help want more top end

[saleen9973]

hey guys i have a stock bottom end ported E7's and milled .025, stock cam, stock rockers, valve springs with 110lbs on the seat. bbk shorties off road h-pipe to flows dumped. 70mm throttle body explorer intake port matched to the heads. 3:73's, electric fan, underdrives. The car is an absolute beast down low i can blaze the tires in 1st and 2nd, but when i hit around 4800 it feels like it flattens out. I would like to rev it to 6000 and try to get more out of my set-up. What do you guys recomend? Should i retard the stock cam 4* or put a new cam in? I want to keep the ported e7's for now but i want more top end?

 

[347HO]

Your valve train is calling it quits around 4500.
If you want more... you're going to have to put something into it.

 

[saleen9973]

Like what a cam? I want to keep the heads for now. Am i just gonna have to live with it for now until i can afford heads and a new intake?

 

[Mustang5L5]

It's the pysical limitations of the parts you have. A cam like a B cam might help the top end somewhat, but the stock heads just don't breath that well at high RPM's...even ported.

If you want more top end, it's gonna take a combination of parts to make that happen. Main reason the 4.6L cars are screamers at the top end is because the stock heads flow VERY well at high rpms

 

[347HO]

Like what a cam? I want to keep the heads for now. Am i just gonna have to live with it for now until i can afford heads and a new intake?

No.
I'm suggesting you put some technology in your valvetrain.
1. multi angle valve job with blend into the bowl
2. much better springs
3. titanium retainers... not required, but taking weight out certainly helps
4. stud rockers... shaft is even better, but not suggested since you plan on upgrading to better heads.

I suggest you find a reputable cylinder head shop and have the machinist go through your heads and fix them so they perform to your requirements.
The above items would run you around 600.00 if you shop wisely and not cheaply.
You'll be surprised how much you left on the table once you run a nicely setup set of E7s.

I suggest you try 1.7 ratio rockers, they "should" move your power band to the right and has been known to increase power sightly.
I'm inclined to say "degreeing" your camshaft is much better than just blindly moving it retarded or advanced and hoping for a positive result.

Good luck.

 

[saleen9973]

thanks for the replys guys i guess i will try 1.7 roller rockers and see how see feels. The heads were just done but i kept the stock valves. i guess shifting at 5000 is not that bad for a street car. Or until i get enough money for new heads and intake.

 

[347HO]

thanks for the replys guys i guess i will try 1.7 roller rockers and see how see feels. The heads were just done but i kept the stock valves. i guess shifting at 5000 is not that bad for a street car. Or until i get enough money for new heads and intake.

My bad... saleen.
In order to run the 1.7 ratio setup, you'll need to upgrade your valvesprings!
I have to tell you I mentioned the 1.7 ratio rockers "if" you've tried all the above and still weren't satisfied.
Consider yourself informed you possibly will toast your valvetrain if you just install the rockers and not get better springs, check for bind, pushrod length, and install height.

 

[5spd GT]

I personally would not put that amount of money in a set of stock iron E7 cylinder heads.

Save that money for a set of aluminum heads that will save you 40 lbs off the nose and give you more power.