MustangWorks.com : Ford Forums - View Single Post - If you have a GT-40 intake and need to go with a 1" phenolic spacer READ

MiracleMax · 07-17-2001, 11:45 PM

Just curious? why are you running a 1" spacer?

Any time you lengthen the the runners, it shifts the torque peak lower in the RPM range (I guess with the stock cam this might not be a problem). If the GT-40 has a comparable runner length to the stock manifold then this might sap some power off the top end (how much I couldn't say?) If the GT-40 has a shorter runner length then things might end more or less even or skewed in favor of a stock cam?

I've got a phenolic spacer on a carbed engine and its about 7/16" to 1/4" thick and does a bang up job of insulating the carb from the manifold. (I would say the manifold is in the 120 to 150 degree range and the carb is barely over 100 degrees when the manifold is to hot to touch).

A 3/8" thick spacer would probably provide similar insulating benefits without altering the tuned aspects of the manifold as much.

07-17-2001, 11:45 PM	#3
MiracleMax Registered Member Join Date: Apr 1999 Location: Hayes, Va, USA Posts: 798	Just curious? why are you running a 1" spacer? Any time you lengthen the the runners, it shifts the torque peak lower in the RPM range (I guess with the stock cam this might not be a problem). If the GT-40 has a comparable runner length to the stock manifold then this might sap some power off the top end (how much I couldn't say?) If the GT-40 has a shorter runner length then things might end more or less even or skewed in favor of a stock cam? I've got a phenolic spacer on a carbed engine and its about 7/16" to 1/4" thick and does a bang up job of insulating the carb from the manifold. (I would say the manifold is in the 120 to 150 degree range and the carb is barely over 100 degrees when the manifold is to hot to touch). A 3/8" thick spacer would probably provide similar insulating benefits without altering the tuned aspects of the manifold as much.