4 replies to this topic

[3gencivic]

ok i was thinking of going and buying a junkyard head and haveing it ported and cleaned up.

is it posibale to port a head yourself if you have the tools. and if so what is the best way to do it and what do you try to do other then smoth out and widen the ports a bit.

and dos it make a diff if say you port a head and then trough it on or do you need to add a better cam to notice anything.

thanks

nick!

[5150CRX]

you should be able to feel something with just the port job..though cams would magnify that.
if you want to port your head your self here's what to do....start with what they call a gasket port...not sure who they are...but they say a lot....basically take the head and bolt the gasket down to the head...both the intake and teh ext...then use what they call diaken blue...but sometimes it red...and spreay the head....take the gaket off. and there should be a small colored portion left on the head use a die grinder and a port&polish kit to remove this material....the kits can be found in a lot of places but try you're local autoports store...who will not have it..but there will be some domestic guy there that can tell you where to get what you're looking for. once you've done you're best evenly and smoothly remove the material that's marked....proced to polish .......on the intake...leave it a little rough....if you polish the intake too much you'll get poor fuel atomization......but mirror shine the ext...try this first....if you mess up a little...don't sweat it...you're not going to hinder the performance.....when you feel comfortable doing this again ask again about how to port it more....and pick up another head.....you're going to cut it into pieces



aidan

[Omega Mugen]

I heard it is very easy to screw up a head port and polish. I also heard that the guys who are good at it had to screw up a half dozen or so heads before they got it right. This is why is costs $3-400 for a job. If your doing it on a junkyard head, it may be an inexpensive learning experience for you. But I think you would be extremely lucky if it worked out well. I've considered the same, but read some discouraging things about it. I've decided to let the pros handle it.

[Erik]

yeah on the intake side just smooth down alittle bit of the casting but don't smooth down the port cause if you do then you will loss...on the exhaust make it a mirror and then you might want to do alittle cleaning up in the chamber around the valves...but do't hit the valve seat cuz if you do then it is no good then you will have to take it in and have a angle cut on the seat and well n/m that it's a mess if you screw up the valve seats...also if you have a harbor freight around you go there they have a kit there with a instuctions and also a video that will tell you alot...also since you don't have a cast iron head you will need the right tip for the soft alum. and also a compound so the bit's won't bind up...

[CRXdan]

Just do a basic polish. Smooth out the intake ports to a 300 grit finish, smooth out the exhasut ports to a mirror finish. Polish the combustion chambers and vales to a mirror finissas well. Youll notice a bit more power, but most of it is to prevent carbon buildup and let the engine run more efficientley (good for turbocharging)

I did a mild port (decreased the short side radii) and port matched with the intake/exhasut manifolds. Expected gain (from butt dyno) with the gas flowed/polished ports: 5-7hp.
But I also did it on a cylinder head that was never shaved and didnt need to be as it was perfectley straight. My old head was shaved..so I did lower my compression, and polishing the Combustion chamber probably lowered it even more. Just basically got it ready for turbo in the Fall.

Edited by CRXdan, 03 September 2004 - 01:58 PM.