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Another 1400 project.....


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I am trying to visualize how the "hi-cam" 1200 must look differently from the V11 at the timing chest/ heads and otherwise.

I seem to recall that the 1200 Guzzi returned to an "alternator" between the cylinders above the engine block, instead of driven off the crank nose à la Tonti/ Spine Frame . . .

Could that be fitted to a Spine Frame?

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Well, there is that. No use staying up hoping for wet dreams. :huh:

 

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Seems the "timing chest" of the 1200 must be a rather complex affair?

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Not really? In what way complex? The primary timing system is basically the same as the early loop frame engines, a train of three gears. Secondary system by chains up the rear of the cylinders, a lot neater and simpler than the 'Old' Hi Cam system with the huge, cooling air flow blocking, belt housing with a complex vernier system for the cams, up the front of the cylinders.

Third gear, below the crank, drives the oil pumps. One for lubrication, one for cooling. The cooling circuit doesn't have a thermostat for the oil cooler though meaning that these engines run stupidly cool most of the time.

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16 minutes ago, pete roper said:

Not really? In what way complex? The primary timing system is basically the same as the early loop frame engines, a train of three gears. Secondary system by chains up the rear of the cylinders, a lot neater and simpler than the 'Old' Hi Cam system with the huge, cooling air flow blocking, belt housing with a complex vernier system for the cams, up the front of the cylinders.

Third gear, below the crank, drives the oil pumps. One for lubrication, one for cooling. The cooling circuit doesn't have a thermostat for the oil cooler though meaning that these engines run stupidly cool most of the time.

??

It is easy for me to understand the "cam in block/ push rods to two valves per cylinder." :huh:

 

 

 

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4 hours ago, pete roper said:

Not really? In what way complex? The primary timing system is basically the same as the early loop frame engines, a train of three gears. Secondary system by chains up the rear of the cylinders, a lot neater and simpler than the 'Old' Hi Cam system with the huge, cooling air flow blocking, belt housing with a complex vernier system for the cams, up the front of the cylinders.

Third gear, below the crank, drives the oil pumps. One for lubrication, one for cooling. The cooling circuit doesn't have a thermostat for the oil cooler though meaning that these engines run stupidly cool most of the time.

You forgot to mention Pete the split drive gear for the jackshaft to eliminate backlash and keep the noise down, nice.

Ciao 

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I've been looking for an image of what the inside of a 1200 timing chest looks like, but then I see Pete say gears in the front, chains  on the rear of the cylinders. This is the case even for the 2-valve per cylinder 1200?

I did find this image on thisoldtractor. I reckon this shows the two cam located on the inside of the heads?

1200cc_8valve_37.jpg

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Best idea if you want to get an idea how it all works is to look at the parts diagrams.

Oh, and if you wanted to see a 1400 Griso? Here's Mark's bike with the first 1400 motor I built. Compare it to the other two in the next pic and you'll see it's indistinguishable.

A2041C1A-84FB-4947-A1AC-411816BB26D7.jpeg

ADC915B4-5D8A-4128-9D9F-AF02077FB240.jpeg

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When you have posted that 1400 Griso before, I wrongly assumed you had put a Guzzi 1400 motor in.  Very interesting that it is a complicated matter of installing the 1400 pistons (and cylinders and cams?) into the 1200 motor.  How much does this increase the bore? And change the compression?

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18 hours ago, pete roper said:

I don't think so Phil? Just straight cut gears, no scissor gears in any 8V I've had apart.....

Ok Pete. Just thought I saw in the 1200 engine training manual an image of a scissor/double gear on the crank and assumed it was a backlash gear.

Ciao

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If you just put a 1400 motor in it won't run due to the different phase sensor/phonic wheel set up. You'd also end up with the weedy little 1400 ports in the heads and spare plugs and plug tunnels necessitating the use of the ugly 1400 rocker covers which on the 1400 are hidden by the vast rocker cover 'Covers'. 
 

While some people are saying that the 1400 combustion chamber in the head is larger I don't think it is appreciably. The added. Volume to drop the CR, or keep it acceptable, is done by the machining of the pistons.

Cant remember offhand how much bigger the bore is but its substantially larger.

The biggest difficulty though is the cooling circuits. The 1200 simply uses a series of cross drilling's around the exhaust valve seats to channel oil to take heat away and the feed goes in the inner side of the head. On the 1400 there are substantial galleries cast into the head similar to the water galleries in a conventional liquid cooled engine. The oil is delivered to a gallery in the barrel and then circulates through those chambers in the head to remove heat and the drain and return system is completely different to the 1200 motor.

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  • 1 month later...

Haven't lifted a spanner for the en-biggening of the motor yet but digging around in my 'Mountain of Munt' I did find the Tenni green bodywork and brown seat off one I wrecked out a while back so today I took off the boring black plastics, (except the front mudguard.) and played swapsies.

Much better than boring black and baboon's arse red seat!

1396EF8A-D79A-4969-A1AD-67206829698C.jpeg

5B4BA310-6447-4141-AA98-9FB5E5ADEDF1.jpeg

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