The Green Phoenix MGB, How Bad is the Engine ?

[@FMFGUF]

Reminds me of a 1972 MGB GT I once bought fairly cheap on E-bay. It had a Gold Seal replacement engine that was re-bored by +0.030" to 1860cc with Peter Burgess cylinder head, Maniflow manifolds, etc., but ran pretty poorly along with oil leaks, etc. I fitted a Weber 45DCOE hoping to improve the performance, took it for a flat-out run along a dual carriageway and saw a huge plume of smoke out the back window, then it ran even rougher, on 3 cylinders! Turns out, it had blown a hole in the piston crown of #4 cylinder. I swapped it for a bog-standard 1800 engine bought cheaply locally, re-fitted the twin SUs and it ran pretty well after that. Got my money back by selling the rest of the old engine; someone even bought the manky bottom end!

[@briand4000]

Looks mighty familiar. I just rebuilt the motor in my '80 MGB. Sure learned a lot! Cam and crank all were within specs, no scoring, no issues anywhere in the bottom end. Like you said here, the cam bearings were in good shape, all within spec. Bottom end of these engines are pretty tough. The smog head, however, was cracked between cyls 2 and 3. Not surprised. Found an earlier model head, machine shop dressed and leak checked it, all OK. Motor back in the car and getting close to startup. It's quite the money pit, but it's been a lot of fun. Thank you for your excellent tutorials and experienced guidance!

[@americanpatriot2422]

Always an outstanding video and presentation. Thank you..

[@mgbgtguy]

Thank you once again, you are always so supportive of my channel. I really appreciate that.

[@americanpatriot2422]

@mgbgtguy May 2025 be a Happy, Prosperous and Healthy New Year for you and your family..

[@johnhufnagel]

subscribed. I gotta get mom's '72 back up and running after it's been sitting for a couple years. something tells me bookmarking your channel will be a smart move.

[@mgbgtguy]

There is lots of information about Mgb‘s already in videos on the channel 👍🏻

[@davidhofman4341]

Many years ago a room mate of mine in aviation school had a 1965 MGB with wire wheels. The crank shaft end of the connecting rod ends got out of round. We replaced it with a later salvaged engine and ran it many years. He sold it to a kid that kept bugging him. A week or so later he burnt the car to the ground. He drove it over bumps in the road until the gasket between the manifold and exhaust pipe was gone. He flooded the engine, gas dripped on the exhaust, and the car burned until the battery stopped running the fuel pump.

[@benandrews5750]

Quick question. Why would The Early Head bead desirable for an owner? it's not like collectors pulling a valve cover to look at date stamps or is that it? Flowspeed set the early casting was replaced soon into production to an improved casting. I will be building one soon and I'm trying to gather the best parts

[@mgbgtguy]

Being an early head, it has no air injection ports, so it would keep an early US market car correct. Some owners really do want all the correct parts, including date codes, even if it takes pulling the valve cover to see it. The early cars are starting to get valuable enough for these details to make a difference.

[@shaknit]

I was wondering if you ever tried or thought about converting the rear drum brakes to disc brakes. Sounds like something doabble?

[@mgbgtguy]

There are kits to convert these out there, but it just isn’t necessary. For the vast majority of people it’s just bling that they can brag about. The brake system on the Mgb is excellent and very well balanced, the tires are usually the biggest limiting factor when all the parts are working as they should.

[@octagongarage3504]

I would say that that engines been a part once before if that truly is a 79 engine, it should have the flat sided crank the crankshaft with the bell shaped counterweights is an earlier design. There’s nothing wrong with it. It will work in that engine I would suspect loss of oil pressure is through the pump or the oil pressure relief valve is sticking

[@mgbgtguy]

The cast crank that’s in it is correct for the late engines, the flat sided ones were pre 1976. We had shimmed the relief valve prior to pulling the engine just to see what would happen. We didn’t show that the cam bearings showed a fair bit of wear, and the oil pump was scored up a bit too ( it was getting late, and we didn’t really look at those until the next day after the video was edited and uploaded)

[@shaknit]

Might not have been using high zinc motor oil and trashed the cam.

[@mgbgtguy]

The previous owner didn’t know a whole lot about these cars and may not have been

[@DaveMcLain]

These engines are known to have cams that are not ground very well with lobe tapers and lifter crowns that are inconsistent.