EWP (electric water pump) Davis Craig jobbie..needs a thermister, temp probe placed in the head...
Thats something I pondered as I wanted a 1 piece water rail from the rear of the head to radiator, to get a probe in the right place, ie the outlet of the engine was gonna mean having some pipe near the head and exhaust manifold and like a kenlowe fan pickup having the wires tracing into the water hose...
Thats just crap. You always have to wind the clips up to the limit then they leak, the hose gets deformed, the wires on the temp probe in the hot water go floppy, expand you have a piece of wire to keep it in place, its just a pants idea.
I couldn't do anything about this issue until the head was off and I could check the water ways etc.
Anyway the ideal solution just came into my head...
The rear of the head has two bosses that are not drilled, so I drilled a 10mm hole through one into the water way, tapped a 7/16th thread. I found a 7/16th brake bleed nipple, cut the nipple off, drilled the centre out to 6.5mm, the diameter of the EWP probe.
Firstly I tested the probe with a multimeter and some hot water, testing that the very end of the probe picks up heat ok and that all the probe doesn't need to be heated etc, as in this setup, not all the probe can be in the head, it worked fine, so work commenced.
Couldnt find any 6.5mm compression fittings hense the use of a bleed nipple, so my favoured stuff was used to stick it together, good old epoxy..Never ever had any issue with this type of bondage (ohh-errr) good as gold smoothered at both ends and in the brake nipple...
You can see the untapped boss at the back...
The probe is about quite close to the chamber roof and exhaust port water jacket area, but not too close, good place for a reading, its on the exit from the head to...They advise fitting the probe in the thermostat location, but being as these funny engines have a thermostat on the inlet, it MUST go here...I need it close to something that heats to get a clean warm up and constant readings...My aim is to peg the temp of the engine at 80C at all times, none of the standard useless water systems spikes and horrible standard head gasket blowing mess.
Anyway more happy with the probe here, its a neat solution, wiring it short, its all hidden and conforms to my simplification tendencies.
Also did a final CR check and chamber CC measurement, I estimate compression at 10.25:1 stock is 10.5:1 the chamber 1.8CC larger than normal after mods and 0.012" skim...
I not willing to skim more off the head, I want to leave enough beef for forged pistons and future skims and whatever as the head is modified and was alot of work!! Forgeries are 1mm taller and give 1 point CR raise..So then 11.25:1...Which is good..Mild comphremises at this early stage, getting it all in fettle is the aim of the game....
I don't want to return to any of the fundemental work, its final.
No comments:
Post a Comment