So my 2004 F150 with a 5.4 3V has a knock in the motor and I'm thinking about doing a rebuild instead of a new motor and get some more horsepower out of it. I'm just going to list out my questions. Thanks in advance for the information I appreciate it.

1. How hard is it to do a rebuild on these motors?
2. with choosing a piston is it best to stay near a stock compression?
3. Porting and polishing the heads worth it?
4. what would be a good camshaft to go with to take advantage of the porting and polishing?
5. what other modifications would i need to do to make everything work together after putting it on a dyno to tune it in?
6. what are these lockouts or limiters for the camshafts that i've heard a little about?

Thanks again i know that's a lot of questions.

 

1. How hard is it to do a rebuild on these motors?

It's best to let a professional do it. A SBF can be rebuilt by almost anyone and any machine shop. A modular engine is a completely different animal and requires a number of special tools. I lost track of how much money I have into them a while ago.

2. with choosing a piston is it best to stay near a stock compression?

Depends. Lower compression offers the use of lower and cheaper grade gas but performance will suffer some. If you feel like you want to always run the truck on 93 octane then 10.5-11:1 compression will of course help power and increase fuel mileage. But only on the more expensive gas.

3. Porting and polishing the heads worth it?

Yes and no.

Will ported heads help make power? Yes.
Is porting heads on a N/A truck worth it? No. The cost of porting heads isnt worth the gain and it's big increase comes when forced induction is used.

4. what would be a good camshaft to go with to take advantage of the porting and polishing?

Custom camshaft is always the answer.

5. what other modifications would i need to do to make everything work together after putting it on a dyno to tune it in?

Intake, exhaust unless I'm reading that wrong.

6. what are these lockouts or limiters for the camshafts that i've heard a little about?

Lockouts are just that. The standard 3V camshaft is controlled by the computer which can advance or retard the camshaft centerlines. This works fine on stock cams but once lift and duration are increased then PTV clearance can become a big problem. The lockouts make it impossible for the computer to advance the cams so far that they run the valves into the pistons.

 

get a used low milliage engine from a junk yard, port and polish your heads, custom made cam and lock outs, bigger TB, some long tubes and electric fans and you are in the 300rwhp territory. Thing is you will spend alot more than most people think its worth for the gains.

If you really want to rebuild it, stock compression ratio is fine at 9:8, youre better of just changing the rods to h beams and if you are going force induction later get forged pistons...