max safe hp for block?

hey everyone i have been wondering for some time now about the maximum safe horsepower you could run on the diffrent blocks that our out there, i have a 97 cobra with a p600b procharger stage 2 at 6lbs of boost and with a stock engine "minus a few little goodies here and there" im at 442rwhp and from what i have heard is that since its a alluminum block with high compression ect... anything past 500hp makes the block very unstable and could crack at any time, now the goal for my car is to have a nice showcar with atleast 600+hp thats still streetable to be taken out 2-3 times a month "shows,track,fun ect..." and for the block i have been considering geting a 03-04 cobra block with forged internals, i have heard that with the 2.2L KB supercharger upgrade the cobras are siting around 600 now you would have to run some high octaine gas for that "100ish" so i have considerd useing a water/methanol injection system from snowperformance so i could still use pump gas, but i like prochargers line up so instead of useing KB i was considering a higher end progharger would the 03-04 cobra block meet my needs? if not what would? if you have any questions or comments please feel free to post your ideas i have plenty of time i dont realisticly plan on haveing the car done for about 2-3 years thanks everyone

Don't confuse 5.0 blocks for 4.6 blocks. The Aluminum Teksid block in your car has been used in setups making as much as 1700 horsepower, same goes for the crank. The cobra blocks will just add weight to the front end of your car, and actually don't have as many bolts on the main caps as the Teksid's.

so what your saying is that the teksid alluminum is able to withstand the 600+ hp mark im going for without fear of it cracking? what about the internals besides the crank? how would i go about meeting my goal of the 600+hp?

The all-aluminum Cobra engine is cast by Teksid of Italy (who also has Ferrari's F1 teams as customers). Crankshafts are forged by Gertach in Germany. The engine is hand assembled by special 2-person teams in Ford's Romeo, Michigan engine assembly plant.

4.6 L Cobra specs (1997)

Engine 90-degree V8, cast aluminum block & heads, iron cylinder liners, forged crankshaft.
DOHC, 4 valves per cylinder.
Bore & Stroke - 90.2mm x 90.0mm
Displacement - 4,601cc/280cid
Compression Ratio of 9.85:1
Horsepower (SAE net) 305 @ 5,800 RPM
Torque 300 @ 4,800 RPM
Redline 6,800 RPM
Twin 57mm bore throttle body. Electronically controlled port throttles open at 3,250 RPM

For 600+ HP you need a set of good rods and pistons. VT Engines has Diamond Pistons and Manley Rods for 1300 bucks, that's all you need.

Stay away from aluminum rods on a street engine.

Stay away from aluminum rods on a street engine.


I second that :grinyes:

:dunno: whats wrong with aluminum rods on a street motor?

Now that I think about, I am not sure why the heck I said that :)

That block can withstand easily 800hp... it's the rods and pistons that make it weak. The crank is fine.

Here is the thing, you can get a stock 97 engine pushing 550+rwhp, but your driving a granade with those Rods and pistions...

The other side of a coin... I seen a Fully built 03 Mach 1 motor trashed due a crappy dyno tune. I'm talking Mahle rods, CP pistons, Comp cams, VT heads, and a 2.4K all turned into a boat anchor due to a very bad tune and a very careless owner.