Hey all.

I have a 5VY R1 motor in my Fisher Fury and I cant seem to get my water temp to stay the same for any length of time.

If i'm cruising along at 50mph and upwards, the water temp seems to read 65ish
If i'm stuck in traffic it can get up to 100.

The fan kicks in and brings it down again, so i'm not worried about being sat still.

Im worried about the water temp not getting high enough when i'm cruising. Although it I get good oil temp, which stays around 80-85 when cruising (water at 65ish).

Was just wondering whats normal for these engines, or do I just have to much airflow through the radiator?

Thanks

Richie K

The 'stat opens at 74c from memory. This weather mine runs between that and 80c if just cruising. The 'stat should ensure it's always above this once warm, so if your 65 is a true reading (check the top hose/ 'stat housing temp with an infra-red thermometer) I'd suspect the 'stat to be stuck open.

Driven hard it can go up to three figures but the ECU switched fan rarely comes on while moving. The fan is switched at 105c. In traffic it will get to this and will hold it's own keeping the temp between 95-105, although I find it easy to stall at that, so use a manual switch to bring it down into the 80's.

The 5VY in the hack usually runs @75-80C regardless of abuse, never lower, so I'd start looking at the thermostat. If the water temp creeps up beyond 85C, the oil temperature is starting to get too high.

The race car runs no thermostat in the summer, that will dip things to 60C on an in-lap, which sounds very similar. Waiting on the line in summer (summer happened one day last year at Combe), the temperature will hit 115C with a lovely smell of hot glycol....

Cheers guys. Looks like a stat stuck open then.
I'll have a look for it this weekend, and get one ordered.

Hope I can figure out how to bleed the coolant.

Richie K

Depending on how it's been plumbed in and what expansion tank and rad have been used it shouldn't be difficult. The engine self bleeds normally. You shouldn't have to drain much coolant as the stat is top of the the engine so probably just the expansion tank above it.

Right. Had a look yesterday, and there is no Stat.

Spoke to Andy Bates, and he says he normally does away with the Stat on his installs because he's seen too many issues when they fail shut!

I'm going to experiment with some cardboard in front of the rad. Once I find the best shape and size to keep temps were I want them, I'll get the piece made out of ally sheet, and come up with some sort of quick release mechanism, so I can easily remove it for track dys!

Another job for the list!

Richie K

Don't often disagree with Andy but in this case I do.

For one thing if a 'stat "fails to shut" then you get the same result as removing it; The engine runs too cool. It's OK if you're running full bore all the time (like racing) but it's not good in a road car. Second it takes longer to get warm and most wear happens while the engine is cold. Now in a race car it'll be fully warmed up BEFORE going out onto track; Do you really want to sit on your drive warning it up before setting off?

Messing about blanking the rad... Well if you want to keep having to stop mess about adding/removing bits every time the weather or your driving style changes, go ahead. Personally I'd fit something that will do the job for you... Ohh, let's think... something like a THERMOSTAT!

There's millions of cars and bikes out there that the owners never have a problem with and every one of them is designed to have a stat.

quote:

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Originally posted by adithorp
Don't often disagree with Andy but in this case I do.

For one thing if a 'stat "fails to shut" then you get the same result as removing it; The engine runs too cool. It's OK if you're running full bore all the time (like racing) but it's not good in a road car. Second it takes longer to get warm and most wear happens while the engine is cold. Now in a race car it'll be fully warmed up BEFORE going out onto track; Do you really want to sit on your drive warning it up before setting off?

Messing about blanking the rad... Well if you want to keep having to stop mess about adding/removing bits every time the weather or your driving style changes, go ahead. Personally I'd fit something that will do the job for you... Ohh, let's think... something like a THERMOSTAT!

There's millions of cars and bikes out there that the owners never have a problem with and every one of them is designed to have a stat.

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Sorry misread it as "fails to shut" which is far more common (buy still rare) than sticking shut.

However, it's rare that they fail shut. There are good reasons for having a stat and just a small chance of it failing. Not having a 'stat will cause more problems than having one.

Would you remove the handbrake because they're known to seize on? Of course not... but I see more of them binding on in a month than I've seen stats fail in 30 years repairing cars for a living.

Have you looked on e-bay for an R1 stat housing?

Yeh, I can get a standard stat housing for not much money.
I take it the standard housing has a bypass for cold running (before stat opens)?

Might be easier to fit an inline Stat, but I'd have to fettle a bypass.

I'll have a good look tomorrow, when I'm up at the garage.

The standard thermostat housing is an in-line unit with a small bleed pipe. It attaches to the pipe from the head and sits on top of the gearbox, mounted with a peg into a grommet in a bracket. The top hose then goes from there to the rad. The bypass as such operates through the oil cooler.

Use a standard thermostat housing if you can, if you can drill a 2mm to 2.5mm hole in the thermostat valve to allow air bleed and a small amount of flow around the thermostat. Don't go mad drilling holes thermostat one 2.5mm or at most two 2mm holes is more than enough if you have a by-pass hose plumbed in.

Aftermarket external thermostat housings tend to be waste of money.


Any external thermostats used by car manufactures (such as Rover, Landrover, Alfa Romeo and BMW) are effective tend to be fairly big, designed for large diameter radiator hoses (32mm or larger) and be a bit award to install neatly.