Hey guys I have a spare evo head and am wondering should I some work done to it or get rid of it. A buddy of mine said there is no need to to port and polish the head on the evo cause they flow good enough and I'll just be wasting my money. Is this true if not what are the gains (also my car is a daily driver/track car).

 

There are gains to be made with porting, but it must be done properly. What's your budget?

 

I want to spend about 1k, already have cams but am thinking of getting new one for the spare.

 

The gains are very minimal below 500hp and if someone botches the port work you will lose power, I say just clean up the casting flash in the ports and blend the bowl areas but even then that won't yeild much of a gain.

I say sell it and use the funds for something else.

 

So gains are only seen above 500hp, I dont see my car having above that anytime soon. So what is a complete head worth?

 

My advice is to look in the marketplace for recent sales to get a good idea.

 

I'm impressed with the good advice in this thread
A correctly finished head takes real skill.

 

With only 1g to spend, your options are limited..but I wouldn't say there is no power under 500whp to be had by doing something to the head. Will you be able to get the head properly ported for $1g or under? Not by anyone you would actually want to get the work done by. Besides, it's not real necessary with your power level yet anyhow.
I would say shoot for some more reliability and a slight increase in power by getting the spare rebuilt with a trick valve job and good valve train components to complement the cams you have. BTW, I would save your money and not buy a second set if there is nothing wrong with the ones you have. Remember, you have to take them out to install your head anyway!

We sell a rebuild package that will increase CFM by 30 on the intake and 15-20 on the exhaust. Will this make your butt dyno tingle when you mash the gas like a fully ported head would? No..but while it is apart you could add some Ferrea, or SuperTech spring kit and or valves(stock size) to aid in you rev ability and reliability.

 

Would it be best to send the head out to get it done or use it as a core. I see 1k does not get me much but i also have a spare short block that I wanted to focus more on thats why the low budget.

 

if that is the case then don't touch your spare head and just build your spare block. personally i would save money and build the head later down the road and have it built by a reputable shop. fyi power comes from the head. rebuilding the buttom end usually is done just to strengthen it except if you increase compression or increase displacement.

 

I spent around that for MAP's stage3 port job, it included port cleanup in the exhaust and intake runners (no reshape, no CC work), new performance valve job, reuse the stock valves but backcut the exhaust valves, new valve stem seals, resurface , assembly, and clean.

My car is has a BBK Full, Kelford 272's, etc and on the pump tune and alky tune, I think the portwork/valve job is worth a solid 15whp/20wtq. The important thing to realize is that to fully realize these gains, tuning must be done. Shane @ DB Performance did my tune and definitely he worked his magic on getting good numbers out of my car reliably.

More info here:
https://www.evolutionm.net/forums/ev...-gas-alky.html

Sorry I don't have a solid before/after, but based on my estimations on my expectations for my car w stock head and the BBK (pump: 360whp/320wtq, alky: 410whp/360wtq)and everything else, then switching to the ported head, I ended up with solid gains (pump: 385whp/340wtq alky: 430whp/390wtq). To me, it was money well spent, but I wouldn't have done it unless I had the head off for a reason (headgasket). My final opinion: do it!

 

Hi Turblue, I will go with any advice that HeadGames will give you.
Those guys are to best you can find for head job! I did 2 cars with them, and I know the next car will be with them also.

 

fwiw - I've built my Evo around the stock 9 head w/ zero porting and my car seems to make plenty of power 575 on our MD which tends to read on the lower side of most.

My car has trapped 137mph as well

When i built the motor i didn't have a large budget so i thought that the head would be the smartest piece to leave un-touched.

I sometimes kick myself in the **** for not doing it as i'm sure the added hp would have already put me into the 9's but it's a fun challenge to try! Don't know of many if any that have gone 9's on the stock head.

 

I know someone who has gone high 8' on a stock junkyard head so it is very possible!

 

Thanks for the advise guys seems like thiers alot of different opinions out there. Still undecided on what I want to do but keep them comin thanks.