5.9 mods

[Braeden Clark]

Hello all. I am coming to ask for opinions on mods to complement my engine. This engine is fully rebuilt by myself. Here is what it has:

fully rebuilt bottom end (stock... and i regret it)
Comp adjustable double roller timing chain
hughes 1110 valve springs
Comp 20-744-9 cam
New, stock heads that are polished
also has been tuned by hemifever

Everything else is stock. I want to add a little more power in the mid rpm range. Here are the mods I want.

52mm throttle body
Shorty headers
1.7 roller rockers. The cam has .480 lift on both intake and exhaust and I want a little more.

Thoughts on this and any other mods? I have the autolite plugs everyone talks about

My main question is the 1.7 rockers. My cam has .480 of lift on both. The rockers would bring it to .510. This sound like a good idea? I know I shoulda gone bigger with the cam but what's done is done

 

[Jadaharabi]

While you have the intake off why don't you take that bottom plate off (you should replace the factory plate with an aluminum one while your at it.) and go inside there and do the modifications to those ports and that will give you a few more horsepower. And then there is that little wedge plate that you put on the bottom plate inside there to direct the airflow inside the manifold. @Mopar Sam can tell you about that. What year is your engine?

 

[Braeden Clark]

While you have the intake off why don't you take that bottom plate off (you should replace the factory plate with an aluminum one while your at it.) and go inside there and do the modifications to those ports and that will give you a few more horsepower. And then there is that little wedge plate that you put on the bottom plate inside there to direct the airflow inside the manifold. Mopar Sam can tell you about that. What year is your engine?

I did indeed do the aluminum plate conversion when I rebuilt the engine. My engine is a magnum block. I think like a 96 or so. Thoughts on paring the 1.7 rockers with the cam? Not too familiar with the mods to the ports though.

 

[MOPAROFFICIAL]

Stock bottom end , as in pistons?
What heads and chamber cc is pretty important..because I have a stock 5.9 bottom end with 307k and 61cc ported heads , all stock besides the headers, muffler, port matched intake and ported headsand it hauls *** n a heavy 4x4 truck.
Let's here more about this motor.

 

[Braeden Clark]

Stock bottom end , as in pistons?
What heads and chamber cc is pretty important..because I have a stock 5.9 bottom end with 307k and 61cc ported heads , all stock besides the headers, muffler, port matched intake and ported headsand it hauls *** n a heavy 4x4 truck.
Let's here more about this motor.

Yes as in stock pistons. If I could go back I'd bump the compression a little but that's way down the line hopefully. Are your heads stock, but ported? Kegger intake?

 

[MOPAROFFICIAL]

Yes as in stock pistons. If I could go back I'd bump the compression a little but that's way down the line hopefully. Are your heads stock, but ported? Kegger intake?

Speedmaster iron magnums, worked w/ 1.94/1.60 valves @61cc, kegger intake port matched. It took work to make them that way, but you can get there with stockers ported. Have yet to get a tune from hemifever but I'm going to.
Stock cam isnt the limiting factor, the heads/springs and cyl pressure are.
Mill the heads to 60cc and port them with verified numbers to know.

 

[jos51700]

What's your application?
Let that drive your parts selection.

 

[Braeden Clark]

Speedmaster iron mag, 1.94/1.60 61cc
It took work to make them that way, but you can get there with stockers ported.
Stock cam isnt the limiting factor, the heads/springs and cyl pressure are.
Mill the heads to 60cc and you'll have enough dynamic for the cam you have.

Makes sense. The heads I have are stock but the aftermarket heads that are stronger. Maybe I will have more work done to them eventually. For now I'm gonna do headers and the 1.7 rockers. What is your tire size and gear ratio?

 

[MOPAROFFICIAL]

Makes sense. The heads I have are stock but the aftermarket heads that are stronger. Maybe I will have more work done to them eventually. For now I'm gonna do headers and the 1.7 rockers. What is your tire size and gear ratio?

Extracab 1/2 ton 4x4 3.92 17" 265
Has a shell ,but trans is built and gets into gear 'holding power'..as walt jr says.
I have some comp 986 dbl springs 135lbs seat and 265lbs @lift. Heads do 230's by .400 int and 204 exh...exh peaks around 218cfm. Peak intake flow is 263cfm @.550. Imo i could use different springs for sure.. but they work. When I say that I mean a higher rate with less seat. Fwiw I had the guides opened 11/32 and valve job done by Machine Tech in Oceanside CA. They do good. I did the added seat angles, chamber massaging,and porting and flow testing, spring seats,guide machining and assembly . I had Mesa Machine mill them .024

 

[Jadaharabi]

I did indeed do the aluminum plate conversion when I rebuilt the engine. My engine is a magnum block. I think like a 96 or so. Thoughts on paring the 1.7 rockers with the cam? Not too familiar with the mods to the ports though.

This is not the video I was looking for but you get a general idea by what this guy has done. There maybe more to it than what he has done also.

 

[Braeden Clark]

This is not the video I was looking for but you get a general idea by what this guy has done. There maybe more to it than what he has done also.

Huh. I'll definitely have to look into that. I don't remember if mine had that stupid center divider or not...

 

[Brooks James]

Hello all. I am coming to ask for opinions on mods to complement my engine. This engine is fully rebuilt by myself. Here is what it has:

fully rebuilt bottom end (stock... and i regret it)
Comp adjustable double roller timing chain
hughes 1110 valve springs
Comp 20-744-9 cam
New, stock heads that are polished
also has been tuned by hemifever

Everything else is stock. I want to add a little more power in the mid rpm range. Here are the mods I want.

52mm throttle body
Shorty headers
1.7 roller rockers. The cam has .480 lift on both intake and exhaust and I want a little more.

Thoughts on this and any other mods? I have the autolite plugs everyone talks about

My main question is the 1.7 rockers. My cam has .480 of lift on both. The rockers would bring it to .510. This sound like a good idea? I know I shoulda gone bigger with the cam but what's done is done

Check the retainer to valve guide clearance, stock, uncut clearance is less than 20 thousandths with a 512 lift cam in my 360. The 1110 springs are good to 550 lift. Hughes make retainers to solve the retainer issue