b20a head on a20a3

[1987AccordLx-i]

i had a noobish thought.. will the B20A head work with the USDM A20A3 block? i found nothing on this build in forums (hopefully i didnt look in the wrong place) and i just wondered if it would work.. thanks

[turabaka]

No I don't believe that it'll bolt up right. Something to do with coolant line not lining up or something like that. I'm not exactly sure though. I just remember a discussion of something like this awhile back.

[86ccord]

No I don't believe that it'll bolt up right. Something to do with coolant line not lining up or something like that. I'm not exactly sure though. I just remember a discussion of something like this awhile back.

yeah, i think it was the coolant line being to short or something, or it was in the opposite place.. i dont remember but something like that..LOL

[Bass Man]

Are you guys saying the coolant PORTS are on the wrong side, or a $2 piece of coolant hose is keeping us from going DOHC.

[Ichiban]

1. The center rear head bolt doesn't line up quite right

2. The oil drainback holes on the B head are too large, and need to be welded up.

3. The B head is about 1.5 inches longer on the cam gear side, so the timing belt lines up with nothing on the block.

[Bass Man]

3. The B head is about 1.5 inches longer on the cam gear side, so the timing belt lines up with nothing on the block.

Can you replace the Crankshaft and oil pump to accomodate?

[turabaka]

In theory if you really wanted to go through all that pain in the ass fab work it could be possible to put a b20 head on an a20 block, but wouldn't it just be easier to fab up custom mounts and drop in a b18 or b16?

[2oodoor]

It is my understanding that at least one person pulled this off but they disappeared off this forum. It takes some tricky machine work, there are not enough coolant ports, and among the other things already mentioned ^^^^

I suggested using a b18 aftermarket dart head base unfinished cast, and machine the proper holes in it. Dart could easliy make one for the A20 but it is just not economically feasable for them since they would only have a hand full of customers and there are other engines they would rather make race heads for for profit.

[1987AccordLx-i]

so guys... would it be better to port/polish and trick out our heads instead of going along with a pain in the ass b20a head swap?

[AccordB20A]

turbo is what makes the a20a a non fail engine

[1987AccordLx-i]

turbo is what makes the a20a a non fail engine

i heard alot on how our engines take turbo applications real well.. i want an official answer.. is it true?

[Bass Man]

Do some searchin! I've heard countless times that the A20's hold 10 lbs of boost without a sweat. And if that is true on the 88-89 LXI's, then I could see an 86-87 LXI hold 12-14lbs easy.

In theory, the best A20 to turbo would be a 86-87 A1 with swapped PGM-FI. But if you are gonna turbo, you might as well buy lower CR pistons and a reground cam anyway, so it doesn't matter.

[1987AccordLx-i]

Do some searchin! I've heard countless times that the A20's hold 10 lbs of boost without a sweat. And if that is true on the 88-89 LXI's, then I could see an 86-87 LXI hold 12-14lbs easy.

In theory, the best A20 to turbo would be a 86-87 A1 with swapped PGM-FI. But if you are gonna turbo, you might as well buy lower CR pistons and a reground cam anyway, so it doesn't matter.

i have an 87 with a swapped A18A1 with an A20A3 head... will that work or should i just save up and rebuild my blown A20A3 block and work it up from there?

[2ndGenGuy]

They're the same block with a different bore.

[2oodoor]

So, what kind of compression ratio does that A18 with FI A20 head have anyway? how are the rods constructed? what do the A18 pistons look like? flat, dished or reliefs?

[1987AccordLx-i]

So, what kind of compression ratio does that A18 with FI A20 head have anyway? how are the rods constructed? what do the A18 pistons look like? flat, dished or reliefs?

im running around .3 less cr then the stock a20a3 blocks cr.. i didnt really look at the rods but the pistons are flat and have grooves for 16 valve configuration but were only running 12 valves.. its not really good on power due to some tuning issues but the a18 does the job if you need an emergency swap.. i plan on putting my stock a20a3 back in the bay but i have to wait a while so i can rebuild it and put everything new

[Bass Man]

86-87 A1 = 9.1 CR
88-89 A3 = 9.3 CR

Plus the 86-87 A1's have a lower lift cam, which I heard is good for turbo.

I don't know about the 86-87 FI or 88-89 carbed CR's, but I know the above is true.

[MessyHonda]

yeah its way easyer to put a port and polished head with a nice cam...even with just a cam my motor feels good even at high rpms

[1987AccordLx-i]

yeah its way easyer to put a port and polished head with a nice cam...even with just a cam my motor feels good even at high rpms

yeah thats what im most likely going to do.. hey the specs for your car are 112hp.. is that pre-88 year model?

[A18A]

thats WHP not at the flywheel, i believe his cars a 1989 honda accord lx-i. according to his sig

[MessyHonda]

yeah thats what im most likely going to do.. hey the specs for your car are 112hp.. is that pre-88 year model?

yeah its making like 135 to the flywheel now i think im making like 120WHP cuz its tuned

[1987AccordLx-i]

yeah its making like 135 to the flywheel now i think im making like 120WHP cuz its tuned

what mods have been done to it? i got a A20A3 block in my garage and im rebuilding it... what would i do to get a HP number like that?

[AccordB20A]

oh noes....... wait for it

i think right now his cars making 0HP due to a ign fail

[Bass Man]

Oh no! Don't tell me the 6AL crapped out!

[1987AccordLx-i]

oh noes....... wait for it

i think right now his cars making 0HP due to a ign fail

ouch

[kyaccord]

got a question has anyone had the cap in you block come out? its a hole right under your exhaust manifold there 2 caps pressed in and one on them came out on me today. when i pour water in it comes right out of it. its not a hole in the block i know that for sure its just that cap. anyone know how much they cost for an a20a3 motor?

[A18A]

i think they are frost plugs, i think they pop out when there is alot of pressure from the cooling system running through it, you should be able to just put it back in/ get it replaced and add more coolant and should be good to go. thats my theory

[kyaccord]

hell yeah thanks

[Kabuki]

It's more likely that the plug rusted through. Doesn't change the fix though. Replace the plug.

[SOHC]

Newbie question, I've read all your guys` posts and I've seen alot of A20A1-A3, How rare is a A20A4 block Thats Fuel Injected and Pushing 122hp Stock ?

[Nafs Asdf]

Newbie question, I've read all your guys` posts and I've seen alot of A20A1-A3, How rare is a A20A4 block Thats Fuel Injected and Pushing 122hp Stock ?

It's pretty common, in Europe. Don't think you'll find one over there tho. The difference is just the emissions crap, so I suppose you'll get pretty much the same results with taking an A20A3 and removing them.

[Bass Man]

I think an A1 with the stage 3-4 vacuum removal is a like an A4 or 5, whichever is carbed...