The 430 Lincoln in my 1937 coupe is always fouling spark plugs. It has 10:1 compression and doesn't like the unleaded regular gas I feed it. I retard the timing accordingly. So I'm going to try mixing e85 to the regular gas and see if there's any improvement. It has 62 jets in the 4100 autolite carb, power valve is plugged. It does run rich with the unleaded regular. Another question is will a multiple.spark discharge ignition box clean up the plugs? I have used them before and seemed to really smooth up the idle and part throttle. Did I break the rules for mentioning the msd ignition? Thank you for any help
Why is the power valve plugged? It's job is to let the mixture be correct under different operating conditions. And how do you expect it to run right with even more alcohol in the fuel? MSD ignition might make a hotter spark, but a stock ignition system, in good condition, will not let plugs foul, if the rest of the engine is working properly. and how does it run with premium fuel, and the timing where it should be?
This plug fouling had been a ongoing problem. I couldn't get the stock distributor to keep the point gap so I switched to a Petronius. Then took a long time to get the advance figured out. I just plugged the power valve to eliminate a possible fuel problem. I'm getting there,. Wouldn't e85 lean the mixture?
I don't know what you are doing, but stock 430's with 10:1 compression didn't foul plugs. I had a 64 Lincoln for about 10 years and never fouled a plug. Is it gas or oil fouling?
An MSD will help the overall ignition action...BUT...if the engine is running rich...FIX THAT problem, DON'T crutch it ! Sounds like you need an "Air-Fuel" ratio gauge to tell you "exactly" what's happening with the carburation. As Squirrel states, you NEED the power valve for the engine to run correctly. It shouldn't be leaking, if it is, get a fresh one. But again, the engine will NOT run correctly with the power valve removed/plugged. ***Are you sure that the spark plugs are "fuel" fouled and not "oil" fouled ? I find it odd that (I presume) a stock carburetor will fuel foul spark plugs. If the jets are stock/original, you have a completely different problem. If they are not original to that car, then get the original sized jets. And as far as E85 fuel is concerned, that's another sticky-wicket you will be getting into. That can be a powerful tool IF the engine is tuned for it. Just use the gas that you will "normally" buy in you area(s) that you drive in. Don't go buying specialty stuff that you normally would not buy, just to try to "fix" an internal problem. Fix the problem, don't crutch it. Mike
What year 430? Exactly how are the plug(s) fouling (wet-dry-carbon-oil fouled)? The first year of the 430 (1958), FORD had to cut down the CR as there was no pump gas available to run it properly. How did a FORD CARB 4100 get on there? You have a 12V SYSTEM? You need the power valve.
Sounds like valve guides or seals. FOMOCO liked umbrella seals which deteriorate over time. I replaced mine with PC style and plugs stay normal. A good working stock ignition or Pertronix will work the same a hotter plug may help but not a cure all. I believe the power valve of a 4100 was called an economizer. When they failed the engine fan rich. Many don’t understand them and used a plug. . Good Luck.
it is definitley fuel fouled. heads have new guides and seals. no smoke on start up like valve stem seals do. I will get a new power valve, but was having trouble determining what number to get. the cam has been reground to 428CJ specs, so I was not sure how to get the correct vacuum reading to get the right power valve. I have been fighting the ignition problem quite a long time now, so now ZI have to figure out the fuel. I rebuilt the autolite 4100 carb, they are pretty simple carbs to rebuild, so I think i got it right. I will try the stock size jets too. thanks for the help, never get too old to learn.
You cannot build a carburetor that is dual, or even tri-fuel. E0, E10, and E85 all have different stoichiometric air fuel ratio requirements. E0: 14.7 E10: 14.08 E85: 9.733:1 You might be able to split the difference on jetting in-between E0 and E10, but you cannot match E85. Modern E0, and E10 will not plug read the same as old-school gasoline. It will be off. E85 plug reads very differently. If you are set on running E85, it is often best to start with a carburetor that was built for alcohol, and to use an wideband Oxygen sensor to tune it. Of course, a wideband Oxygen sensor would be calibrated for E0, so for each other fuel, or mixture, you would need to mathematically compute the offset, and interpolate the range. That is, however, if you are having pinging issues with a proper mixture and timing on the current configuration. Freestyle mixing E85 with E0 or E10 will leave you with an unknown stoichiometric air fuel ratio, and will vary by fillup, unless you are using graduated containers. Keep in mind, E0 has a stoichiometric range of a maximum of about 12.5:1 to 15.5:1 (and 15.5:1 is potentially dangerous for a non-EFI, not spark controlled engine). For perspective, E85 has a stoichiometric range of a maximum of about 6.98:1 to 8.47:1. Note how VERY different those ranges are. TL;DR: Putting E85 in the mix will lead to rage and/or tears.
Another note: If you build a dedicated E85 fuel system and end up out on the road, low on fuel, and are unable to find E85, putting even E10 in it might snuff your plugs getting to an E85 station.
Put the right power valve in and the stock jets and you problem should disappear! 62s are too large for the front of the 4100, on a street machine, IIRC! Bones
You need to get the carb right first. But Dad was a Lincoln guy, and he had a number of them including a 62, and a 67 460(?). Mother would putt around to the grocery store and hair salon and then complain the car didn’t run right. Dad would take it out (my chance to ride in the front seat), get on the freeway slow, and hammer the car up the Kennydale hill. Biggest cloud of carbon you’ve ever seen. Mom would go putt around for a month, and I’d get another ride for a cheap thrill. They need to be tuned carefully and driven. In something light like a 37 in todays world it’s probably not as easy.
The FORD 4100 and HOLLEY 4150/4160 use the same theory. The article describes how to arrive at correct POWER VALVE (FORD TERM - ECONOMIZER VALVE) SOURCE - HOLLEY TECH ARTICLE - https://www.holley.com/blog/post/how_to_tune_the_power_valve_in_a_holley_carburetor/
thanks again for the help. I think I actually drilled out the front and rear jeat to .070! I was desperately trying to figure out the worn out distributor and junk Power master starter that would only turn the engine over with the timing retarded way too much too run on so I had to manually turn the distributor to get it started and then t advance it to run. I thought the starter was weak, but just didn't beleive my own trouble shooting. So the distributor is fixed, new point plate and prtronics module. so now the fuel problem that I thought would fix it.
took a compression test. #3 cylinder has 120# compression but is dead. ill try a new plug and see what happens
UPDATE. I took a compression test of all cylinders and all have 120# give or take 5#. Pulled early plug wire and found #3 we're not firing, no change of the running of the motor So I took the top off the carb and shot carb cleaner through the booster and air bleeds. Put it back together and it runs great.
If you're running 62 or 70 or whatever jets in the primary, you are most likely rich enough that you will foul plugs, and I'd be worried about washing down the cylinders. I think my Thunderbird's 390 has 54s in the primaries. A couple version had larger jets, but most were smaller (some had 48s). See the chart below. https://www.carburetor-blog.com/knowledge-base/autolite-4100-jet-sizes/
I wasn't gong to ask until I figured out what I had missed in a previous post, but apparently a few others have missed the same thing I did. I too, am confused.
Power valve sizing is based on engine vacuum readings, so put a vacuum gauge on it and size the power valve at just less than half engine vacuum at idle. So if it had say 10" of vacuum, I'd go with a 4.5 PV. Betting it's more like 15" of vacuum so maybe around a 6.5-7.0
Cleaning out some carb passages and then having 2 dead cylinders come back to life sounds like a coincidence rather than finding the cure. Sounds more like a temporary plug wire connection issue.
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