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73 MGB - remove #1piston without removing engine?

Is it possible to remove the number one piston without pulling the engine? This is a USA model if it makes any difference. I had blue smoke filling the engine compartment, rough idle and low power. The back 3 cylinders were all 155lbs but the front one was 90. It came up 5 lbs with a spoon of oil added. Re-torquing the head didn't change anything. Head removal didn't show any problems with the gasket. The cylinder isn't scored. Inspecting the valves faces while still installed in the head show they aren't carboned or dirty or distorted or worn looking. Any ideas? Thank you for your time.

Reply to
cosmo
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Hello,

I certainly would think you could pull the head again, take the oil pan off, loosen the connecting rod journal bolts, and pop the piston/connecting rod assembly out the top. After all, when you install a piston the connecting rod is already attached, and you use your piston ring compressor tool to slide the piston back in.

Certainly would not be a small job, however. You may want to mic the cylinder walls to make sure you don't need an overbore. I think an overbore would necessitate pulling the engine...

Regards, Dan

Reply to
Dan Beck

You can, but the problem is, you need to remove the oil pan and the front couple of bolts are blocked by the crossmember.... I have heard of loosening the front engine mounts and jacking up the engine to get to those bolts, but depending on the year of your car it may be difficult to loosen the driver's side (LHD) mount if the steering shaft goes through it (i.e., rubber bumper models).

Dan D '76 B '65 B Central NJ USA

Reply to
Dano58

Oh, just saw the subject - with a '73, you may be able to loosen that driver's side mount. On my '76, you actually have to remove the entire steering rack assembly to replace the engine mount!

Dan D '76 B '65 B Central NJ USA

Reply to
Dano58

Oh, just saw the subject - with a '73, you may be able to loosen that driver's side mount. On my '76, you actually have to remove the entire steering rack assembly to replace the engine mount!

Dan D '76 B '65 B Central NJ USA

Reply to
Kevin Hall

Hmm,

another thought...

Seeing how you only gained 5 lbs wet it makes me wonder if your valve guides are bad, and maybe losing compression because of bad valves. Find yourself one of those pressure hoses with the spark plug adaptor, used for pressurizing a cylinder in order to change valve springs with the head still on. Connect this hose to an air compressor, set the #1 piston to TDC, and pressurize the cylinder to 100 psi. Listen to the tailpipe (bad exhaust valve), open up the throttle and listen to the carburetor air inlet (bad intake valve), and take off the radiator cap and see if you have gas leaking into the coolant (leaky head gasket).

Regards, Dan

Reply to
Dan Beck

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