Hi guys,

I'm a constant lurker and have thus far answered my questions using the search tool - hence my lack of posts.

I have installed the F20c engine into a Lotus 7 type chassis, everything is running fine and dandy apart from the fact that the thermostat will not open. I have tested the stat in boiling water and it opens fine. Bit of backround on my install; I have removed the heater pipes and looped the outlets together and I am using a del sol racing radiator that has the same size outlets/inlets as the S2000 standard rad. Basically the engine gets up to temp, the top hose gets hotter and hotter the bottom hose remains freezing then the fan cuts in. no matter how long i leave the engine running for the bottom hose remains cold due to no flow through the stat.

I'm thinking that it must be an airlock. Ive tried using the bleed valve on the inlet manifold but it doesnt seem to be making any difference. Does anybody know of any good bleeding methods or of any other possible causes ?

Any help much appreciated as the car is booked for a tuning session on a rolling road in a weeks time

Thanks Dan.

 

Definitely sounds like an air lock. When we bled my system we just filled it all up including the rad and then squeezed the bottom pipe that feeds the rad until there were no more bubbles. It took a while back and forth waiting and then repeating the process but that did the job.

 

Is the rad new? Have you checked for physical obstructions and in particular that you haven't left something like a blanking plug in place?

When refilling, try doing it with the engine running and very slowly.

 

Jacking the front end up also helps.

Sent from my GT-I9300 using Tapatalk 2

 

I'm pretty sure honda has a step by step guide for filling the coolant system?

 

To give some closure on this issue if anyone is interested?The only way (after trying everything) to get the thermostat to open was to drill two off 5mm holes either side of the oem air hole. This probably lowers the early start up temperature of the engine but as said earlier nothing else would work.

HTH Dan.

BTW the engine is now running in my kit car. The weight weight of the car is around 620 kg, As you can imagine its very fast. The Vtec is set to come in @ 4500, so theres no real kick just a progressive linear shove from 4000 to 9000 rpm.