All I wanted originally was sufficient information to make a seized LLB work. One year later I realise, probably due to a lack of seven day a week study, there are Seagull foibles which I did not want to know about but its Bulldog virtue has demanded curiosity.
I now have beside the '58 Century, Silver Centuries and 40's and thought now the only way up was to the QB via the flawed 170. But now I understand the '102' has been available alongside the other similar capacity engines ; standard and plus, with or without clutches!
So what is its advantage or difference?
102 / Century? I'm missing something . . .
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rosbullterier
- Posts: 710
- Joined: Mon Dec 18, 2006 12:23 am
- Location: Cornwall UK
Differences between the 102 series and the centuries you mean?
Well to all intents and purposes you have the same capacity, bore and stroke. You have the same transom bracket, crankcase, driveshaft and tube.
With the 102 you have an integral cylinder block/head, with the centuries they have a separate alloy head with gasket.
I - and others - have no real clue why they ever bothered with the centuries at all. Maybe it's because of the success of the early forties, and a perceived need for a motor 'in between' the forty plus and the 102. More likely was the perception that the 102 was beginning to look a bit 'old fashioned', which of course it was. (In the view of many it was looking old fashioned in the late thirties)
The first Centuries were modelled on the forties, which is surprising considering the difficultes they had with their Little Model Forty and its brethren. But the LLS and CP did bridge that gap, and they sold quite well.
When the Silver Centuries appeared in the mid sixties it was effectively in competion with the three 102s that were still available, and although popular, many still reckon that the 102 was a better device.
The 102 had a huge water jacket capacity compared to the Century, and of course was considerably quieter because of the coolant feed into the exhaust. It pumped better than the Century, too.
The lack of a separate cylinder head meant you would never have gasket problems, and the method of tank attachment meant you wouldn't break a delicate alloy lug necessitating a new cylinder head.
The gearbox and clutch on the 102s was different, but equivalent..
I did hear a tale that suggested cylinder block castings for the 102 were difficult to manufacture and therefore expensive, but having spoken to people from Poole Foundry where they were made I understand the Century blocks with their thin walls gave the more trouble, so it can't be that.
I personally prefer the 102 range.
Well to all intents and purposes you have the same capacity, bore and stroke. You have the same transom bracket, crankcase, driveshaft and tube.
With the 102 you have an integral cylinder block/head, with the centuries they have a separate alloy head with gasket.
I - and others - have no real clue why they ever bothered with the centuries at all. Maybe it's because of the success of the early forties, and a perceived need for a motor 'in between' the forty plus and the 102. More likely was the perception that the 102 was beginning to look a bit 'old fashioned', which of course it was. (In the view of many it was looking old fashioned in the late thirties)
The first Centuries were modelled on the forties, which is surprising considering the difficultes they had with their Little Model Forty and its brethren. But the LLS and CP did bridge that gap, and they sold quite well.
When the Silver Centuries appeared in the mid sixties it was effectively in competion with the three 102s that were still available, and although popular, many still reckon that the 102 was a better device.
The 102 had a huge water jacket capacity compared to the Century, and of course was considerably quieter because of the coolant feed into the exhaust. It pumped better than the Century, too.
The lack of a separate cylinder head meant you would never have gasket problems, and the method of tank attachment meant you wouldn't break a delicate alloy lug necessitating a new cylinder head.
The gearbox and clutch on the 102s was different, but equivalent..
I did hear a tale that suggested cylinder block castings for the 102 were difficult to manufacture and therefore expensive, but having spoken to people from Poole Foundry where they were made I understand the Century blocks with their thin walls gave the more trouble, so it can't be that.
I personally prefer the 102 range.
I agree i much prefer the look of the 102 block
and the coolant feed into the exhaust is excellent as you say.
i wish actualy that there was a similar block for the smaller engines also!
you can exchange the gearboxes and shaft etc however the centre of the exhaust is about 10 mm further out on the 102 than the century which means the exhaust will be at a slight angle!
but still works fine...
sorry purists!
and the coolant feed into the exhaust is excellent as you say.
i wish actualy that there was a similar block for the smaller engines also!
you can exchange the gearboxes and shaft etc however the centre of the exhaust is about 10 mm further out on the 102 than the century which means the exhaust will be at a slight angle!
but still works fine...
sorry purists!
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rosbullterier
- Posts: 710
- Joined: Mon Dec 18, 2006 12:23 am
- Location: Cornwall UK
102 / Century? I'm missing something . . .
Well . . . that is truly fascinating - so the Silver Seagull was just a fashion whim! Next I must look for a 102. I suppose the idea of an integral head harked back to the old fashioned side valve car engine.
How is the Silver century uprated to the Century - is it just from the enlarged carb throat and Amal Carb?
Does this mean the 102 with Amal carb should produce the same push as the Silver Century?
How is the Silver century uprated to the Century - is it just from the enlarged carb throat and Amal Carb?
Does this mean the 102 with Amal carb should produce the same push as the Silver Century?
A 102 with Amal carb should produce a similar push - provided you match the gearboxes/props.
The Silver Century was the Amal carb, naturally on a Silver Century block.
The ordinary Century is quite a good motor. It benefitted from the upgraded 'Hydrofan' prop, which gave it a theoretical 10 % increase in power, and could be made to go a bit better by enlarging the inlet compensator orifice.
Maybe 'Fashion statement' is a bit strong, but I can't think of a better reason for the Century's introduction!
By all means get hold of a 102, you won't be disappointed. Vintage looks with quietness added.
The Silver Century was the Amal carb, naturally on a Silver Century block.
The ordinary Century is quite a good motor. It benefitted from the upgraded 'Hydrofan' prop, which gave it a theoretical 10 % increase in power, and could be made to go a bit better by enlarging the inlet compensator orifice.
Maybe 'Fashion statement' is a bit strong, but I can't think of a better reason for the Century's introduction!
By all means get hold of a 102, you won't be disappointed. Vintage looks with quietness added.
