[ETD66SS]

"I" took the intake off of my LS-6 to bead blast it. "I" have a mororso lifter valley oil baffle that the previous owner removed. Also he left the intake crossover ports open. The engine had a 1/4" Mr. Gasket heat dissipator between the holley 4150 and the aluminum intake. What exactly does the intake crossover do? Should "I" put the intake back on with the lifter valley tray, block off the crossover ports, and use the heat dissipator under the carb?

 

[Fred Aldrich]

Exhaust cross-over heats the intake manifold and carb when starting cold. Heat valve at outlet to right exhaust manifold is a thermostatic device that's closed when cold forcing exhaust gas through cross-over in the intake manifold. If you're looking for the absolute max in performance, close off the crossover and disable/remove heat valve. Drivability cold will be awful and warm-up will take a long time but that's the price for slight performance improvement.
Lifter valley baffle serves a similar purpose, it keeps internal engine heat off the bottom of the intake.
My '69 396: Headers, open exhaust crossover, no heat valve and a baffle. Warm-up is slow but I can live with it since I only drive the car in the summer.

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Fred Aldrich
Web Site: www.GeoCities.com/~69_chevelle


[This message has been edited by Fred Aldrich (edited 04-17-99).]