I was talkin to a guy who owns a srt6 with custom heads pushin ova 500hp. He told me he opened up the exhaust valves because that was the bottle neck in these cars. Was wondering if na crossfires would benifit from the same thing

 

Was He smoking something while he was talking to you.

 

500 HP??!! I would love to see that one. Jim has the fastest xf.

 

So he did a valve job on his and has over 500 hp.... Well, that is a first for me... I guess the rest of us have missed something....

 

Naw I kno you don't get 500 for just a valve job lol, he had many more mods. Jus seein if there were more people that did it to there car, and if so wat gain did they see
I kno he was blowin some smoke

 

It's actually a pretty common thing on the 55K's. I don't know what their gains are to the ground or anything but I remember hearing that just on bored valves the engine was able to flow 20% more air in, and 15% more exhaust out. Pretty huge gain, and that IIRC that wasn't including the porting. Which on the heads for sale was extravogent to say the least, they shaved a TON of aluminum out. And I've seen the inside of the heads on the NA's the SRT's and the NA V8's in person, NA55 and 55K in pics. All of them could DEFINITELY use a good port job. The one downside? The set I just saw go used on the MBWorld forum went for $3500...

 

Wow 15% is alot
Jus not sure if it's worth over 3k for the gain
If I can find some heads for cheap I think id try to get it done

 

Exactly.. hp/$ it's not really worth it unless you're trying to get everything out of the motor possible and don't care. When the 55K motor is in the crossfire I'll get it done someday but I wont be doing another swap so I might as well.

 

I'm getting there. 409 at the rear wheels. 493 at the crank if you want to figure 17% drivetrain loss guesstimate.

 

Doesn't NW sell them...

 

Yeah, I don't think they figured that Jim is over 500 to the wheels lol. 500 crank on an SRT could definitely be done before internal work.

NW's, Eurocharged, Renntech, Brabus, Evotech... Plus you could just go get it done yourself for a reasonable amount if you know what exactly you want. Snag 55K valves, go to a local shop that does that stuff, tell them what you want, pay the money and Bam. Done.

 

NW's, Eurocharged, Renntech, Brabus, Evotech... Plus you could just go get it done yourself for a reasonable amount if you know what exactly you want. Snag 55K valves, go to a local shop that does that stuff, tell them what you want, pay the money and Bam. Done.[/QUOTE]

I need to research this more, but your saying grab the exhaust valves off 55 and machine the v6 head so they fit
Beause if this can be done within the hundreds id consider this

 

I need to research this more, but your saying grab the exhaust valves off 55 and machine the v6 head so they fit
Beause if this can be done within the hundreds id consider this[/QUOTE]


Not the 55, the 55K, as in the Supercharged 55's. They're different.

I don't know about it being in the hundreds, but depends on your machinest. I'd get it ported too. Then tuned or you'll probably lean out.

 

Actually Josh, as long as it is a 55, not a 500 or 550, they are the same valves. I have done extensive research on this topic. I would not spend the money on valves and porting on N/A or SRT-6. The HP/$ ratio is just not there. Even with a Code3 supercharger pulley and 185mm crank pulley, the gains were marginal on Eurocharged black C32. That car had Schrick cams too.

 

The NA 55 valves are the same bore as the 55K's????? Crazy, I didn't know that lol.

That's what I was saying though, not worth it unless you just have tons of money to blow. The gains on a 320 wouldn't even be close to 20/15%... Even on a 32 they wouldn't be that high. The gain's I mentioned were a 55K, and that was overall flow increase and it has 2 more cylinders. I'll try to find the thread.

EDIT: And the 5.4's are much bigger displacement cylinder/cylinder than the 3.2's.

 

Well, I was backwards on intake/exhaust gains but here's bored and ported...

Ported 55k heads anyone? - MBWorld.org Forums

 

He seemed to pretty pleased and had only a slight tune to it. Only If prices was reasonable

 

Like the SRT, only even crazier, you just look at the things the right way and you get 20 to the wheels lol. It's literally mind boggling the numbers the 55K guys pull on mods. Same with the turbo'd V12's, but once again, even crazier lol.

 

I could see porting and polishing. But I don't think you will see large gains. Every little bit helps. But that isn't magic...

 

On the 6 cylinders you're right. If you can get 35whp for $1K that's not too shabby though. You just need more displacement to use the extra efficiency.