here's what i'm thinking
More Turbo
Joined: Dec 1999
Posts: 582
Likes: 5
From: New Orleans United States
here's what i'm thinking
i recently bought the O2 sensor and mixture guage out of Summit's catalog and also bought a crossover tube to mount it in to be able to adjust both sides of the engine. What they don't tell you is that the exhaust gas has to be 600 degrees F to work correctly. So now i'm thinking that i'll just but one more mounting ring and welding it to the other header collector, higher in the system and pluggin it when not in use. That way i can swap the O2 sensor to either header and get a true reading so I can finally win the battle with the slightly oversized 750 Holley. And it's on a mildly built 400M.
Fleet Owner
Joined: Jun 1999
Posts: 24,552
Likes: 74
From: Creedmoor, North Carolina
here's what i'm thinking
brt, pitch that carb and put a 600 cfm on there and most of your problem will be solved. I believe you are trying to force more gas in the engine than it is able to use.
IMHO, of course
John
jowilker
66 F100s
In the still cool hours of the night, you can hear chevys rusting away.
IMHO, of course
John
jowilker
66 F100s
In the still cool hours of the night, you can hear chevys rusting away.
Freshman User
Joined: Apr 2000
Posts: 27
Likes: 0
here's what i'm thinking
If you went up on the cylinder bore at rebuild, I recommend the 650cmf, but Jo is right. 750 cfm muy larga!! Quit messin with that monster and put something on that beast that will work.
More Turbo
Joined: Dec 1999
Posts: 582
Likes: 5
From: New Orleans United States
here's what i'm thinking
I got the 750 for nothing and can't fork over the cash for a new holley. Plus i'm gonna port match the intake and exhaust ports and open up the exhaust side of the head a little more. I'm Using the O2 sensor to monitor the mixture in real time so i can tell what needs adjusting on the carb.
Junior User
Joined: Mar 2000
Posts: 89
Likes: 0
here's what i'm thinking
I remember my dad using a vacuum gauge to check his carb settings. I do not remember the exact set up, but maybe one of these other fellas can give you the details. I just remember him hooking it up to a line out of the intake manifold (maybe the vacuum line going to the tranny). He was able to check the timing this way and then used a heavy piece of heavy cardboard and slowly started to place it over the top of the carb. If it sped up, he adjusted the idle mixture screw until it evened out. He kept doing this until there was no change in the idle speed until the cardboard nearly sealed off the top of the carb. I believe these gauges are relatively inexpensive and can be used to check other system functions also. I tinker around with mechanics of a vehicle, but am not a mechanic. I tear up just as much as I fix most of the time. I should have payed more attention to what pops was doing when he was trying to teach me something about them as a kid. I just thought this might be easier to do than trying to get an Oxygen sensor to work.
Mike
'64 F100 Short-Box Project
Rebirth of "Salvage Yard Scrap Iron"
Mike
'64 F100 Short-Box Project
Rebirth of "Salvage Yard Scrap Iron"
