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408 Ford stroker build underway! Direct drive

hdsadey

Well-known member
Engine block was cooked the other day. Shot peened to get all the nasty off. Put it in the Rottler after work today and took it .025 over. Will hone it the rest of the way to .030. Ordered the rotating assembly today. Eagle cast crank 4.000", Eagle SIR I-beam forged rods 6.200 long and Icon dished forged pistons. Can't wait, it's like Christmas is coming lol.
 

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I had a 392 stroker with Z heads and Webers in my kit car. Was an absolute torque monster. I always wondered how that engine would have done on an airboat. I'll be watching this thread.
 
Honestly I have no idea on torque and hp as every bit of information on the interweb is focused on big numbers above 3500 rpms. No one seems to care about low end power. My current 302 with a Fitech injection turns 2800 on the trailer with a Waterwalker Sig. 72" on the no. 2 mark. My hopes are that the extra 1" of stroke will allow me to put a significant amount of extra pitch in it. Looking for tractor type push from this. Aluminum heads ought to get me close to the current weight setup with iron heads. Its gonna be interesting to say the least. Might invest in a cheap crane scale to weigh boat before and after as well as pounds of torque pull on the trailer.
 
You're gonna sh*t a twinkie when you romp on it for the 1st time. It will allow you to add pitch, but the biggest improvement you will notice is how much quicker it winds up compared to your stocker (as long as your cam is ground to hit max torque in your target range). It will jump out of the hole much quicker.
 
Damn I hope so! Crank, rods, bearings, and rings showed up today. We're gonna mock up the rotating assembly in the block to mill the deck to near zero. Icon forged pistons will be -22cc dished. Looking for 10 to 1 compression with a set of Edelbrock E-street heads with a 60cc chamber and 170cc intake runner.
 
Has anyone ever dynoed a few DD motors to see what the real hp and torque is at the 3,000 rpm mark? I would think some of these folks paying as much as they are for DD Buddy Branch cadillac motors would pay the extra few bucks to dyno one.
 
Airboat direct drive market appears to be so small that no one does. I know a guy in Sarasota who has an engine dyno. Gonna talk to him to see how feasible it would be to make pulls from lets say 1200-3500 rpms. Plus he's a Ford nut so that should work in my favor. Lol
 
hdsadey said:
Airboat direct drive market appears to be so small that no one does.l
Direct drive has been around since the dawn of aviation. Ford takes you way out on the end of the limb. Anything you can do with a SBC you can do with a Ford product, just at 2x the cost (but I am interested in the flat 8 they are working on!) .

There is a reason you just don't find many folks mixing 7075 aviation aluminum with cast iron in the same product. I mean, why not build the motor out of aluminum and the hull out of cast iron, at least you would have something to run the glades pinnacle rock for sure.

Oh yah, that's already been done!
 
Gator that was in reference to Strikers comment on dynoing dd auto engines. I will agree that there is no substitute in direct drive for aviation engines. Power to weight ratio does not compare, especially when considering the extra weight of cooling. I don't agree with the 2x cost although SBC is less expensive, but not half. Biggest advantage is Windsor blocks can handle more stroke than SBC at less weight. 4.000 stroke is big block territory in Chevy unless aftermarket block is used. I intend to keep an accurate accounting of price for all to see.
 
Flat 8? Are you talking about the 5.2 liter Voodoo flat plane crank engine in the GT350R? Or is Ford workiing on something else?
 
Striker543 said:
Has anyone ever dynoed a few DD motors to see what the real hp and torque is at the 3,000 rpm mark? I would think some of these folks paying as much as they are for DD Buddy Branch cadillac motors would pay the extra few bucks to dyno one.

The cost to dyno is $550 and most folks decide it is just not worth the coin.

Mr Branch has a catalog of direct drive engines and can tell you exactly what prop the engine will spin and on what pitch setting. Many he has on video to show the entire build and then the running engine on the boat pushing and performing. He has a huge big screen TV in the shop for clients to watch a variety of builds perform in the field.

As an example my old DD 514 would spin a 2 blade 76 inch NGQ pitched at around the 3 setting turning 2750 rpm / 2900NOS
That engine was a series 2 hybrid or custom it had a great set of 120cc heads and true flat top KBs but only was a 8.75 compression ratio so there was more that could have been gotten out of the platform if the compression was bumped up and Weisco pistons used.



REAL ANXIOUS TO SEE THE FORD IN THE MIX......really great to see you work the 351 platform up for a boat. That block cleaned up nice!



"The proof is in the prop.....WATERTHUNDER"
 
Thanks Swamp. I'm anxious as well. I've been contemplating this build for a long time. Fallen down a lot of rabbit holes doing research.

It's amazing how clean they come out. The oven charrs all the oil and grease then the Steelabrator makes them look like brand new cast iron! Perfect for that fresh Ford blue coating. All of our rebuilds get this treatment. Not biased or nothin (well maybe a tad) but if your engine doesn't look like this before the machine work starts you might have the wrong shop.
 
That process dos a nice job for sure.

I hot tank and wire brush most of my cores. Maybe when you get a few spare minutes you can do a thread on your process and post pics. Venice is a bit to far for me but I admire the job you have done to prep the core for paint.

Keep up the good work and post your build steps.
 
Swamp it sounds like your old DD was turning more prop than a standard angle valve 0540. I’m out of the Cadillac game myself, but I’d love to see those videos if they ever get put YouTube or something similar.
 
hdsadey said:
Gator that was in reference to Strikers comment on dynoing dd auto engines.
I understand, it was just such low hanging fruit. :stirpot:

I like different and cool stuff and am looking forward to the outcome, this motor should turn some prop for sure. But I am with swamp on the subject of Dyno testing the engine, these boats come with a built in dyno. The prop may not give exact Hp figures, but the prop it pushes is all that matters anyway.

hdsadey said:
Flat 8? Are you talking about the 5.2 liter Voodoo flat plane crank engine in the GT350R? Or is Ford workiing on something else?
Yah, the flat crank 8 voodoo. Not really a direct drive motor, but made to turn like a mofo (8,250 redline).
 
Lol. Gotcha. I might spend the dough for some hard numbers. Too many claim big numbers with Desktop Dyno, have zero paper to back it up.

The last place I worked, the owner had a brand new GT350R. It was one nasty sounding ride! He took it to Sebring for a track day and it was an animal. Might work well with a gearbox. It sure would wind up quick!

If you like unusual then you might like the V-12 flathead I have that came out of a Seagrave fire truck. 531 cubic inches. Weighs twice what a Cad 500 is. Bought the truck for the engine, scrapped the rest. Gonna rebuild that soon, put it in a ratrod dually or 31 roadster with a rumble seat and dually rear. Haven't decided yet.

Yes I have a problem! Admitting it they say is half the cure. Lol
 
hdsadey said:
The last place I worked, the owner had a brand new GT350R. It was one nasty sounding ride! He took it to Sebring for a track day and it was an animal. Might work well with a gearbox. It sure would wind up quick!

Don't know if the Voodoo is a better design than the Coyote, but I agree, that flat plane crank engine sounds nasty, and pegs the cool factor needle!
 
hdsadey said:
If you like unusual then you might like the V-12 flathead I have that came out of a Seagrave fire truck. 531 cubic inches. Weighs twice what a Cad 500 is. Bought the truck for the engine, scrapped the rest. Gonna rebuild that soon, put it in a ratrod dually or 31 roadster with a rumble seat and dually rear. Haven't decided yet.l
Talk to Swamp, he likes heavy stuff! Yah, that would be a cool ratrod motor, definitely a dually, but miles of hood! Stretch the front end more than needed just to accent the V12 and put the cab right over the rear axle, so it is some kind of ratrod dragster. Keep the dually rear, just narrow it a bit.
 
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