[Mike113]

Originally Posted by Shaun03GT Why are you guys building the block, but putting cast cranks in? I know its not common to hear crank failure, but a steel crank takes away a lot of stress on the rods and pistons. Thats why the 5 speed Machs rev to 7000rpm, and the auto Machs (cast cranks) rev to 6000rpm. The thing that hurts the cast crank the most is RPM's. So if you spin that motor 6500rpm + with a cast crank and a power adder, youll regret it. Its like an extra $500-600 to go forged. Just sayin'

at most, I might throw a 150 shot of nitrous at it. Its my DD and I make 8.35/hour. I dont plan on going much over 500hp. One day when I'm rich and famous I'll build a motor to handle excessive amounts of boost. But for now, I dont even plan on supercharging this car.

[Orange2V]

Originally Posted by Shaun03GT Why are you guys building the block, but putting cast cranks in? I know its not common to hear crank failure, but a steel crank takes away a lot of stress on the rods and pistons. Thats why the 5 speed Machs rev to 7000rpm, and the auto Machs (cast cranks) rev to 6000rpm. The thing that hurts the cast crank the most is RPM's. So if you spin that motor 6500rpm + with a cast crank and a power adder, youll regret it. Its like an extra $500-600 to go forged. Just sayin'

4.6 Liter Ford Engine Crankshafts


"The SOHC 4.6 is delivered from the factory with a cast-iron crankshaft, which has proven to be
entirely adequate for all applications up to 500 horsepower. In fact, we have never seen a broken
cast-iron 4.6 crankshaft, nor to my recollection have I even heard of one coming apart. This glowing
recommendation should be tempered with the adage that for applications of over 500 horsepower,
we always install a forged crank. So if you are building an SOHC engine within the 500-hp limit, you
do not need to break the piggy bank for anything stronger. There are two different cast cranks that
I am aware of, a 6-bolt flywheel style, and an 8-bolt version. The 8 bolt showed up on the 2000
Mustang with the Windsor engine, while the Romeo continued to use the 6-bolt unit. Some F-150
trucks in 1997 and 1998 also may have used the eight-bolt pattern. The 8-bolt unit would of course
be the preferred choice for a drag race application, but most flywheel manufacturers offer their
flywheels in both patterns"

[bottled2v]

okay guys some of the prices people are giving out are rediculous. any machine shop that charges 1500 to clean/machine a block and assemble a shortblock is getting away with murder. it should cost no more than 750 for all that, if it does find another machine shop.

I bought mmr's rod/piston kit for 800 bucks and it's good to 900whp. add in bearings and it'd be a little over 900. so combine all that and it'd still be under 2000 even after an oil pump and main bolts etc.

with the op's goal i would not go with a forged crank. however if you do they can be found cheap. i bought a used cobra crank for 200 bucks shipped and it just needs a very very slight polishing.

as far as hp. with the added compression and cams i would guess in the 320whp range with a good tune. i dont see over 350 with just ported stock heads and a stock intake tho.

[NeverEnuff]

Originally Posted by Orange2V 11.5 is a lot of compression with pump gas. A good dyno tune will be a must! My best HP guess: 4.6 11.5:1 stock PI heads and stage 2 cams is probably around 325-345 HP assuming you have TB, Plenum, headers and a bitchin dyno tune. Add stage 2 MHS port job and you will be around 380-390 HP. Add a after market intake like Edelbrock and you won't gain a huge amount of HP but it will run your power up in the RPM range and kill your low end torque a little. Will help if you are sprayin nitrous tho. I would only go aftermarket intake if you are going nitrous. Keep in mind with 11.5:1 compression I wouldn't spray much nitrous unless you go with a dedicated fuel tank with race gas on the nitrous feed or drain your gas tank and run race gas when you know you're gonna spray. ****Remember this is just a guess. Thats the best anyone can do. Things always sound better on paper. That setup is pretty common though and you will be happy with is as a street driven car no matter what the dyno says. Enjoy!

11.5 isn't 'a lot' for pump gas...will it req a good tune, yes. I just built a BB bullitt on 12:1 on 92 pump. Runs great, just gotta tweak the tune some more.

All other bolt ons, stock heads and PI intake. I think he will be more around the 310-320rwhp...His stock heads and PI intake is what would hold him back from 320+rwhp.

Get ported heads (CNCd by the best in the country) and I could see 340-350rwhp with that compression on a good short intake like a edelbrock with a 6061elbow...that intake WILL give him power gains cause the RPM and cam will help the combo with the compression and heads (ported I am assuming) he will be running. You don't just throw combos together..you build things together that make the other perform better...Why put a huge duration cam in a stock head and stock intake car? You cant rev it to where it wants power and it don't have the comp you need to take advantage of it.

As far as spraying on 11.5 comp. Just keep the car cool...160* thermostat, and run good pump gas. The dedicated fuel cell is a great idea, but isn't a MUST. Just once again a good tune, and have fun.

[NeverEnuff]

Originally Posted by Shaun03GT Why are you guys building the block, but putting cast cranks in? I know its not common to hear crank failure, but a steel crank takes away a lot of stress on the rods and pistons. Thats why the 5 speed Machs rev to 7000rpm, and the auto Machs (cast cranks) rev to 6000rpm. The thing that hurts the cast crank the most is RPM's. So if you spin that motor 6500rpm + with a cast crank and a power adder, youll regret it. Its like an extra $500-600 to go forged. Just sayin'

Um. Cause it works and is cheaper...and 70+% of the ppl don't make enough RPM or power to need a forged crank.

The thing that hurts the crank is neither HP or RPM...its BOTH.

I spun my cast crank, same one in my 8100rpm BB motor right now, to 7000rpm in my 99 GT Twin Turbo, 600+rwhp on 15psi and upped it to 18psi at the track. Tore the motor down. Guess what. Yeah...crank is fine, and am still using it in my current motor...perfectly.

This was the same crank that was in a F1 2v motor spinning 7k, P1 and D1 4v motor, running 18psi. and it all worked fine.

Im not just talking...ive done it and others have as well...cast crank is fine...and if I kept the RPM under 6500-6200...I wouldn't hesitate to run 800-1000hp...

and for your info...they limited the cast crank Mach 1s, for the trans/driveline...not the crank.

[NeverEnuff]

Originally Posted by bottled2v okay guys some of the prices people are giving out are rediculous. any machine shop that charges 1500 to clean/machine a block and assemble a shortblock is getting away with murder. it should cost no more than 750 for all that, if it does find another machine shop. I bought mmr's rod/piston kit for 800 bucks and it's good to 900whp. add in bearings and it'd be a little over 900. so combine all that and it'd still be under 2000 even after an oil pump and main bolts etc. with the op's goal i would not go with a forged crank. however if you do they can be found cheap. i bought a used cobra crank for 200 bucks shipped and it just needs a very very slight polishing. as far as hp. with the added compression and cams i would guess in the 320whp range with a good tune. i dont see over 350 with just ported stock heads and a stock intake tho.

Yup.

yup.


and yup...

[Mike113]

You guys are all champions in my book. Thanks for all the good info!

Once again, the whole idea was to not only fix my bad rod bearing, but to get a little more out of spending my money. For now, the build short block and cams will be pretty awesome. I probably make 240whp right now, so if it makes 310 that'd be sick!!

Down the road I plan to get a stall converter, gears, then finish up the motor with either trickflow heads or ported PI heads, as well as a good intake, then spray it

[bottled2v]

oh you're auto?! with that said, when the trans is out pull the pump out of it and put in a spiral ring retainer, that part alone costs like 6 bucks, and then you'll want a new pump gasket but it's easy to do and without it I wouldn't rev the car to anything over 6k. I think that's the main reason they limited the auto mach's.

but anyways, might not wanna hear this but depending on how bad your rod bearing is the crank may not be any good. my buddy's ls1 spun a rod a couple weeks ago, since then he's started it 3 times in total for very short times, and when we tore it apart this week the crank is completely shot, it wore the journal wayyyyy down. just food for thought.

[Mike113]

Originally Posted by bottled2v oh you're auto?! with that said, when the trans is out pull the pump out of it and put in a spiral ring retainer, that part alone costs like 6 bucks, and then you'll want a new pump gasket but it's easy to do and without it I wouldn't rev the car to anything over 6k. I think that's the main reason they limited the auto mach's. but anyways, might not wanna hear this but depending on how bad your rod bearing is the crank may not be any good. my buddy's ls1 spun a rod a couple weeks ago, since then he's started it 3 times in total for very short times, and when we tore it apart this week the crank is completely shot, it wore the journal wayyyyy down. just food for thought.

Thanks bro, the guy who is building my motor actually has extra iron blocks/cranks laying around at his shop...so he said hes gonna grab some and send em off to be machined. He's not even gonna tear open my motor. He's just gonna pull it out, take the heads/intake off and set it aside.