300ci inline six

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mel

Member
Hi, my project is a 30s vintage air racer, sim to Art Chesters "Goon".The big prob is no Manascos. However there is an engine that has been around for a long time and quite dependable. This is the 4.9 300ci inline six. The only prob with that is that it has to be run inverted. Oil isnt a prob but cooling is. I am wondering what would be the best way to accomplish that. One idea I have would be to put holes and pipes in the waterjacket at the base of the cylinders ganging them in a manifold to a thermostat. Endles posibilites. Any body have any ideas? Tks Mel

velojym

Well-Known Member
I have one of these in my '88 Ford van, but I'm not sure how well it'd work
for an a/c engine. Kinda heavy.
But, if anyone can explain how this would work well, I'd be quite interested, as the engine is the only thing working right now on the van, and it's not really worth fixing at this point.

wally

Well-Known Member
Hi,
This is just some of my thinking "outloud". The water should circulate just fine with the existing water jacket and water pump. The only place there might be a problem is trapped air in the bottom (now the top) of the water jacket. THis could be taken care of easily by connecting a small tube (capable of 15psi min) from the block drain(s) to the highest part of the cooling system. This would prevent air pockets. It might be found that an additional one or two will be needed depending on how the engine sits.

Rotax does this on some engines and they call it a steam vent line. Just a return tube from the highest part of the cooling system back to the top of the radiator. GM had to do this on some newer cars by adding a manual vent in the middle of a high loop of coolant hose that has to be bled of air whenever refilling the radiator.

Just get one, weld up a stand out of angle iron, give it a try and let us know!

You might need to build an oil catch tray above the crank and add a scavenge pump to help with return oil.

Yeah the Ford 300 straight 6 is heavy but known as a very dependable motor. All of our older tugs (about 500 of them) here on the airport have this engine with a C-6 transmission that is locked out of high gear. They will pull tons of stuff.
Wally

Midniteoyl

Well-Known Member
Reverse Flow the water.. In the heads, out the block.

gahan

Well-Known Member
upside down! water dont worry me as much as oil in rocker cover may need baffels and drain ports between baffels. back to the heavy part they are real heavy!

Midniteoyl

Well-Known Member
Oil is easy - dry sump.

orion

Well-Known Member
But what about the oil that will have a tendency to pool in the pistons and cylinders - hydraulic lock tends to be one of the more problematic areas of inverted engines - although in the same breath it seems that the Walter-LOM engines don't have any problems with this.

jumpinjan

Well-Known Member
Yes, the up-side-down pistons are getting way more oil than they were in a car. Oil control is going to be problem, I wonder? Certainly, the need for an oil ring and the oil supply holes in the ring lands is not required anymore. Look at the Ranger pistons, and they have 3 compression rings, no oil ring, no oil supply holes.
Jan

gahan

Well-Known Member
Where does the dry sump start ? I would think the rocker cover .becomes the oil pan. is the cam exposed to the crank if so the holes around the push rods should let most oil get down to the rocker cover to be sucked away in a dry sump set up. I would like to see this in an air boat for a summer, no since p@\$&g off the neighbors when you can have fun on the water and keep them mad at the other end of the lake!

PTAirco

Well-Known Member
Oil in the pistons

I always wondered about that too, but there have been countless inverted engines where the problem, if it exists, has been solved. The Gypsy engines for example, had their steel cylinders extend into the block for a couple of inches, so oil flung around the crankcase would not simply flow straight back into the bore/pistons. This would form a sort of reservoir which you wouldn't get with a regular cast iron block running upside down. But on the other hand the speed of the piston flying up and down would seem to preclude oil actually pooling in them while running. Once you shut down, of course it would all drain into any piston on their upstroke (downstroke? This is geting confusing...) Perhaps boring out the block and inserting steel sleeves that protrude into the case like the gypsy engines is practical. It would depend on clearances of other moving parts of course.

Midniteoyl

Well-Known Member
Well, it would take a litte work on the block, like drilling and tapping the oil passages for the oil lines, oil restrictors in the head, etc, but its doable. Remember, a dry sump system is a scavaging system. Its under high pressure on one side, and under vacuum on the other. There really wouldnt be much 'pooling' per say. Especially when its running. The oil that doesnt go in, do its job, and get sucked out would be the minimal amount that escapes from places like the bearing caps. The standard oil control rings can handle that.

But yes, it does take a little thought and knowledge of the particular block.

org

Well-Known Member
One thing: probably the dry sump oil system will be the most expensive part of converting the engine. Even on engines that already have dry sump systems designed for them, the cost is in the multiple thousands. I doubt the 300 Ford has anything already designed for it, so you'd be paying for all the pump brackets, pullies, and so forth.

Olen

Mike Armstrong

Well-Known Member
I admit I dont know alot about aircraft powerplants but, why are some engines 'inverted' in the first place?

Midniteoyl

Well-Known Member
Usually engines are inverted in Direct Drive situations where you need the crank to be inline with the prop.

Midniteoyl

Well-Known Member
One thing: probably the dry sump oil system will be the most expensive part of converting the engine. Even on engines that already have dry sump systems designed for them, the cost is in the multiple thousands. I doubt the 300 Ford has anything already designed for it, so you'd be paying for all the pump brackets, pullies, and so forth.

Olen
True. Although it shouldnt be 'multiple thousands' it does add up.

Mike Armstrong

Well-Known Member
Usually engines are inverted in Direct Drive situations where you need the crank to be inline with the prop.
Interesting, thanks.

JimC

Well-Known Member
The 440 Ranger oil consumption is greatly alleviated by running rings from a 351 Ford engine (the 351 truck engine, not the Windsor or Cleveland). Speaking of that, the 351 might make a good candidate for an inverted engine as well.
JimC

Old Jupiter

Active Member
The Ford 240/300 "Big Six" is a favorite of mine. Two problems were cracking pistons in the 300, and the phenolic cam drive gear in both versions. Both of these can be addressed during a rebuild with aftermarket pistons and cam gear,and you can build a dandy engine, albeit heavy for an airplane (more on this in a minute). The best heads came on the later engines with fuel injection and have swirl ramps in the intake ports. The next best heads are the closed-chamber heads from the early 240. Don't use the open-chamber smog heads from the seventies and early eighties, which are fuel-inefficient and gutless. When you rebuild, tell your machinist you want the block decked to get a squish-height of about .036-.040" which makes for an efficient, detonation-resistant engine.

I don't get the idea that you won't need oil control rings, the purpose of which is to scrape excess oil off the cylinder walls so it doesn't get into the combustion chambers. The modern 3-piece oil ring is one of the best inventions in the history of 4-stroke piston engines. Furthermore, maybe you could think about mounting the engine upright and using a belt-drive to let the engine wind up to 3600rpm or so while keeping prop-speed down. This will still give you the high-mounted prop. You don't have to mount the engine upside down to get this, but it's just a thought.

There is a good group of knowledgeable guys building these engines and they can advise you on the best pistons, rocker arms, and other parts you'll need. Go to www.fordsix.com and check the FAQs first.

And get this: the fordsix guys are manufacturing aluminum heads! By the time you've replaced the cast iron head and intake manifold with aluminum pieces, and the cast iron exhaust manifold with a steel tube header, you've taken a bunch of weight off this engine (a lot more than you would add with a propellor reduction unit), besides making it much more efficient (the stock iron manifolds are pretty bad).

Old Jupiter

Active Member
Another thought. Most stock factory water pumps for car engines are crap nowdays. It used to be that the pump impellers were cast iron and shaped for efficient operation. Now they are stamped steel in the interest of saving a few pennies. These stamped impellers are open on the back, cutting efficiency (go to your auto machinist and take a look at one). You could make a sheetmetal disc and bond or braze it to the back of the impeller to make it work better. But the best idea is to spend a little more and buy a new pump from one of the makers of hot rod parts, which have very efficient impellers. Also, these aftermarket pumps have aluminum housings and impellers, saving weight.

There's a very informative book entitled, "Cooling System Basics" by Randy Rundle, as I recall. Even talks about radiators for old airplanes. well worth the price of getting it for your tech library.

ddoi

Member
Do any of you know specifically how much the 300 (aka 4.9) weighs? Ford parts lists 217 lbs for the short block assy. Other numbers I've found are all over the place; from less than a 302 (5.0) V8 to over 570 lbs in a DVII replica with PSRU:

Alternate Engine Data

A baseline dry weight for the long block would be really useful. I may have to buy one (they're plentiful and relatively cheap) and report back.

250 ft-lbs of torque @ 1600 rpm seems close to ideal for a direct drive aircraft engine.

Thanks, Dai

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