Engine reboring
- Thread starter Graham_Wright
- Start date
rogerthebodger
Well-Known Member
The old BMC B series engine first came out as a 1500 cc then to 1625, then to 1800 the next one up was the C series that was straight 6 up to 3 lit in the healey 3000 and MG C.
I used to tune BMC's mainly A series up to just over 1300 cc and the B series up to 1800. I currently have an 1800 n my MG B.
Al these petrol but the same block used for the diesel version.
Graham
When you rebore you replace both the pistons and rings most BMC could be rebored 10,20,30 and 40 thru oversize. You need to check the position as generally the crown is marked with the oversize 10,20,30 and so on. It you engine is currently 1500 over size 40 you con rebore to 1800 of sleeve back to 1500 and bore out to the oversize of your pistons but do fit new rings.
If you go to 1800 you may need the injector recalibrated for 1800. It would be useful to have the injectors and pump checked out anyway if of unknown condition.
Also check the crank and replace the bearings anyway if the crank is OK otherwise it a crank regrind and new bearings.
Nissan still make the 1500 B series and I think it may be still in the Ambassador taxi used in India which was an old BMC A55 car
I used to tune BMC's mainly A series up to just over 1300 cc and the B series up to 1800. I currently have an 1800 n my MG B.
Al these petrol but the same block used for the diesel version.
Graham
When you rebore you replace both the pistons and rings most BMC could be rebored 10,20,30 and 40 thru oversize. You need to check the position as generally the crown is marked with the oversize 10,20,30 and so on. It you engine is currently 1500 over size 40 you con rebore to 1800 of sleeve back to 1500 and bore out to the oversize of your pistons but do fit new rings.
If you go to 1800 you may need the injector recalibrated for 1800. It would be useful to have the injectors and pump checked out anyway if of unknown condition.
Also check the crank and replace the bearings anyway if the crank is OK otherwise it a crank regrind and new bearings.
Nissan still make the 1500 B series and I think it may be still in the Ambassador taxi used in India which was an old BMC A55 car
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coopec
N/A
Graham
I go along with everything Roger says but if it was my motor I would stick with the current capacity of around 1500cc as the starter, cooling system, fuel system and head was designed for 1500cc. I think increasing the capacity to 1800cc is asking for trouble.
I go along with everything Roger says but if it was my motor I would stick with the current capacity of around 1500cc as the starter, cooling system, fuel system and head was designed for 1500cc. I think increasing the capacity to 1800cc is asking for trouble.