Engine troubles
- Thread starter flatjack9
- Start date
andyg
Senior Member
bent rod here too...on the upper end. doesn't take much. as stated before though it could easily have been tight at the bottom of the bore in the beginning.
i used to work for an oil company that made oils for many uses so i will keep my mouth shut about about the whole oil thing.
hope you get it running again soon!
i used to work for an oil company that made oils for many uses so i will keep my mouth shut about about the whole oil thing.
hope you get it running again soon!
flatjack9
Well-known member
No bent rods. The bores all measure 3. 312 to 3 .313 and the pistons are 3.309. #5(the one with the scuffing) is 3.307 and the bore is 3.314. There was no chamfer cut on the bottom of the bores. I plan on using a hone to remove the slight metal transfer in #5 and use a bottle brush on the others and will install new pistons and rings. Obviously I'll chamfer the bottom of the bores. Still can find no good reason for the scuffing on that piston. I bought the pistons from Motor City Flathead 17 years ago. I'm sure they were installed as per specs, but don't have any paper work anymore.
Ronnie
Well-known member
Try this skidoo guys use it.
If the piston has seized and smeared aluminum on the cylinder you will need to remove it . You can do this with Muratic acid. Just take medicine dropper and put just a few drops on the aluminum that has been smeared in the cylinder. The acid will eat the aluminum but will not hurt the steel of the cylinder. DO NOT GET THE ACID ON YOU . If you do get it on yourself, water and baking soda will get it off. Also don't get it on any aluminum unless you want that aluminum eaten up ! You can get Muratic Acid at any home improvement store. They sell it buy the gallon, which will do about a billion cylinders. they use it for... swimming pools .
If the piston has seized and smeared aluminum on the cylinder you will need to remove it . You can do this with Muratic acid. Just take medicine dropper and put just a few drops on the aluminum that has been smeared in the cylinder. The acid will eat the aluminum but will not hurt the steel of the cylinder. DO NOT GET THE ACID ON YOU . If you do get it on yourself, water and baking soda will get it off. Also don't get it on any aluminum unless you want that aluminum eaten up ! You can get Muratic Acid at any home improvement store. They sell it buy the gallon, which will do about a billion cylinders. they use it for... swimming pools .
Buckelew
Member
A few months ago the blow-by in my '48 59Y (Mercury crank, dual strombergs, mild cam) got to be too much -- causing a big mess.
#7 was running 70 PSI and all the others 120. Pulled #7 to find skirt scuffing well below the oil ring. Decided to look at the rest of 'em.
All the rest had scuffing, too. The top compression ring on #1 was broken in half(!).
Visual inspection revealed no problems with the cylinder walls. Repeated snap gauge measurements reveal minimal wear (each measures between 3.312 and 3.313) -- the block seems to be in really good shape. Crank is fine, too.
Piston scuffing is not noticeable to the touch, and there is no taper to any piston. All pistons measure and look good otherwise.
Washout/detonation seem to be the causes, but a long time ago it suffered intermittent loss of oil pressure, when the oil plug fell out(!).
Gonna carefully re-check everything, hoping for just good honing and new rings
#7 was running 70 PSI and all the others 120. Pulled #7 to find skirt scuffing well below the oil ring. Decided to look at the rest of 'em.
All the rest had scuffing, too. The top compression ring on #1 was broken in half(!).
Visual inspection revealed no problems with the cylinder walls. Repeated snap gauge measurements reveal minimal wear (each measures between 3.312 and 3.313) -- the block seems to be in really good shape. Crank is fine, too.
Piston scuffing is not noticeable to the touch, and there is no taper to any piston. All pistons measure and look good otherwise.
Washout/detonation seem to be the causes, but a long time ago it suffered intermittent loss of oil pressure, when the oil plug fell out(!).
Gonna carefully re-check everything, hoping for just good honing and new rings
Last edited: