The only things I can think to do after reading all the excellant mechanical advice given in this post is if you are still unsure if something was accidentally dropped into the motor you could remove the spark plug and reach a flexible magnet extension into the cylinder to see if anything metal could be floating around in there, also even with a good oil pressure reading there could be some oil starvation to the rocker\rod area by either low oil level or a plugged passage in the rocker shaft (if its like the y-blocks). I have no flattie first hand knowledge.
So if you take the head covers off, while your in there make sure there are no gummed up passages for oil flow, if you cant adjust the rockers then spin the valve stems\ pushrods and anything else that moves in there to check for varnish or wear and tear binding.
Good luck with it, remember...1\2 the fun of fixing them is telling how you did it.
Ed

 

What makes these engines special is that there is no moving parts in the head - the valves are in the block. The head does not have a cover - it is just a flat slab of cast iron with some water passages to cool the top of the firing chamber, plus the holes for the spark plugs.

There is no rocker shaft, the lifter rides on the cam and pushes against the valve stem, lifting it off its seat. Therefore there is no push rods or rockers.

If you ever took a lawnmower apart you have likely seen this sort of valve arrangment - the B and S engines use it.

 

This might help - not only does it show that Hot Rod used to sell for 35 cents, but it also shows a flathead V8. Note that the red engine block is capped by a chrome flat head - it is less than 1 and 1/2 inches tall.

 

Hey Willey B,
Thanks for the quick lesson on the flat head internals...I knew they a different animal and as I stated...I have'nt messed with one. I have seen where the parts costs for them has gone up. I'm running the original 239 OHV in my 54 and I know if I had a flattie I would be keeping it as well.
Most of what I know comes from putting hands on or reading posts on this site (which is full of great helpful folks). I try to return that help where I can, but sometimes dont look before I leap.
So, how would you eye-ball it, drop the oil pan and check it from that end?


ps...I like the truck & cop deal at the bottom of your post!

Ed

 

Like you, I am no expert on flatheads - by the time I started messing with engines the OHV was the new thing. However, I remember that you can not see the cam or the lifters from the bottom, and the valves are serviced from the valley. You remove the intake to see them. The valve springs and keepers are in the valley.

I enjoy the cartoon too - seems to fit this forum. A FTE member having a bad day? Maybe a loose wire causes you to die and coast to a stop, but you can't find it. A swift kick in the right place gets it to working again - so you jump in and peel out, trying to get to work on time.

Of course, there is always a cop around when you don't need him!

I will leave it up a few more days, but I think it takes a lot of server power to run it. It is not fair for me to use more than my share.

 

*****, don't worry about using the animated GIF in your signature. It gets transferred once to the reader's computer, then runs locally. There are built-in limits on the size and complexity of signature blocks.

 

That truck in *****'s Signature looks like a mid-50's GM, no wonder it needs kicked every time ya see it.

HA HA Humor, I Love Humor HA HA

 

I like to do the easy stuff first when diagnosing a problem. First, install a oil pressure gauge on the engine where you can watch it while the engine is running. Does the pressure drop when the clatter starts and then raise when the clatter stops? This would indicate an oil pump problem or perhaps an oil flow problem. Instead of the before mentioned solvent, I would use a quart of automatic trans fluid. It is high detergent. But you will need to change the oil afterwards. Another idea might be to change the oil and use a quart of Slick 50. It has lots of detergents that can clean out your oil journals also. Either of these ideas will free up sticky valves, if that is indeed the problem. Good luck, Jag

 

PLEASE, PLEASE, PLEASE
After any of the above mentioned procedure to loosed, clean, freeup, stuck, crudded, or clogged lubricating system, change to oil and filter and clean the screen/pickup of the oil pump.

 

You might try dumping a can of STP in that Flathead, every once in a while one valve in my Flathead 6 will start clanking and the STP takes care of it right away.

Just a thought
Rod

 

Assuming that:

-- you're using a modern detergent oil
-- the truck hasn't been driven at full operating temperature for any extended periods in a long time
-- the noise really is valve noise due to varnish

...the easiest thing would be to just drive it around at moderate speeds to get fresh oil all over the valve train. Flatties are famous for collecting vapors up in the valve chest (late-model 8BA's less so) where it condenses and forms sludge and varnish. Modern oils are pretty darn good at breaking it up. If you've been just starting it up every so often to keep it in shape, but not driving it around, it has probably been building up varnish. If it's in any shape to drive around at 30 mph for an hour or two, try doing that. It's a lot more fun too! If that doesn't help, or god forbid it sounds worse, then by all means start some surgery.

And yes, by all means change your oil after this! Chevron Delo 400

Here's a pic of the valve chest, a relatively clean one. Note that on a flathead V8, you don't even have to drain the coolant to pull the intake. It is one of the easiest engines to get into to this level.

 

LOTS of good advice in this thread. Thanks, everyone!

Well, I live in a rural mountain area, and my local 15 mile road sees about one vehicle per hour, never any cops. So even though the truck isn't licensed or insured, I think I'll venture out and try this remedy first. I'll take my CB along to call the wife to come get me if it something breaks.

If a simple extended drive or two fixes my problem, I'll be dancing with joy!