Eagle/SCAT/ProSport flathead Ford connecting rods - any difference?

[PackardV8]

I'm considering an obsolete build which could use the Eagle/SCAT/Pro Sport flathead Ford 7.0" forged rods. Does anyone here have any experience with these? Are all three brands likely to all be the same forging?



This is a 7,500 RPM build and I'd be going with these long rods to be able to use a shorter, lighter piston.

Would anyone be afraid of the .750" pin in a 400 - 450 horsepower build?

[GOSFAST]

I'm considering an obsolete build which could use the Eagle/SCAT/Pro Sport flathead Ford 7.0" forged rods. Does anyone here have any experience with these? Are all three brands likely to all be the same forging?



This is a 7,500 RPM build and I'd be going with these long rods to be able to use a shorter, lighter piston.

Would anyone be afraid of the .750" pin in a 400 - 450 horsepower build?

Hi Jack, we sell a whole bunch of these "H-beam" Flathead Ford rods in the Flathead Ford stroker kits. We keep about 10 kits on hand at all times, from 4.000" up to 4.250". Have about 80 (Scat) rods on hand here today. Am in the process today of building 4 or 5 59A and 8BA Flatheads. The Ross pins are a fairly "stout" piece weighing about 120 grms and measuring .750" x 2.700"

On a side note the Eagle forgings and the Scat forgings are totally different and I don't know anything about the other brand you mention above! I would be comfortable with either at 400 HP but the Eagle rod would be a bit stronger than the Scats. They have "wider" beams. The bolt size would be another concern, would recommend upgrading to the ARP-2000 series. The RPM band might be too risky also at 7500?

Thanks, Gary in N.Y.

P.S. Can't tell you how many discussions I've had with Tim down at Eagle with why we cannot use their H-beams, every rod leaves here is Scat ONLY in every one of our kits! There is an inherent design issue with the Eagle rods and they refuse to address the problem!! We could purchase 5 kits at a time directly from them if their rod's overall dimensions were changed. We do use ONLY their cranks, not Scats!

[PackardV8]

Many thanks, Gary. That's the kind of immediate and expert answer on totally weird stuff, complete with measurements and photo, available only on Speedtalk.

[Dan Timberlake]

"There is an inherent design issue with the Eagle rods and they refuse to address the problem!! "

Is the beam width the problem, or something else ?

thanks,

Dan T

[GOSFAST]

"There is an inherent design issue with the Eagle rods and they refuse to address the problem!! "

Is the beam width the problem, or something else ?

thanks,

Dan T

Hi Dan, exactly the problem, the beams are simply way too wide and I can't really see any reason at all for the added material?? It adds weight overall to the rods (shown in the photo above) and creates the "fit" problem!

Let me give you this, I used one single set of the Eagle rods and only on that one unit, didn't have much choice at the time as we were already deep into the build. When I went to install the pistons/rods they wouldn't clear the cylinder bore bottoms. It posed a real dilemma at the time because the entire block was assembled, cam/valve train in first (this is how we do the Flatheads here), then the pistons/rods. There was no way in hell they were going in (as-is), period, end of discussion.

After some initial thinking I simply clamped the rods in the Bridgeport using our rod bushing fixture and machined the beams down to narrow the width's, but only needed one side AND one short section on each rod done, wasn't even enough to affect the overall balance job! The build has been running fine for about 12 years now. It is the ONLY Flathead I've built/delivered with the Eagle rods! I still have a set or two on the shelf that I refuse to even sell for the Flathead use?

Thanks, Gary in N.Y.

P.S. If anyone wants to verify this just contact Tim at Eagle and ask about the rods, you can tell him I told you so!! Almost all our Flathead builds get Ross pistons (metric ring packs), Scat rods, and an Eagle crank. We find their cranks do work easier than the Scats.

[jed]

Could you give us some specifics as to HP, dome or flat top Pistons, valve size, how close to the back of the head are the valve and clearance from top of valve to the head, are the blocks relieved,
What kind of head, did you have a method of flow testing the engine.
Lots of questions please share what you care to.

[Kahuna]

I can't wait to see an engine like this.
Also, why the aftermarket rods?
Jim

[jsgarage]

Ever see a stock flathead rod? They're so flimsy looking, Speedway used to sell them for a few bucks for making your own slingshot.

[peejay]

Ever see a stock flathead rod? They're so flimsy looking, Speedway used to sell them for a few bucks for making your own slingshot.

The cast iron "bolts" always got me...

[DaveMcLain]

Ever see a stock flathead rod? They're so flimsy looking, Speedway used to sell them for a few bucks for making your own slingshot.

The cast iron "bolts" always got me...

The rods used in the Flathead V8 and 8N Ford tractor are not cast they are forged and the bolts and rods are all one piece. They are made out of very high quality materials so this isn't a problem. Have you ever seen one that someone put into a vice and twisted around and around?

[Kahuna]

My friend Ken has run these stock rods to 7K twice without incident.
Maybe these Scat Rods are better, who knows?

[Keith Morganstein]

Maybe Jack Vines will enlighten us more, but from his post, it seems he wants to use the rods in another engine (not a flathead Ford V8)

[PackardV8]

Maybe Jack Vines will enlighten us more, but from his post, it seems he wants to use the rods in another engine (not a flathead Ford V8)

For true, Keith. A customer wants the most possible reliable horsepower from a NA Studebaker 259" V8. The DynoSim says it will need to turn 7,500 RPMs. The OEM piston compression height is 1.73". It was my thought to use the aftermarket flathead Ford V8 7.0" rods, having the same 2.0" crankpin as the Studebaker V8 and thus lighter, shorter custom forged pistons.

The bore will be in the 3.625" range (92mm) and there are many imports in that diameter for which the manufacturers offer forged pistons. A small adjustment to the pin height and finishing to .750" (19mm) diameter would get us what we need.

[DaveMcLain]

Maybe Jack Vines will enlighten us more, but from his post, it seems he wants to use the rods in another engine (not a flathead Ford V8)

For true, Keith. A customer wants the most possible reliable horsepower from a NA Studebaker 259" V8. The DynoSim says it will need to turn 7,500 RPMs. The OEM piston compression height is 1.73". It was my thought to use the aftermarket flathead Ford V8 7.0" rods, having the same 2.0" crankpin as the Studebaker V8 and thus lighter, shorter custom forged pistons.

The bore will be in the 3.625" range (92mm) and there are many imports in that diameter for which the manufacturers offer forged pistons. A small adjustment to the pin height and finishing to .750" (19mm) diameter would get us what we need.

If your bore is 3.625 then you might be able to use the Eagle version without any trouble just depending on how the Studebaker V8 block is configured at the bottom of the bore.