I doubt there would much gain unless JHM is also going to offer some kind of porting or polishing option in the future. The 3 angle valve job may give you a slight power bump and better flow. The valve train components are lighter also, but I doubt there is much of a benefit you will see in the 1/4 mile. Stock cams so not too much changes besides heavy duty valve train components and well basically better than brand new heads.
I would imagine that they have taken care of the casting issue.
With the IM(which you have) and headers, they should be awesome. That is assuming that the heads were the next restriction after the headers/manifold are upgraded. Still not ported though, but I recall reading a few times that they flow pretty damn good as is.
I think a big reason for the heads built is to support future built motors to handle more boost.
but while there out have them port them. cause theres a picture somewhere on the interweb with ported heads i belive. but shit lets just say its 1k more 4500 for ported polished and built heads with no casting issues that could mean low to mid 12s on motor and 11’s on spray and mid 11’s on SC man thats a huge diffrence. and thats still stock bottom end so yeah i need to win the lottery so i can just buy another motor and ship it to jhm smh!!!
Get more information on the head work stuff and let us know. Head work is the foundation of more power… If done right that is. If you can get a solid port job and the full head work package your going to be able to pull out more power from the motor. If you have the heads off and you have the time I would call it a must… once again if done right.
Correct me if I’m wrong, but too much head work without a properly matched cam to take advantage of the better flow can hurt performance or gains. Our 40 valve V8 seems to have a pretty good design from the get go. I just think in the end, even if you had custom cams made and found someone capable of tuning it (CV), it wouldn’t be worth the time and money.
If only we had an LS1 “like” motor to throw a heads/cam at and gain 80hp
Anybody have bench flow testing numbers for the stock heads? How much do the heads flow compared to the intake? Where will you run into a ceiling first?
Wow… That’s fan-fucking-tastic. Just when I was thinking that I took care of everything I needed to while I was doing the timing repair. And just when I was beginning to forgive the early '04s for all their faults.
Time to clean her up and up for sale she goes… Tired of this shit.
Lol your good bro it didnt happen till 118k so it’s not horrible just something to be aware of with Jhm’s head program there’s a good chance that it can or IS fixed. Just keep an eye out
anything with an internal combustion engine would likely be too scary if that’s your reaction to something that, until today, you had never heard of. My lawnmower had a problem iwth the carb last year. I guess you had better sell your lawnmower now.
I have never heard of a head issue so I would say it is very very isolated and rare. Half of the 04’s out there have well over 100k and you don’t see people posting threads with this issue.
The heads were flow tested by JHM, as they said in their thread on AZ. Not sure if we will be able to beat the information out of them.
Very slippery slope. To be frank. When you look at the design of the head thats where you start to make conclusions. Each head is not alike. The Audi guys… and Im not saying present company. The Audi guys tend to think that each car is just like every car. There are very specific things that separate motor class from motor class.
You’re right. Maybe I overreacted a bit. Back story… I only heard about the timing component issues about 2 weeks before it happened to me, so I’m still a little shell shocked about all these issues.
I only have 60k miles now, so if it all goes bad in 40k miles from now then I think I will be ok. By then I should be ready for a JHM motor.