All Small Six Running Rich
- Thread starter Maverick57
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- 200 ci carb ford low vacuum
This relates to all small sixes
Maverick57
New member
Installed a regulator, and it gave me control over the mix screw. Still has a dead miss at idle.
Media blasted all my plugs and after about 15mins of running, all but #5 are black as night.
Compression on #5 when cold is showing 130psi, and 65-70psi when hot. Took the valve cover off and checked valves and rods on #5, and they have a full range of motion.
Media blasted all my plugs and after about 15mins of running, all but #5 are black as night.
Compression on #5 when cold is showing 130psi, and 65-70psi when hot. Took the valve cover off and checked valves and rods on #5, and they have a full range of motion.
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Maverick57
New member
I made about a 10-mile round trip, and it seemed to clear up some. Off idle is great with no oddities. I pulled the plugs, and they also confirmed it clearing up.
Around 30mins after shutting it off, I did a compression test again, and these were my numbers.
#1 - 115psi
#2 - 110psi
#3 - 105psi
#4 - 116psi
#5 - 93psi
#6 - 113psi
Around 30mins after shutting it off, I did a compression test again, and these were my numbers.
#1 - 115psi
#2 - 110psi
#3 - 105psi
#4 - 116psi
#5 - 93psi
#6 - 113psi
You had the choke and throttle fully open for the test. . .
Maverick57
New member
Yes. I drove it 60mi yesterday and it really seemed to clear up. I'll repost pics of the plugs here in a bit, and also do another compression test.
Maverick57
New member
After a 60-mile trip.
I got a little lint from my shop rag on #6's ground strap.
Had some oil on the back 3 plugs due to some loose valve cover bolts. Got those tidied up
| #1 - 118psi | |
| #2 - 120psi | |
| #3 - 117psi | |
| #4 - 126psi | |
| #5 - 115psi | |
| #6 - 130psi |
I got a little lint from my shop rag on #6's ground strap.
Had some oil on the back 3 plugs due to some loose valve cover bolts. Got those tidied up
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Just a thought, since you don’t know the history of this engine, it would be interesting to run a de-carbon spray thru it. I used it on my outboards. It does a good job of removing carbon. It will smoke like crazy! But let it do its thing. Follow directions- not complicated 
I would not hurt to change the valve seals.
Maverick57
New member
The car had new valve stem seals put in about 2 months before I bought it.
I think it was done to combat the smoking, but I'm thinking what took place is that someone changed the fuel pump, which caused an overfueling issue because of fuel pressure overload. They put a new carburetor on to try to fix it, and over time, it carboned up the combustion chamber so badly that it was losing compression.
I changed the oil with 15w40 Rotella before doing any work on the car. That oil, after about an hour of runtime, was extremely black and gas-washed.
Once I put a fuel regulator on, the car still ran rough and smoked, but I put fresh oil in and half a bottle of Rislone. After making that 60-mile trip and rechecking plugs and compression, the engine is coming around. Oil was clean, and the smoke is down to probably 1/10th of what it was.
I'm going to remove and clean the distributor tomorrow and put in a new set of Autolite AP46's and get my timing dialed in, also going to get it on a steady diet of Berrymans in every tank or a bit and put some miles on it.
Once the oil starts to get tinted, I'll change it again and recheck compression and post updates.
In just 60 miles, my average compression went from 108psi to 121psi, so it is waking up.
I think it was done to combat the smoking, but I'm thinking what took place is that someone changed the fuel pump, which caused an overfueling issue because of fuel pressure overload. They put a new carburetor on to try to fix it, and over time, it carboned up the combustion chamber so badly that it was losing compression.
I changed the oil with 15w40 Rotella before doing any work on the car. That oil, after about an hour of runtime, was extremely black and gas-washed.
Once I put a fuel regulator on, the car still ran rough and smoked, but I put fresh oil in and half a bottle of Rislone. After making that 60-mile trip and rechecking plugs and compression, the engine is coming around. Oil was clean, and the smoke is down to probably 1/10th of what it was.
I'm going to remove and clean the distributor tomorrow and put in a new set of Autolite AP46's and get my timing dialed in, also going to get it on a steady diet of Berrymans in every tank or a bit and put some miles on it.
Once the oil starts to get tinted, I'll change it again and recheck compression and post updates.
In just 60 miles, my average compression went from 108psi to 121psi, so it is waking up.
My guess is that you’re right. The fuel pump over pressuring the carb was the major problem. I doubt that it carboned things up though. That might be more of a result of the tune or timing. More than likely it just washed gas down the cylinders into the sump and wreaked havoc on your cylinders and rings.
That you’re able to get the rings to bounce back sounds promising. My dad used to swear that adding a quart of ATF to the sump (after removing a quart of oil) and then putting about 10-15 miles on the engine before doing an oil change could get the rings to bounce back. I’m not sure that he was correct about that but I can’t see it making anything worse if it’s done, driven for 10-15 miles and then dumped and replaced with fresh oil.
Oh, one thing about Rotella. I run the full synthetic Rotella in my motorcycles and find that it is an excellent oil but I chose not to run it (or any full synthetic) on my 200 because I have read that synthetics don’t play very well with the seals and gaskets on older technology engines. Apparently, synthetics can slip past the seals and develop oil leaks. I’ve never had a problem with it on my motorbikes in about 20 years but it was something I came across in a vintage auto site somewhere.
Good luck getting the compression back up. It sounds like you’re on the right track.
That you’re able to get the rings to bounce back sounds promising. My dad used to swear that adding a quart of ATF to the sump (after removing a quart of oil) and then putting about 10-15 miles on the engine before doing an oil change could get the rings to bounce back. I’m not sure that he was correct about that but I can’t see it making anything worse if it’s done, driven for 10-15 miles and then dumped and replaced with fresh oil.
Oh, one thing about Rotella. I run the full synthetic Rotella in my motorcycles and find that it is an excellent oil but I chose not to run it (or any full synthetic) on my 200 because I have read that synthetics don’t play very well with the seals and gaskets on older technology engines. Apparently, synthetics can slip past the seals and develop oil leaks. I’ve never had a problem with it on my motorbikes in about 20 years but it was something I came across in a vintage auto site somewhere.
Good luck getting the compression back up. It sounds like you’re on the right track.
Maverick57
New member
ATF is game changer in the sump.
As far as the Rotella, I run T4 Conventional Rotella in all my flat-tappet engines. I highly recommend it, especially for the zinc content. I run it in my 1970 Cadillac Coupe Deville. Started Hot Rod Power Tour this past June, burning 1qt every 150mi to 1/4qt every 500-600mi by the end of the 2000mi trip. Usually swap to 10w30 Rotella in the winter months.
Sounds like you have a plan
Not sure which Rotella you are using, but I would recommend not using the diesel oil. It changed a few yrs back- not what it used to be and diesel oil is formulated specifically for diesel engines. Use what you want, but just info I have come across
Yes, the debate on Rotella for flat tappet engines is a bit of a rabbit hole. I like Rotella and I’ve been using it in my bikes for more than 20 years but I’ve read some stuff about flat tappet hot rods and I’ve watched the oil guy’s videos which convinced me to spend the money on Valvoline VR1 for my little coupe.
Rotella is full of ZDDP; almost as many parts per million as the Vavoline VR1 but what convinced me to use VR1 in mine is that whereas VR1 carries a high load of secondary ZDDP which is better for protection as a sacrificial mechanism, Rotella has a higher load of primary ZDDP which is less sacrificial but better for high heat environments, like a diesel (or my oil cooled motorcycles). I’m not sure that it will make a difference for my engine or anyone else’s that isn’t putting out hundreds of horsepower but for the few dollars difference it makes, VR1 gets my paycheck.
Maverick57
New member
Sorry for the oil controversy; that's one of the Ten Commandments of online forums, along with ported or manifold vacuum advance, so I repent of my sins, and it won't happen again.
I'll post updates of plug readings and compression tests on this engine as I do them in the future.
Thanks
I'll post updates of plug readings and compression tests on this engine as I do them in the future.
Thanks
Definitely keep us informed of how the rings rehab back into business. It sounds pretty positive now that you’ve reduced the smoking by 90 percent or so and the compression is bouncing back. Always good to discuss oils too. Every bit of knowledge counts.
