Question for Roush 427R owners

[SwiftDB4]

Originally Posted by 209

I have the same engine as you and I don't see a kick in the pants with your improvements. Mine has been rebuilt once by Roush and I'd be happy if it used one quart per k. I got as far as 9k with the 1st motor and pushing 3k on this one. One quart per 500 hurts. Sorry about the rant. See what others say.

Guess I won't complain. I get 1200-1500 miles/qt. Sounds like oil consumption goes along with strokers? My 427SR saw the biggest improvement with a 750dp Quick Fuel Carb. The adjustability of the Quick Fuel is better than a Holley especially if you do some A/F monitoring to tune it in.

[jhv48]

For all the guys with Roush motors that have changed from the Street Avenger vacuum secondary carbs to mechanical secondary carbs, that is just the first step in improving the breathing of these engines.

You will find a whole bunch more horsepuppies if you then replace the restrictive sidepipes with ones that allow the motor to exhale properly. My stock SPF sidepipes measured about 1 3/4 inches on the inside baffle. My new ones are 3 inches. Slide a mirror inside yours and you will see how restrictive the stock ones really are.

They need to inhale and exhale properly. Just replacing the carb is only half the fix!