Eb1 bore to 74mm?
Civic1200 Discussion Board: : Eb1 bore to 74mm?
You THINK??? Sorry but I cant tell you how much money I have wasted going by what people think... thats why its so important to KNOW before posting as you may cause allot of grief. Most likely your displacement increase (if any) was the result of a en1 crank not a massive overbore.
You THINK??? Sorry but I cant tell you how much money I have wasted going by what people think... thats why its so important to KNOW before posting as you may cause allot of grief. Most likely your displacement increase (if any) was the result of a en1 crank not a massive overbore.
You THINK??? Sorry but I cant tell you how much money I have wasted going by what people think... thats why its so important to KNOW before posting as you may cause allot of grief. Most likely your displacement increase (if any) was the result of a en1 crank not a massive overbore.
I dont know what measurement... but i think my EB1 block has been bored out from 1180-1390cc ;)
OK, once again I will say that mine was a street car, I did not autocross it, and in my city you can only get "sideways" to a limited degree without risking a skyrocketting insurance premium. Believe it , or don't believe it, I have smoked many cars with it that you wouldn't have expected, but then again most drivers never put their resolve to the test on the street, so it is always a matter of who backs down first, not necessarily which car is the fastest. I gotta believe you guys put too much faith in headers giving you so much power...especially on the street where most of the driving is low to midrange RPM. Once again I point to the current RSX, and the relatively small diameter pipe used by Honda on a 200HP motor. The main reason I went back to the modified stock manifold was after four Missouri winters, and several bumps with assorted concrete obstructions the Header, to ME, simply wasn't worth the hassle. I definitely felt more bottom end torque with the stock manifold, and the time I spent at 4,000RPM or above didn't warrant a new header every few years. I now have an RS manifold so the next time around I will use it. Regarding the DGV series, I have been running them on various cars for around 20YRS and have had almost no problems with reliability. That is what counts to me, the few times I have dealt with fuel starvation usually meant the loose crap went flying off of the dashboard at the same time, a sign to me to "be cool". Once again I do not autocross the car. All the considerations of which you speak ,Don, and by the way I know you are quite knowledgeable, and I respect your position, are largely problems that only surface in conditions beyond what most people would consider to be "street use".
Give me a break! If you did not notice much of an improvement with a real header then that should be your first clue 
. "85-90" through a stock eb3 smog manifold is a dream, and if that target is reached the engine will be very much improved as soon as the jetting is changed and header is added.
The info given below wasnt Improved touring or High RPM race only. Ask Ted or others about the DGV... even for street use! If you think the DGV carb is OK then you never really pushed it in corners. Bigger brakes are nice but Porterfield pads can be used on stock brake setups with great results even when used in competition.
While I do belive your combo produced results better than stock a few changes could have produced a much better combo.
Hi guys,
Just thought I'd add another 2 cents worth into this thread...and I don't want to contradict anyone needlessly either. Lots of good advice, but some of it is for high HP "racing" uses, and some of it is for what I would call "improved Touring" purposes. I will state my own personal experiance, in that an EB3 block and head, with 72.5mm Goldwing pistons, 1300 EJ(EN) crank and rods, mild port job, A/T "A" cam grind, and 32/36 DGEV on an A/T custom downdraft manifold yielded for me between 85-90HP. It would easity rev beyond 7000RPM, though I almost never went beyond 6000 as it was not necessary. I put 70,000+ miles on this motor,(the car rusted out beneath it). It averaged 27 MPG in town and on a steady highway trip with the 5-sd, mostly running 75-80 MPH, yielded an average 38.5 MPG. I was never able to jet the weber in tight enough to bump up the in town mileage, but I always felt it should get over 30MPG if you mostly kept your foot out of it. I also felt the highway mileage could go over 40 MPG, but the carb refused to cooperate. I would normally rev to 3000-3500 RPM as a shift point, as with the 1300 crank that was all that was necessary to keep up with traffic. I also was running a stock exhaust manifold with the USA spec air injection ports plugged.
As a side note, the car I had before that one had an A/T header on it, and after smacking it a few times on different objects, and noticeing a loss of bottom end torque, decided it was not worth the trouble on the street. An RS manifold however I do believe is a good compromise, and worth the trouble to find.
Back to the carbie, as I noted in an earlier post a 32/32DGV or DGEV on a stock manifold modified as Kyle noted above is a better match for all around fuel economy and power in balance, the larger secondary barrel is not necessary on the street, and always seems to tend to run too rich.
Honda never recommended boring beyond .5mm on the EB blocks, 73mm(a full mm) was always considered safe by most everyone, but beyond that one IS running on the ragged edge, though some have done it and claimed to have no problems. I have thought about doing it too, but it is a risk and it junks the block for further use.
Is the oil cooler necessary? A/T Engineering always thought so on a modified motor, and anyway you look at it an extra quart of oil or so capacity IS extra insurance, let alone the lowered running oil temperature. The Air Cond. adds a lot of stress and heat into the equation too, so I'd say it is a wise precaution.
Oh, and I would say you should add bigger brakes as well, the stock ones are barely up to a stock motor as it is.
Thanks guys.
Kyle, I also have that picture stuck in my head for a while and remembered as "someone has made his own down adapter and it looks a lot easier than fabricating your own dual side draught manifold like the other guy". Still, my retired - bored mechanic/machinist friend reckons that he can make it me. What would be the recomended thickness of the adaptor?
John S, is oil cooler esential? I'm planing on up grading my radiator, will that somehow help cool down the oil as well?
Thanks for covering that for me Kyle. I had a brain fart.
Kyle Thomson (no P) here on the board didn't do his custom, he just modified the adapter he bought at Oversea's Auto cause it was crap =)
Whoever designed it must have been drinking at the time, the secondary chamber of the carb was about 1/3 blocked by the adapter, so I spent a good amount of time with a die grinder and a flap wheel, reshaping the manifold and adapter to the largest and least restrictive size I could. Its not perfect, but its a heck of a lot easier than trying to make my own.
I have a pic of it here: http://66.183.190.188:8080/civic77/cars/lg_P1010006.JPG
If you're going to use 1200 rods with a 1300 crank you MUST use custom pistons. Any others will have the pin too low in the piston and they'll stick out the top of the block at least 3mm and very few pistons will have enough meat on them to allow you to skim 3mm off their crowns.
EN crank and rods, EB2 pistons, EB1 or 2 head is a combo that will give a good strong motor with fairly high CR (I wouldn't run it on regular unleaded).
Personally I wouldn't go to 74mm, especially for a road car. An EB1 out to 72 or 72.5mm will be plenty strong enough with an EN crank/rods in it and it should be reliable.
well, check out this link http://www.1stgencivic.com/phpgdv2/hpower.php?c=6
I respect Don's knowledge, and his article here is really good (look under carbs by Don)
I don't know if it's better or not...just different. From reading some of Ted's info as well he had issue's with his weber on hard cornering, the carb couldn't handle it, he went dual. But he had that sucker on 3 wheels to , so I mean hard cornering
So dual carbs may be better for your application. However the cost is dramatic, and after reading the information I have, 32/36's get great review's, and really work well.
I am no expert, I'm not a preofessional. I'm a regular guy with a couple civics....you need to do what you want...I was bent on getting duals, they look cool and everyone talks about them. But after reading a bit, I changed my ways.
Nathan, I always throught the duel carb setup was better than one 32/36. I have a single 32/36 with an adapter to keep it from leaning out in the turns. I was thinking of switching to a duel sidedraft. Do you think I should just stick with what I have?
no, there is a local store here in Vancouver Canada that has reconditioned webers and adaptors of all kinds. I could price one and ship it to you for what it cost's me? -let me know...
Your dollar is a bit stronger so it may not be bad...I'll check it out (click my name for my e-mail)
I think Kyle Thompson here on the board did his custom?? He could maybe help you out, he's a good guy.
-Cheers.
Don't forget to have the flywheel lightened and the entire rotating assembally balanced.
I'd recommend boring your block to 72 mm, using the eb2 head putting in a 1300 crank 1200 rods. The 1300 crank will give you higher compression, how much I'm not sure. The 1200 rods will give you a better rod ratio and you can rev it higher.
Now, all you have to do is figure out what pistons you want. Custom pistons are not any more expensive than OEM pistons and you can have them made to give you whatever CR you want. Or you could possibly use goldwing pistons. or maybe even stock pistons.
Then hot intake, cam, headers, exhaust and you could be bumping 100hp.
Nathan, I was going to use EN1 top only if I use 73mm or 74mm pistons. If I bore to 72mm then I'd use EB2. By the way, did you purchase a kit or fabricate the Weber adapter yourself?
Lazaruk, I live in Australia mate, so shipping here would kill me.
Do'nt know if you'd be interested but i have a brand ne eb1 that came shipped into the States and is in perfect condtion. Still on the crate and had the stickers on it. been in a barn for 30yrs.
Jerry
o you cannot get more origianal then that.
a single 32/36 is better than dual carb setup....but by no means does it save fuel. It's more use of fuel, dispertion and burn ability...so fuel use efficiency is very good with a 32/36 DGV.
I don't know if an EN head on an EB1 block will do much, it may decrease compression??
I'm stickin to my EB1 RS piston, EB3 head, new cam, and weber (or dual dellorto's), header combo for best bet recommendation (basically an RS 75 HP) .... but good luck with your build
I forget to mention that I don't my mind using/purchasing EB2 or EN1 head. I was the second highest bidder on 1983 Civic twice (it went for around AU$550 - for the whole car). I already bought a 32/36 DGV (AU$60) and also trying to get a 32/36 DGAV to see the different and for the auto choke. As for header - I'm still looking for one but seems like I'd have to do the " 2 inch EN1 exhaust bore " like some one did instead or at least for now. What I'm trying to say is that I don't mind forking out the money to buy the parts (at the right price of course ;-) But I just want to keep its original engine block and its original serial number with the car.
So at this point I'm thinking 73mm piston(If I can find them)with EN1 top. Or 72mm piston with EB2 top (from an EB2 or EN1). (Both with EN1 crank and rod) How do they sound? Would Weber Carbie improve fuel conpumption as well, really? I thought that Weber was for people that want power and don't worry about fuel economy. But that is a big plus!
Don, once again good point. I am currently doing a rebuild of an EB2. Through reading and listening and assessing what I want in the end, the answer is sometimes easier, same amount of money and work, just different area's.
Building a compression horse is tough on an engine...you have to think about a lot of parts to do it right. Otherwise you will be tearing it apart every week, for new bearings, blown rings, head bolts, gaskets, valves...not to mention custom pieces on top of all that.
Why not consider these EB1 RS pistons http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&rd=1,1&item=4558208282&sspagename=STRK%3AMEWA%3AIT with new rings and complete engine rebuild kit, to keep what compression is there, really strong. Drop a cam, run a good (i'd say 32/36 Weber for better fuel consumption) and get a really good header and exhaust system. It'll be reliable, simple, clean and relativly inexpensive.
Or it sounds like you have an EN1 or want to use an EN1....swap it in the car and chuck a EB3 head and weber on it, same thing with a header and exhaust...you'll fly and it'll probably be less headach's in the end.
I am also new at all this as well...so I may be off on some things, pardon my ignorance. But I have read a lot and talked to guy's like Don, Adrian, Ted, Justin, Kyle and more....and they really helped me understand what to do, to get what I want outta the car without opening my wallet and saying here...then spending everyday under it. I know it's exciting, but relax and take it slow, do it right, especially if this is a gift for your girlfriend or wife....let her have fun in a reliable car
Best of luck, keep us informed
If your sucking through a stock intake and exhaust manifolds even if modified, why bother even increasing displacement? Those items are big restrictions with 1200 CC’s let alone bigger cubic inches!!! One thing needs to be made crystal clear increasing displacement CAN decrease HP if the other systems are not up to task. Paper thin cylinder walls can hurt HP and reliability. From my perspective your both barking up the wrong tree
If your after torque to pull the AC then a 1300 crank can help but the bigger engine will run out of breath sooner than its little brother if the other areas of the engine are not given some serious redesigning.
Thanks a lot John. Could anyone please give me the cylinder's outside diameter on an EB2 and EN1.
OK,
I'd use the early block, but bore to "stock" 72mm,(EB2),this leaves you plenty of room for later overboring, you can sometimes find the standard size 72mm pistons CHEAP, as how many people can use them? Then find an EN1 crank and rods...this will get you the biggest bang for your bucks, and then use an EB3 big valve head with the matching EB3 slight dome pistons. A mild cam grind, mild port clean up on the head and a 5 angle cut on the valves and a Weber 32/32DGEV carbie. You might even want to send the stock exhaust manifold out to be Extrude honed...short of finding an RS manifold. You WILL be suprized at how strong it would be, matched with the right 5-speed it can get amazing economy and run on standard octane as well.
Look up "DR Zoom" website and under the cars look for the pictures of "Beastie" to see what this setup would look like.
Oh and, the Goldwing pistons only yield about 9:1 compression with an EB3 head, and are too much for an EB2 head on pump gas, so it is not worth the extra money...even if you can find them. I don't think you will have much trouble pulling an air cond setup with such a motor, but I'd sure add an oil cooler as well, they really need one in stock condition anyway.
Well looks like your on your own then.... give it a try and let us know.
Well this 1974 car and its engine are the same age as my wife so somehow I feel it's important to keep the original engine. This 1170cc car come with factory aircon which is quite funy since it's already struggling to go up hill. Yet the previous owner had a tow bar fitted! I'll restore this car - respray it, increase its power, up grade to 5 speed and give it to my wife as a birthday present(if not this September will be next) Since its my first project car ;-)
Also it's harder to fine 73mm pistons (Goldwing) than 74mm (Suzuki Switf or EL Accord) here in Australia.
Why not just save the original block and use a newer block? I have a spare eb3 block that I can sell. I may even have a 1300 crank to go in it too.
I know that there are people who've done it on EN1 but I have not yet come across anyone who's done it on EB1.
Is it possible to bore an eb1 engine block to 74mm? I'd like to keep the original 30 year old engine but want more power to use the aircon.