Saving Old Seagulls

I think you are right B, there is no substitute for a proper clean out to ensure the waterways are clear. I do this to every engine before use. It's a bit of a job stripping down the little 40 though..

I don't understand why they didnt make the 40 and century water jackets a bit bigger, so less prone to clogging?

Thank you, Inspector. Those pictures clearly show how a cylinder head should appear compared with one with just enough garbage in it to retard cooling. It's easy to imagine cooling water entering from the bottom rear of the visible cavities straight upward & towards the right, then out the discharge port without much meaningful cylinder contact. Would you speculate that this engine was put away wet, with the spark plug downward?

I also noticed that the head bolts in one photo are slotted screws. Interesting.


-Ted

I keep reading about magic solvents that people fondly imagine will de-gunk the waterways in their motor. It's not just Seagulls that clog, of course. Many of you will have read of my tribulations last year with my Volvo MD6a - a raw water cooled two cylinder diesel.

The point is that - as pointed out on this forum - it's not a water pipe, it's a water bath, and it's that bath that does the job of cooling. Water that simply whizzes past in some internal pipe insulated from the hot iron by an amalgamated rusty claggy concrete simply won't do the job of cooling.

I hear of kettle descaler being used, that's fine if the clag in the water jacket is in fact limescale, which I suppose is possible in some areas where the motor runs in fresh water rich in minerals. But most of the clagged up waterways I see around here are blocked with a rusty salty silty stuff. Sometimes it's soft enough to dig out with a screwdriver blase; mostly it's turned into a dark brown stony hard concrete that has to be chipped away with a hammer and a hard pointed thing. It takes ages, but it works. It is astonishing to see just how much of this rubbish you can get out of a clagged-up cylinder block!

I have on mad occasions when boredom is threatening taken piles of the resultant black filth and attempted to dissolve it. Kettle descaler didn't even fizz, vinegar didn't either, and citric acid, oxalic acid, and Cillit bang didn't touch it. Even the Coca Cola so loved of the rust destroying fraternity didn't touch it, nor the phosphoric acid it is reckoned to contain.

So for me, if there's a reduced water flow it's off with its head!

I have, I must admit, busted a couple of head bolts, but I find that if the heads wind off they tend (not always) to leave a stub that you can grip in a vice. Experience teaches you how much muscle to apply, and my failure rate has improved over time.

So don't bother with patent solvents, do the proper job.

Hi all, so my 71' Century Seagull appears to have good water flow, after reading this im questioning it now.

The temperature seems to be luke warm at the most, its only running just above idle to get the water flowing and its in a test tank so not revving hard.

After 5 or ten minutes of running should this be hotter than luke warm ?

Jesse

Not necessarily, Jesse. Others will correct me if this is not the norm though my two critters pour out lukewarm water regardless of throttle. Well it is a little warmer on the one at low speed, when not so much coolant is being pumped in the first place.

I would say that you should be able to put your hand on the cylinder block opposite of the carb for a moment or two and not get burned excepting that the edge of the head itself will be hot. A real rough and sloppy test on other engines I've had has been to splash a little water on the head while running. If the water mostly sits and evaporates, that's fine; if it rapidly bubbles away as steam, then it's running on the hotter end of the scale. I think you have to put the two together - if your water discharge is relatively cool yet the head violently objects to being wetted, you're not getting the benefit of the cooling system. Which is usually the fault of crud and junk in the water passageways. As Charles points out, the best way to deal with that, is by means of the "Armstrong" method....

Be safe,

Ted

I couldnt sleep, It was nagging me so i stripped it down, Just blocked up in the jackets by the head face, behind that the jackets were open so i suspect its had a pretty good life. Needless to say, its going to get a birthday to satisfy myself that there is no future cooling issues.

Jesse

Widowmaker wrote:I couldnt sleep, It was nagging me so i stripped it down, Just blocked up in the jackets by the head face, behind that the jackets were open so i suspect its had a pretty good life. Needless to say, its going to get a birthday to satisfy myself that there is no future cooling issues.

Jesse

It is a nice surprise when the forth bolt comes undone.

Good result. If you have a 5/16" BSF tap then run it down the threads before you put it back together. Also make sure the bolt threads are clean and greased.

If you want to reuse the head gasket you will need to anneal it, if you don't have a blowlamp stick it on the gas cooker untill it glow red hot then quench in water.

H-A

Oh ok, i didnt know that. I was just going to reuse it with a rtv gasket sealer.

So i get it red hot and then drop it in water. Will i still need to use a sealer when putting it back on ?

Jesse

Yes, just a thin smear. Seagull used a red/brown coloured silicone on the later engines.

H-A