purpose of bypass hose

Post by **picky** » Thu Jun 07, 2007 4:40 pm

Im currently rebuilding a 1275 engine, and I have a metro turbo head for it. the head has no provision for a bypass hose, but my water pump has. Am I right in thinking that the bypass hose is to let a small amount of water to flow round inside the water jacket if the thermostat is shut? eg when the engine is cold. Was it deemed unnecessary and removed on the later engines? I need one of the rubber "dead ends" to put over the water pump with a jubilee clip...

Picky

Post by **LukeBoorman** » Thu Jun 07, 2007 5:02 pm

You just need to drill some holes in the thermostat, to allow a little water to flow before it opens (see previous posts) or leave the heater open. I just fitted a new water pump without a bypass hose take off - as the blanking plug is £7.50 and a new water pump with gasket £12.

Will the turbo head not be low compression?

Post by **picky** » Thu Jun 07, 2007 5:12 pm

thanks luke, i could shell out on a new water pump without the pipe i guess.

yes the turbo head should be low compression, although if there is a difference it is very slight.

Picky

Post by **bmcecosse** » Thu Jun 07, 2007 6:09 pm

Heads are all the same at 21.4cc - the comp ratios were varied on the pistons - both dish and height. Bypass was just there to annoying the living £$&^ out of people. Get a pump without and drill 2 x 1/8" holes in the rim of the stat - problem sorted.