tdangelo

If you are interested in developing an intake manifold to accept a Weber 32/36 then you may want to take the same approach that I did. I took an EA82 Carbureted manifold and modified as follows. 1. Remove all non-essential vacuum port tubes by physically pulling them out of the manifold. (you will have the holes welded up). 2. Cut or grind off all non-essential "bolt and screw bosses" and sand the areas where they were at, smooth. 3. Turn the manifold upside down so that the bottom, where the hot water passes underneath the manifold, is accessible and easy to get at with a "Sawzall" or a high speed cutter with a thin carbide cutting disk. 4. CAREFULLY cut a slot through the water passage area only. You will make 2 of these cuts. One of the cuts will be about 1.5's from the NON THERMOSTAT end and the other in a diagonal manner running parallel to the "heater feed water pipe boss" on the end that has the thermostat housing. The cutts should be clean and wide enough to insert a piece of aluminum bar stock to act as a water passage dam. Note that the cut on the thermostat end of the manifold will be on the side CLOSEST to the center of the manifold "carberator intake bowl" where the water heats the intake plenum. 5. Take the intake manifold to a shop that performs aluminum welding and have the 2 "DAM PLATES" welding into place so that there are no water leaks. Have all of the vacuum port opening, that you are not going to use, welded up also. 6. Take a can of "LOW EXPANSION" POLYURETHANE INSULATION and carefully fill the void BETWEEN the 2 "dam plates" with this insulation material. I used the snorkle tube that came with the insulation inserted in the hole in the carb mounting area where the water came up to heat the lower edge of the carb body. Let this cure for 24-48 hours to make sure that it is well cured. 7. Have a hole drilled in the WATER PASSAGE ELBOW area of the manifold, in the bend if you can(that is where miine is at) and have it threaded to receive a "pipe nipple" suitable to permit a good flow of coolant out of the the drivers side head. Plumb this into the heater supply pipe which is still on the manifold. The permits a coolant flow in the same manner that existed prior to your intake modifications. You have, in effect, created a "cold air intake carburetor manifold". It is a fact that Subarus have a horsepower drop between a cold engine and a hot engine due to the heating of the "Intake plenum bowl" with hot coolant. You now have a cold intake plenum bowl and therefor will realize a gain in power when using a Werber Carb with the set up. I know that it is a long post but I felt compeled to post something after looking at the engineering feat of the FRANKINTAKE.

I think that if you go to the Baldwin Filters site you will find some interesting date. Baldwin filters down to 10 mocrons whereas Napa Gold and some of the others that you fellas have talked about only filter down to 30 microns. A micron is equvilant to about 1/25,000 of an inch. I have run Baldin for years. Their filter cases are almot "bullet proof". Another filter of SURPERIOR quality, like the Baldwin, is the one sold by Amsoil, the only oil that I have used in my service truck, my International School bus and all of my POV's accept my sons VW Diesel Rabbit. I also run Baldwin fuel filters and K&N air rilters on all of my rigs.

Has anyone played with this arrangement other than the SPFI pistons in the push rod motors?

Datsuns were my "cup of tea for years". Both L series as well as A series motors. That is where my knowledge of "pipe poppers" comes from as well as my backround in compression heights, cylinder columes, sweep volumes, share fuel charges, dedicated fuel charges and the list goes on ad infinitum. What I am looking for is, as you put it, "hybrid parts".

I would appear that the only way to derive any "concrete answers" is to get some heads from the different engines in question and determine their combustion chamber volumes using a burret and triple distilled water. Some purists use alcohol in place of the triple distilled water but you must have an absolutely airtight valve and seat in each hole in order to retain all of the liquid. The other approach is to find some one who has already performed this or find a Field Services Manual with that information. We may even be lucky enough to find an "authentic Subaru parts counter man" who would know where to go for that information.

Well when all else fails go find a book. Here are the compression heights on the EA71, piston 92mm across, and the EA81, piston 92 mm across,. Both pistons have a compression height of 32mm. This means that if you use an EA81 crank shaft and connecting rod with either piston you will get the same compression. Both pistons are listed as flat top pistons. The EA71 is not domed and therefore can not possibly produce a different compression ration than than the EA81 piston. Granted the measurements come out of a Sealed Power piston catalog and are for a replacement piston. But if they are the suppliers of after market, for engine builders, I would tend to believe that they are as close to OEM as is possible. Now the next question is where we are getting a 9.5:1 ratio from a SPFI piston in an EA81 Block. It appears that the connecting rod on the EA81 and the EA82 are the same length. Unless there is a compression height difference between the EA81 piston and the EA82 SPFI piston I would tend to believe that the compression ratios are the same. This leads me to conclude that the the OHC EA82 SPFI head has a different combustion chamber measurement than the EA81 head or for that matter the lower compression EA82 carb engine. Anyone with "hard numbers" and experience on this?? I have built a few "pipe poppers" in my time. Some by interchanging parts and some by using "racing competition stuff. I am trying to make a "pipe popper" using stock parts and a creative machinst.

Do you know where the "red mark" on the Yugo temp guage is at? I have had the speedometer needle sitting on that. It will cause a 5.0 Mustang to wonder what is wrong with his car when you sit beside him at 100mph is a Yugo. Life is good sometimes. haha

I have been noticing referals to using EA71 pistons and rods in an EA81 block and using the EA81 crank. What is the final outcome.? Do the pistons stick up above the deck of the block? Is there a chance of valve/piston "kissing". I am working on an SPFI engine using the EA81 platform. I want to get as close to the EA82 SPFI engine numbers as I can or maybe even exceeding them. I will lighten the flyswheel as well. I am using heads that have the EA82 intake valves installed in them and will be having Delta Cams, in Tacoma, grind a bump stick for me. When this is all done I am going to put it in my 1983 Red Wagon. I would play with a Turbo set up as well but that would mean that I would have to change my custom built exhaust. I do not want to do that. It flows too darned good to do that. Thanks for the input.

I have watched the board for a period of time. Every so often someone brings up the issue of using EA71 pistons and rods in an EA81 block and using an EA81 crank. What is the final outcome compression wise? Is it in the neighborhood of the SPFI engine? Do the pistons stick up above the deck? Is there a chance of piston/valve "kissing"? Since I am building an SPFI engine I was hoping to get as close to the EA82 SPFI engine in an EA81 configuration. I am foing to get Delta, in Tacoma to do a cam for me and when I am finished with the engine I am going to stuff it in my 1983 Red Wagon. I will probably have the flywheel lightened as well. I would play with a turbo, but then I would have to give up my "custom made exhaust system". I don't want to do that. It flows way too good to change to anything else. I will run a Weber setup on this current engine until I am finished gathering parts and information on the best method to build the SPFI engine. Thank you for all of the input.

Is it possible to interchange some of this stuff, such as the SPFI setup from a 1989 to include the wiring harness and use the ECU, Distributor and fuel pump from a 1985-86? Or is the an issue with the SPFI Injector being different?

I have just aquired the intake manifold with the wiring harness and all of the sensors for a SPFI setup. I know that I need the wiriing harness and ECM plus the fuel pump and presure regulator. It also uses a "crank sensor". Do I need to get the distributor and change the drive gear as well? Any tips would be appreciated. Thanks YEPABUS

What kind of jetting are you using in the primary and secondaries. What size imulsion tubes and air correction jets are you using in the primary and secondaries and what size idle fuel jets ate you using. Do you have an O2 sensor welding into yuour exhaust and a "stoich meter" (rich/lean meter) of some sort in your system for tunning? When I was running performance Datsuns I just read the spark plugs, but that was befor all this new fangled technology came on the scene. haha YEPABUS

I have read some posts that refer to the problem of coolant leaks under the Weber adapter plate, especially when doing the conversion on an EA82 engine or adapting an EA82 intake to an EA81 engine. This is how I solved it. I made another plate out of 16 guage aluminum which had "more meat". or was wider, over the area of the Hitachi Carburetor pre-heat pocket which is built into the manifold.(The open coolant hole) I then cut an additional gasket, to match the "thin adapter plate" and placed the gasket on the intake flange using some "fuel resistant RTV sealant" on both sides. I then placed my "thin adapter plate/water port sealer" on next. I then stacked the adapter plate mounting gaskets in the appropriate order with the adapter plate for the Weber being last, of course. The addition of the "extra sealing surface" of the 16 guage "adapter plate" addition and a gasket to match that plate used under the Weber adapter and the Weber Carb has solved the problem. I used the commercial 2 piece adapter plate set up because it gives a smoother fuel/air charge transition between the bottom of the carb butterflys and the bottom of the intake plenum, It also has the additon of more "shared fuel charge" which increases the bottom end torque. I will try to post some pictures of this whole set up, or I may solicit the help of calbez to do this. Notice in the pictures how sanitary the intake is. I removed all of the vacuum ports that aren't being used and had them TIG welded shut. You can pull all of those brass tubes with a pair of side cutters, just clamp onto them at the base and using a little preasure to bite into the tubing you can "lever them out". YEPABUS

Yes I too was, and still am if I let the urge hit me, Datsun Addict. I had a 510 which I modified for street racing. It was so hot that a man from Japan bought it from me and shipped it back to Japan to race in a special class. That was in 1985. I also built a 1200 Coupe and it too was also so quick that another man bought it from me in 1992 and took it back to Southern California to campaign Road Ralley's. I still have a complete collection of the orignial "Five and Dime" magazines and a copy of the complete suspension "blue printing" for the 1200 Coupe. I got into Subarus because they are 4wd and use the "boxer configuration" engine which I find to be a challenge for finding interchangeable parts, ala salvage yard, that can make them faster. There is a philsophy which states "with enough money and todays technology we can do anything". I am from the old school (I am in my 60's) that says study first and then create. This is a great board and I enjoy the idea interchanges. YEPABUS

A few days I posted a thread on head castings. In that posting I also included some information on Hitachi Carbs and their application to Datsuns. I concluded that the bolt pattern on the "Dastun Hitachi" and the Carburerted EA82 were one and the same. Today I made a trip to a local salvage yard and located a late '70's Datsun pick up with a Weber conversion on it. The Weber and the associated adapter plate cost me $25.00. I layed the adapter plate on the EA82 carb manifold and it was a perfect match. When I flipped the adapter plate over I noticed an indentation which may require either some aluminum welding and surfacing or maybe some JBweld and a file. I have looked at both the Weber adapter plate sold for the Subaru and the one sold for the Datsun "L" series engine. The Datsun is indeed "beefier" and in my opinion much easier to come by if you are a "salvage yard addict" like I am. The L series engines can be found in 1973-1982 Datsun P/U's and cars that are a model 510-610-710. A lot of these had Weber conversion done by their PO's. The old adage about work smart not hard also has some hidden messages about work smart and it may also be cheap.