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Guest Message by DevFuse

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Changing A EA81 intake to A SPFI EA82 intake

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3 replies to this topic

#1 ru'sdaddy


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Posted 20 April 2012 - 02:13 PM

I am trying to get anybody's input on putting A EA82 SPFI intake on my 1985 hatchback's EA81. I have installed the weber/redline conversion on the EA81 intake. I am trying to get away from the EA81 intake because it has to many design imperfections, such as: the intake runners have to much restriction, the runners are to small, the coolant passages are veined all thru it causing A much hotter air charge. I have A friend that runs A very good machine shop and he can tig weld the weber/redline adaptor to the EA82 intake. The EA82 SPFI appears to have larger and much smoother runners. As far as the coolant passages in this intake, I am uncertain as to exactly how to coolant cross's over. It appears to have A passage on the bottom, going from one head to the other. The ea82 SPFI intake that I am looking at is on A 1989 GL10 wagon I own. I have taken the throttle body off of the intake to clean it and the intake remains bolted to the engine, so I am not real sure if the EA82 intake will work on my EA81. I am almost sure it will bolt right up, because I have read posts about converting an EA81 to fuel injection. My goal is to put A intake on my EA81 that will perform the best with my weber/redline set up. Any ideas and input as to the best intake for my carb set-up would be greatly appreciated! PEACE! Kelly

#2 GeneralDisorder


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Posted 20 April 2012 - 02:21 PM

Not really worth the effort. Not unless you also do higher compression pistons, port/polish the heads, and change the cam. The engine isn't setup for that much air. The EA82 carb intake is easier - you can buy a new adaptor that already fits it. The SPFI intake has just as much coolant flowing through it as all the others. You have to have a place for the coolant the cross over from one head to the other.


#3 MilesFox


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Posted 20 April 2012 - 08:00 PM

with the spfi intake the fuel could drop out of suspension with too smooth surfaces. If your fabricator knows what he is doing, you will want to rough the insides or invent something that induces turbulence in the air charge.

the ea82 hitachi carb has larger bores than the ea81, in regards to using an ea82 carb intake.

you migh have some clearance issues to work around with either option

If you tig guy is crative, cut the head side runners off on an spfi and build off it for a carb.

If you fit an spfi intake onto the ea81, you could consider swapping the harness and ecu for an spfi swap.

#4 ru'sdaddy


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Posted 20 April 2012 - 10:28 PM

Allright! Great information. I am having problems keeping A seal at my intake gaskets on my EA81. It seems as though its trying to get more air. I have used shorter bolts to get more clamping force, always use felpro gaskets, coated the connection with edelbrock gasgacinch (great stuff!), and torque the intake down to 18lbs. I bought studs to replace the bolts that hold down the intake for the gasket replacement and was trying to find the best intake for the weber setup since I am not having much luck with the way it is now. Any suggestions as to the best intake to use would be great. Hopefully someone has tried some different setups and can suggest the best way to go. Also, does anyone know the maximum horsepower you can get out of an EA81 naturally aspirated? I do mean A high level of precision by being very meticulous by, milling, port and polishing, valves, cams, pistons, and balancing, to the point that it is still capable of every day driving and being dependable. I have three more EA81's, and plan to build one as far as it can be taken, just for the thrill of seeing what I can acheive. I have two 2.2L out of early legacy's that I plan to transplant into one of my hatches. Right now I want to super-tune my good old, rock solid EA81 and I am looking for advice. Also horsepower/torque numbers that are reasonable for A daily-driver. PEACE! Kelly.

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