f20b sohc vs. dohc
 

i have a f20b that the bottom end got trashed on and i was wondering if there was a difference between the single cam and dual cam bottom ends, basically all i need is the block and crank. i got new pistons and my rods are still very good. so does anyone know if these parts are interchangable

thank you

Eric

Re: f20b sohc vs. dohc (h23isnotabigblock)
 

single cam f20b?

I've been out of the game for a few years but are you talking about f20a's?

I know there are single and dual cams of those (I had a dual cam f20a in a civic)

Re: f20b sohc vs. dohc (h23isnotabigblock)
 

when you say the bottom end got trashed what do you mean? do you want to sell the junk short block>?

there are f20s that are sohcs, they have the saem stroke but i don't know if the rods are as nice as the f20b . . if your talking about any f22 they all have 95mm stroke..

Re: f20b sohc vs. dohc (prelittlelude)
 

Same bore and stroke (85 & 88mm respectively). The SOHC version wasn't necessarily designed to rev as high and as such the rods might not be as beefy. Can you explain more what you doing? DOHC crank/rod --------> SOHC block or the other way around? Honestly I don't see why they wouldn't be interchangable.

Re: f20b sohc vs. dohc (94Vtecluder)
 

ok so my f20b spun a main bearing, and it created hot spots on the crank, so my machinist told me that it would not be a good idea to reuse the crank. he said that the hot spots will create sharp edges no matter how much it is polished that will eventually take out the bearings. when the bearings spun it also displaced material on the block and now the main journal on the block is out of round. it could be welded and trued but for that kind of money id jsut assume get another block. the rods were not harmed..

i guess at last resort it can be fixed but im risking the chance they might not ever be right and i dont want to take that chance..

so im looking for a block and crank essentially, to replace mine. everything else is in very good shape, but i dont want to spend the big money on another dohc f20b. i found the jdm sohc f20b which shares the same bore and stroke and i was wondering if i could re-use the block and crank from that motor and the rest of the stuff from my dohc motor.

so basically im just trying to find out if the block and crank interchange, which i would believe would being as they share the exact same bore, stroke and id code (f20b)

also yes id be interested it getting rid of block crank and pistons for a decent price if this idea works. i plan to re use the rods.

thanks

Eric




Modified by h23isnotabigblock at 11:32 AM 6/21/2007

Re: f20b sohc vs. dohc (h23isnotabigblock)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by h23isnotabigblock &raquo;</TD></TR><TR><TD CLASS="quote">

so im looking for a block and crank essentially, to replace mine. everything else is in very good shape, but i dont want to spend the big money on another dohc f20b. i found the jdm sohc f20b which shares the same bore and stroke and i was wondering if i could re-use the block and crank from that motor and the rest of the stuff from my dohc motor.
</TD></TR></TABLE>

the sohc f20b should be the same stroke and rod length, but are the crank and rods the same is the real question. THey will swap in and out with other h and f honda parts, but i don't know if the dohc f20b has special crank and rods, or better than the sohc f20s.

Re: f20b sohc vs. dohc (prelittlelude)
 

yeah thats what im trying to find out. i want to pull the trigger and buy the single cam because it is considerably cheaper and i want to get this done asap... but i dont want to get it and have nothing work like i want it to and be stuck with more useless parts.

thanks

Eric

Re: f20b sohc vs. dohc (h23isnotabigblock)
 

also im wondering about the blocks, that if im going to have to plug off some drain back ports in the head like what has to be done with the other h/f swaps.

from an economical stand point i would think that the blocks would be identical, and on that merit so would the cranks, but i know that the dohc crank is jsut essentially an offset ground h22 crank, but the sohc has been around for a long time so i dunno..

i guess i wouldnt be so big on the f20b bottom if it wasnt for the fact that i just got pistons for it already and new oil pump and water pump and stuff like that. if it wasnt for that fact id go to the local junk yard and pick up a f22 and slap my head on it.. oh yeah and i love the hi rev part too..

if anyone has any information on this situation i would very greatly appreciate it.

thanks

Eric

Re: f20b sohc vs. dohc (h23isnotabigblock)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by h23isnotabigblock &raquo;</TD></TR><TR><TD CLASS="quote">also im wondering about the blocks, that if im going to have to plug off some drain back ports in the head like what has to be done with the other h/f swaps.

from an economical stand point i would think that the blocks would be identical, and on that merit so would the cranks, but i know that the dohc crank is jsut essentially an offset ground h22 crank, but the sohc has been around for a long time so i dunno..

i guess i wouldnt be so big on the f20b bottom if it wasnt for the fact that i just got pistons for it already and new oil pump and water pump and stuff like that. if it wasnt for that fact id go to the local junk yard and pick up a f22 and slap my head on it.. oh yeah and i love the hi rev part too..

if anyone has any information on this situation i would very greatly appreciate it.

thanks

Eric</TD></TR></TABLE>

as far as pluging the drain holes, it is a good possibility, it depends on what honda did for the f20s, they may have used the f22 stype blocks, or the f20b/f22b style block, there is only one way to find out.

so are you going to sell me the junk crank and rods? https://honda-tech.com/forums/images...es/emsmile.gif

Re: f20b sohc vs. dohc (prelittlelude)
 

ill sell the block, crank, and pistons, but not the rods. if i can im going to re use those bad ass rods, they just look like they are begging to be pounded with boost..

sorry!

i think im just going to buy one and find out..

i just have a hard time thinking someone else hasnt even thought to try this.. it would be a budget f20b dohc, like jsut put an h22 head on one and boost the shit out of even the stock motor with the low 9.1 comp ratio. if i didnt already buy the custom pistons id just slap my head on and boost it..

Eric

Re: f20b sohc vs. dohc (h23isnotabigblock)
 

does anyone else know anything about the sohc f20b.

basically all i want to know is the parts interchangability between the single and dual cam motor.

thanks

Eric

Re: f20b sohc vs. dohc (h23isnotabigblock)
 

i recently had a f22b given to me that has about 50K miles on it, so i think im going to just put my vtec head on that block now and get a 57 trim to bolt to it. i am still curious about the f20b sohc in comparison to the dohc though..

still want my parts?

Eric