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Another 1725 died the heat death...

bernd_st

Bronze Level Sponsor
Didn't examine them deeply yet, but they seem to be slightly worn. May consider to put new ones in but have to see how they work with a renewed camshaft...
 

DanR

Diamond Level Sponsor
First things first! With 40 over and the heat condition, I believe I'd scrap the block. The crank and the rods accordingly.

Not much there to salvage!
 

65beam

Donation Time
It all goes back to lack of maintenance. Coolant was neglected and it would be interesting to know what oil was being used. Todays oils will withstand in excess of 400 F temps before breaking down. The bearings were probably well past the max clearance, the pump may have been totally worn out or a combo of both. The bearings look discolored which is typical of high temps.
 
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bernd_st

Bronze Level Sponsor
Yep, I have a new Iranian crank and a set of rods already. 40 over makes it costly though. Block would need liners . My engine shop recently did a great job installing a set and cutting them down to +0.020. Was never really keen about liners since some guys in our club had head gasket sealing issues. However this shop did the trick leaving a step at the very bottom of the bore where the liner can rest on and not dive away.
So the block can be rescued provided the extra expense.

Regarding the oil PO used the wrong one, a modern 10W whatever. On top oil got thinned by fuel seeping through a small pinhole in the fuel pump. It almost flowed like water plus smelled like fuel we opened the pan screw :-((

Steel pan yes, however an oil cooler wouldn't have prevented this engine failure...

P.S. Interestingly the oil pump is still good. Appearantly the filter mesh has done it's job...
 
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Tom H

Platinum Level Sponsor
I'm the guy who asked about what evidence of overheating you can see in the photos. I can see the scoring of the cylinders in the later photo, but the top of the block does not show anything to me. And the rusty plugs are really evidence of rust and poor coolant. I had my 1725 engine go bad, breaking a piston ring and burning the valve seat on cyl#4 partly due to overheating, but I also found that overheating usually warped the head. - several times on my SIV , back in the late 60's. Hope all goes well on your rebuild. Are the combustion chambers in the head all OK? When I rebuilt my 725, I did the Vizard mod, Chevy rods, and bored and stroked it to about 1820 cc's using custom pistons. I also cleaned a fair amount of gunk and sand out of the block behind the #4 cyl.

Tom
 

bernd_st

Bronze Level Sponsor
Tom, I'm with you that this block can be rescued. The head too, lots of meat but certainly needs a skim. The chambers are ok. Will always rescue late heads as much as possible just to get rid of those dreaded plug tubes. Think Rootes realized themselves in the later 60's that this was a stupid idea. Will disassemble the valves today and check the guides...
 

Bill Blue

Platinum Level Sponsor
What is hot for one engine is middlin' warm for another. Know a guy who overheated his Ford truck. He could tell it had been hot by the puddled babbitt in the oil pan. Replaced the bearings and drove it.

Bill
 

moonstone SIV

Donation Time
And for some time prior to this mechanical inconvenience the temperature and oil pressure gauges were being monitored by.....?
 

bernd_st

Bronze Level Sponsor
Like the wording "mechanical inconvenience". Don't ask. PO is a nice guy, but his classic car skills are close to zero. Temp sensor wire not connected. Old radiator from 1963. Oil pressure gauge very low reading, loud mechanical noises, but the guy just went on. Actually not for very long when on a nice Summer's day the engine got burbling hot and refused to start ever after. I built him a well going 1725 earlier - the one with the liners - which he is now enjoying. On a side note he ran a Weber 28/36 DCD with to lean jetting, this is cured as well now...
 

bernd_st

Bronze Level Sponsor
The engine tended to run very hot by poor coolant flow around #3 & 4 , old rad and a lean mixture. Diluting oil gave it the exitus...
 

bernd_st

Bronze Level Sponsor
Ok, today was head take apart day. Started really bad, because on all valves the wedges sat really deep and firm their conical seats. My valve compressor gave up and bent sideways on them - and this was despite I gave them a good shock with a big hammer before. Big "Hmm" moment.

Straightened and reinforced my valve compressor but still no whatsoever movement. Changed my strategy to brute force then. Put an ball race bearing under the valve and gave the spring holders a good slap on the top with a tube and a big hammer. Bang and hey presto the wedges flew out. Collars could be removed then but still the valves couldn't be pulled because their heads were mushroomed as stated earlier. After a good circumference grind with a Dremel they moved out. What puzzles me however were rubber rings which had been installed by previous workshop in order to avoid oil being burned in the combustion Chambers. One bigger ring around the guide and one smaller ring on the valve stem. Weird setup and most rings already split or deformed. Complete nonsense. Name of the workshop also found " Performance Clinic" wow and beer time again ...

IMG_20200813_213346.jpg

IMG_20200813_213446.jpg
 
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