Porting and Polishing

[Vr4junkie]

Alright i want to port and polish my head now that its apart im going with this kit click from jegs i been watching a few video and doing some research so i kind of have an idea about what to do. ANY TIPS AND POINTER GREATLY APPRECIATED /ubbthreads/images/graemlins/smile.gif

I was thinking about porting It to were those 2 red lines are at and stop when it meets the Gasket and stop were that Black line is..What do guys Too Much or can i take it a little bit further??? /ubbthreads/images/graemlins/confused.gif




Not sure how much i can take off on this area i might just smooth it out

 

[Barnes]

Is this a 2g cylinder head?

Honestly, I wouldn't even bother. It sounds like you have never attempted something like this, and I don't recommend experimenting with it. Unless you really don't care about potentially ruining that head, or having poor performance if you do it incorrectly. Generally a ported/polished head only helps out when you are really getting up there in the power numbers. There are members of this board that do porting/polishing professionally if you are really interested in getting it done and want it done right.

Also, I'm pretty sure with that kit you couldn't do much porting. You could however clean up the casting flash from the ports and smooth things out. That certainly won't hurt performance and you probably won't screw anything up.

 

[rdomeck]

Do not attempt porting unless you know what you are doing. The first time I did a porting job was with a flow-bench to test things on and I went though 4 heads before I gained anything. What you think will work has the opposite effect. You can clean up the casting marks. I did just take some sanding wheels to my head tonight before I did the valve job and I didn't see much that could be improved easily....Just a few sharp edges that I smoothed out. Spend the money and have a 3 or 5 angle valve job done would be the most benefit.


It's not about making the ports bigger it's about making them better and unless you have a very good idea of what you are doing you will end up trashing the head.

 

[Vr4junkie]

This is a 1g head ...i might just smooth out the walls for now and play it safe...ok lets say if I make the ports a little bit bigger and and make them all the same size and smooth every thing out and give them a nice shape I plan on taking my time on this ...how would this affect performance I know I I can damage the head s if I grind to much .

 

[Terry Posten]

How much power do you want to make?

That head will make well over 500 horse power stock with new valve guides and a good valve job.

Take it to a shop and have them do a $100 guide/valve job and bolt it down.

 

[Vr4junkie]

I plan on making 450 in the long run stop there but for now I plan on getting a big 16 g 2g pistons upgrade thee intercooler etc...so porting the heads won't really do anything to increase hp or make a noticeable difference

 

[Terry Posten]

Nope, I dynoed 445 bhp (361whp) at 18psi on pump gas and could easily hit 550+ with some 100+ octane gas just by turning up the boost and I only have has my head polished when it was rebuilt.

Leave the head stock. It will perform the best in all type of driving.

 

[Vr4junkie]

Ok im just going to clean all the ruff spots just make it really smooth ...that's wired i would think it would perform better if the ports were bigger and smoothed out with a really fine wheel

 

[rdomeck]

Bigger is not better......And don't go to smooth. You don't want a polished surface, You want to leave it with about 80grit sanding marks!

 

[fastfalcon94]

I watched this video before. I'd feel comfortable trying it myself, at least the exhaust side and intake runners. As for the combustion chamber I'd feel comfortable getting rid of the sharp edges and smoothing it out, but I wouldn't take off too much here unless you really know what you are doing. Company's like Dynamic Racing and good machine shops will actually reshape the combustion chambers for better performance. I wouldn't dare try that on my own

click

 

[alansupra94]

Port matching for your exhaust and intake manifold would probably yield better results than trying to port anything.

 

[turbowop]

Quoting vr4junkie:
This is a 1g head



Are you sure? That looks like a 2g head to me. Look how small the ports are compared to that 1g style gasket. The difference isn't usually that large.

 

[Vr4junkie]

Quoting fastfalcon94:
I watched this video before. I'd feel comfortable trying it myself, at least the exhaust side and intake runners. As for the combustion chamber I'd feel comfortable getting rid of the sharp edges and smoothing it out, but I wouldn't take off too much here unless you really know what you are doing. Company's like Dynamic Racing and good machine shops will actually reshape the combustion chambers for better performance. I wouldn't dare try that on my own

click



This is one of the same videos i watched and felt fairly comfortable doing it myself. Also doesn't seem too difficult in the video but i guess there is a lot more that goes into it other than making the ports bigger and smoothing them out. But im just going to clean up the walls and the casting marks from both intake and exhaust I already bought the dam thing so i might as well use it

 

[Vr4junkie]

Quoting turbowop:
Quoting vr4junkie:
This is a 1g head



Are you sure? That looks like a 2g head to me. Look how small the ports are compared to that 1g style gasket. The difference isn't usually that large.



well to be honest with you im not 100% sure its a 1G head the bottom end is a 6Bolt so id imagine its a 1G head but who know they could of probably replaced it at some time or another. /ubbthreads/images/graemlins/dunno.gif

here are some pics maybe you can see if its a 2G head

 

[Barnes]

I'm 99% sure it is a 2g head, or perhaps an Evo3 head? Easy way to tell is to try and put a 6-bolt/1g head stud/bolt through one of the holes in the head. If it doesn't fit, it's not a 1g head.

 

[curtis]

I'll add 1% to Mr Barnes..Thats a 2G head. You can so screw up a cylinder head doing the most minor things. Mirror smooth doesn't work. Fuel doesn't atomize correctly. Shape, port velocity, angles everything comes into play. Even the thickness of the angles on the seats and valves can kill a port. Margin areas, bowl area,the roof, short turn radius etc all have to be correct. You want it done right send me your phone number and I'll pass in on to Chris he built his own flow bench and knows whats up. If he didn't Mike's evoII wouldn't be rolling close to 240 in the standing mile.

I've ported a few dozen of these things and my first one was in 1996, I've personally turned more than a few into scrap metal. You can remove a tad to much on the roof or the sides and your in a water jacket and sometimes don't know it until you've heated it up. My head from my car had the number one port give way after about 2 days and turned into a antifreeze injection port under boost. Just shows you a casting can have thin spots because every place in the head matches the other 3 ports. It was all mic'd, measured and used a laser on a mount to make sure I was measuring every spot correctly. More or less 60 hours shot down the tube. Plus 2G heads are even more tricky with how the casting is formed and they have a harder alloy than a 1G head... As said before knock off the rough stuff gasket match a 2nd gen intake to that head and stay the hell away form the chambers you can lay over the edge a thousandth to much and a gasket will never seal. Instant boat anchor


Oh by the way a second gen head will never match to a 1G intake. You'll have to find a 2g intake. Got some of those in the shop if you don't have one, been planing on building sheetmetal plenums for them but just haven't got there yet. Just yell.