Heavy duty 300 specs

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Rusty_Old_F250
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Heavy duty 300 specs

Post #1 by Rusty_Old_F250 » Fri Dec 29, 2017 6:47 pm

Does anyone have a complete spec sheet on the HD motors used in the 500/600's? Compression ration, cam specs, valve dimensions and material (sodium filled? Stellite faced?)

Essentially, something I can give to the engine builder and say "Here you go, build me this, with a few changes."

I won't be building an exact copy, but pretty close. Going to use a cast crank, EFI head, E7TE block.

Sam

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Re: Heavy duty 300 specs

Post #2 by pmuller9 » Fri Dec 29, 2017 10:11 pm

The two HD replacement pistons are a 7.8:1 and 8.3:1 compression ratio with the 76cc carburetor head.
They are Hypereutectic with a stepped dish and an accumulator groove has been added between the first and second piston rings.
The Silvolite replacement part numbers are 3117H and 3118H respectively.
The 3117H will give you a 8.3 compression ratio with the EFI head.

The reason for the lower compression is the HD truck engines spend most of the time over 3000 rpm at WOT closer to the horsepower peak and the engines run hot. The reduced compression reduces the chance for detonation.

The HD engine had a higher volume and larger outlet exhaust manifold.
The are available on Ebay as new casting runs are completed. Here is one of the last runs.
https://www.ebay.com/itm/300-4-9-Ford-H ... 0005.m2219

As far as I know there wasn't a change in camshaft profile or modifications to the head.

Stellite exhaust valves along with hard exhaust seat inserts would be a good upgrade.

Can you tell us more about your project?

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Re: Heavy duty 300 specs

Post #3 by Rusty_Old_F250 » Sun Dec 31, 2017 9:52 pm

Much appreciated! 8.3-1 sounds like a safe number, the goal for this project is a long living gasoline 300 that still has a chance for efficiency. I've got an HD manifold, paired with a 1bbl intake. Lucked out and found that in a junkyard several years ago. I'd really like to find the HD clutch/flywheel/bellhousing but that's not really necessary.

Here's the only pictures I have of the truck at the moment:

Image

Image

Image

The truck's name is Frankenstein :mrgreen: Not just because he's green, but because there's parts off so many different trucks on him, and some off heavy equipment for good measure! When I got him he was a wore out stock f250 Camper Special. Currently, he still has his original frame and cab/clip. I installed a (also green) 68 f350 9ft stepside box, and built a set of Gin Poles. Original drivetrain was 360/c6 then 390/c6 (was still setup that way when I got him) then 390/np435 then 390/np435/4spd brownie (also swapped in a 10.25 sterling at the same time), and now 300/np435/4spd brownie.

Sam

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Re: Heavy duty 300 specs

Post #4 by pmuller9 » Sun Dec 31, 2017 10:03 pm

Great Project!
What connecting rods do you have?

Rusty_Old_F250
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Re: Heavy duty 300 specs

Post #5 by Rusty_Old_F250 » Sun Dec 31, 2017 10:18 pm

Thanks!

I was planning on using the ones from the 86 core motor, but I also have a set of 240 rods

For the new engine, this is what I have planned so far:

Head:
EFI Fast Burn style
hard seat inserts (exhaust and intake)
positive valve guide seals
Stellite faced exhaust valves
Stock rockers

Block:
Full rebuild, surfacing, boring no more than .030 over, line honed

Rotating assembly:
Silvolite 3117H pistons (thank you pmuller9!)
Stock resized/rebushed rods
cast crank ground and polished
Complete balancing

Cam:
Not sure yet

Ignition:
Duraspark dizzy

Fuel:
Carter 1bbl on iron intake

Exhaust:
HD manifold

Sam

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Re: Heavy duty 300 specs

Post #6 by pmuller9 » Sun Dec 31, 2017 10:43 pm

Since you will be running a manual trans with a clutch you need torque right off an idle.

The stock cam has a long advertised or .006" duration of 268 degrees to keep the dynamic compression ratio low for detonation and a short .050" duration for low rpm torque.
The aftermarket "off the shelf" cams fall short on the advertised duration and make tuning a real problem.

The stock cam is hard to beat for what you want to do.
Install it straight up with the intake lobe center at 110 degrees ATDC

More lift is always a plus and most use a higher ratio rocker arm to accomplish it.
Scorpion just came out with a pedestal mount 1.73 ratio roller rocker arm that bolts to the EFI head.

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Re: Heavy duty 300 specs

Post #7 by Rusty_Old_F250 » Mon Jan 01, 2018 1:44 am

Interesting! You got me thinking, and since I used to be a parts guy, I dusted off that part of my brain and looked up the stock camshaft specs, or atleast, the specs of the stock replacement Sealed Power sells. Turns out they list exactly the same camshaft for everything 300, carb'd or fuelie, pn# CS-1230, and they even have the HD motors listed! Same bumpstick. I find it hard to believe Ford wouldn't have played around with the specs just a bit, but apparently it wasn't enough to warrant SP making a second grind.

Whatever happens, I'll have Oregon Cam's grind up something, even if it has exactly the factory specs. I trust those guys, they make good stuff. And their logo (beaver chewing a cam out of a log) cracks me up every time! And if I decide to go with a bit more lift, I'd rather get it from the cam than the rocker, that's just me though, roller rockers make me nervous.

While I was digging through the SP catalog, I noticed they make the 7.8 ratio piston in hypereutectic with coated skirts, it's about $60 more than the Silv-O-Lite, might be worth it though. pn# H554CP

Sam

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Re: Heavy duty 300 specs

Post #8 by Rusty_Old_F250 » Mon Jan 01, 2018 1:48 am

On a sort of related note, I wonder how hard it would be to whip up a set of pedestal mount, adjustable rockers for a 300... That is one thing about the FE's that I really like.

Sam

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Re: Heavy duty 300 specs

Post #9 by pmuller9 » Mon Jan 01, 2018 7:37 am

I don't care for higher ratio rockers either. the extra pressure on the cam lobes doesn't help with longevity.
I also don't use aluminum rockers for longevity sake.

Stock cam specs are .397”/.397”, 192/192, 268/268, 110deg LSA
The cam is set 4 degrees retarded with the intake lobe center at 114 degrees ATDC
The retarded cam closes the intake valve late at 68* ABDC for a low Dynamic compression Ratio.

If you have a cam ground make the valve lift near .450" with a 1.6 ratio rocker.
The intake valve closing ramp is responsible for the Dynamic compression ratio.
The Exhaust lobe can have a shorter advertised duration and the intake valve can be asymmetrical with a fast opening ramp and a very long closing ramp.
If the intake valve can be closed even later than 68* ABDC the block can be decked so the piston is closer to zero deck height clearance for better quench.

Here is a Comp pedestal mount adjustable rocker.
http://www.compcams.com/v002/Products/C ... rs'-0.aspx

The Speed Pro H554CP piston is not a HD piston.
It doesn't have the large quench area or the accumulator groove between the first and second ring to prevent ring flutter.
The accumulator groove will also aid in the use of a ZGS (Gapless) second ring from BWE.
I'm also not sure how long that particular coating stays on the piston.
I've seen reports on other sites where the coating on the Speed Pro pistons was gone after a short period of run time.

We have tried several different coating on our BBC blown alky hydroplane engine with similar results
We finally settled on hard anodizing the entire piston that keeps the piston cool enough to allow .002" less piston to cylinder wall clearance and better ring control.
It's expensive because the piston ring grooves need to be machined for the .0004" anodize thickness.
I'm not suggesting you go this route, it was for added info on coatings

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Re: Heavy duty 300 specs

Post #10 by Rusty_Old_F250 » Mon Jan 01, 2018 1:23 pm

After finding an actual picture of the 3117H I see what you mean! I like the quench area, it's much MUCH better than the SP H554CP.

I appreciate the info on coatings, good to hear from someone with "field" experience. Have you experimented with chamber and piston top coatings? I'm just a few miles from Performance Coatings in Kent, it would be real easy to go crazy and have them coat everything. :mrgreen:

I just noticed in my earlier post I said pedestal mount rockers, I meant shaft mounted. From my experience with the FE's they're a rock solid system, especially for a truck engine.

Sam

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Re: Heavy duty 300 specs

Post #11 by THE FRENCHTOWN FLYER » Tue Jan 02, 2018 6:13 pm

Rusty_Old_F250 wrote: I find it hard to believe Ford wouldn't have played around with the specs just a bit, but apparently it wasn't enough to warrant SP making a second grind.

I once looked at blueprints for every 300 Ford cam Ford built. While the part numbers differed all the cam specs were the same.

I like shaft mounted adjustable rocker arms too. If I were king the new 300 crossflow performance head would have them.
FORD 300 INLINE SIX - THE BEST KEPT SECRET IN DRAG RACING

Rusty_Old_F250
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Re: Heavy duty 300 specs

Post #12 by Rusty_Old_F250 » Tue Jan 02, 2018 8:52 pm

THE FRENCHTOWN FLYER wrote:I once looked at blueprints for every 300 Ford cam Ford built. While the part numbers differed all the cam specs were the same.

I like shaft mounted adjustable rocker arms too. If I were king the new 300 crossflow performance head would have them.


Now that is fascinating! I guess if it works why change it, eh? Whoever designed these engines was a genius, I just wish the bean counters would've left him alone to do his thing. I can only guess at what he/they would've come up with, perhaps a block with a .250" thick deck, .250" thick cyl walls, forged steel crank as standard, forged pistons, shaft rockers, crossflow head? :hmmm:

I must admit, as much as I like the idea of a crossflow head, the U-flow does produce a very "tidy" looking engine, reminds me of the old flathead sixes and 4cyls. I have a couple F163 continentals in Lincoln welders, like the one in the photo above. They're solid little engines.

Sam

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Re: Heavy duty 300 specs

Post #13 by pmuller9 » Tue Jan 02, 2018 9:50 pm

Rusty_Old_F250 wrote:I appreciate the info on coatings, good to hear from someone with "field" experience. Have you experimented with chamber and piston top coatings? I'm just a few miles from Performance Coatings in Kent

Have not done chamber coating because you want heat conduction into the water jacket for cooling.
All of our racing turbo pistons were top coated which helped the piston fron absorbong heat.

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Re: Heavy duty 300 specs

Post #14 by Rusty_Old_F250 » Mon Jan 15, 2018 7:37 pm

I got the core motor tore down and loaded up, going to drop it off at the machine shop wednesday.

Any suggestions for good quality stellite valves and matching seats?

Sam

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