Time for a built head! options?

[talon187]

Ok im looking to build a head. I have already hks 272 cams im looking to rev to 9k if i want to. I wondering if 1mm over sized vals will be worth it or not. Im also wondering whos a big place to have a head done and what i should get for parts as far as brands go. im also going with a 30r dual ball bearing turbo im looking to make alittle over 500whp thanks!

 

[bling5tatus]

i don't think oversized valves is a necessary expense. Many people would argue that it is, but I'd honestly say worry about getting some nice springs (I say beehive) and having the valves you already have machined to seat properly in the head.

oh and i hope you have a transmission that can shift at 9k.

 

[tsiAWD91x]

deff dual vavlespring and retainers and i say fierra valves 1mm oversized get the coaded nitrid if you can get em' thats the set up i got. DEFF 3g lifters. might want to look into a bigger grind of a cam is your goin that big and its not a street car

 

[talon187]

its a street car i may bo with sbr stage 5 head because i can get one for 900

 

[talon187]

yes my trans was all built i also have a twin disk cultch

 

[TOONAH]

There is no doubt, that the best way to get a few more foot pounds of torque is to increase the flow through put of the cylinder head. A 20% increase in cfm's can mean 20 more horses. However, there is also the velocity factor. Just grinding out material from the ports is pointless if you do not increase the 'bowl' area and increase the valve diameter. I chose Manley racing 'tulip' undercut stem type ss OS valves. If the seats are in good condition they can be machined to accept the 1 mm OS valves.
If you are building an all out engine, desiring to get the most possible horsepower, then you deserve to get a performance head job.
I would highly recommend the sponsor of this forum, FFWD, to be your guide on this subject. They are highly knowledgeable and build some kick ass motors too. Visit their webpage and or give them a call. Also refer to Cosworth. Although they only do EVO heads
for 4G63's, they know about performance cylinder heads. My last bit of advice is call FFWD
before you go anywhere else.

 

[Turbocharged]

The stock 4g63 head is already high performance. Money is better spent elsewhere if you have any "holes" in your setup. In my opinion 3g lifters, light porting, and cams are all you need. High performance springs are a nice addition and provide insurance on your investment.

Also, there is no need to spin the engine to 9k. There are only a select few that make power past 8k: DSM Dyno Challenge - Highest Horsepower