Adapter pitfalls

[johnsjunque]

First post here....

Going to a Edelbrock 7116 intake manifold on a 350 sbc Volvo Marine engine with a Q-jet carb,

This is after install of a LT4 roller cam and Vortec heads.

The intake has a square bore  mounting (2 oblong holes) vs the spread bore of the q-jet.

I've seen adapter plates with a 4 hole set-up. (the two larger holes are hollowed out)

Other adapter plates are fully open with a widened area in the wider throttle plate area.

Supposedly, the plates can be used to install a square bore carb on a spreadbore intake and

if the plate is flipped over, can utilize a spread bore carb to a square bore intake.

Are there any problems associated, i.e. leaks/ performance issues with these adapter plates?

John

[omaha]

just the noemal things you have to watch out for like warped surfaces. sinch down the carb then unbolt it al and look for the impressions left on the gaskets, this will give some idea as to if its sealing in the correct areas or not. the impression shoud transfer. Other bad things about the adaptor is that it increases the plenum volume (good, bad ???depends) raises the carb up, disrupts some of the flow due to the transfer of the square pattern to the spread bore pattern.(smoothing with a burr helps this) the raising of the carb somewhat screws with the signal to the carb but usually the effect is negligable. One other tidbet is that some of the adapters leave the a baseplate screw in a non closed off position so that the screw could potentially falll off into the engine because the plenum is open, this cant happen on a factory intake cause it is "closed off" (just the butterfly holes are open to the plenum)