Optimal 2.0L Head

[Carmenpzito]

Yes, I searched; no I didn't find my answer, which brings me here. I'm in the process of doing research for a cylinder head build-up. My goals are to make 400awhp and to rev to 8500 RPM. I plan on a mild port and polish. I want a broader powerband that takes advantage of the FP3052's quick spool and considerable top end.

I'de like to discuss the pro's and con's of dual valve springs, +1mm valves (intake/exhaust/both), and O ringing the head rather than block.

1) Valve springs...are dual kits overkill for my goal? I've heard claims of single kits supporting 9k RPM but have found no proof of them doing this. I actually only plan to rev a little past 8k but want a cushion of 500 or so rpm's. I plan to run FP2x (if dual spring) or BC 272's so I don't think clearence will be an issue.

2)Oversized valves...Is it best to get them all oversized, just int. side, or just exh. side? I've heard much debate about restriction vs. velocity. I also read somewhere that +1mm valves are great for 2.3l due to piston speeds and flow characteristics, but may be sub-optimal for 2.0L at the 400hp level.

3)O Ringing...I realize this is mainly for 30+psi monsters and not needed for my goals. That said I am wondering how this affects head gasket wear. Also are there any differences in performance/durability when O ringing a block rather than head?

 

[Carmenpzito]

Anyone have any input? Preferably those of you with first hand experience

 

[bigjdog84]

Yes, I searched; no I didn't find my answer, which brings me here. I'm in the process of doing research for a cylinder head build-up. My goals are to make 400awhp and to rev to 8500 RPM. I plan on a mild port and polish. I want a broader powerband that takes advantage of the FP3052's quick spool and considerable top end.

I'de like to discuss the pro's and con's of dual valve springs, +1mm valves (intake/exhaust/both), and O ringing the head rather than block.

1) Valve springs...are dual kits overkill for my goal? I've heard claims of single kits supporting 9k RPM but have found no proof of them doing this. I actually only plan to rev a little past 8k but want a cushion of 500 or so rpm's. I plan to run FP2x (if dual spring) or BC 272's so I don't think clearence will be an issue.

2)Oversized valves...Is it best to get them all oversized, just int. side, or just exh. side? I've heard much debate about restriction vs. velocity. I also read somewhere that +1mm valves are great for 2.3l due to piston speeds and flow characteristics, but may be sub-optimal for 2.0L at the 400hp level.

3)O Ringing...I realize this is mainly for 30+psi monsters and not needed for my goals. That said I am wondering how this affects head gasket wear. Also are there any differences in performance/durability when O ringing a block rather than head?

You will not need dual valve springs for bc 272's reving to 8500. FP2x on the other hand, I would suggest dual valve springs since they have much more aggressive ramp rates.

OS valves are up in the air with a bunch of people. I personally prefer them, however in your case with the amount of power you would like to make, they are unnecessary.

If the o-ring protrusion is set correctly they work very well for high boost applications. Head or block, its really in preference. I've seen both work well. I wouldn't O-ring anything in your setup. Just make sure you have extremely smooth and true surfaces, use a mitsu MLS and some ARP's and you'll be good to go. I've had good luck so far with them at around 35 psi on a few different cars.

 

[90laserRSfwd]

Yes, I searched; no I didn't find my answer, which brings me here. I'm in the process of doing research for a cylinder head build-up. My goals are to make 400awhp and to rev to 8500 RPM. I plan on a mild port and polish. I want a broader powerband that takes advantage of the FP3052's quick spool and considerable top end.

I'de like to discuss the pro's and con's of dual valve springs, +1mm valves (intake/exhaust/both), and O ringing the head rather than block.

1) Valve springs...are dual kits overkill for my goal? I've heard claims of single kits supporting 9k RPM but have found no proof of them doing this. I actually only plan to rev a little past 8k but want a cushion of 500 or so rpm's. I plan to run FP2x (if dual spring) or BC 272's so I don't think clearence will be an issue.

2)Oversized valves...Is it best to get them all oversized, just int. side, or just exh. side? I've heard much debate about restriction vs. velocity. I also read somewhere that +1mm valves are great for 2.3l due to piston speeds and flow characteristics, but may be sub-optimal for 2.0L at the 400hp level.

3)O Ringing...I realize this is mainly for 30+psi monsters and not needed for my goals. That said I am wondering how this affects head gasket wear. Also are there any differences in performance/durability when O ringing a block rather than head?

Ok so here goes:

1) VALVE SPRINGS: I understand why you would think you need duals. The ramp rates on the FP's are very aggressive. I personally don't see a reason to use dual springs. You can get a set of beehive springs from Darren @ ffwdconnection that will do you just fine, up to and beyond 8500 rpm. Plus beehive springs are easier on the valves and guides at lower ramp rates (meaning when the spring is starting to compress) then the dual springs. PM if you want more info on this.

2) OVERSIZED VALVES: Unless you plan on making some very serious power (I'm going to use 600+awhp as a starting point), over sized valves are simply not needed. You can however, get some after market stock sized valves (such as ferrea's) because they are usually lighter weight and will handle the stress's of a high rev motor better then OEM stuff. Another thing to keep in mind is that, if your on a budget like myself and most other dsmer's, you can use the stock evo 8 valves which are lighter then dsm's and the exhaust valves are sodium filled which will handle heat better then the OEM dsm ones.

3) O RINGING: Talk this over with your machine shop. I personally recommend doing the block. For 400whp this is simply over kill and not necessary.

Some other things I'd like to point out for you consideration as well. Porting and Cylinder head choice. From personal experience, building both 1g and 2g motors, the 1g's flow more air from factory where as the 2g heads keep higher velocity. I personally think the 2g heads are better. It's hard to explain. Porting: This is very simple (and VERY VERY easy to ruin a cylinder head completely if you don't know what your doing) and forward. The quality of the port work on the cylinder head can make the difference between gaining HP and torque and loosing velocity and making the turbo take even longer then it should to spool up. I personally recommend spending a considerable amount of timing doing some blending of the bowl area's and unshrouding the valves. Polishing the chambers helps as well as knife edging the intake splitters and getting the exhaust runners as smooth as possible. You don't have to do any of this though just to hit the 400 mark.

to sum up my little novel I have going here, take this as advice and nothing more. I don't want you to think you need a ported race head and help from Jesus himself (both nice things to have though) to make 400hp. The more you research and read, the better you'll be able to decide exactly what you want. More or less it comes down to how much money you want to spend... Let us know how you make out.

Here's a link to the springs:

FFWD Connection - Race Injuns That Will Freeze Your Brain

 

[Carmenpzito]

Thanks a lot for the link. Ive been on that site at least a dozen times but never saw those...and they look great. That's probably the way Ill be going.

With Evo8 valves, are these drop in fit or is additional machining required?