Yesterday I bought another Century 100. Its compression is a lot lower than my original Century 100.
Its not been run in the water yet (it runs fine in the tank) but i'm assuming that it will need new rings and or barrel/rebore ??
It has studs and nuts on the head rather than bolts. I have not done a head strip down yet but gather its not easy ??
Any chance of it running on lower compression or is it a strip down job ??
Century 100 compression
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40TPI
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If it runs much the same as your original engine in terms of performance on your hull I'd say leave it alone and enjoy it. Seagull did not offer oversized pistons and rings for what was an over engineered low compression motor. People just keep running them!
Unless you know you have a broken ring or the waterways are blocked and you have overheating I'd say there is no reason to strip it down. On the other hand maybe spanner jobs are your pleasure!
Taking a head off can either be a walk in the park if all the bolts come out easily or an absolute nightmare if you shear one or more of them and have to head for the machine shop. Depends on how much corrosion has taken place. However since your Century is an early one with studs and nuts it shouldn't be as much of a problem. True you do risk a sheared stud but difficult nuts do offer more options than an inch of corroded 5/16 BSF thread hidden down a bolt hole. A decent sized torch and a wire brush should make it easy! If you still decide to have a go have a search through the old posts or the FAQ on the main SOS site
I have not seen or heard any good reason why the head studs on the early Century model were changed to bolts. The Century was the first Seagull to have a "modern" separate head and they were fully aware of the practical issues of rusting water jackets and brine over many years experience with the 102. (Which has a totally inaccessible water jacket.) Bolts would predictably be much more problematic to remove than nuts after a time in service so why did they change and loose the opportunity to do simple(r) head removal to access the waterways? Seems a retrograde decision.
Peter
Unless you know you have a broken ring or the waterways are blocked and you have overheating I'd say there is no reason to strip it down. On the other hand maybe spanner jobs are your pleasure!
Taking a head off can either be a walk in the park if all the bolts come out easily or an absolute nightmare if you shear one or more of them and have to head for the machine shop. Depends on how much corrosion has taken place. However since your Century is an early one with studs and nuts it shouldn't be as much of a problem. True you do risk a sheared stud but difficult nuts do offer more options than an inch of corroded 5/16 BSF thread hidden down a bolt hole. A decent sized torch and a wire brush should make it easy! If you still decide to have a go have a search through the old posts or the FAQ on the main SOS site
I have not seen or heard any good reason why the head studs on the early Century model were changed to bolts. The Century was the first Seagull to have a "modern" separate head and they were fully aware of the practical issues of rusting water jackets and brine over many years experience with the 102. (Which has a totally inaccessible water jacket.) Bolts would predictably be much more problematic to remove than nuts after a time in service so why did they change and loose the opportunity to do simple(r) head removal to access the waterways? Seems a retrograde decision.
Peter
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pdc1@tesco.net
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40TPI
- Posts: 451
- Joined: Fri Jan 26, 2007 7:08 pm
- Location: North Buckinghamshire, 110 miles south of Yorkshire, England.
Charles Large called to temper my enthusiasm for nuts and studs on heads. I'm reminded that early LLS have studs that go all the way through to the crankcase side and also have the interesting steel head gaskets; similar scheme to the FVs. Apparently a design not loved in the Seagull Service dept. according to CharlesP researches.
Which may help account for the demise of through studs.
I'd still say an opportunity lost for short studs.
Peter
Which may help account for the demise of through studs.
I'd still say an opportunity lost for short studs.
Peter
Stripping them down
If it aint broke don't fix it!
Certainly an addage I have used more than a hundred times for the Seagull.
Follow the FAQ tips and do gentle maintainace, then go and enjoy!
Regards,
John
Certainly an addage I have used more than a hundred times for the Seagull.
Follow the FAQ tips and do gentle maintainace, then go and enjoy!
Regards,
John