B18 intake manifold

[shepherd79]

ok,
i am trying to figure out if B18 intake manifold will bolt on with some minor modifications.
I am going to rip my engine apart this summer, and i am trying to decide on what kind head to drop A20 or A18.
A18 head should support 2 mikuni bike carbs plus it should give me higher CR.
A20 head....... well it is another story.
So will B18A intake manifold fit on A20 head?
thanks.

[PhydeauX]

Yes the b18a/b intake manifold will fit. The b18c5 manifold will also work, but the b18c1 wont. Its basicaly the same process as a b16 manifold, but with one less hole to drill. I don't know if you've been able to find out for sure or not but last I checked no one could confirm if the a18 head fits the a20 block. If you do manage the a18 head you can also pick up a dual weber conversion kit for it from TWM (www.twminduction.com). Complete bolt on for this one, no fabrication required. The intake ports are smaller on the a18, I have no idea what it flows but I would expect it to need some porting to work as well as an a20.

andy

[shepherd79]

Andy, thanks for the reply.
I was talking to mike(A20a1), and he said it is posible to drop A18 head on A20 block.
here is the link he gave me http://www.cardomain.com/member_pages/view_page.pl?page_id=281725&make_type_query=type%3DENGNE&model_brand_query=brand%3DWEB&tree=Weber%20Engine%20Components)http://www.cardomain.com/member_pages/view_page.pl?page_id=281725&make_type_query=type%3DENGNE&model_brand_query=brand%3DWEB&tree=Weber%20Engine%20Components
he also said that the guy told him: "internal parts are ll the same between Accord and Prelude, if you wanted you could put the A18 head onto the A20 this will give you higher CR and also allow you to run the twinSU's or two twin choke Webers!! Your biggest problem on your car is the fuel system you need to loose that inlet manifold which is strangling the engine!! also a good headjob will work really well too!!"

[CARBurn]

Shepherd79:
That a18/a20 setup on that prelude is interesting.

Phydeaux:
I don't know if you have had a chance to look at a carbed JDM b18a but I'll ask this question any way, I am looking at getting this engine this summer but am wondering about the intake manifold. I would like to install some performance carbs. I have already been told that the carb manifold from an a18 will not fit and definitely a manifold from an a20 will not fit. I want to know what options I have. Having a manifold custom made to fit a set of carbs or is there a chance of modifying possibly an existing manifold made to fit a18?

[shepherd79]

wait a minute... so B18 intake manifold is diff., right?
Carburn, when you get B18 could you please take the picture of the intake manifold, and engine itself. we don't know much about this engine.

[PhydeauX]

CARBurn:
Sorry I've never seen one up close (assumeing your refering to the one that came in the 3rd gen accords in japan). I believe it was carrot who posted a pic of one a long time ago. It's got a pair of those kehin CV clone carbs on it like the dual carb preludes have. Those are easy enough to replaced with a pair of bike carbs, but as for swaping the whole manifold I'm not sure. It kinda surprises me that the flange is diferent. Just about all the bXXa series motors use the same port layout. My guess would have been that the manifold would be similar to the dual carbed b18a that was available in the integra.

andy

[CARBurn]

Shepherd:
Yeah, from what carot told me the manifold is different from the A18. I was hoping the manifold setup was simliar to the a18 because then I could use the same performanc carbs setup.

Once I purchase it in a few weeks(looking to begin this project in late june/early july), I will take some pictures but can I ask you to post them here since I am not a foundation member.

[CARBurn]

Phydeaux:
thanks for replying. I just want to be able to get a better set of carbs for performance. If I don't have to swap the manifold to accomplish this, that will be fine. If I need to just get a set of bike carbs then that would be better.

I'm trying to see what options I have in performance carbs because I was very satisified the weber/a20 combination in my 87 accord.

[shepherd79]

yeah i know that A18 head is diff when it comes to intake manifold. that is why i want to see if i can fit B18A intake manifold on A20. it should be easier in my opinion.

[CARBurn]

I think your right, but nobody has had the chance to make the comparison. Less is known about the b18a than the b20a. This should change. I think the b18a is a good upgrade for carbed accords.

[CARBurn]

Still thinking of possible intakes that can fit the JDM B18a. What about the B20a3 dual carb that came in the 3rd generation Preludes. Going from what Phydeaux said about the bXXa series motors, they should all have the same port layout. Well if the the dual carb from the a18a is not a match then the only other thing to try would be to see if the dual carb manifold from the b20a3 would fit. I know I need to go to a junkyard to find one to be sure. I found a b18a1 intake from an Integra in a junkyard that I want to take and see if it will bolt on the the JDM b18a.

One other question has anyone seen performance carb kits made for the b20a3 in the prelude?

[PhydeauX]

I overlooked one thing when I made that post. I was refering to the b18a that comes in the integra, not the jdm 3rd gen accord. You'll be asking for trouble with the 3rd gen lude carb manifold. The b20a3 leans the other way, when you put that manifold on an a20a its going to be pointing up quite a bit. Carbs normaly need to be stitting level to work properly, and they most likely arn't going to like that. I will make one note here. I saw a pick of a corolla on the net that had a pair of dcoe carbs stuck to the side of it that were mounted at a +30° angle (the manuals say +-5° is the limit). I emailed the guy about it and he said he didn't have any problems wiht the setup, just had to play with the floats a little bit.

andy

[CARBurn]

I see what your saying, pretty much like you said before if I want some performance carbs go with some bike carbs or have a custom made manifold using the flanges of the manifold that came with the JDM b18a.

I'll just have to get the motor and go from there.