I got my 235 "dialed in" timing set, carb adjusted, valves adjusted, but she SMOKES like crazy!!! I did a compression test and got these results: front to back... cyl #1: 130 lbs., #2: 120 lbs., #3: 120 lbs., #4: 117lbs., #5: 120 lbs., #6: 140 lbs.!!! Is this basically saying the rings and valves are good BUT THE valve seals are bad??? I hope so, as I have a done/machined head ready to put on, BUT if you see something else there let me know!!! There IS oil coming out of the tail pipe, so I realize SOMETHING is going on, enlighten me PLEASE....Ken
I need to know too...mine smokes also. I am leanin towards a SBC, but would like to stay with the 235 if it can pull its weight.
Does it smoke all the time or just when you start it? If it smokes all the time is it worse when you start it or pretty constant? Also, what kinda smoke is it? Oil?(blue) Gas?(Black) Water?(white) If it's a new build, maybe all the rings haven't seated yet..
You gotta drip oil in the cylinders and retest. If the numbers go up, it's rings/cylinders, if not it's at the top end. The oil will temporarily seal the rings and give you better numbers. They do appear to be within 20% of each other, which is a good sign, but you absolutely have to retest after running a tbsp or so of oil into each cylinder through the spark plug holes to know for sure. Also, make sure you test it both ways next time and do it with the motor warmed up....
Need to do a leak down, could be broken oil ring(s) guides/seals, crackage etc. it's just speculation otherwise.
Don't have to add oil as when I did the test oil was "flowing" out of the cylinders already!! Smoke is both "blue AND black" yes I know blue: oil, & black: rich!! NOT a new re-build, a car pulled out of a field after sitting 15 years!! rebuilt the carb, idle adjustmeants may be the black smoke! Smokes ALL the time, warm, cold, at idle, driving!! If I leave it at idle for about 3 minutes, the smoke "subsides" a little bit, BUT the moment I step on the gas to take off in gear, she "billows"!!!! out like a chimney! The compression test was AT TEMPERATURE, and like I said, no oil is needed as it is already at the spark plug threads!! I am just trying to figure out if it is valve seals, or rings. Temp. guage shows good at 195, and oil pressure guage reads 25 at idle and moves up and down when I step on the pedal.....Ken
doubtful that it's valve seals cause all there is is little flat o rings under the keepers. these don't have the umbrellas. TOO much oil up there in the valve cover? Maybe the drain backs are plugged up, or too much getting pumped up there. And your flooding the valve stems. or really bad wore out valve guides. Too much oil on the rocker shaft can be solved by crimping off that little oil tube near the center of the shaft, till you get just an ozze of oil to keep it happy. Frank.
Check inside the valve cover for a blocked return hole. And didn't the 235 still have a draught tube? Could be kinked or blocked.
I had a 235 that did that and I pulled the head and found a burned piston. It was burned down one side.
HMM... lets see, I am looking at the motor, I see oil leaking down where the threads are where I just removed the 6 spark plugs, and ....... uh yes there is oil slowly dripping down the side of the head where the plug screws into the head !!! SO YES there IS a way oil is at the threads!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
it wouldn't run if a cyl was full of oil....liquid don't compress. the oil u see is prolly pooled ontop of the plug from the valve cover. like I said....there is no damn way. I wasn't being a asshole but thats the way it is...
a year ago I put one in a guys pickup and the donor motor sat for 15 years. It smoked like yours. I tried fast idle for an hour or two and it was slightly better. Then I just put it on the road a few days and it cleared up. But if you have black smoke too, you need to figure that out too, maybe carb or ignition.
If the engine sat idle for many years, try a can of G.M. Top Engine Cleaner. Follow the directions on the can. If it's got stuck rings, this will usually free them up. If not, you're out six bucks.
sounds like the oil rings are stuck, what I have done in the past is an atf and diesel mix, pull the plugs fill all the cylinders and let it sit for a day or so... then turn it over to clear the cylinders put the plugs back in refire and try again.. good luck it is a 50/50 trick sometimes it works sometimes not... remember a 235 is going to have cast iron compression rings so with the ballance you have looks like the compression rings are working, but the oil rings below them are stuck... if you can't free them at the least you will be doing a rering on the motor.... which if it were mine and i couldn't free it up, I would do anyway. Gaskets and rings are cheep....compared to feeding it oil....
I'm sure you drained the old oil and replaced it already. My 216 did the same thing when I got it with the coupe and started it first. The crankcase had TOO MUCH OIL! About 2 quarts or more overfilled... Seafoam is another top engine cleaner. Sounds like it's time to pull the head anyway, since you got a new one ready to go...
I may be way off base here but didn't the early 235 have a double diaphragm fuel pump that smoked like hell if a diaphragm split? New a guy in the early 60's that re-ringed his '53 Vette motor only to find a ruptured fuel pump.
Yeah, that is a possibility worth considering. Sounds like the plot in one of those old "Gus Wilson and the Model Garage" stories!
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