Insanity Evo

iTrader: (7)

I was just wondering if the gains are really worth the cost on getting the combustion chambers ported. I bought an already built/machined/assembled ported head but the combustion chambers aren't ported. I was wondering if it would be worth it to get that done. From my research I have read that it helps with heat build up and also helps prevent detonation.

My goal is only 500 whp or high 10's. Do you guys think it would be necessary or worth it to get done? Thanks.

EvoPower81

iTrader: (14)

The stock evo chambers have some sharp edges between valves which can cause hot spots and detonation. In smoothing these out you will have a higher boost and timing threshold hence make more power. The downside is you lower compression slightly. Just my 0.02

Insanity Evo

iTrader: (7)

I could always combat that with a cosworth headgasket that raises compression, couldn't I? This is all some what confusing but very interesting to think about the different combinations I can do for just my head lol.

EvoPower81

iTrader: (14)

Yes of course a thinner HG would bring back up the compression but I wouldnt recommend going thinner than stock

boostedtres

iTrader: (4)

i am no expert in the matter you are discussing, but it is a very interesting thing to think about. obviously a thinner HG would help, but like the above poster said, increasing boost/heat etc....going thinner than you already have could be dangerous. for 500whp to me, it does not seem worth it money wise. however, if you have the cash, it would def. prove beneficial in the long run esp if you end up doing a full build with higher whp expectations. since you already have a built head, it may not be a bad idea while you are in there. i no I have been of no help, but this has got my head thinking about the infinite possibilities! gl with w/e route you choose!

Insanity Evo

iTrader: (7)

Anyone else have any input...or maybe some from some people who have had it done?

Thanks...

03whitegsr

iTrader: (8)

I don't know what effect it has on flow, but because of core shift, you can get a decent amount of valve shrouding around some valves and not others. Porting the combustion chamber allows you to help eliminate some of the valve shrouding which should improve flow.

Beyond that, just smoothing things out should provide better overall resitance to detonation.

The stock chamber has some pointy edges from the valve fly cuts towards the center of the chamber that can be removed pretty easily. You can also smooth the transition to the spark plug protrustion. Other then valve shrouding, it's pretty minor work. You have to be careful though as it is pretty easy to make contact with the valve seats, requiring a valve job to fix.

HeadGames

iTrader: (2)

I think it would depend on who does it as well...some just blend in the chamber without changing it's shape and just take away the sharp edges. Others will take it out to the gasket..there is alot of ways to skin that cat. There is alot of room for improvement there. We change some the shape of it on the quench area, and blend it straight into the top cut of the valvejob. It will increase airflow at low lift by taking away the restriction next to the valve, and you can run more timing thanks to the sharp edges being smoothed or removed.

Kracka

iTrader: (49)

Nice pics of a ported combustion chamber:
https://www.evolutionm.net/forums/7976560-post100.html

RSMike

iTrader: (1)

good info.

on the flipside of that comment, the more efficient a Combustion chamber is, the less timing it requires to make the same amount of power?

Insanity Evo

iTrader: (7)

I'm wondering this as well. So you would be able to run more timing, which equals more safety at higher boost levels right?

But also, would getting them ported decrease torque also? I'm sticking with stock size valves by the way.

Also headgames, do you happen to know the going rate for just the combustion chamber porting? And also what is your input, ie: is it worth it getting done for my goal, like how much of a difference would it make?

Insanity Evo

iTrader: (7)

bump for my latest questions!

Insanity Evo

iTrader: (7)

bump

HeadGames

iTrader: (2)

not ignoring this, just been busy!

also have been thinking of a way to answer it, because some tuners like to use boost and low timing and while others use aggressive timing and lower boost...I probably shouldn't have mentioned it because that is opening the door for something I don't care to argue about theory. Either way, it would decrease your chances of running into detonation by having them done.

and again, depending on who is doing the work and should I say how they do it would dictate if the work would decrease torque. We don't take ours out to the gasket, and honestly don't see any benefit in doing so. I can only talk about us and in my opinion there would be no drawback, only benefit to doing the chamber. We have never let a 4G head leave here without the chamber being done so we would have zero knowledge of how much such a thing is worth in hp or torque and makes me wonder if the person whom ported your head thought it was a good idea to leave the shop without it being done, what does the rest of the head look like?!
Makes me wonder about the valve job as well, has to be not that aggressive. Our valve job takes out so much material in the chamber it would look ridiculous to send it out like that.

And if it's on a already running motor it would start to get expensive because it would have to be dis-assembled, cleaned, chambers done, milled and cleaned again then assemble. I'm trying to not get into trouble here with pricing, but I would imagine someone would charge in the neighborhood of $400-700 to do the job right. $700 would be on the high side, and include machine work. I don't know what you paid for getting the head done in the beginning but goes to show you can sometimes save now to pay much more later for getting the job done right.

Insanity Evo

iTrader: (7)

Well the head was ported by Turbo Trix Racing and it was just the bowls ported. I bought it off another forum member. It was given a 3-angle valve job if I remember correctly. I think I know which direction to in and I'll have to talk to my tuner about it. Thanks for the info!