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Living in a cage of fear
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Discussion Starter #1
Got them on and all set up to test.
Float levels set.

Ran it on the trailer today, everything looks great for testing tomorrow.

5 lb. pump pressure.

Primary jets are 75's, secondary's are 76's, PV are 6.5, primary squirters are 25, secondary are 31's. (30cc pumps on all 4 bowls)

Idle at 1100 RPM, 11 in. vacuum, 20 degrees in at idle, 34 total all in at 2600 RPM.

Sound right?

It runs awesome on the trailer, hits hard and fast at the crack of throttle.

They are to holley specs except for the 6.5 PV, (Holley says 8.5) and the secondary squirters are 1 number higher I believe.

(30 over 454 with 9.5 CR, 575 lift Hyd roller, 295 advertised duration)
 

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Got them on and all set up to test.
Float levels set.

Ran it on the trailer today, everything looks great for testing tomorrow.

5 lb. pump pressure.

Primary jets are 75's, secondary's are 76's, PV are 6.5, primary squirters are 25, secondary are 31's. (30cc pumps on all 4 bowls)

Idle at 1100 RPM, 11 in. vacuum, 20 degrees in at idle, 34 total all in at 2600 RPM.

Sound right?

It runs awesome on the trailer, hits hard and fast at the crack of throttle. holley specs except for the 6.5 PV, (Holley says 8.5) and the secondary squirters are 1 number higher I believe.

(30 over 454 with 9.5 CR, 575 lift Hyd roller, 295 advertised duration)
What cylinder heads?
 

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Living in a cage of fear
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16,462 Posts
Discussion Starter #3
What cylinder heads?
Brodix 280 cc rectangles. (BB1 with 119 chambers) I have ran these for 3 years now on the same engine with 660's, wieand TR. Pulled 5600 RPM at 86 MPH in the Miller with a stainless A and the 660's, but damn did suck the fuel!!
That's the primary reason for the carb swap.
 

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Living in a cage of fear
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16,462 Posts
Discussion Starter #4
OK, this seems strange to me.

Ran the boat all day with the new carbs. It ran great, nearly identical to how it performed with the 660's on it.

Last pass of the day I made another 80 MPH blast, let off and it started missing and misfiring pretty bad. It still idled, and I limped in to the trailer.

Got it home and pulled plugs. 1-5 were covered with black soot, but a decent brown underneath it. (From idling in, my guess) 6-8 looked absolutely brand new, no color what so ever?

I did a cranking test, 150 lb. on all cylinders dead even. Pulled the valve covers, everything is in order, nothing bent, worn, or out of place.
Float levels still correct.
Timing is still correct.

Basically, I can find nothing wrong with it. Getting ready to pull the carbs and plug PV holes and square up jets?

Could header water have washed the rear plugs clean like that?
 

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Tommy, don't panic! could have hung a float after a hard blast and washed a couple of cylinders down !Try it again. IMLAO. M
 
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