Horsepower of original 427

[wkooiman]

Hot Rod did a comparison of 60's small blocks in the Jan 2010 issue. They configured the engines as closely as possible to the originals, and ran them on a modern dyno with dyno headers and the same holley carburetor. They did not test a 427FE, but the numbers are interesting.

Shelby 289 - rated 306HP, tested 302HP
L76 327 - rated 365HP, tested 356HP
Boss 302 - rated 290HP, tested 372HP
69 DZ302 - rated 290HP, tested 356HP
70 LT1 (350) - rated 370HP, tested 353HP
70 351C Cobra Jet - rated 300HP, tested 365HP
71 LT1 (350) - rated 330HP, tested 359HP
71 Boss 351 - rated 330HP, tested 383HP

[Ron61]

I had a 64 Galaxie 500-XL with the dual four 427 and it was rated at the 425 horse given above, but the small tires they came with made it impossible to really get on it until you were above 60 MPH. But I don't believe it had as much power as they claimed. My 69 NASCAR Cobra with the 428 Cobra engine which was rated at 335 horse I had dynoed and it came out at 440 horse using the original exhaust manifolds which were the same as the 64 427 had as it has 427 heads and the bottom end is LeMans rods and stuff.

Ron

[DanEC]

Originally Posted by Ron61

I had a 64 Galaxie 500-XL with the dual four 427 and it was rated at the 425 horse given above, but the small tires they came with made it impossible to really get on it until you were above 60 MPH. But I don't believe it had as much power as they claimed. My 69 NASCAR Cobra with the 428 Cobra engine which was rated at 335 horse I had dynoed and it came out at 440 horse using the original exhaust manifolds which were the same as the 64 427 had as it has 427 heads and the bottom end is LeMans rods and stuff.

Ron

When I picked up my motor from Keith Craft's shop he had a couple 428 CJ restoration (stock) motors sitting near the dyno room after testing. I asked the dyno operator what they ran and he quoted getting around 430 to 440 HP I believe from memory.

[blykins]

I've done a couple of "period correct" engines, both street and race.

I built a 428CJ for a guy in Mississippi. It had the correct CJ heads, we just did a good valve job and put some Ferrea valves in them. Used a 227/233 @ .050" hydraulic roller cam, about .600" lift. Intake was the 75 lb cast iron CJ piece with no porting whatsoever. Compression was 9.7:1. It made 422 hp and around 460 lb-ft if I remember correctly.

Also did a 427 LR 2x4 for an FIA road race Galaxie. It was a rules engine, but we used the factory heads (did some heavy work on them), the factory 2x4 LR intake, and a solid flat tappet camshaft. It was an 11:1 engine. It made 510 hp @ 6000 through 6500 and 511 lb-ft of torque. That particular engine had a $ crank, with the rod journals turned to 2.200", Oliver 6.800" rods, and RaceTec pistons running .043/.043/3mm ring sizes.