Noisy V-12 startup

[trades707]

Forced home stay is good for something. Finally put the flathead V-12 together enough to start. By no small miracle it started, idles way too fast and makes terrible racket, sounds like more from front of engine. Something is knocking, any wild guesses before I pull the pan?


https://soundcloud.com/user-17353757/20200408-102737a.


Gages don't work yet, but seemed to have lots of oil flow from the Melling 15 pump when I turned over with the intake off.
Thanks
Abe

[J Franklin]

Sounds like my air compressor. Better take a close look.

[G.M.]

Originally Posted by trades707

Forced home stay is good for something. Finally put the flathead V-12 together enough to start. By no small miracle it started, idles way too fast and makes terrible racket, sounds like more from front of engine. Something is knocking, any wild guesses before I pull the pan?


https://soundcloud.com/user-17353757/20200408-102737a.


Gages don't work yet, but seemed to have lots of oil flow from the Melling 15 pump when I turned over with the intake off.
Thanks
Abe

At least put a mechanical gauge on before running, No oil pressure kill
it NOW. I had one years ago with oil pressure problems, Ill have to
think about it a while. I would put the gauge on, pull the plugs and
spin it to see if there is any pressure before doing anything else. Let
me know the oil pressure. G.M.

Something rings a bell in my weak little brain that the V/12 has
hydraulic lifters and when they sit a while they loose oil. It takes
a minute or so to get oil pressure to pump up the lifters. They make
a lot of noise during that first minute.

[cdan34]

That sounds exactly like my v8 did when I started it years ago. I shut it off immediately, took the heads off and, I'm embarrassed to say, on one bank of cylinders I forgot the head gasket. The pistons were hitting the heads a slight amount maybe .005. Pan off, check rods, bearings etc. All seemed ok. It's been running fine now for 5000 mi. I hope that isn't your problem. Good luck

[Ken/Alabama]

Friends V12 had similar racket . His was the stamped steel pulley on the crankshaft had a couple of spot welds turn lose and when the belt came around it was causing the pulley to open up then snap together. I welded it back in place and it lasted for a while until the pulley finally broke and we replaced it . Remove the Belt and start it up . If it goes away you’ll know .

[Graeme / New Zealand]

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Soundslike an MG43 in full flight

Gb

[Jack E/NJ]

Sounds more like a gatling in slow motion. https://www.youtube.com/watch?v=nG3Hi7K9MU4


Jack E/NJ

[drolston]

What is the last work you did on the engine? Could be a collapsed lifter or excessive valve lash. Maybe a fuel pump push rod too short, or fuel pump not all the way down on its mount.

[G.M.]

Originally Posted by drolston

What is the last work you did on the engine? Could be a collapsed lifter or excessive valve lash. Maybe a fuel pump push rod too short, or fuel pump not all the way down on its mount.

Are you talking to G.M.??? That was years ago and I don't remember
every thing. I know it leaked oil at the pan gasket and both valve
covers I may remember as I think about it. I can see in my mind
some of the things I did but the 90 year memory bank must be
getting a little slow or foggy. G.M.

[drolston]

Originally Posted by G.M.

Are you talking to G.M.??? That was years ago and I don't remember
every thing. I know it leaked oil at the pan gasket and both valve
covers I may remember as I think about it. I can see in my mind
some of the things I did but the 90 year memory bank must be
getting a little slow or foggy. G.M.

Just some "wild guesses" for Trades to check out before dropping the pan. But I believe your thought regarding hydraulic lifter is the most probable cause.

[G.M.]

Originally Posted by drolston

Just some "wild guesses" for Trades to check out before dropping the pan. But I believe your thought regarding hydraulic lifter is the most probable cause.

I think the oil was to thin and heavier oil fixed it but it took a lot
of time figuring it out. G.M.