dual carb conversion?

[lostforawhile]

does anybody know if the dual carb 88 lude manifold bolts up to our block? I don't believe it's cvcc due to the fact the intake and exaust are cross flow. I don't care about the crappy keihin carbs,thats an even worse bowl of troubled spaghetti then what I have now. I was thinking of setting up a couple of honda bike carbs as duals on that manifold. remember I have the use of a machine shop and access to aircraft grade aluminum. that makes making adaptors,linkages etc. relativily straight forward. any input on this would be appreciated. or if anyone else has done bike carb conversions before. not even sure what particular carbs to look for yet as this is in the idea stage. this idiotic keikin POS is about to drive me nuts. If I didn't have to drive this car everyday,I know where there is a pair of SU carbs on an old MG,I enjoy tinkering with those type of carbs and still remember how to rebuild them with my eyes closed,but they are some of the most unreliable carbs ever made. if I was driving this car for fun it wouldn't bother me to have to stop on the side of the road and tear into a carb,but not on a daily basis. on this same subject does anybody remember if the old alfa's had webbers stock? there is one here in the yard also and it would be sweet to open the hood and see dual sidedraft webbers. they are closed until monday though

[A20A1]

the head + manifold will.

well hrm... the SOHC lude, not the DOHC.

[lostforawhile]

so what is the issue with the manifold fitting on our head? is it the bolt pattern or what? I think this is the single overhead cam. I'm going to consult my chiltons honda manual also. so you are saying the single overhead cam one can be swapped out? if it will work will be a good time to get some cyl head work done

[Vanilla Sky]

mounts differently. go DCOE. i'm sure you can get a manifold made since you have a machine shop available.

[rustlude87]

the 88 has a b20a3 which won't fit on the A20a3, your better off doing webers

[lostforawhile]

didn't some of the preludes have the a20 with the dual keihin sidedrafts? this is def not a dual overhead cam motor the valve cover is way too small. I've got a pic somewhere let me see if i can find it. I wondr if it's a late 87 model.

[lostforawhile]

here are a couple of pictures of it,maby someone can identify exactly what I've got. i hope this manifold might fit,it would give me the option to do something completly different.

[snoopyloopy]

b20a3 was sohc. that's the b20a3.

[stat1K]

definitely looks like an a20 just with a different valve cover. which isn't that strange. but it definitely looks like an a20 but the car doesn't appear to be the right year, it looks like an 88-91 at least the bumper and the headlight buckets do. but i don't think the lude came with any other variant of engine other than the b20 a20 and b18 but the b18 was still dohc if i'm not mistaken. definitely a strange one! try it though!

edit:
after snoopys comment i looked it up and sure enough.
huh! i've never seen a sohc b20 that's so weird looks just like an a20 minus the valve cover... it definitely is tilted back like all b series... so weird.

[Vanilla Sky]

like i said, don't bother. you'd have to correct the angle on that manifold so the carb operates correctly. by the time you've done that and machined the manifold to fit, you've built your inlet manifold. toss a set of DCOEs on there and be happy with your newly gained 25 HP (most likely a gross overestimate).

[2ndGenGuy]

That's probably not an A20. It leans backwards. The A20 leans forwards 15 degrees.

[shepherd79]

even if you find A18 dual carb engine from 86-87 prelude, you still have to swap the head with intake manifold. the reason, a18 and a20 heads have diff intake manifold bolt pattern. By going with A18 head you can increase your compression a little too.

[lostforawhile]

even if you find A18 dual carb engine from 86-87 prelude, you still have to swap the head with intake manifold. the reason, a18 and a20 heads have diff intake manifold bolt pattern. By going with A18 head you can increase your compression a little too.

so it will just bolt up? no major engine mods needed? I'm going to start working on another engine soon anyway so I could just get this head rebuilt. then I would be able to fit up the dual carbs on the head off of the car. all I would need to do is figure out the angle the head sits on the a20 then build a stand for the head to make sure the carbs are level. what about the exaust manifold? is the bolt pattern the same? or do I need to get the manifold also? also with the prelude head are there more options for headers? it's actually a pretty good idea. I think fitting a set of honda bike carbs would work pretty well. I may have a little bit of a problem off of choke but they are really easy to work on and more options for tuning. I just have to figure out what cc bike and divide by half for two carbs.

[shepherd79]

boy you have a lot of researching to do.
where should i start.
well, 86-87 prelude has two keihin carbs. They are like bike carbs but only two. the stock ones are very small. i hope you upgrade them with something better.
the cylinder head from A18 will bolt up to A20 block without any problems. You may want to check on the size of the valves and the size of the ports. the reason i am saying that is because they may be a little smaller than A20 head, but i could be wrong.
You can use regular A20 manifold. It will bolt up without any problems. they are no other options for headers since A18 and A20 share the same header bolt pattern.
If you are going to upgrade the carbs go with 45mm at least. get the biggest you can find. Remember, they are going to be working twice as hard as if you had 4 bike carbs.

PS. there are pictures of people running 4 bike carbs on A20 montors without any problems. you will make intake manifold the same way as if you had 4 individual throttle bodies.

[lostforawhile]

boy you have a lot of researching to do.
where should i start.
well, 86-87 prelude has two keihin carbs. They are like bike carbs but only two. the stock ones are very small. i hope you upgrade them with something better.
the cylinder head from A18 will bolt up to A20 block without any problems. You may want to check on the size of the valves and the size of the ports. the reason i am saying that is because they may be a little smaller than A20 head, but i could be wrong.
You can use regular A20 manifold. It will bolt up without any problems. they are no other options for headers since A18 and A20 share the same header bolt pattern.
If you are going to upgrade the carbs go with 45mm at least. get the biggest you can find. Remember, they are going to be working twice as hard as if you had 4 bike carbs.
PS. there are pictures of people running 4 bike carbs on A20 montors without any problems. you will make intake manifold the same way as if you had 4 individual throttle bodies.

yea the stock keihin carbs and nightmare control system are going in the trash,I just want the cyl head and intake manifolds,with the dual intake manifolds I have the option to run the dual sidedrafts. I work in a machine shop so I can make any modifications to the manifolds I need to or make any adaptors needed. there is no way in the world I would even attempt to hook up that factory dual carb system and controls again,thats the factory carb spaghetti mess X 2. any suggestions on particular sidedrafts that would work well with this system? they have that Alfa romaeo out there in the yard,it would be nice to find it has dual webbers on it. good place to start. I haven't had the chance to look at it yet. it's an older convertible,possibly from the seventies,they came factory with that crazy mechanical fuel injection system,but it was so much trouble that a lot of them were converted to dual sidedraft webbers. there are also a couple of MGs out there, it was popular to convert them from dual side draft Sus to webber. lets hope they were

[shepherd79]

since you work at mashine shop, why don't you keep A20 head and make intake manifold to run DCOE carbs.
run two 40 or 45 mm sidedrafters and you will be a lot better off than some bike carbs.

[lostforawhile]

well I could do that,but if the a18 head is good,being on a lude of that generation I would assume the valves are probably the same,why not get that head rebuilt and use the existing manifolds? I need to get a head rebuilt anyway since i'm going to be building another motor. it's only 150 bucks if I have the core. parkers machine shop here has been rebuilding motors for 50 years and do excellent work. I'm not rushing this project,i'm going to be building this motor over a period of time. thats why it's in r&d I will keep updating this project as it progresses. I really hope one of those brittish cars has a set of webbers already on it. It doesn't bother me to rebuild them,i have a good source for parts already. I also have a friend with an mg thats been under a collapsed barn for years and years. he said it might have had dual webber sidedrafts on it.

[Vanilla Sky]

tim, here's a tip. if you even hear the word "weber" and "sidedraught" in the same sentence, go right then and grab them. DCOE series carbs are worth about $50 for the body only on ebay.

[lostforawhile]

best place i know of is pierce manifolds,they have everything webber available.
motivation:

darn,just drooled on my keyboard

[Vanilla Sky]

tim, sign onto AIM.

[lostforawhile]

tim, sign onto AIM.

I can't everytime I sign on to aim my computer crashes,I will pm you if you want to give me a hollar on the phone,I talked to the tech guy at pierce manifolds today,he said they have another carb that is very popular,it's the OER brand,these are sidedrafts just like the webber,they even use webber jets etc. but they are japanese sidedrafts.so you can put a set on a lot cheaper then the webbers and use webber parts to tune them. they will even set up a set in tune however you specify when you order.

[lostforawhile]

well the car with the manifolds is an 88,it is a single overhead cam though. I looked it up on the majestic honda site and it's def an 88. wierd. so will the dual carb manifold fit the a20 head or will the lude head fit the a20 block? this changes everything

[shepherd79]

that year head will not fit accord block. i just said that a few post up..
You need 86 or 87 year prelude.

[cygnus x-1]

This might help. Here are some pics of my A18 (1.8L) carbs, intake, and head from an 87 Prelude:

http://bluegreenlabs.com/Prelude/A18/A18Carbs.jpg
http://bluegreenlabs.com/Prelude/A18/A18CarbsBottom.jpg
http://bluegreenlabs.com/Prelude/A18...take-Carbs.jpg
http://bluegreenlabs.com/Prelude/A18...take-Ports.jpg
http://bluegreenlabs.com/Prelude/A18/A18Head.jpg

Now while you might be able to modify this intake for Webers I think it would be faster and easier to build one from scratch. Webers have 2 barrels per carb and the stock carbs (and intake) only have one, so it will take a serious amount of hacking to get them to fit up. The stock intake also has water passages that will probably get in the way.

The A18 head has an advantage of smaller ports for more velocity but the ports are not centered to the combustion chambers. So one valve tends to flow better han the other, and in fact on mine the far valve has a lot more crud buildup than the closer valve. The valves are the same size as an A20 head. This head will fit an A20 block and so will an A20 head fit an A18 block. (I just had my A18 block bored to the stock A20 size and bolted an A20 head to it, so I know it fits.)

C|

[Civic Accord Honda]

whay not do a EFI SAwp wouldent efi = more powe then a carb ?