Bogging in the Swamp

[Anonymous]

Did these modifications to the Comet yesterday

1. Installed new pushrods and adjustable rocker arm assembly
2. Changed idle jet on the 5200 from 90 to 55
3. Plugged vacuum advance, tried setting it at 38 all in but got pinging, ended up with 20 initial no ping.
4. Adjusted tranny modulator in 3 turns

Response and power are GREATLY improved. I no longer have to baby it off the line, the bog is almost gone. I know this is a lot of initial timing but the motor likes it though I still have some bog. My primary is 346 and secondary is 325. Should I reverse these? I tried running with the air cleaner off but it made the bog worse. Putting the cleaner on makes it richer, right? Also the bog was completely gone with 25 degrees initial but I had pinging. So should I go richer or leaner?

I love the sound when that second barrel comes in, the turbo muffler is sweet.

Thanks
don

 

[Anonymous]

Trying to figure out what size jet's to order.

Last night was cooler and even though the car was warmed the bog was back. This makes me think it is too lean as the cooler air is denser. Once I get the rpm's up there is no bog, none in the secondary either. It is bad only when the car is cold or the weather is cool or when I take off the air cleaner.

Thanks,
don




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[barishiman]

how can I tell what jets I have on my Holley/Weber? The 2brl is a new experience so I want to soak up as much info as I can.

Andrew

 

[Anonymous]

you'll have to take the top off of the carb and unscrew the jets from the bottom of the floatbowl

 

[Anonymous]

Trying to figure out what size jet's to order.

Last night was cooler and even though the car was warmed the bog was back. This makes me think it is too lean as the cooler air is denser. Once I get the rpm's up there is no bog, none in the secondary either. It is bad only when the car is cold or the weather is cool or when I take off the air cleaner.


The Chevette I have uses a 5200 carb and suffers from the same problems as yours. The problem is ususally related to what we in the chevette circles call manifold icing. The presuure drop through the carb and into the manifold cause a large temp drop which when the humidity is high and temps lower causes actual ice to form in the intake!! This causes a bog and loss of power. The solution is a heated air supply and adjusted choke. My jetting is just right on my carb and this problem disappeared once it fixed my carb and hooked up the tube from the exhaust manifold to the air filter assembly. I've had the problem appear in temps as high as 78degrees so try these ideas before you mess with the carb jetting.

 

[Anonymous]

That makes sense. The OZ intake has fittings for water that I have not hooked up. Also I read in another thread about a "thermostatic" air cleaner. I suppose a trip to the junkyard is in order. I can be quite dense at times. something my wife will attest to, but it makes sense that I take advantage of the enginering Ford did to get the engine to operate in it's optimum range. Now what low profile aircleaner should I look for, was it the 4-cyl Fairmont?

tks
don

 

[Anonymous]

Oki;

The 4-cylinder Mercury Capri (1970-1975) had 2000cc engines with the H/W 2bbl and low-profile air cleaners that sort of wrapped over the top of the engine. They also had the thermostatic control, bimetallic type, so no extra vacuum hoses were needed to run the thing, which would be most convenient. I would, however, cut short the air horn as much as possible, because it had a long snout to reach the front of the engine compartment for cooler air and less noise inside the car. The snout was a little small for the 200 CID six's lungs.

All of the 4-cylinder Fairmonts I remember had vacuum control for the thermostatic valve, which will mean installing a vacuum switch into the cooling system (usually in the coolant thermostat housing) just to make it work. That's OK if you don't mind the extra plumbing, etc., but the old Capri setup is cleaner.

 

[Anonymous]

MarkP,

Thanks, thats just what I needed.

don

 

[Anonymous]

The 5200 carbs were on the fords and chevys and unfortunately they used a different bolt arrangement for the bolts that go into the air cleaner. Make sure yours has the ford setup and not the chevy one!!