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-   -   b18b1 vs b18a1 (https://honda-tech.com/forums/tech-misc-15/b18b1-vs-b18a1-1367808/)

tobe1424 Sep 11, 2005 08:21 AM

b18b1 vs b18a1
 
what the difference btwn the b18b1 block and b18a1 block...would the a1 accept a hydrolic tranny or the b18b1 head...im going to build it but i find more a1's than b1's so im i need a reply asap..thanx

SLR ef9 Sep 11, 2005 08:29 AM

Re: b18b1 vs b18a1 (tobe1424)
 
only thing that i think is different is the years b18a is 90-93 ls and b18b is 94-up ls motor.

tobe1424 Sep 11, 2005 08:34 AM

Re: b18b1 vs b18a1 (SLR ef9)
 
so u think or you know the only thing different is the year....everything else is interchangable?

mmuller Sep 11, 2005 08:49 AM

Re: b18b1 vs b18a1 (tobe1424)
 
everything is interchangeable, differences are subtle ( some wiring, fan switch is in a different loc. and some other little crap)

but yeah, tranny, head, etc. can be interchanged

BLUE EH3 Sep 12, 2005 05:25 PM

Re: b18b1 vs b18a1 (mmuller)
 
the bigger diff is the intake mainfold. and the the tranny.. and i think the header is lil small too

tobe1424 Sep 13, 2005 09:21 AM

Re: b18b1 vs b18a1 (BLUE EH3)
 
well in the junk yard and all i can find is a1's and ima build it anyways so i really was just wondering if everything from a b1 fits on the a1

sir2sol Sep 13, 2005 10:37 PM

Re: b18b1 vs b18a1 (tobe1424)
 
the a1 and the b1 are fairly much the same the a1's just older than the b1, a few simple things might be different, but nothing should be too much different.

tobe1424 Sep 23, 2005 10:09 AM

Re: b18b1 vs b18a1 (sir2sol)
 
so i can put on a b18b head on with out worrying about tapping any holes or nothing?

mmuller Sep 23, 2005 11:01 AM

Re: b18b1 vs b18a1 (tobe1424)
 
bolts right in.

tobe1424 Sep 26, 2005 09:48 AM

Re: b18b1 vs b18a1 (mmuller)
 
another quik question...how can i distinguish a b1 head from an a1 head...is there any serial numbers or codes around it

mmuller Sep 26, 2005 10:05 AM

Re: b18b1 vs b18a1 (tobe1424)
 
you can just look at the year by the exhaust manifold

tobe1424 Sep 27, 2005 05:53 AM

Re: b18b1 vs b18a1 (mmuller)
 
is it near the ports of the head or the actualy stock exhaust manifold

lileghatch Mar 5, 2009 12:56 PM

Re: b18b1 vs b18a1
 
I got a b18a1 and its the excat same u can build an a1 the same way u can build a b1 there is no differnce besides obd0 and obd1 so an a1 can make the same whp as a b1

K7-1Ktrevor Mar 5, 2009 01:51 PM

Re: b18b1 vs b18a1
 
the a1 also has the breather box in the back of it that the b1 doesn't, so if your going hi performance with it its a better block to have because of less crank case pressure issues.

fireblaze2k1 Mar 9, 2009 12:28 PM

Re: b18b1 vs b18a1
 
Yeah but the B1 flows better. 10-12 hp more than the 90-91 a1. The 92-93 a1 wouldn't be to bad to work on, but the b18b1 head is the one I'm looking for to put on my b18a1.

ltrkstr2k Mar 10, 2009 04:37 PM

Re: b18b1 vs b18a1
 

Originally Posted by K7-1Ktrevor (Post 37659481)
the a1 also has the breather box in the back of it that the b1 doesn't, so if your going hi performance with it its a better block to have because of less crank case pressure issues.

my b1 has the black breather box its on all bseries motors

all4show97 Apr 8, 2009 08:16 PM

Re: b18b1 vs b18a1
 

Originally Posted by ltrkstr2k (Post 37721540)
my b1 has the black breather box its on all bseries motors

X2 im swapping a b1 for an a1 as we speak. the b1 has the breather box. there are a few differences like on the back of the block the b1 has a plug next to the oil pressure senor and the a1 has a sensor which im not sure what it is yet. also there is an extra nipple on the thermostat housing on the a1. other than that and the cams they are exactly the same

kyden Apr 9, 2009 04:33 AM

Re: b18b1 vs b18a1
 
94-95 b18b's have the breather box. 96+ do not.

V8 Eater Apr 11, 2009 12:35 AM

Re: b18b1 vs b18a1
 
the b18a has a cable tranny,a breather box,an fitv(fast idle valve) and its 12 hp weaker due to its different style intake and exhaust manifold,its ecu mapping,its cams. the b18a and newer b18b do also have different valve covers aswell

crxsirvtec Apr 11, 2009 03:47 AM

Re: b18b1 vs b18a1
 
i belive the B1 has stronger webbing around the cyls..

and some sensors will be in different locations


b1 = 140hp
a1 = 130hp

Kelvin Racing Apr 11, 2009 04:27 AM

Re: b18b1 vs b18a1
 
Yeah we had some trouble because my 2000 b18b1 had a crank sensor and the my older b18b1 block did not. So more work ended up being done then planned.

If you plan on putting an aftermarket ecu on the car then don't worry about this.

slowsedan Jun 18, 2010 01:08 PM

Re: b18b1 vs b18a1
 
i have a 2001 grs head. could i put that on a a1?

v.ice1 Jun 18, 2010 01:58 PM

Re: b18b1 vs b18a1
 
yeah u can but that then becomes ls/vtec and have to tap a few holes and do a little work on head and block so it can be "relaible"

aubrwy123123 Apr 22, 2022 08:09 AM

Re: b18b1 vs b18a1 (BLUE EH3)
 

Originally Posted by tobe1424 (Post 17523433)
well in the junk yard and all i can find is a1's and ima build it anyways so i really was just wondering if everything from a b1 fits on the a1

let me know how your build went. How much horse did you get out of it

Htxstevooo Apr 20, 2025 02:24 PM

Re: b18b1 vs b18a1
 

Originally Posted by Kelvin Racing (Post 38127878)
Yeah we had some trouble because my 2000 b18b1 had a crank sensor and the my older b18b1 block did not. So more work ended up being done then planned.

If you plan on putting an aftermarket ecu on the car then don't worry about this.

how did you get it to work ? I’m running obd1 I believe my b18b1 had crank sensor but my b18a1 doesn’t. I’ve been stuck on this all day


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