Im not sure whats going on here. This 8BA I have keeps fouling plugs. Not just one, but all of them. The strange thing is it didnt do it before. I drove it for 3 years without a problem. Its a stocker with 2 97's. 45 jets. edmunds heads with autolite 386 plugs. Somehow it managed to foul the plugs while I was going down the highway last week. Not sure if I should run hotter plugs??? (what would they be?). Its a mallory dizzy. Only thing I changed lately was going from an Offy super dual to an Edmunds 2x2 to clear a generator. Any advice?
Dry black fluffy deposits are an indicating a rich mixture. Make sure your mech power valves are seating and dont have any dirt/grit keeping them open which would cause a rich mixture. Are the PVs new? Trying to find out if a 97 PC is leaking can drive you nuts. They also need a gasket under them to prevent leakage - if the gasket has slowly deteriorated then they could be leaking. Are you running a good /fresh fuel filter? Rat
Yeah I know its running rich. The power valves are new 65's. I guess I could take them out and check them. Would that cause it to load up like it is?
Are those power valves still rated like...65 is a 6.5 in of vacuum? If so then I would hook a vacuum gauge up and see what it's running down the road and idle also.If you think you have a power valve issue. Just an idea.If not you are probably just jetted too big for a stocker. Headed out to Salina in a minute! Later, Lippy
Stromberg PVs aren't vacuum operated... I want to say I heard that the new replacement Stromberg PVs have a longer needle on them, bringing them into play slightly sooner, but can't recall where I heard this, or if I imagined it (****s getting old!)... They can also be damaged if you install them with a regular screwdriver...
It can damage them... At the end of the day, it's a valve that is held closed by a spring and opened with a plunger. Any damage to the plunger or the valve will result in leakage...
I had the same problem with two 97's on a Fenton 2X2 manifold, also using a Mallory dual point distributor and a Max One cam. When I built the 8BA motor, I replaced the stock #45 main jets with #43's. Still too rich. I recently went to #38's. Much, much better! No black soot anymore. I also considered the adjustable type jets.. too pricey. Here's a good link for replacement 97 stuff. pigpen http://www.thehotrodcompany.com/shopnow/show_dept.asp?dept_id=50&filterkey=jetpv
Don't stop thinking yet; your car's performance CHANGED without you doing anything to carbs. Something could have altered mixture, like if you have little chrome filters a stray gnat could have lowered air flow there, or your emulsion yubes could have gotten plugged up air bleeds... OR Mallory could already be breaking down from bad rubbing blocks or grounding of th connector straps inside, its main bad points. Failing ignition can mimic richness... You just might be correcting an ongoing problem with jets that are outside the carb's normal range here. If you have the little chrome cleaners, first test is ALWAYS to take a ride without them.
Good to hear that. What size jets did you wind up with? I've been checking the plugs every so often on mine. The #38's seem to be doing just fine. A rich mixture will not always show itself right away and can appear to happen "all of a sudden". With clean plugs it takes awhile to load up. pigpen
I had the same problem with mine 239 +0.125 8ba,,engine is ported with 97s on a Navarro racing intake and race camshaft from H&H....first had change the mallory dual point and put a chevy modified from Bubba's,....car run a little better but the plugs were black in 10 minutes !!.....so i think my engine can't support all this fuel with those modifies...i change the jets from 45 to 37.....now the engine starts and runs really better ....plugs are in a nice color.....bingo!
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