FE Power Forums
FE Power Forums => FE Technical Forum => FE Engine Dyno Results => Topic started by: CaptCobrajet on October 14, 2025, 11:00:59 AM
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1016 hp at 7700 rpm. 805 ft lbs torque at 5500 rpm. It has 990+ horsepower for 1700 rpm up top. Four digit power from 7000 rpm to 8200 rpm. Shelby big bore block, Losito billet heads with a little love and valve job here. 4.500 Crower crank, CP pistons. Dual three circuit 1050 Dominators. We cammed it for making the Drag Week drive. I think this engine would make 1100 hp with a 1-inch lift cam, but it wouldn’t make the street miles like that. Pretty good like it is. I think my son is going to put it on our Facebook page and uTube when he gets the opportunity.
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Blair, tell us more about the heads and rods.
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You should probably put the big camshaft in, put it back on the dyno, just because....
On second thought never mind. That's a very cool build.
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Dumb. How about a round about on the camshaft, less than 750 lift?
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How do you make that crank stroke fit ? Nice power !!
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How do you make that crank stroke fit ? Nice power !!
I was thinking the same thing! Hard to keep the rods from hitting the cam lobe even with a 4.375 stroke crank. Maybe a 1.888 Honda rod journal or SBC small journal 2.000 for rod clearance? Nice build and great power, should run hard in Scott's Cougar?
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A 2.1" rod journal and SBC rod will make the 4.500" stroke possible.
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This one has a 2 inch journal. It has about .040 clearance to the lobes on the back four cylinders. The front four don’t get as close. A 2.100 rod would not clear in this engine. A 4.400 is as big as I have been able use with a 2.100 crank pin.
Joe, you are in the ballpark on lift. The heads flow to 1-inch, and the ports are really big. A little too big in my opinion. I think the cross section is just about right for 600 inches, but it sure does come to life about 5500 rpm. It is extremely long winded for the duration it has now. A big boy cam would put peak power at over 8000 rpm. Kinda makes me draw up a little to think of turning a 4.5 crank 8500 through the traps, lol. It’s a neat combo like it is, and the valvetrain is all stuff that has worked for us before in Drag Week. One thing about this cam being smallish for port and cubes is that it makes the torque and power curves really broad. It gets near peak power at 7200 and just stays there past 8200. Should be a neat piece for Jack and Scott to work with.
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What is the intake valve size?
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What a wicked build. Incredible heads on top as well
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is that billet head an inline valve head?a lot of hp for an fe engine for sure.
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Was looking at those cylinder heads Blair with a 280 cross volume do you need to be speeding or filling those runners.
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I think probably almost 200 horse more than he had. She’s gonna scoot.
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Only 51 more HP than the last conventional Pro Port headed piece we had in it, but this thing has a lot more area under the curves. It has its peak torque for almost 1000 rpm, and same with the power. The billet head is a serious departure from the OE layout. The valve orientation is the same, but they are canted and the ports are tilted. Meanest head there is that bolts on the top of an FE block. Some day I want to do a 4” crank in an iron BBM block and spin it about 10,000 rpm with heads like this.
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What would be the benefit of a 4.0 crank than just using a 428 3.98 arm. Besides cubic inches.
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What would be the benefit of a 4.0 crank than just using a 428 3.98 arm. Besides cubic inches.
I'll take a stab...10K RPM on a cast crank at those power levels may not end well :)
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Exactly right, Ross. The cast crank wouldn’t make it. The narrow 2.438 journal size wouldn’t either. We found ways to make the FE journal live to 8500 when we had to, but even there, not those power levels. The 2-inch is size of choice for me. The 1.888 Honda at that power level won’t make many runs before service. There isn’t enough load bearing surface area at that power. The Honda is good at 800-900hp. The 2-inch is more durable past that. On the stroke, the piston speed would be a problem at 10K rpm. The stroke eventually becomes a parasite when you swing the mass faster and faster. Comp Eliminator guys have had success with a 4-inch stroke, so it is doable. You won’t find long strokes in Pro Stockers……They make the bore as big as possible, and plug in the stroke number to make 500 inches.
The 800 inch mountain motors don’t rpm like the 500 inch ones do.🙂
For most purposes the FE journal, or the normal 2.200 that is common to the stroker cranks is just fine. I’m doing a twin turbo 400 inch FE for myself. Not a super high revving engine. I prefer the 2.200 in this case, for the wide bearing and generally available “boost” tolerable shelf rods. We want to make 1000 hp below 6500 rpm with .550 max lift, so it can drive anywhere. Still debating draw through carbs with water-meth versus port injection with an intercooler. The latter will probably prevail, but the carbs would be much less complicated for a Holley carb guy. Okay….. am getting off the subject….
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I understand but I wasn’t talking about a stock crank. I thought when scat makes them you can get them as a steel crank and they were the same 2.20 journals as the 4.250 cranks. That being said I understand what you are saying.
When you got off the subject with the 400 inch boost motor a lot of guys around here are running blow through carbs with procharger. My buddy a few houses down (Chevy 540) makes 638 naturally aspirated with 600 lbs torque with procharger he makes 1070 Hp and 1247 lbs of torque. Makes me want one maybe next setup.
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I understand but I wasn’t talking about a stock crank. I thought when scat makes them you can get them as a steel crank and they were the same 2.20 journals as the 4.250 cranks. That being said I understand what you are saying.
When you got off the subject with the 400 inch boost motor a lot of guys around here are running blow through carbs with procharger. My buddy a few houses down (Chevy 540) makes 638 naturally aspirated with 600 lbs torque with procharger he makes 1070 Hp and 1247 lbs of torque. Makes me want one maybe next setup.
I was only teasing...
Boost is fun, we did a 347 2 years ago or so, 585 HP on 8 lbs of boost, sounded like a Granada at idle, HP curve looked like a steep mountain. Would have made more if we spun the blower faster, but we were afraid of the block splitting in two!
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No sweat I’m not that thin skinned. But really if you get a 3.98 from scat they are 2.20 rod journal right.? There’s a guy around the neighborhood has like a notchback with a 347 I don’t know what kind of block he has but he runs 12 psi with a procharger she scoots along pretty good. That’s why I was saying maybe Blair will keep us informed on his 400 cube motor
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No SCATs 3.98 have FE rod bearings. I wish they did have that option to use a better bearing and longer rod, or at least an FE I beam to get some weight down on the cast crank builds
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They are available from Scat in a custom.
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You can get a 410 CID engine, using a 361, steel FT crank and a SBC journal. 4.13 x 3.83
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396 if you wanna hear it scream lol
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396 if you wanna hear it scream lol
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By looks at least I could be wrong but is that piston heavy? Also looks like thick ring set.
Sorry missed the box picture. That is a heavy piston. What is the benefit of the weird design.
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Trim to fit pistons for maximum compression. Also pretty old, hence the wide rings
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Only 51 more HP than the last conventional Pro Port headed piece we had in it, but this thing has a lot more area under the curves. It has its peak torque for almost 1000 rpm, and same with the power. The billet head is a serious departure from the OE layout. The valve orientation is the same, but they are canted and the ports are tilted. Meanest head there is that bolts on the top of an FE block. Some day I want to do a 4” crank in an iron BBM block and spin it about 10,000 rpm with heads like this.
Blair is that 51 horsepower difference with the same drag week camshaft ?
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Similar cam, but not exactly the same.