I may be slightly out of line by asking this;

[TTkickedin]

I''m only asking because i wouldn't know how to word this on google to figure out the answer. I'm tech savvy but this would be the first time i'd ever get in this deep into a motor.

I have my motor disassembled, the heads are off the block, and i figured while its out that i would slightly port and polish the exhaust and intake leads (wrong term, i know, i mean the valve 'ports')

would i have to tune the ecu to augment the porting job?

[NolimitZ32]

you don't need to tune for just a PnP but be weary, if i were you id find some s*** heads to practice on before taking the rotary to your good heads.

[TTkickedin]

I had a feeling you didn't have to but I wanted to be 100% sure. What's the correct term for those ports I mentioned? I'm referring to the ones on the either side of the heads. And would porting and polishing really make a worth-while performance increase? And roughly what could I expect to gain?

This kinda goes hand in hand with how the car was maintained with the previous ownerN but I noticed that the coolant passageways appear to be rusty (came as no suprise to me as the motor had no thermostat and was running on a 95-5 water/coolant ratio and had been rusting the block.) Should I be concerned about this? I'm going to try to scrub it out with a cylindrical wire brush and compressed air to see if I can clean it. I'm under the assumption that I may have to clean the whole block in a hot tank.

Anyway, I'm sure my dad has some spare heads laying around the shop from and old mercedes. I'll check with him tomorrow.

[NolimitZ32]

Intake and Exhaust ports its how I've heard them described. The performance gains might be minimal especially if your not running huge turbos, These heads were designed very well and there isn't much to gain. Now as for the water passages being dirty I say spend the few hundred extra dollars and go get your block and heads cleaned and dipped at a machine shop, you wont be able to get into every little space but acid/hot-dip will.

[TTkickedin]

Thanks dude, appreciate the help. Turns out he does have a few heads laying around. Ill bring one home monday.

[AZhitman]

Do you know what you're doing? Or are you just going to randomly remove material inside the combustion chamber and hope it works?

[TTkickedin]

Do you know what you're doing? Or are you just going to randomly remove material inside the combustion chamber and hope it works?

I have an idea of what to do, no need to belittle me. Theres a 'lip' on the intake and exhaust port, not the combustion chamber, that can be removed via grinding and polishing it down with a dremel tool. Provides better flow of air/fuel and exhaust gases through their respective ports.

Anyway, I'm going over to my fathers shop to pick up the Mercedes head, this will not be used anymore..

[AZhitman]

Wasn't belittling... I've done several engines and still don't know much about headwork, and have seen people create more problems than horsepower.

[TTkickedin]

Ok, didn't know where you were coming from with that, thanks for clearing it up.

But anyway, I got the Mercedes head today from my dad, and I'll be uploading some pictures in the next 5 minutes!













You're probably wondering why I didn't take the valvetrain out; time conflicted with my schedule, and I didn't really care to take it out since the head won't be used again.

I don't know what the exact order of the pictures are, but basically, the first intake port was my first shot, the second, and third in respective order. I messed up at first because I didn't use the correct attachment #1 and #2 I didn't use the correct strokes/form with the rotary tool. This resulted in a few bumps here and there, and an uneven intake gasket surface.

I have a good idea about how I will approach the exhaust ports the correct way next time. This has definitely been some good practice for me. I

[TTkickedin]

I've determined that the best attachment out of the few I have was the sanding bit. It gave a nice, even surface on every stroke. The green attachment was good for a while, but it broke off. The orange attachment isn't necessarily the best for porting because it takes too much surface off of the port.

As for polishing, the best attachment would be the wire polisher not shown. It did a great job of polishing, but it has a very short lifespan (probably because of applying too much downward force.)

[TTkickedin]

Can anyone offer some feedback for me?

[NolimitZ32]

Wish I could but this is one thing I've never messed with, like Hitman said, this is a special skill and though I too have built a fair share of engines I have no clue about how to actually PnP, I know the theory but that's not enough.

[TTkickedin]

Ah, yeah I'll hold off on doing this to my heads then, wouldn't wanna make em worse. I already need another piston because one of my pistons melted and I JUST found out about it. FMFL.

[NolimitZ32]

thats ok man, rebuild is how you will gain tons of knowledge about it, first engine i ever rebuilt was my JDM DETT cause it arived with a bent rod, i was pissed and dumped unreal amounts of money into it (much more than i planned) but now i'm not afraid of any engine, as a result i rebuilt my subie STI engine in pretty much a weekend and have since had my hand in many a build of all sorts.