Is the Griso 8V the ultimate Guzzi big block ?

[Chris Wilson]

45 minutes ago, Lucky Phil said:

I've never found sitting on the side of the road with an overheating engine waiting for it to cool down before you can continue riding to be particularly cool myself.

Ciao

Phil, noted in another forum elsewhere but, my 1950's technology air cooled dinosaur read 52 Celcius on the dash whilst stuck in traffic on Parramatta Road in the middle of summer and it was so hot in the sun it was actually cooler with my gloves on!

And yet the engine was fine.

I defy any liquid cooled bike to survive that and not have the fan kick in and promptly roast your legs.

Probably down to using the best synth. oil and having THE best design for air cooling ever.

Chris.

[Lucky Phil]

15 minutes ago, Chris Wilson said:

Phil, noted in another forum elsewhere but, my 1950's technology air cooled dinosaur read 52 Celcius on the dash whilst stuck in traffic on Parramatta Road in the middle of summer and it was so hot in the sun it was actually cooler with my gloves on!

And yet the engine was fine.

I defy any liquid cooled bike to survive that and not have the fan kick in and promptly roast your legs.

Probably down to using the best synth. oil and having THE best design for air cooling ever.

Chris.

So what your saying is on a Sydney summers day sitting in heavy traffic lets say a 38deg C OAT day your engine oil temp was only 14 dec C higher than atmospheric temp. That doesn't even make any sense. The normal operating oil temp for your engine is around 90-100 deg C.  You should get your bikes indication checked. At 54 deg C your engine is still on the warm up fuel trim. You have an indication issue. 

Ciao 

[po18guy]

Liquid cooling allows higher compression ratios, and dampens "ambient" engine noise - Euro 5, 6, 7 etc. We've already breached the fuel injection Hadrian's wall, so all the rest should not result in twisted undies. Not to mention emissions. For the goggles and scarf crowd, there will always be V-7s and all subsequent carbureted, air cooled models. As they become classic, we may even see Jay Leno doing a segment on one. Right after the Velocette.

[Chris Wilson]

27 minutes ago, Lucky Phil said:

So what your saying is on a Sydney summers day sitting in heavy traffic lets say a 38deg C OAT day your engine oil temp was only 14 dec C higher than atmospheric temp. That doesn't even make any sense. The normal operating oil temp for your engine is around 90-100 deg C.  You should get your bikes indication checked. At 54 deg C your engine is still on the warm up fuel trim. You have an indication issue. 

Ciao 

No I am saying that the dash temp read 52 and that dependant on the air intake sensor.

My seat on pants thermometer more than backed this up as I was close to passing out whilst riding.

Now if this was my old BMW the fuel would have boiled and the thermo fan would have cut in throwing super heated air directly at my thighs.

But the old tech Guzzi took this in its stride.

Chris.

[Lucky Phil]

34 minutes ago, Chris Wilson said:

No I am saying that the dash temp read 52 and that dependant on the air intake sensor.

My seat on pants thermometer more than backed this up as I was close to passing out whilst riding.

Now if this was my old BMW the fuel would have boiled and the thermo fan would have cut in throwing super heated air directly at my thighs.

But the old tech Guzzi took this in its stride.

Chris.

Ok so I looked at the Bellagio owners manual and the ambient temp indicator. If that is taking it's reading off the air intake sensor then in traffic it would be pretty useless as the engine will be idling off hot engine air. 

So the actual OAT would be lower if the dash indication uses the IAT sensor.  Lucky your bike doesn't have a bulk oil temp indication. 

As for the the air cooled Guzzi's ability to happily sit in traffic idling in summer weather well yours must be the only one in the world that can happily cope. Don't know what was wrong with your BMW or what BM it was but both my K100RS's and were fine in city traffic on a hot day and yes the thermo fans operated as would be expected but no fuel boiling issues.

To say that an air cooled engines in general and Guzzi's in particular cope with the hot traffic condition you describe goes against all logical comparisons and evidence. 

Pete Roper has experience with engines damaged by prolonged idling and not even in hot conditions. Maybe he'll give us the benefit of his practical customer experience in the matter.

Ciao 

[Chris Wilson]

24 minutes ago, Lucky Phil said:

Ok so I looked at the Bellagio owners manual and the ambient temp indicator. If that is taking it's reading off the air intake sensor then in traffic it would be pretty useless as the engine will be idling off hot engine air. 

So the actual OAT would be lower if the dash indication uses the IAT sensor.  Lucky your bike doesn't have a bulk oil temp indication. 

As for the the air cooled Guzzi's ability to happily sit in traffic idling in summer weather well yours must be the only one in the world that can happily cope. Don't know what was wrong with your BMW or what BM it was but both my K100RS's and were fine in city traffic on a hot day and yes the thermo fans operated as would be expected but no fuel boiling issues.

To say that an air cooled engines in general and Guzzi's in particular cope with the hot traffic condition you describe goes against all logical comparisons and evidence. 

Pete Roper has experience with engines damaged by prolonged idling and not even in hot conditions. Maybe he'll give us the benefit of his practical customer experience in the matter.

Ciao 

Hi again Phil,

I had a K75 for 10 years and being a three cylinder made less heat than the K100, and my bike had foil insulation under tank that was designed to prevent fuel boiling and yet under extremes it did not stop it.

BMW had a recall on the K100's to address the same. Norges had the same issue but I digress.

In real world riding I know that liquid cooling protects the engine better than air but is worse for the rider in extreme conditions.

Engines being heat exchange units have to reject heat somewhere and with an air cooled Vee twin at idle the hottest areas are the furthest away from the rider and heat simply rises when there is no flow.

Liquid cooling in extreme temps needs air flow and guess who suffers at the expense of the engine?

My bike, a short stroke big block with massive finnage and deep sump that really is designed for a much bigger engine handles temps on the edge of human endurance just fine.

Wouldn't want to prove that all the time but I have proved it in heavy traffic again and again.

As far as 'real' big blocks like the Griso I remember them as being and I quote 'vastly overcooled' so it's hard to imagine that having a 200cc smaller engine is going to counter that comment.

Chris.

[Lucky Phil]

8 minutes ago, Chris Wilson said:

Hi again Phil,

I had a K75 for 10 years and being a three cylinder made less heat than the K100, and my bike had foil insulation under tank that was designed to prevent fuel boiling and yet under extremes it did not stop it.

BMW had a recall on the K100's to address the same. Norges had the same issue but I digress.

In real world riding I know that liquid cooling protects the engine better than air but is worse for the rider in extreme conditions.

Engines being heat exchange units have to reject heat somewhere and with an air cooled Vee twin at idle the hottest areas are the furthest away from the rider and heat simply rises when there is no flow.

Liquid cooling in extreme temps needs air flow and guess who suffers at the expense of the engine?

My bike, a short stroke big block with massive finnage and deep sump that really is designed for a much bigger engine handles temps on the edge of human endurance just fine.

Wouldn't want to prove that all the time but I have proved it in heavy traffic again and again.

As far as 'real' big blocks like the Griso I remember them as being and I quote 'vastly overcooled' so it's hard to imagine that having a 200cc smaller engine is going to counter that comment.

Chris.

From memory the Griso was the engine that Pete was required to rebuild after the owner had started his bike and was distracted by a phone call for 45 min or so and the bike was left idling and overheated so badly it required new pistons and rings and a Griso is partially oil cooled. Over cooling on them only happens in winter here and when they are on the move as they have no oil cooler thermostat. Wedggie here owns a Guzzi Daytona powered Magni Australia that overheats in 10min of Scottish suburban traffic at 20 deg C with oil temps of 140 deg C and the low oil pressure light stars coming on. 

 

[pete roper]

Old Hi-Cam and New Hi Cam are very different beasts. One of the major differences is that the newer engine has a separate cooling circuit fed by a separate pump and that circuit, (Nor the lubrication circuit.) run a thermostat. 

The lubrication circuit remains very similar to the older 2V motors with the filtered oil being delivered to the main bearings and big ends but from there things change a bit. After the mains the front feed splits and some oil goes to the under piston spray nozzles and the rest goes up the front inner studs to the front cam bearing and cam end rocker pivots. The rear main feed then goes up the rear outer stud and lubricates the outer rocker pivots. Cam lobes and tappets are splash fed from oil spilt into a weir by the cam bearings.

The cooling circuit is completely separate. Oil is delivered, unfiltered but pressure regulated to the cooler and thence to the cooling circuits in the head by external hoses. On the 1200's the oil goes directly to the heads. On the 1400's it is delivered to a large gallery in the wall of the cylinder and then flows around large, cast in, galleries in the heads. The 1200 and 1400 cooling systems are completely dissimilar and is one of the reasons building a 1400 motor to put in a 1200 bike is not a task of simply bolting on the bigger cylinders and pistons.

It is this lack of thermostat that is the main contributor to the gross over cooling the new 8V's suffer from. In anything other than 30*C+ ambient temperatures it's actually quite difficult to get the oil hot enough to sublime water out of it! At least it is unless you are stuck in traffic or thrashing the bejasus out of it!

I can't remember offhand if the Bellagio has an oil cooler but if it does it, along with the other 2V bikes of the period, does have a thermostat. In reality it is unlikely that any big block Guzzi, with the exception of 'Old' Hi-Cams maybe, is going to cook itself in traffic. Let's face it the engine was originally designed to sit idling in summer traffic in Milan with a fat copper sitting on top of it. The cylinders are grotesquely over finned but that doesn't mean getting so hot is good for it and clearances for things like piston to bore and ring to piston have to be a lot sloppier than they would be with acliquid cooled motor.

 

As for the bike Phil referenced? That was an 8V Griso that belonged to a customer who had started the bike and then left it to 'Warm up', truly an unnecessary thing, and claimed he had been 'Distracted', (I think by his missus asking for a length of the 'Veal Dagger!') and by the time he got back to it it had stopped and wouldn't re-start. The tank vent wasn't working and when he opened the tank it blew five litres of fuel over the red hot engine and garage! It was lucky his house didn't go up!

When I got it to the workshop and lifted the tank I found that the pressurised tank had swollen so much it had pressed the spigot of the fuel pump against the reservoir cover for the cam chain tensioner on the right hand cylinder and melted it to a blob, it must of been seconds away from bursting when the engine stopped and it only stopped because the phase sensor expired from overheating! If it had burst the engine would of stopped but the pump would of kept running for four seconds! Quite enough to spew enough fuel out onto the superheated engine to cause a calamity! There was a shit-tonne of good luck involved there. The bike was in his garage under his roofline. It could of got very nasty!

When I stripped the engine I was actually amazed by how little damage I found! Everything was still within spec! From memory it got rings and a set of valve guide oil seals. That was pretty much it! It's now living in Townsville and continues to run like a freight train.

They really are very hard to kill!

[Chris Wilson]

Ok, but you would have to admit that a 45 minute phone call is a constructed stupidity.

In the real world when sitting astride the vehicle my contention is that the rider expire long before engine damage sets in. That and any one with an ounce of wit would turn the vehicle off if stopped more than a few minutes.

If that's not the case then I am riding one very damaged Bellagio.

Chris

[Chris Wilson]

As an aside here I have the excellent Beetle map installed, iteration 2.

Mark 1 map was perfect, too perfect in fact and would only run fantastically on a prewarmed engine.

But when starting from cold the engine was a bit 'dry' and lean, and would easily stall at the smallest applied load on take off.

Enter the even more excellent mark 2 map with a bit more fuel added across the range and I am back down to a three minute warm up before my cold blooded reptilian bike even thinks that it likes to pull out of the garage without the fast idle collar still being rotated.

I honestly can't think of a better air cooled motorcycle of this size for handling traffic, let's face it, when you live in Australia's largest capital you are going to face more stop start than high speed cruising.

Chris.

 

[docc]

1 hour ago, pete roper said:

As for the bike Phil referenced? That was an 8V Griso that belonged to a customer who had started the bike and then left it to 'Warm up', truly an unnecessary thing, and claimed he had been 'Distracted', (I think by his missus asking for a length of the 'Veal Dagger!') and by the time he got back to it it had stopped and wouldn't re-start. The tank vent wasn't working and when he opened the tank it blew five litres of fuel over the red hot engine and garage! It was lucky his house didn't go up!

They really are very hard to kill!

I know this same "phone call" story of a BMW GS that idled on its stand for "45 minutes." It was a total loss.

[Lucky Phil]

55 minutes ago, docc said:

I know this same "phone call" story of a BMW GS that idled on its stand for "45 minutes." It was a total loss.

Yes air cooled bikes don't like it. Petes reference to the origins in Police work has to be tempered by the fact that the Police don't sit in traffic jams now do they and they were on older less powerful models. As long as you can keep the revs low and the bike moving even at 5 kph you generally have just enough cooling effect. It's the idling with no movement that kills them AND low speed with moderate or high rpm. I rode my V11 about 2 klms at 2500 rpm once in 2nd gear when the rear wheel bearing was about to collapse. The OAT was about 25 deg and I just needed to get it home in the one gear and avoid gear changes and there was a hill to negotiate. So minimal throttle and low speed maybe 20kph max. It was in a local suburban back streets and by the time I got it home it was rather rattily and stinking hot. Shut it down and and let it cool. Friction from the elevated rpm and minimal airflow across the fins and you have a recipe for overheating. Even caught me by surprise at how fast it occurred. I was expecting  to get an increase in engine temp but it happened faster than I was expecting.

Ciao      

[ScuRoo]

6 hours ago, Lucky Phil said:

I've never found sitting on the side of the road with an overheating engine waiting for it to cool down before you can continue riding to be particularly cool myself.

Ciao

Yup, I agree.

But anytime that’s ever happened it’s always had a radiator!

Definitely ain’t cool.

😎

[Chris Wilson]

At 2500 rpm I wonder if enough oil was circulating to conduct heat away.

Chris.

[Lucky Phil]

49 minutes ago, Chris Wilson said:

At 2500 rpm I wonder if enough oil was circulating to conduct heat away.

Chris.

That wouldn't be an issue. There would be enough oil circulation at that rpm and remember the loads were low. A V11 obviously uses oil as a cooling medium but not like a Griso or oil head BMW. Riding at 2500rpm at 60-70 kph is no issue but at 20kph it's a problem at least at 25deg C. The issue with air cooling is the system has no elasticity, the capacity to cool is completely governed by the OAT and the airflow available to shed the heat. A liquid cooled system has the ability to absorb transient running condition due to the fact that it requires exponentially more and more energy to raise the temperature of water per degree of increase. That's one of it's big advantages. In addition to that you can control engine temp much more accurately and when you do need the airflow at a standstill the method of providing it is compact and simple unlike an aircooled engine with large fans and ducting etc.

I've owned plenty of water cooled bikes that have had cooling issues, like the first GPZ900 Kawasaki. The coolant temp used to increase quickly in traffic which scared the riders so Kawasaki modified the system with a resistor in the gauge wiring to change the indication. All 3 of my MV Agustas ran really hot in city traffic because they were fully faired and exhausting the cooling air from the radiators was an issue. The naked bikes were fine. 

I guess the discussion has expanded but the reality is liquid cooling is far superior in virtually every way on a motorcycle bar simplicity but you pay for it. It's a bit like the EFI V Carb argument, it's a pointless discussion because it's overwhelmingly obvious from a technical point of view where the advantage is.

Ciao