MGB GT Seized Engine

Technical MGB discussion
Post Reply
RichardDy01
Posts: 1
Joined: Wed Jul 03, 2024 1:32 pm
Forename: Richard
Surname: Dymond

MGB GT Seized Engine

Post by RichardDy01 »

Afternoon all,

My elderly father in law has an MGBGT "M" Reg, i believe 1973/4 ? It has been garaged and sat idle for twenty years at least and the engine is seized, we want to get it up and running and restored, we have removed the plugs and put some diesel and WD40 down there to try and free it but to no avail we still cant hand turn it. The liquid has gone from three of the pistons but not the fourth which would indicate that this is the one causing the problem. Does anyone have any other solutions that we could try, any help would be much appreciated. Regards
Vic Butler
Posts: 812
Joined: Wed Dec 21, 2016 6:07 pm
Forename: Vic
Surname: Butler
MGCC Member: Yes
MGOC Member: Yes
Location: North West Hampshire

Re: MGB GT Seized Engine

Post by Vic Butler »

Try 70% diesel, 20% paraffin and 10% Coca Cola.
1977 Stage 2 MGB GT
1975 SWB Series 3 Land Rover with a later 2.5 petrol engine
Ian F
Posts: 1085
Joined: Fri Mar 27, 2015 8:18 am
Forename: Ian
Surname: F
MGCC Member: Yes

Re: MGB GT Seized Engine

Post by Ian F »

If you have removed the head you could try tapping the seized piston with a block of wood.
In any event I would think an engine rebuild is called for.

Ian F
MGCC member
1972 BGT, Blaze, Navy trim, recessed grill
1961 Midget, 948cc, now sold
Not_Anumber
Posts: 415
Joined: Tue Sep 22, 2020 9:33 am
Forename: Chris
Surname: S
Location: UK

Re: MGB GT Seized Engine

Post by Not_Anumber »

If that frees the piston you may be able to get away with running a honing tool down the bores once the head is off. The B series engine is thankfully an easy engines to work on and parts such as head gaskets are not expensive. Do a compression test once the cylinder head is back on and if the compression appreciably lower on the cylinder which had the stuck piston then it would be worth more of a strip down to change the piston rings etc. Hopefully it wont need the cylinder rebored but even if so it shouldnt be prohibitive so long as you do all the stripping down yourselves and just drop the engine block and pistons into an engineering workshop for the rebore.

Is your intention to get the car into a running state and then restore it to keep in the family or will you sell on to someone as a running project ?
1979 MGB GT
1999 Jaguar XKR
2003 MG TF
Ian F
Posts: 1085
Joined: Fri Mar 27, 2015 8:18 am
Forename: Ian
Surname: F
MGCC Member: Yes

Re: MGB GT Seized Engine

Post by Ian F »

Good advice

Ian F
MGCC member
1972 BGT, Blaze, Navy trim, recessed grill
1961 Midget, 948cc, now sold
Not_Anumber
Posts: 415
Joined: Tue Sep 22, 2020 9:33 am
Forename: Chris
Surname: S
Location: UK

Re: MGB GT Seized Engine

Post by Not_Anumber »

Have you got it turning Richard ?
1979 MGB GT
1999 Jaguar XKR
2003 MG TF
Post Reply