The 1957 "The Dope" Dauphine

Double post

Sorted out the rad paneling last night and ran in the wiring for the fan as the relay turned up this morning. It's a 6v relay with a built in fuse so adding some protection. It came with a 30amp blade fuse in but I think I can swap that out to a 15amp based on some online calculators. All the wiring is in place so just waiting on the thermo switch and housing for that to be complete. Once proven I'll wrap it all so it's a little less of a mess. All the fluids should be here early next week so I should be ready to test it properly out on the road. I still need to sort an exhaust out, for now I'm going to try and modify the original until I have some more spare funds to buy all the bits for a complete system. Fingers crossed I can get some proper road tests done next week and nothing too major arises 👍🏻

The last of my bits turned up today so i got them fitted. Wiring finished and the temp switch for the rad fan fitted. Tested it at idle and allowed it to warm up and cool down over a few times over. Working great so really happy with that.

Then on to the oils. Engine oil dropped, filter changed and new oil in. Gearbox oil was another story, took about 2 hours to gravity feed it into the box. Still filled up and all good.

Right onto the test drive, its pokey and goes very well doesn't feel too bad at all. Pulls very cleanly in all 4 gears and is probably at the limit of the chassis and brakes that are on there. Only down side is it runs very hot. No leaks, no over pressurising runs very well, no smoke and no mixing of oil but when cruising along it gets hot enough to keep the fan running, so it 92+ degrees. If you pull over and idle itll drop back down on the fan. Anyway a quick chat on the drive with the mechanic neighbour and hes going lend me his timing gear and comp tester again just to set everything up. Ive just twisted and turned the dizzy till it started and left it there. His suggestion was the timing being out followed by carb jetting thought the carb looks to be an renault 8 item. I decided to do a quick search of a french renault 8 website and low and behold the first hit that came up for "température du moteur" was a chap with an r8 whos car was running very hot, fitted a new rad, cowling and electric fan only to find his timing the issue. Maybe and fingers crossed the engines are just a little sensitive to timing.

7 Mile test drive and it hasnt blow up yet.

Fan’s definitely rotating in the correct direction?

Otherwise, as it cools down when it’s idling, it’s either fuel (v.weak) or ignition.

ETA - the only other option, being rear engined, is the airflow to the rad doing funky things when you’re on the move.

As you've lowered it , are the airflow dynamics changed ?

Air enters from the side, not the bottom.
Lean, rich , timing out, all deffo hot running. Try colortune, that always works for us. How's your waterpump? And is there enough advance? Are the weights stuck in the distributor?

whats the scoop on the left hand underside for that looks like it does nothing but direct air up towards the rad? opposite side to the fuel tank.

I checked the advance and its at 6degrees which is where i thought it should be. I set it back to 0 and it made no difference so ive put it back to 6 btdc. Water pump was good and looked fine when fitting. Ill colortune it tomorrow and try again.

It might be worth buying a cheap infrared temp sensor to see if it is getting hot first. I can’t remember the details, but is it a mechanical or electrical sender / gauge? Are they matched? Older engines tend to have lower temp stats compared to modern engines 80-90 deg C sort of range modern engines could be over 100. The fan switch is generally higher operating than the stat like you say, with an on temp at say 100 and off at 90 to stop constant cycling.

I spent 13 years testing and developing cooling systems for an OEM supplier. One car was failing all tests. We had the biggest radiator we could fit and a large wattage fan but still no good. I went up to watch testing after a year and half and all the coolant temperatures were down by 6 degrees and passing all tests just because they’d finally got the engine tune right.

My van doesn’t seem to get hot even though the carb is off a 1400 and the distributor doesn’t seem to make any difference to how the engine runs no matter where you swing it.

I don’t know if any of this helps.

Is it showing hotter than normal in the gauge? With the fan switch temp so close to the stat temp it’s going to run but make no difference to temp when the stat is only just open. The mechanically joint radiator you have fitted doesn’t transfer heat as well as a brazed radiator And the air side pressure drop is a lot more so in the back without as much ram air as it would have in the front it could potentially struggle. Check you have a temp problem first and lower the stat temp to stop the fan running constantly before you change anything else though.