Honda / Acura K20a K24a Engine Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
1,175 Posts
Discussion Starter #1
hey guys. ive recently got my hands on a good k20a3 bottom end for nothing. i have a full peakboost kit ready and waiting for summer. i would like to build a bottom end for summer without downtime to my own car. i know of some differences between the 2 bottoms but im looking for more insight as ive searched and specs are hard to find , for me at least.

i know the cranks are different , but how much weaker is an A3 crank vs/ A2? will an A3 crank be able to handle 500 whp? ive been working on hondas for 15 years and ive personally never seen a crank have a problem unless of course the rod bearing went. the rule of thumb for me for all honda cranks in B and D series was they can handle what you throw at them.

i know the bearings for the A2 and A3 are also different. i dont know the difference though. are both mains and rod bearings different? how so?

i know the A3 doesnt have squirters , im not worried about that as the engine will be running wiseco forged pistons and forged rods as well.

can the sleeves handle power in stock form like the A2 sleeves? i cant see the sleeves being any diffeent between an A2 and A3 as far as composition or thickness , but i dont know.

ive looked up the part numbers and the A3 engine as far as i can tell uses the same oil pump as the type s.


so im thinking , k20a3 bottom end with bored and honed to make room for its new forged internals. once im ready this spring , take my k20a2 out , swap over whats needed to the A3 bottom , and hopefully put down some good numbers. any insight appreciated , thanks guys.
 

·
Registered
Joined
·
373 Posts
hey guys. ive recently got my hands on a good k20a3 bottom end for nothing. i have a full peakboost kit ready and waiting for summer. i would like to build a bottom end for summer without downtime to my own car. i know of some differences between the 2 bottoms but im looking for more insight as ive searched and specs are hard to find , for me at least.

i know the cranks are different , but how much weaker is an A3 crank vs/ A2? will an A3 crank be able to handle 500 whp? ive been working on hondas for 15 years and ive personally never seen a crank have a problem unless of course the rod bearing went. the rule of thumb for me for all honda cranks in B and D series was they can handle what you throw at them.

i know the bearings for the A2 and A3 are also different. i dont know the difference though. are both mains and rod bearings different? how so?

i know the A3 doesnt have squirters , im not worried about that as the engine will be running wiseco forged pistons and forged rods as well.

can the sleeves handle power in stock form like the A2 sleeves? i cant see the sleeves being any diffeent between an A2 and A3 as far as composition or thickness , but i dont know.

ive looked up the part numbers and the A3 engine as far as i can tell uses the same oil pump as the type s.


so im thinking , k20a3 bottom end with bored and honed to make room for its new forged internals. once im ready this spring , take my k20a2 out , swap over whats needed to the A3 bottom , and hopefully put down some good numbers. any insight appreciated , thanks guys.
as far as the cranks go the major difference is the fact that the k20a3 crank is not counter balanced like the k20a2 crank. just use your k20a2 crank. i also believe that the aftermarket k20 rods on the market are made to fit k20a2 cranks.

i'm pretty sure the sleeves are the same and should be able to handle as much power as stock k20a2 sleeves.

as far as the oil pump goes, it differs. there are 2 k20a3's. one being from the ep3 and one being from the base model rsx. the one from the ep3 has the prb intake manifold and a balancer shaft type oil pump. the one from the base model rsx has a black plastic intake manifold and has the same oil pump as the k20a2.
 

·
Registered
Joined
·
1,175 Posts
Discussion Starter #3
yes i know the differences between base rsx and ep3. the engine i have is the ep3 Si. are the main journals of the A3 and A2 the same though? will an A2 crank fit in an A3 block without modification? im assuming yes and only the rod journals are different. cause like i said , the bearings between the 2 engines are different. hopefully just the rod bearings are different and the mains are the same.

maybe thats what ill do , get my hands on a type S crank , and than ill have pretty much an A2 bottom end minus the squirters , which you dont need for forged internals anyways so.

any and all insight welcome. thanks guys. summer is coming quick , lol.
 

·
Registered
Joined
·
748 Posts
yes i know the differences between base rsx and ep3. the engine i have is the ep3 Si. are the main journals of the A3 and A2 the same though? will an A2 crank fit in an A3 block without modification? im assuming yes and only the rod journals are different. cause like i said , the bearings between the 2 engines are different. hopefully just the rod bearings are different and the mains are the same.

maybe thats what ill do , get my hands on a type S crank , and than ill have pretty much an A2 bottom end minus the squirters , which you dont need for forged internals anyways so.

any and all insight welcome. thanks guys. summer is coming quick , lol.
correct, the cranks are direct swappable, provided you use new bearing colors because the charts are different from grooved bearings to flat bearings (a3 to a2), the ranges are cmopletely off and shoudn't be mixed, as when you mesure them, you can mesure the grooved from the lower grooved part vs the flat/top end.....

see your service manual or qualified local k-series expert for more information. LMFAO..

ps squirters are also used because of the difference in ring packs, a3/a2 etc and oil control rings, failure to use them, will also accelerate bore wear, compared to use with them, also the pressure drop is also minimum.

if you wanted a built k20a turbo block you could just send me some money and i'd give ya the one wrapped and sealed on the stand and save you some hassle... LOL...
 
1 - 4 of 4 Posts
Top