What size carb jets are you running?
07-02-2007, 02:22 PM
#4
3rd Gear Member
Join Date: Jun 2006
Location: Northern Virginia
Posts: 528
RE: What size carb jets are you running?
ORIGINAL: sixt5
...but when i sit and idle for a while it starts flooding.
...but when i sit and idle for a while it starts flooding.
That being said, you could still be running rich with jets that are too big. There's a formula for the correct sizing (based on engine efficiency, max rpm, etc) that you can use. I don't remember it off hand, but perhaps someone else does. It was on a thread a while back. I know I havea book at home that will have it.
07-02-2007, 02:51 PM
#5
1st Gear Member
Join Date: Dec 2006
Location:
Posts: 135
RE: What size carb jets are you running?
ORIGINAL: crunchyskippy
I'm not sure I follow... Can you explain a little more? Although I don't know much about the 4150, it sounds like more of an adjustment problem (since you're at idle).
That being said, you could still be running rich with jets that are too big. There's a formula for the correct sizing (based on engine efficiency, max rpm, etc) that you can use. I don't remember it off hand, but perhaps someone else does. It was on a thread a while back. I know I havea book at home that will have it.
ORIGINAL: sixt5
...but when i sit and idle for a while it starts flooding.
...but when i sit and idle for a while it starts flooding.
That being said, you could still be running rich with jets that are too big. There's a formula for the correct sizing (based on engine efficiency, max rpm, etc) that you can use. I don't remember it off hand, but perhaps someone else does. It was on a thread a while back. I know I havea book at home that will have it.
The VE is a number that represents how well your heads, intake, and exhaust flow, (for stock engines = around 75%)
a handy calculator : http://www.buicks.net/shop/reference/carb_cfm.htm
arthur
07-02-2007, 03:33 PM
#7
2nd Gear Member
Join Date: May 2004
Location:
Posts: 349
RE: What size carb jets are you running?
If it is a 4150 and idle is all that is affected then I would guess a high float or the wrong power valve. If you are running an aftermarket cam the original #65 valve is open at idle. Try a #55 or even a #45. Adjust the float levels first though just in case.
07-02-2007, 08:37 PM
#8
6th Gear Member
Join Date: Apr 2007
Location: California
Posts: 10,468
RE: What size carb jets are you running?
For a 65 power valve to be open at idle you'd need to have a 6.5" or less of vacuum idle, and that would be a pretty radical cam. I'm running a 2,000-5,500rpm roller cam and run an 85 power valve, since that's what it runs best with. If the power valve isn't damaged and there's no leaking fuel into the manifold somehow, then it's a float issue or an idle metering issue
Thread
Thread Starter
Forum
Replies
Last Post
NorthAmericanTuning
Vendor For Sale / Group Buy Classifieds
5
11-09-2016 11:45 AM
NorthAmericanTuning
Vendor For Sale / Group Buy Classifieds
3
11-09-2016 11:44 AM
NorthAmericanTuning
S550 2015-2023 Mustang
3
03-18-2016 11:21 AM
YoungStangsMan
5.0L (1979-1995) Mustang
15
09-05-2015 07:01 PM
mustangsrforever!!!
Pennsylvania (Philly/Tristate) Regional Chapter
0
08-06-2015 12:04 PM
