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| willygrice |
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OK guys I am thinking about rebuilding my ED motor (if I have any time as am doing about 80 hours at work this week) and I was wondering if it is possible to port my head at home?
-How hard is it? -What tools will I need? -How do I do it? -Also how else can I increase performance from the rebuild? On top of that, when I replaced the head gasket in my EL and I had my head faced/shimmed/machined the guy offered me two options. He said I could have it machined for 60 or rebuild (he may have said reconditioned) for 360. -What could the rebuild/recondition have possibly meant? As the engine is only a standard (non tickford) engine, it has all staqndard internals. -Should I upgrade the valve springs, valves or anything else? -What uprgade parts do you recommend? -On my EL I used a Ford AU head gasket, Are the ACL sets for the AU from repco just as thin as the Ford ones?
_________________ I dont care how fast your car is, mine goes faster through the bush. |
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| Andrew J |
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Gernally, if you dont know how to do something that professionals do, then you shouldnt attempt it yourself. A light tidy up with a die grinder may help a little bit to smooth the airflow, but i wouldnt suggest too much modification of the inlet runners or compression chamber yourself.
_________________ The problem with America is stupidity. I'm not saying there should be a capital punishment for stupidity, but why don't we just take the safety labels off of everything and let the problem solve itself?
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| GTBob |
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Definately NOT a job for a beginner TOO easy to do damage and ruin a perfectly good head. If you want to experiment get an old head from the wreckers that has cracks or is otherwise no use to them and practice on that for a few years LOL.
 
_________________ Rotten Old Revhead!!! XW GTHO + EF ex cop car (exractors 2.5 cat back zorst !6" Simmons K&N +airbox mods Lowered with Bilstein shocks+Whiteline Bars NEXT THING Swap HO for GTP or Ferrari! |
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| benno's ed |
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On an engine with standard internals a ported head will make little or no increase. By all means have your head reconitioned as they pull the valves out and check for wear and replace anything that is needed.
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| moody |
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a head recondition will give you an acid bath, new valve stem seals, they will re-set your valve springs/tappets as they are hydraulic, and they will also lap you valve seats. ontop of this you will get it machined/decked aswell.
ive ported dirtbike barrels before and i presume it would be similar, you need to lay you gasket on each side of the head (one at a timeobviously) and mark it out with a pen (the holesthe that the air flows through  ) then using a di-grinder/dremel or similar, grind back the excess on the head so that the gasket will line up perfectly. also try to make the grind as smoothe as possible for better flow. being an alloy head, iits easy to grind but sorta not easy to do lol. that applys for both sides, inlet and exhaust. im 18 and i did my first bike port job at 16 as long as your patient and not a butcher with precision, you should be fine but be careful and take it slow.
though anyone please feel to add in anything ive missed or even correct if i am wrong as i have only done bike barrels. i cant see youneeding heavier springs or bigger valves unless you runnning a really harsh cam or aiming for huge power, but on a bike, i know taht porting makes a HELLUVA difference to throttle response and gets that bit more top-end out of my bikes, but a car may be difefrent, anyway good luck if you attempt it yourself. |
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| stockstandard |
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moody wrote: a head recondition will give you an acid bath, new valve stem seals, they will re-set your valve springs/tappets as they are hydraulic, and they will also lap you valve seats. ontop of this you will get it machined/decked aswell.
ive ported dirtbike barrels before and i presume it would be similar, you need to lay you gasket on each side of the head (one at a timeobviously) and mark it out with a pen (the holesthe that the air flows through ) then using a di-grinder/dremel or similar, grind back the excess on the head so that the gasket will line up perfectly. also try to make the grind as smoothe as possible for better flow. being an alloy head, iits easy to grind but sorta not easy to do lol. that applys for both sides, inlet and exhaust. im 18 and i did my first bike port job at 16 as long as your patient and not a butcher with precision, you should be fine but be careful and take it slow.though anyone please feel to add in anything ive missed or even correct if i am wrong as i have only done bike barrels. i cant see youneeding heavier springs or bigger valves unless you runnning a really harsh cam or aiming for huge power, but on a bike, i know taht porting makes a HELLUVA difference to throttle response and gets that bit more top-end out of my bikes, but a car may be difefrent, anyway good luck if you attempt it yourself. You cant go for much more than a mild cam on an I6 without changing the springs. Also headwork doesn't have a big payoff on these engines as the heads are pretty good from the factory. If you want to do something while the head is off, get a 3 angle valve job, grind the boss', clean up the ports (leave the intake port rough, polish the exhaust port as best you can). The ports themselves are big enough and dont need enlarging. There are areas in the head where you can get some worthwhile gains but if you dont know what your doing you will be going backwards.
_________________ Stoke me a clipper, I'll be back for Christmas |
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| moody |
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so obviously not the same go with bike top ends in most areas then lol, as i mentioned, never done any port work to cars or heard about results. cheers for the info though, like learning
and whats considered mild? like a couple of brands/profiles would b nice, just for future refernce cheers
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| stockstandard |
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I wouldn't use std valve springs on a cam with much more than .490-.500" lift (with typical street profile ramps).
_________________ Stoke me a clipper, I'll be back for Christmas |
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| vibr8n |
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how come you don't polish the inlet ?
_________________ crow cam,cai,exaust,bbm,190 reg & el injectors,xr6 interior,guages,white cluster,pioneer/mtx stereo,big boot install w.i.p, 17"rims,koni/pedders shocks&springs with nolathane re-bush,ssv kit,stainless inserts,clear lights,t5 & short shifter,chardonay/pearl paint |
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| cjh |
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I have always polished the inlets and the exhaust, and chambers. Never had a problem.
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| vibr8n |
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it wouldn't be a problem, but theres obviously a reason for it!
_________________ crow cam,cai,exaust,bbm,190 reg & el injectors,xr6 interior,guages,white cluster,pioneer/mtx stereo,big boot install w.i.p, 17"rims,koni/pedders shocks&springs with nolathane re-bush,ssv kit,stainless inserts,clear lights,t5 & short shifter,chardonay/pearl paint |
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| The Dog |
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Two reasons to not polish inlet ports: The roghness keeps the air/fuel tumbling therefore well mixed. Also, I beleive what tends to happen is the air molecules sit inside these rough areas and can sort of act like little bearings keeping the air flowing even faster. Also if the port walls are too smooth the fuel can actually turn back into a liquid and stick to the port walls eventually just causing a puddle in the ports (but this is extreme).
This is the way I understand and the theory I worked on when I was building engines for a living.
_________________ You'll ride a black tornado across the western sky
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| Slick |
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I'll polish just the exhaust port, the carbon particles won't stick to smooth finish as easily as that on a rough surface.
But as xhute0 said, rougher surface on the intake port is crucial for fuel & air delivery. I've seen the deference between a polished port & rough port finish. after a few years the polished port look like it was sprayed with some sort of material. surface area appeared caked up with black silt & varnish like finish from the sticky fuel that never made it to the combustion. but the rough finished just had a bit of discoloration & bits of black carbon here & there. the deference was noticeable when the ports where measured with a inside caliber.
_________________ Mind f**k!!! it works on feeble minded ignorant sheeples... there's plenty of em on this site... some are very intelligent but by god they are so thick!!! Pakrat wrote: You can buy them seppertly
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| cjh |
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xhute0 wrote: Two reasons to not polish inlet ports: The roghness keeps the air/fuel tumbling therefore well mixed. Also, I beleive what tends to happen is the air molecules sit inside these rough areas and can sort of act like little bearings keeping the air flowing even faster. Also if the port walls are too smooth the fuel can actually turn back into a liquid and stick to the port walls eventually just causing a puddle in the ports (but this is extreme).
This is the way I understand and the theory I worked on when I was building engines for a living. Ever heard of " K-Jetronic" fuel injection? This system injects fuel all the time wile the engine is idling or reving out. Think about it, the inlet valve opens & closes about 5 times per second at 650Rpm. So how long has the fuel got to sit there at 4,000rpm? Somewhere in the 1,000ths of a second. If you leave the inner curves rough, this helps with turning the airflow around the curve.
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| The Dog |
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It doesn't hurt to smooth the intake ports ie. get rid of casting marks but don't polish them.
A stockstandard said the I6 heads flow pretty well standard. Probably the weak point is the springs. The xflow heads are the same to a certain extent. Most power can bextracted using a good cam. The headwork on these can get very technical such as raising ports etc and that is kinda hard to explain using just a keyboard and is very easy to f**k up.
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