okie bill Posted December 17, 2011 Share Posted December 17, 2011 I have a line on a new Weber which was purchased for a Beetle and never installed. May be free but benjamachine's thread re: high altitude, and skishop69's post about filling and drilling jets has me thinking. In the process of the weber conversion why not first try to improve the Hitachi? I crawled around under my 87 BRAT the other day and couldn't find the cat or the O2 sensor so I'm thinking my feedback circuit is already kaput. If I'm thinking right, pitching the feedback selenoids and about 10,000 vacuum lines will make it run rich, so I would need to do the same as benjamachine. Am I thinking right or do I have it backwards? Those Hitachie jets look like they might be removable with the carb still mounted. Are they? Has anyone tried converting from vacuum to manual secondary. Sorry for the long post Bill Quote Link to comment Share on other sites More sharing options...
Subarule Posted December 17, 2011 Share Posted December 17, 2011 I think "improve" and "Hitachi" are mutually exclusive terms. Quote Link to comment Share on other sites More sharing options...
Idasho Posted December 17, 2011 Share Posted December 17, 2011 yeah, just weber it. You wont regret it. Quote Link to comment Share on other sites More sharing options...
bonvo Posted December 17, 2011 Share Posted December 17, 2011 ive had my car since september and ive had to take my hitachi apart 3 times once to rebuils once you replace the base so that i got rid of vacume leaks and yesterday to clear out the power valve these carbs are junk they were from the factory same goes for my datsuns stock downdraft the weber improved everything on the datsun im expecting the same for the subaru Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted December 18, 2011 Share Posted December 18, 2011 The design of the Hitachi limits what can be done with it. In the first place it's very small - and you can't mechanically open the secondary without a huge flat spot because it has no means of properly transitioning. Even if you solved all it's issues and tuned it to the moon it would never be a progressive Weber - it's just too small. They also have a metering port system that's just silly and complicated. The feedback versions are best left with their ECU and sensors intact - they get better mileage that way and that's really all they are good for. The non feedback versions don't do any better than a properly tuned Weber so you might as well just pitch them in the trash. GD Quote Link to comment Share on other sites More sharing options...
Quidam Posted December 18, 2011 Share Posted December 18, 2011 Ha, I'll post a pic of the "Race Hitachi" tomorrow. Yea, I got a line on a new cheap Weber too. Buyers market these days. FYI, these Hitachis came in 26/30, 28/32, 32/34, and 34/38. Post is worthless without pics:) Doug Quote Link to comment Share on other sites More sharing options...
okie bill Posted December 18, 2011 Author Share Posted December 18, 2011 I'm still trying to figure out what I have, remember my motor came in a basket. I'm assuming a 306-XX, where the XX tells me more than the 306. My motor included reman heads which were painted a silver color. The carb is the same color, and the machined flat spot on the float bowl where I assume there should be some numbers has either been painted over or sonic cleaned. No numbers. Is the "race Hitachi" streetable, or does it just want to run flat out? I saw a post by an Aussie talking about a mechanical secondary. Is this a different Hitachi or just different linkage? A small carb is not much of a concern. Look at my age. I got past 1100 double pumpers some years ago. I guess I need a book. Any recommendations?? Oh, and I already have learned something. It's spelled Hitachi:D:D Bill Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted December 19, 2011 Share Posted December 19, 2011 306 means it's a 30mm secondary with a 26mm primary barrel. That is the factory size for an EA81. The fact that you want a progressive mechanical linkage for the secondary sugests that you are concerned with performance. Otherwise - why bother? The factory Hitachi's have vacuum operated secondaries and thus are not designed with proper enrichment for rapid WOT opening of the primary and secondary at the same time. If you mechanically link them and slam the pedal to the floor you will get a massive lean condition and the engine may just die. I'm sure that Hitachi has copied a number of good carb designs and that they have made race versions of stuff. Doesn't mean they are easy to find. or will easily bolt up. What IS easy to find and bolt up is the Weber DGV. Performance is more than adequate for a stock EA series engine and you can have a brand new one up and running for less than $300. A new-from-Subaru factory EA Hitachi carb is in the $500+ range. The Weber is a bargain and completely adequate and 100% tuneable. There is no reason to try and mess with the factory carb. They are old, needlessly complex, and full of gotcha's when it comes to trying to tune them. GD Quote Link to comment Share on other sites More sharing options...
bonvo Posted December 19, 2011 Share Posted December 19, 2011 i dont know about the later carbs but my 79 has mechanical secondaries i know datsun used vacuum secondaries and it sucked either way ive messed with 2 hitachis and hated them both there downdrafts are meant for smog and mileage so they suck for performance and drivability Quote Link to comment Share on other sites More sharing options...
Quidam Posted December 19, 2011 Share Posted December 19, 2011 Ha, I'll post a pic of the "Race Hitachi" tomorrow. Yea, I got a line on a new cheap Weber too. Buyers market these days. FYI, these Hitachis came in 26/30, 28/32, 32/34, and 34/38. Post is worthless without pics:) Doug Ok, here it is. 28/32 Hitachi. It's not finished and won't be ran on and engine untill next year. Rejetted of course, power valve mods, primary and secondary venturi mods, and I'm going to install a manual choke. It has no choke in it now hence, the Race Hitachi name. I can swap the tops on and off as needed. It has mechanical secondary wired up in this picture. But theory don't mean squat if it doesn't work. I'm aware of other people's attempts at mechanical secondary on this carb and I'm positive I can make it work. Exactly how I'll know sometime in the future. How have you done mechanical secondary on this carb? Or how would you do it? It has a bread tie on it now:popcorn: Doug Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted December 19, 2011 Share Posted December 19, 2011 A prettied-up EA82 Hitachi (That's a DCZ-328 variant) with no choke that's had a bunch of untried modifications done to it? That's your offering? What a joke. P.O.S. GD Quote Link to comment Share on other sites More sharing options...
Quidam Posted December 19, 2011 Share Posted December 19, 2011 Oh, I'm going to modify that yellow 1/4 inch socket driver to fit the Hitachi Jets. It fits through the access holes for the jets well and I'll grind/file/epoxy it to fit. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted December 19, 2011 Share Posted December 19, 2011 Why don't you get back to this thread when you have actually ran that thing? In the meantime your *speculation* really is of no use to this thread. And I'm pretty sure the original poster doesn't want to do that much uneccesary work - a Weber will do everything that Hitachi will do and won't require any "mods" to do it. A bread tie wrapped around the linkage to make it function as a mechanical linkage is silly - besides that it's been tried by me and others (years ago). Without a lot of modifications it's just not viable. They don't like rapid throttle openeing when you run them like that. GD Quote Link to comment Share on other sites More sharing options...
okie bill Posted December 19, 2011 Author Share Posted December 19, 2011 As we say around here "Y'all please don't get in a pissin' contest." I am enjoying both sides of this conversation. Please review the first sentence in this thread. My planned 1st step in improving my Hitachi is to replace it with a Weber:brow: Now according to Bonvo and Dirk in Bonvo's adapter thread over in the historic section, at least some EA61's and EA71's came with 306's with mechanical linkages. Dirk I'm sorry I called you an Aussie Bill Quote Link to comment Share on other sites More sharing options...
Quidam Posted December 19, 2011 Share Posted December 19, 2011 ""Y'all please don't get in a pissin' contest." " FYI, GD is blocked and I don't see a thing he writes. He knows why and it's peacfull since I put him on the Ignore list. Doug Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted December 19, 2011 Share Posted December 19, 2011 I don't reply with the intention of Quidam reading or liking what I have to say. As in any good debate - it will be up to the crowd to pick a winner. Thus he doesn't need to read anything that I post. In fact that just means he can't refute anything I say. But I suspect he still reads them anyway. In a debate - the goal is not to try and convince the other side - it's to convice the audience. The only reason he doesn't like my posts is because I'm one of the most outspoken about the pitfalls of the EA82 Turbo. Which virtually no one around here likes but him. Sure - I'm loud about it - but nearly everyone on this board feels the same way. GD Quote Link to comment Share on other sites More sharing options...
benjamachine Posted December 19, 2011 Share Posted December 19, 2011 ok, the hitachi is a bit stodgy, but it does turn in good fuel economy numbers, and it works ok (not great, but ok). i had mine rebuilt a couple of years ago, and it gives me between 29 and 32 mpg on the freeway, depending upon altitude, road conditions, and fuel type (some locales use higher concentrations of ethanol, which is not a very efficient fuel). with stock wheels and tires, would a weber give even close to the same gas mileage? Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted December 20, 2011 Share Posted December 20, 2011 ok, the hitachi is a bit stodgy, but it does turn in good fuel economy numbers, and it works ok (not great, but ok). i had mine rebuilt a couple of years ago, and it gives me between 29 and 32 mpg on the freeway, depending upon altitude, road conditions, and fuel type (some locales use higher concentrations of ethanol, which is not a very efficient fuel). with stock wheels and tires, would a weber give even close to the same gas mileage? Yes - if you tune it right and you pay attention to all the other factors that affect fuel economy. The feedback Hitachi can best the Weber by a couple MPG. A non-feedback is almost identical to a properly setup Weber. I have one on my EA81 4WD hatch and I've had a lot of Hitachi's and a lot of Weber's over the years. My fuel economy didn't change a bit going from the non-feedback Hitachi to the Weber. I get about 27 give or take .5 in town and I get 31 on freeway trips - give or take .5. And this is on an EA81 with 140 psi on three cylinders and 110 on the #2. I know a board member that has a FULLY functional (new from Subaru) EA81 feedback Hitachi on an excellent condition engine. He gets 32 to 34 MPG most of the time. But it takes a special kind of insanity to maintain the feedback system and making it run right past 300k miles (last I heard it was around 325k on it) involved buying a new carb at nearly $600 a few years ago. GD Quote Link to comment Share on other sites More sharing options...
okie bill Posted December 21, 2011 Author Share Posted December 21, 2011 One question, then I will let this die a natural death. How does a Hitachi carb "wear out"? What goes away that can't be rebuilt? Just curious. Bill Quote Link to comment Share on other sites More sharing options...
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