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Guest Message by DevFuse

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Ea81 and Ea82 head porting.

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6 replies to this topic

#1 Jerry DeMoss

Jerry DeMoss

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Posted 14 December 2005 - 09:15 AM

I would like to know if someone knows how important that little runner is on the intake side of the ea81 and ea82 heads.I have taken that out when porting a ea81 engine that I had in a hatch I used to own, and it ran like a monster.I just wondered how much that would decrease my port efficiency if at all.I just thought I would see if anyone has experience with that.Also I have no way of testing it as I don't have a flow bench to test it on.But my overall thought is that the effiency shouldn't be hurt that much as there is a great increase in volume of air with making the ports larger.Someone let me know what you think. Thanks for reading my post.:)

#2 soobscript


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Posted 14 December 2005 - 12:03 PM

Are you talking about the cast line in the intake area that runs with the flow?

I guess I can't really help, since I have no experience in the matter. But... I would grind it down.

Hmmm... someone with a flow bench and spare parts (and spare time) should test out the best porting method for our heads.

#3 Jerry DeMoss

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Posted 14 December 2005 - 12:08 PM

Are you talking about the cast line in the intake area that runs with the flow?

Yes that is the one that I am refering to.I guess I should be a little more specific.

#4 Jerry DeMoss

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Posted 14 December 2005 - 02:14 PM


#5 Ross


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Posted 14 December 2005 - 03:32 PM

I doubt it would be doing much, as far as i can remember the ports are symmetrical? If so, the flow should split properly without it.

Just remember - when it comes to porting, bigger is definitely not always better!

#6 BoostedBalls


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Posted 14 December 2005 - 06:53 PM

I just ported the heads on my EA82T and I know the ports are not symetrical.

Unless you are turning insane RPMs, I would remove only small amounts of material in areas that protrude into the direct flow. I grinded down the areas under the intake mounting holes. I took a course sanding wheel to just knock off the casting flash and give a smooth transition. I also matched the intake and gaskets also. The key factor to remember is that VELOCITY makes power. That mixture needs to blast into the chamber with some serious motion. Too large of port will only slow this down. Your cam needs to match your ports, you will throw away power if they don't match. I'm running stage 3 cams and I'm still on the conservative side with my porting. Seen too many people open ports up wide only to find out that their engine doesn't do crap until the RPM comes up; by then the race is already over.
Usually. people do more harm than good when porting heads. A good 3 angle valve job can give you excellent results with a stock port.

Rule of thumb- remove material only in the narrow areas, and only remove a small ammount if you have no flow measuring equipment.

#7 coronan


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Posted 29 October 2014 - 08:40 AM

Have before and After pics of your port job?

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