Differences between B18c1 and B18c5

Hey, I have a friend who is looking into doing a b18c5 swap into his civic, but was wondering, before he does this, what are are the physical differences between the two engines? Obviously you would have different cams, intake manifold, and cam gears, but what about the block itself, the crank, stuff like that? is it all different from the c1 and if so, what makes it different?

Thanks much

the main difference is the head.

the b18c5 is the b18c1 block w/ a b16 head (simply because it flows much better.)

then, of course, higher compression pistons, different header etc...

i'd tell ur buddy that if he wants a motor for FI (turbo/super), then i'd suggest going for the b18c1. its cheaper, and takes a turbo application much better.

the b18c5 CAN be built to handle it, and of course u can make it faster than the b18c1, BUT overall if he has a tighter budget the b18c1 makes more sense for straight line power.

tell him to consider a b18b1 as well (especially if he's going for turbo). the lower compression and longer gear ratios make for an ideal (as far as stock honda motors go) turbo set-up.

I'm confused by that b16 head... is it literally the b16 head with a new valve cover or is it just similar in its structure and specs?

Its been port and polished for better flow. So yes, it is a B16 head, only P&P by Honda and they have red valve covers put on instead of black.

Its been port and polished for better flow. So yes, it is a B16 head, only P&P by Honda and they have red valve covers put on instead of black.

u sir...are correct.

muuuuy interisante, so sounds like a c5 is a big waste of money compared to a C1 if one is going to go turbo, since you're gonna wanna drop the compression anyhoo and getting a P&P b16 head wouldn't be that costly, especially if ya Ebay-off that C1 head to some Ls/Vtec craver.

Am I correct on this thought?

Thanks :biggrin:

Correct. I dont know about a big waste of money, but unnecessary none the less.
I'm wondering if he port and polishes the head, should he p&p the intake manifold too?

I am buying a GSR and im going to turbo charge it. How much boost can a stock b18c1 take? I was going to build it up a little and try to get around 15 for the occational race, but it sounds like i dont need to? thanks

I am buying a GSR and im going to turbo charge it. How much boost can a stock b18c1 take? I was going to build it up a little and try to get around 15 for the occational race, but it sounds like i dont need to? thanks

nonono, if u plan on boosting more than 6-7 psi, ur going to need to build the motor up and lower the c/r.

the stock motor CAN handle it, but depending on the motor, it won't nessecarily last for TOO long.

thats what i thought, thanks for the info.

Question... I am planning to swap a vtec head onto my 91 ls motor, planning on turbo in april. since the b18c5 head is really a b16 head should i just use a b16 head or use a b18c1 head for lower compression? also does any1 know the crank/rod ratio for the ls block?

get a Gude b16 head and swap it into the c1. port and polished, valve job, bunch of other goodies. claims 50hp if done to a b16 if i recall correctly.

i think the b18c5 has slightly different stroke figures and thus would have different crankshaft and rods..

you must've misread. I have the b18a ls motor and plan on a vtec head swap. just wanna know what the better head would be. I figure it would be the b18c5 because it is the same as the b16 head just ported and polished from the factory. by crank/rod ratio i mean that i need to know the crank stroke and rod length for my ls block so i can determine the highest redline this block can mecaninally handle... the optimum ratio is 1.74.... I hope this clarifies my question

The Type-R head is NOT a B16 head. It's a bare B-series cast ported to perfection. The same cast that the use for the Type-R head is the same for GSr and Si Civics.


StemarMotorSports, if you're gonna build a turbo B-series, just start with any B-series head and build that for turbo specs. The Type-R head is designed for all-motor high-revving...it'll work really good with a turbo but I think you're better off building a B16 head piece by piece. And having the head shop make valves specifically for turbo.

The differeneces in between B18c1 and B18c5 are the throttle-body,intake manifold, entire head (includes cams valves and other parts), pistons, I THINK rods, (crank is the same), the header and exaust is also different.

The Type-R head is NOT a B16 head. It's a bare B-series cast ported to perfection. The same cast that the use for the Type-R head is the same for GSr and Si Civics.



uhm...YES it IS the b16 head that has been port/polished.

u jus said it urself.

the civic SI came w/ the b16 (never heard of a civic si rockin the b18c1 stock...) so...that'd make it two seperate heads.

check ur facts, they're off.

All b-series heads start from the same cast, and tehy're built differently...the type-R is ported and has all the good stuff (cprings/valves/etc.).

I did'nt say it's a B16 head just ported and polished, I said it's a B-series CAST, the same one used for the GSR as well...check your eyes...they're off.

Just in case you still don't get it...while assembling any B-series engine, be it Si, GSR, or Type-R, they start with the same cast but just build them differently.

All b-series heads start from the same cast, and tehy're built differently...the type-R is ported and has all the good stuff (cprings/valves/etc.).

I did'nt say it's a B16 head just ported and polished, I said it's a B-series CAST, the same one used for the GSR as well...check your eyes...they're off.

Just in case you still don't get it...while assembling any B-series engine, be it Si, GSR, or Type-R, they start with the same cast but just build them differently.

it isn't a different head tho, thats wut im trying to get through to u. yes, the b18c1 and b16 head are different, but the b18c5 isn't.

why do u think ppl call the b18c1/b16a head frankenstien motor a "poor man's type r" motor?

its the exact same head once again, simply port/polished, along w/ the extras.

EDIT: btw, if u'd like to continue this, i'd be more than happy to discuss it in PM's...

no need to argue off-topic on here...not trying to get the last word here, simply ending it now is all.