I wouldn't put foil in there. Take the crank, rods/pistons to machine shop and let them polish the crank pins to fit a new quality set of bearings at full torque.
Great video! I'm curious how things turned out with the rod clearances. I'm having the same problem now with my XPAG motor. How many layers of foil tape did you need? My bearings are .020" oversize.
I need to pull it apart because the rear main seal is leaking badly. So I'm going to take those apart again and do some measurements. Maybe get a machine shop to help me out. I don't think putting foil in between the Caps is the right choice.
instead of chasing all the threads in the block, an alternative might have been to simply throw some brake cleaning the holes and blowing them out. then, on re-assembly only chasing the threads that show a reluctance for the bolt to thread normally. and then only by hand. in addition to dressing the top of the block, being so critical, would be something i would want a machine shop to do. no matter how careful one may be the corners and edges of the top of the block will most likely be rounded over by a thousandth of an inch or so making the head gasket's task more difficult. i'd also have them take a few thousandths off the head and balance the pistons, rods, crank, clutch and flywheel and possibly hone the cylinders. the precision was pretty poor in the early '50's compared to what can be had for a reasonable cost (assuming a disassembled engine) these days. doesn't cost much if you hand the parts to them in a box. throttle response will be vastly improved along with massively reduced wear. chasing with that drill is fraught with error, IMO. can't tell if the center and end cam bearings were lubed before assembly, but it a good practice to do so. if not, they will probably remain dry until the oil pump is primed and can build up pressure. of course, it may be possible to present oil to the oil pump and turn it with a drill or something and pre oil all the bearings at some point before attempting to turn the entire engine over. IDK. i found that i could easily install the pistons from the top without a ring compressor. i simply pushed the piston in until it reached a ring, then squeezed the ring together by my fingertips. then along with a little downward pressure on the piston top the piston and ring slide in. i did this for each successive ring and piston. doing it from the top naturally aligns the piston in the sleeve to begin with. i used plasti-guage to measure crank bearing clearances using the old bearings and bought the appropriately sized bearings. to determine that, i would buy one crank bearing of standard size (or borrow one). then use the plasti guage and buy a full set of crank bearings. i would not trust the aluminum shim. aluminum is a soft metal and will compress over time and cause premature bearing wear. anyway, don't do what i did and put too much paint on the block and head and rocker cover. i spent a couple of years sorting out an overheating problem in the summer only to have it eventually go away on its own as the paint and my ignorance peeled away. good video. should be a real help to those rebuilding a similar MG engine. :)
Yep,. My machine shop did all that. All the threads were rusty the bolts never having been undone in 70 years. Chasing the threads made reassembly a breeze. Didn't have to stop every ten minutes to figure out another bolt hole.
Thank you! Great video, super helpful
Glad I could help 😃
I wouldn't put foil in there. Take the crank, rods/pistons to machine shop and let them polish the crank pins to fit a new quality set of bearings at full torque.
i'm on pins and needles.... :) already "liked" it.
👍
Great video! I'm curious how things turned out with the rod clearances. I'm having the same problem now with my XPAG motor. How many layers of foil tape did you need? My bearings are .020" oversize.
I need to pull it apart because the rear main seal is leaking badly. So I'm going to take those apart again and do some measurements. Maybe get a machine shop to help me out. I don't think putting foil in between the Caps is the right choice.
Better to get it right the first time than to spin the bearings.
I have never heard of shimming big end or main bearings.. Are you sure the ctank journals are the correct diameter?
Yep
instead of chasing all the threads in the block, an alternative might have been to simply throw some brake cleaning the holes and blowing them out. then, on re-assembly only chasing the threads that show a reluctance for the bolt to thread normally. and then only by hand.
in addition to dressing the top of the block, being so critical, would be something i would want a machine shop to do. no matter how careful one may be the corners and edges of the top of the block will most likely be rounded over by a thousandth of an inch or so making the head gasket's task more difficult. i'd also have them take a few thousandths off the head and balance the pistons, rods, crank, clutch and flywheel and possibly hone the cylinders. the precision was pretty poor in the early '50's compared to what can be had for a reasonable cost (assuming a disassembled engine) these days. doesn't cost much if you hand the parts to them in a box. throttle response will be vastly improved along with massively reduced wear.
chasing with that drill is fraught with error, IMO. can't tell if the center and end cam bearings were lubed before assembly, but it a good practice to do so. if not, they will probably remain dry until the oil pump is primed and can build up pressure. of course, it may be possible to present oil to the oil pump and turn it with a drill or something and pre oil all the bearings at some point before attempting to turn the entire engine over. IDK. i found that i could easily install the pistons from the top without a ring compressor. i simply pushed the piston in until it reached a ring, then squeezed the ring together by my fingertips. then along with a little downward pressure on the piston top the piston and ring slide in. i did this for each successive ring and piston. doing it from the top naturally aligns the piston in the sleeve to begin with.
i used plasti-guage to measure crank bearing clearances using the old bearings and bought the appropriately sized bearings. to determine that, i would buy one crank bearing of standard size (or borrow one). then use the plasti guage and buy a full set of crank bearings. i would not trust the aluminum shim. aluminum is a soft metal and will compress over time and cause premature bearing wear.
anyway, don't do what i did and put too much paint on the block and head and rocker cover. i spent a couple of years sorting out an overheating problem in the summer only to have it eventually go away on its own as the paint and my ignorance peeled away.
good video. should be a real help to those rebuilding a similar MG engine. :)
Yep,. My machine shop did all that. All the threads were rusty the bolts never having been undone in 70 years. Chasing the threads made reassembly a breeze. Didn't have to stop every ten minutes to figure out another bolt hole.