leaving the thermostat out

[str11ker]

I have a overheating problem that i havent managed to crack yet, but wondered what affect leaving the thermostat out of a 1300 marina engine will do, will the engine run cooler as the water is circulating all the time or will it affect the cars performance, i thought i would try this as I've just had the thermostat housing off and replaced it without the thermostat and i havent got another gasket.....so its worth a try, also as i've just rejoined i dont feel bad asking for advice...as simple as it may seem...thanks in advance...

[macdonald.dm]

Re: leaving the thermostat out

Hmm. Not usually a good idea as it's main effect will be to drastically slow down the warm-up time of your engine; you really want your engine to get up to running temp as quickly as possible to reduce wear and fuel consumption. As I'm sure you know, the idea of the thermostat is not just to regulate the running temp by opening and closing the gap as required, but to initially pretty much prevent ANY water flow through he engine until it's up to required temp, thereby getting it up to temp asap.

I've noticed quite a few threads on here regarding overheating - I think most recommend going for a larger/more efficient radiator. Have you tried a search for, say, 'overheating'?

[Dane_Rescueman]

Re: leaving the thermostat out

The last "A" series engine I worked on was a hevily modified frogeye engine, bored to 962 thumping cc. I found that my thermostat, when open, closed off the small bypass between head and block. Leaving the stat out actually caused my engine to overheat; maybe due to the bypass remaining open.
This was a long time ago though!

[b_caswell]

Re: leaving the thermostat out

Are you sure its overheating as the gauge can read high if its not wired correctly.
You could make sure the thermo stat is opening fully by plopping it in a saucepan on the stove if havnt got a thermometer it should open just before the water boils.
It is possible to get a stst with a lower temp set.
Try flushing the cooling system thoroughly, check the timing and mixture. Another thing is to make the air flow go through the rad and not over it by blanking off the top of the grill nose area.

[kdn17]

Re: leaving the thermostat out

does it mean that without the thermostat the car will need the choke for longer, or what other affects will it have?

[dogoncrazy]

Re: leaving the thermostat out

As Ben says-are you sure it's overheating .When I built my roadster [1300 A series ] it initially showed a high gauge temp which was down to a mismatch between the sender and the Smith's gauge I was using which I'd taken out of a Mini. The sender I ended up using which gave the correct reading was from a 1275Gt mini [the ceramic bit or whatever in the middle was coloured black as opposed to red which I presumed was for the other capacity mini's.As for running without a stat-one word DON'T as it can cause the cylinders furthest from the front i.e 3 and 4 to run much hotter, the only way round not using a stat is to install a blanking sleeve in it's place, they are available as a competition item and as such are really intended for race use!

[AndrewKB]

Re: leaving the thermostat out

Another THEORY I've heard is that removing the thermostat allows the water to pass through the radiator TOO quickly and thus it doesn't stay in there long enough to cool down. I certainly tried the "remove thermostat" option some years ago and it seemed to make b****r all difference whereas a new three-core rad made ALL the difference. Andrew.

[macdonald.dm]

Re: leaving the thermostat out

Hi Andrew.

Hmmm, not sure about that other theory!

Removing the 'stat might not make a huge difference to the average running temp of some engines, but it will most certainly slow down the warm-up time. I think you'll also find that, in very cold weather, your engine will struggle to reach the best operating temp, and will therefore be running harmfully cool.

Some engines seem to rely more on the 'stat more than others to regulate temp.

[lizbillings]

Re: leaving the thermostat out

Hi Andrew. I found out that my Berli hadn't got a thermostat in when we decided to change it. Now it runs smoothly and isn't icing up the carbs etc and so far it hasn't overheated. The test will be towing a caravan to Lee's event.

[ggrum]

Re: leaving the thermostat out

Hi Keith,
It's been a long time since I swapped out the 1300 A series engine in my car but I seem to remember it only had a tendency to overheat a bit when stationary in traffic and I always put this down to the fact that the belt driven cooling fan was 'several' inches away from the radiator due the steering rack being between them. If you haven't already done so, have you thought about fitting an electric fan to the front of the radiator. If the engine overheats when moving theres a good chance the rad is partially blocked and, as suggested already, needs flushing out.

[kdn17]

Re: leaving the thermostat out

Thanks everyone, I have flushed everything out and will hunt out another gasket before replacing the thermostat, i need to disconect the temp gauge to stop the worry factor and then see what happens, thanks for all your help

[b_caswell]

Re: leaving the thermostat out

I can remember a comment in the Motor Mechanics mag that if the car was overheating the time to stop was when the oil light came on. Dont quote me when it goes bang.
When copetition cars did away with the thermo stat they used a restictor plate in place of it to stop a vortex forming in the water pump.

[b_caswell]

Re: leaving the thermostat out

Must try harder with spelling COMPETITION RESTRICTOR

[Dane_Rescueman]

Re: leaving the thermostat out

Ben,
Did that restrictor close off the by-pass twixt head and block?

[colin_kiddell58]

Re: leaving the thermostat out

howdy,
ive had many a trouble with overheating as past threads will show, i found the best way to combat it is to get my rad recored, as others say don't take the thermostat out, will cause more problems. get a recore and you will be fine, my car has an 1800 "b" series with a 1300 viva rad, works fine now!
good luck