7 replies to this topic

[minipac]

hi I have recently built up my engine its a 1098cc which has been put into a A+ block the block has been pocketed and a 1275 (12g940) head fitted all that left to fit is the clutch and water pump but it wont fit because of the head has anyone done this before for and had the same problem or has anyone got any suggestion cheers

[MiniMick]

Don't you have to fit a 1275 water pump 9If i remember rightfully)?

[The Matt]

Is it the water pump that won't fit or is it the fan/water pump pulley? If it's the pulley, then there are different sizes available. From memory, the 1275 pulley is smaller???

[roofless]

is it me or does this initial thread contradict itself? is it an 1100 block, or a 1275?

[dklawson]

Or... is it that you're fitting the high-flow pump to the 1098 block?

From the MiniMania/MiniSpares listing for high-flow pump GWP134...

It's warmer here than in the UK. This higher capacity water pump moves more coolant than the stock one, and is better quality. GWP134 has by-pass hose take off, GWP154 is without take off. These super high quality water pumps have a much larger than stock impeller; it sticks into the block slightly more than 1/2". This water pump will fit all 1275cc blocks and all 998cc blocks after 1969, and with a slight amount of work on the impeller can be made to fit a small bore block. Use of a high capacity water pump helps to reduce cavitation in the water jacket, particularly at high RPM, as well as circulating a greater volume of coolant. Further reduction of cavitation is achieved by using a large diameter water pump pulley CAM6408 as originally fitted to the Cooper S and reintroduced on the A-Plus engines. It is necessary to check clearance between the large pulley and the head; if a lot of material has been machined from the head face it may foul the pulley. Small bore engines with 12G940 heads can't use CAM6408 and it is necessary to modify the top edge of the high capacity water pump or the 12G940 head will rest on the pump and not seal properly; modify for at least 1/16" gap.

[[email protected]]

Its a 1098, with a large bore head. A smaller water pump pulley is required for the conversion, then it will go on

Beaten to it!

Edited by [email protected], 18 February 2008 - 09:54 PM.

[minipac]

Or... is it that you're fitting the high-flow pump to the 1098 block?

From the MiniMania/MiniSpares listing for high-flow pump GWP134...

It's warmer here than in the UK. This higher capacity water pump moves more coolant than the stock one, and is better quality. GWP134 has by-pass hose take off, GWP154 is without take off. These super high quality water pumps have a much larger than stock impeller; it sticks into the block slightly more than 1/2". This water pump will fit all 1275cc blocks and all 998cc blocks after 1969, and with a slight amount of work on the impeller can be made to fit a small bore block. Use of a high capacity water pump helps to reduce cavitation in the water jacket, particularly at high RPM, as well as circulating a greater volume of coolant. Further reduction of cavitation is achieved by using a large diameter water pump pulley CAM6408 as originally fitted to the Cooper S and reintroduced on the A-Plus engines. It is necessary to check clearance between the large pulley and the head; if a lot of material has been machined from the head face it may foul the pulley. Small bore engines with 12G940 heads can't use CAM6408 and it is necessary to modify the top edge of the high capacity water pump or the 12G940 head will rest on the pump and not seal properly; modify for at least 1/16" gap.

hi I have to types of water pump one was taken from the original block 998 and the other came from the 1275 engine in which the head come from and as you said above its the top edge of the water pump that is fouling the head so it seems I will have to modify the water pump to fit cheers for clearing that up for me

[1984mini25]

If you have put a large bore head (12g940) on to a small bore block (850,998,1100) you will need to file down the top of the water pump. You will also need to use the smaller water pump pulley as the underside of the 12G940 head it a bit larger round the bottom of the thermostat area.