Does a radiator guard restrict airflow?

[Pbassred]

obviously it does but has anyone anyone had any experience of it causing a problem? In the UK we rairly see above 34°C , but my Honda CBR500 doesn't have a gauge (my CBR125 did ) so I can't see if I'm pushing a limit.

[learningtofly]

I was wondering that too. My bike is 70% air/30% oil cooled and I recently fitted a guard over the oil cooler... slightly worrying in this weather when I'm stuck in traffic.

[Mississippi Bullfrog]

You can buy oil temp gauges that replace the oil filler plug. Varies from model to model of course but if you're worried about engine temp then that's one possibility.

[Gerontious]

Yes it will.. But not in any way that's harmful. It may be hot at the moment but this is nothing compared with Southern Europe.. Or more extreme, the Middle, Far East and Australasia in particular where 40c is normal. When airflow drops due to being at a standstill the fan should come on to help maintain the temperature within the range designed in by the manufacturer and you can bet there is a lot of leeway at the upper levels before genuine harm is caused. It's nothing to worry about, ever, in the British climate.

My GS is air/oil cooled and in the baking heat of southern Italy... Or stop/start in the PO valley and Roma. It went up by one bar. No big deal.

[Grumpy Old Git]

My bike 'switches off' one cylinder - the rear one and 'pumps air' if I am stationary for more than about 30 secs. Designed to improve cooling but sounds a bit weird when it switches from a twin cylinder to a big single!

[Smithers]

If it's a water radiator I wouldn't worry about it, most bikes are fitted with a thermostatically controlled cooling fan should it get too hot.

[Marino]

No worries nothing bad can’t happen because of it. Went yesterday on a ride , boiled my balls but engine survived, engine temperature from 85 to 93 Celsius. In south Europe that will go from morning to evening, sometimes all night for over 3 months.

[xMachina]

You can buy oil temp gauges that replace the oil filler plug.

 

I have one of these because they look cool. They do very little with regards to measuring oil temp though, at best its a guestimate of the crankcase air temp as its only really being splashed with oil rather than sitting in it.

[Mississippi Bullfrog]

You can buy oil temp gauges that replace the oil filler plug.

 

I have one of these because they look cool. They do very little with regards to measuring oil temp though, at best its a guestimate of the crankcase air temp as its only really being splashed with oil rather than sitting in it.

 

There are specific ones which have the probe long enough to be in contact with the oil. It depends on the model.

[Mr Fro]

Don't worry about it, just stick Evans coolant in it.

[winston smith]

Don't worry about it, just stick Evans coolant in it.

 

....not taking the bait Mr Fro

[Throttled]

All car radiators are all behind covers as such and they work fine, so I do not see how fitting a radiator cover would stop a bike radiator working or reduce its effectiveness.

[fastbob]

Someone had fitted a medium mesh over the entirety of the rad on my GSXR 1100 and it always stayed in exactly the right temperature range according to the guage . I think the fan only kicked in a dozen times in ten years and that was only when I got stuck in traffic after riding fast .

[Pbassred]

All car radiators are all behind covers as such and they work fine, so I do not see how fitting a radiator cover would stop a bike radiator working or reduce its effectiveness.

Yeah, but cars are designed with a radiator size appropriate for their amount of grill.

[winston smith]

Forget car rads - yes they are recessed behind covers, but that bodywork forming the covers also channels air towards the rad(s), intercoolers, a/c units etc.

Bike manufacturers spend time and money during design stages to make sure the cooling system is adequate for many engine speeds, road speeds, altitudes etc, and design in a fair amount of flexibility around an "optimum" running temp. Rads have electric fans to assist airflow if required, and rad caps are design to blow off excess steam/pressure if the temps are high enough.

Most engines will run quite happily between 70 - 110 deg-c water temp. Which will likely be some around 600-800 deg-c engine head temp - which is far more important than water temp.

A rad cover will restrict airflow a small amount, but that is balanced by having an extra metal surface on the rad which conducts heat into the airflow.

So don't worry about your bike, it'll run fine with a rad cover, as long as the fan isn't on constantly, or it's blowing through the safety valve in the cap, and as long as you keep to a fresh 50/50 mix every 2 years.

[Throttled]

All car radiators are all behind covers as such and they work fine, so I do not see how fitting a radiator cover would stop a bike radiator working or reduce its effectiveness.

Yeah, but cars are designed with a radiator size appropriate for their amount of grill.

 

Which some motorcycle radiator covers do;

and the rest are mostly mesh or grills, so they just let the air flow through.