Merge collectors

Billy Nees · 10-03-2015, 03:56 PM

Quote:

Originally Posted by Darrin Christen

Interesting read. What would be the tell tale signs that a engine may be over scavenging? Anything noticeable in the tune up that would be an indicator of this condition?

Pretty much an over-simplification but the car won't be responsive to timing or jet changes.
If the combo can handle it, open up the exhaust lash and make a run.

junior barns · 10-03-2015, 04:26 PM

Been out of racing for about 15 yrs but I can remember when we changed from our Stahl headers (2 inch) to a Davis step header (2,1 7/8,1 3/4). Didn't see much gain until we added an 18 inch extension on the collector. Really brought it to life.

What was it trying to tell me???

Lee Valentine · 10-03-2015, 05:59 PM

Billy is dead on,you can't seem to get it rich enough. You'll be putting jet in that makes no sense, loosening the exhaust lash and picking up shows the exhaust is pulling unburn
,ed fuel out on overlap,

10-03-2015, 04:26 PM	#2
junior barns Senior Member Join Date: Jun 2006 Posts: 541 Likes: 11 Liked 20 Times in 14 Posts	Re: Merge collectors Been out of racing for about 15 yrs but I can remember when we changed from our Stahl headers (2 inch) to a Davis step header (2,1 7/8,1 3/4). Didn't see much gain until we added an 18 inch extension on the collector. Really brought it to life. What was it trying to tell me???

10-03-2015, 05:59 PM	#3
Lee Valentine Senior Member Join Date: May 2004 Location: Brookfield, CT Posts: 708 Likes: 13 Liked 319 Times in 68 Posts	Re: Merge collectors Billy is dead on,you can't seem to get it rich enough. You'll be putting jet in that makes no sense, loosening the exhaust lash and picking up shows the exhaust is pulling unburn ,ed fuel out on overlap, __________________ Lee Valentine 1661 STK

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