better to port and polish the head, get oversized valves, or both?

[Kastigir]

Ok, I lost a timing belt, and trashed my head. I'm curious as to whether or not it's better to port and polish the head, get oversized valves, or both.

 

[GSX93DSM]

You can to both just depends on and the power,cams you are going to run. Also your money.

 

[93blueGS]

I wouldnt get oversized valves if you aren't going to completely build the head.. You won't see much gain from a reasonably stock car..

 

[19BLACKGST98]

Yea if you are just going to do one then get it ported and polished. If you want to do both then thats fine also if you have the funds to cover it. Thats one of the few things that I have left to do to my car (its a street driven car)

 

[snowborder714]

What are your goals?

 

[Cappa]

ehh well if you have 500 dollars to throw into cams, i would reccomend 272 race cams, they sound nice!!!

 

[Kastigir]

I'm stripping the head completely. Plan was port and polish work. New bronze valve guides. New valve seals. BC oversized valves. BC springs and retainers. HKS .272 cams, with adjustable gears. And a nice, newly powdercoated valve cover.

 

[93blueGS]

Sounds like you have it all planned out then..

 

[Kastigir]

Sounds like you have it all planned out then..

Yes, but I'm always willing to listen to those who have more experience than me. I've never really modded a car before, beyond bolt-ons.

 

[93blueGS]

Are you still running the stock turbo?

 

[xsboost]

If it's flow your after why not find a bare 1g head and build that one?

 

[Kastigir]

Are you still running the stock turbo?

Until I can upgrade.

 

[ontario AWD]

Time for a six bolt with a 14b.

 

[snowborder714]

So you're putting a fully built race head on an otherwise stock car? Personally, that seems like a waste of money until you have a turbo that will benefit from it and a better bottom end.

 

[kottyking]

Porting a head isnt necessary. Most people hurt more, then they help matters. Especially without a flow bench.

 

[DougR]

Just rebuild the head with quality components.
Untill you hit Really high boost daily. There is NO need for anything more then a gasket match and a decent bowl blend.

Now thats not to say that a good port job isn't a good way of making some power. Its simply at your LVL of engine build its Totally a waste of Cash!
As already stated above, you could build up the bottom end (within reason!) at the same time as that head build for the price of a port, unless someone just hacks away at those ports. Which will HURT! performance. And eventually force you buy another head (unless you epoxy the ports. Can you say $$$$$$$).

Anyways. Save some cash, Leave the ports and valve sizes alone.
Use the saved cash for some good fuel components And SAFC 2 with a logger (used from someone who upgraded to DSMLINK).
You will gain Twice the power with those and turning up the boost!. Compared to doing ANY form of head porting and or larger Valves.

Just my 2cents .

Gl, buddie.

 

[B005T3D_1]

makes sense... if your not going to build the rest of the engine at the same time and build it comprable to the head work then there really isnt any point...(at least not now) i bought a head from the junk yard for 50 bucks, and am currently awaiting it to be re built... meanwhile i can drive what i got set up

 

[TOONAH]

I have to agree with the above posts. I just spent $1700 bucks doing a stage 5 1G head. Actually Jason ruined the first one. He took too much material out and it kept failing the pressure test. Don't bother porting a 1G. If you want a better performing head then port a 2G. If you do go 1 mm OS then get Manley valves because they have a racing edge called a valve stem undercut and have a unique and proven tulip design. I believe they use Manley's in the Lotus Exigy. Don't even think about 1mm OS valves unless your machinist knows how to enlarge the valve bowl area. No sense in a bigger valve if you can't flow more air throught the bowl and hence to the port. Actually the best thing you can do for a 1G head is upgrade to 264 cams. Forget 272's unless you increase the flow through put. I strongly advise that if you do want a Stage 5 head then buy a pre-made one with some sort of warranty. Spare yourself the pain I went through and the money. But if you want to get into modding big time then start with the crankshaft and work you way up to the head. But doing a block right is $1000 and an Eagle crank is $800. Mahle pistons and Eagle rods another $700. Plus your $1700 head. Wow $4200 already.... Good luck! If you want an all out, kick ass 4g63, get a Cosworth short block.!!

 

[DSM1G90]

deleted

 

[Kastigir]

I appreciate your responses. Some people talk about it being a waste of money if I'm not building other things. I feel it's a waste of money to rebuild a stock head, then rebuild the bottom end, to only do a performance rebuild on the head at a later date. I'm not made of money, but I'm not afraid to spend it if I have to. Fact, the head needs rebuilt, the block as of now does not. Crankshaft endplay was only .004" out. I think I will go with a port and polish, Leave the valve sizes alone, even though it won't cost more for the oversized valves outside of the machine work. I was considering a 264/272 cam setup instead of going full out 272. Friend of mine with an Evo is upgrading his turbo soon, so I should get a pretty good deal on a moderately used Evo 16g. Again, thanks for your input. Also, this post in no way means I'm finished listening. If somebody else has something to add, I'd be more than happy to hear it. I haven't bought any parts yet.

 

[DougR]

If you feel your bottom end is capable of handling what you will be doing, Fine leave it alone...

Regardless of what you do to that head.
Cams, Turbo upgrades, Porting. Still requires More Fuel!
If not your Limited to no more than 15psi on that 16G alone, Probly 13psi with the turbo And cams, before you hit Fuel cut. That is a Big
Shure it might be alil faster, But your on the knife edge of poping that HG (get some crap gas on a hot day, and boom, your done).
Why risk it after Doing all that work to a Head that netted you almost nuthing in power Vs, more Fuel and a Good tune...

Ultimatly its your engine, And you are going to do what you feel is best.

GL, Bro

 

[JusMX141]

If it's flow your after why not find a bare 1g head and build that one?

It's been proven that the 2G head can be ported to outflow the 1G head by port design. The 2G head has more removable material which allows the ports to be shaped better by someone with a flow bench that knows what they're doing.

But for someone just looking for a cheap "bang for the buck" upgrade for the 2G head, a 1G head and intake manifold are a must-have.

 

[garage16]

Seems like BC springs and retainers with a set of HKS 272 cams is your best bet. I was running almost same thing on a 1G head till I went all out and grabbed a set of FP 308cams and Kiggly racing beehive springs

 

[fergulus]

I'm curious, at what point do y'all think a full blown head upgrade would be warranted? Everyone is saying to wait until he's got better injectors, turbo, and supporting mods. I am almost at the stage where I have completed bolt on mods, including a larger turbo. Would it be warranted in my case to get a better head (possibly a 1G)? Pricing everything except porting, all the parts can be attained for about 750, excluding cams. Would this also put a greater strain on the short block?

 

[kiggly]

Both ports are decent in stock form for reasonable revs. The stock 2g port can make a lot of power, my setup currently isn't even that highly ported. The smaller 2g port has better midrange. I've found more power in cams and with big cams, stock size valves allow more cam timing adjustment while keeping adequate intake to exhaust valve clearance during overlap.

I've been recommending people to stick with stock size valves.

Kevin