leak?

[mod71m]

Actually those ports are intended for water to be plumbed through them in a marine application. A good idea would be to plumb some C02 through there!!!

[brad hibbard]

that's a good question Bmod141----older style heads and intakes did have an exhaust port running across the center of the heads and through the intake ----however the votec style head has eliminated this passage and that was an excellent change for the racing application as we strive to keep heat off of the intake manifold

if you recall on those older heads we use to block that exhaust from getting to the intake

the heat being applied to the intake is for street driving applications primarily for cold weather driving
If you are in your 50's or even 40's I am sure you remember how hard it was to keep a carbureted vehicle running when it was 30 degrees outside----that exhaust heat was intended to help that

when GM engineered a "street" intake manifold for the vortec head they used water from the cooling system to help heat the intake for cold weather drivability
the intake on a 602 engine is a performance intake but does double duty as street version for the vortec head

in racing applications we do not want the heat

to directly answer your question ---NO you will not have an exhaust leak
you will not have any leak what so ever by removing them plugs


mod71m---interesting thought about marine application----not sure I can comment on that because I do not have any info either way ----I wonder though if the marine application would pull cold water from the lake and run it through that cavity "cooling" the intake manifold ----that would be sweet
I like the CO2 thought but most tech guys get uptight when they see a bottle strapped to a chassis---LOL

Brad
www.race-1.com

[Bmod141]

Thanks for the quick reply, Brad.

[mod71m]

I'm not sure if they are cooling under the carb or warming it up for cold starts. My boat with a Mercruiser engine has water lines connected there but I've never paid much attention where the lines are routed.

[mod71m]

The next idea is to connect a helmet air blower up there. It's a lot safer than a CO2 bottle in the race car.

[brad hibbard]

now your talking-----not sure its really worth it though

I was helping a guy many moons ago when 602's first came out and we ran a hose from the nose piece and into a brake duct air funnel back to the right side port of the intake and a hose from the left side intake port back under the car as an exit---------I don't think in the real world it really did anything but it sure grabbed a lot of attention from the competitors

just keep the hot water out I am sure is close enough