Stroker B18 rods to A20

[ZackieDarko]

think it would work?

they are expensive but if they worked we would be going from about 2.0L to upto about 2.4L-2.5L with just the rods with custom pistons and a little boring we could get even more displacement
or am i just crazy wacko nuts?

or is a 2.5 2.6 or 2.7L A20 possible? shit would the lower rotating assembly even be able to handle that? would the compressoin just be way to low to do that? could run a shit ton of boost if it would work tho

on another note

how much do you guys reckon would need to be taken out of a stock A20 to get to a TRUE 2.2L? would custom pistons be needed for this?

i have been toying with the idea of having teh new engine made to a true 2.2L so i can get even more tq when its boosted :-D

[shepherd79]

it is not just the rods, you need crank, rods, and pistons. if you can get the crank fit you should be OK.

[Legend_master]

it is not just the rods, you need crank, rods, and pistons. if you can get the crank fit you should be OK.

Isn't the water pump located on the crack in the b-series? that would mean you would end up with a very large gap at the end of the crank. That's to say that the journals even line up.

[MessyHonda]

you would have to sleave the block and overbore it to .050 over and still that will only get your like 2.1L of displacement. i would just get custom pistons to lower the compression with the LS rods and ARP bolts

[rjudgey]

Hey give me $10k and i'll give you a long throw crank and rods from Arrow makers of formula one engines. At least you wouldn't need any special pistons cause even flat tops would give you big boost in CR ratio with a bigger stroke!! Not sure what you could get out of a longer stroke depends on howmuch room there is to swing in there maybe a couple hundred cc at most before rods hit the block, at least the rods would be shorter and lighter!!
Stick with stock stick with 2.0l just spend the money on headwork, parts, and a quality induction and tuneup at least with the 2.0l block you can rev upto 8k without too many issues even higher if you don't mind head rebuilds every 20-30k miles. 180-220bhp is more than enough fun for on the road driving on these old gals!!

[Legend_master]

Hey give me $10k and i'll give you a long throw crank and rods from Arrow makers of formula one engines. At least you wouldn't need any special pistons cause even flat tops would give you big boost in CR ratio with a bigger stroke!! Not sure what you could get out of a longer stroke depends on howmuch room there is to swing in there maybe a couple hundred cc at most before rods hit the block, at least the rods would be shorter and lighter!!
Stick with stock stick with 2.0l just spend the money on headwork, parts, and a quality induction and tuneup at least with the 2.0l block you can rev upto 8k without too many issues even higher if you don't mind head rebuilds every 20-30k miles. 180-220bhp is more than enough fun for on the road driving on these old gals!!

if you guys really want to spend some money on an a20 project, try converting to a head that has 4 valves per cylinder SOHC or DOHC. I mean the loss in perfromance we get with the head on the a20 is terrible.

[MessyHonda]

yeah....if i ever get enough money i would rebuild the head...3 valve angle job, new springs, retainers maybe 272 delta or triflow, b16 intake mani ported to head, exhuast ported....everything...the better it flows the faster it will rev up.

[shepherd79]

great website.
http://g-speed.com/pbh/bore-vs-stroke.html

Generally longer stroke motors produce more torque, has a lower rev limit, and also revs slower. Short stroke motors are the exact opposite.

i hope that would explain why people stroke it out B series motors.


if you look at A series engine you will see that bore is 3.25in (82.55mm) and stroke of 3.58in (90.93mm). that would explain why our engines have shit load of torque and low reving.
now lets looks at F and H series motors.
A18 series bore 3.15in (80.01mm) and stroke 3.58in (90.93mm)
A20 series bore 3.25in (82.55mm) and stroke 3.58in (90.93mm)
F22 series bore 3.35in (85.09mm) and stroke 3.74in (95mm)
F20C1 (S2000) bore 3.43in (87.12mm) and stroke 3.31in (84.07mm) redline 9000rpm
F22C (S2000) bore 3.43in (87.12mm) and stroke 3.57in (90.68mm) redline 8000rpm
H22 series bore 3.43in (87.12mm) and stroke 3.57in (90.67mm) redline 7500rpm
H23 series bore 3.43in (87.12mm) and stroke 3.74in (95mm)
B16a series bore 3.19in (81.00mm) and stroke 3.03in (77mm)
B16B (type R) bore 3.19in (81mm) and stroke 3.03in (77mm)redline 9000rpm
B17A1 (GSR) bore 3.19in (81mm) and stroke 3.21in (81.4mm)
B18A/B (LS) bore 3.19in (81mm) and stroke 3.50in (89mm)
B18c1 (GSR) bore 3.19in (81mm) and stroke 3.43in (87.2mm) redline 8200rpm
B18C5 (type R) bore 3.19in (81mm) and stroke 3.43in (87.2mm) redline 8400rpm
B20B/Z (CRV) bore 3.31in (84mm) and stroke 3.50in (89mm)
K20A (type R) bore 3.39in (86.11mm) and stroke 3.39in (86.11mm) redline 8400rpm
K20A2 (RSX type S) bore 3.38in (85.85mm) and stroke 3.38in (85.85mm) redline 7900rpm
K24A2 (TSX) bore 3.43in (87.12mm) and stroke 3.90in (99.06mm) redline 7100rpm
C32B (NSX-T) bore 3.66in (92.96mm) and stroke 3.07in (78mm) redline 8000 rpm.

So as you can see, the shorter the stroke the higher it can rev, but torque numbers suck. But as soon as you move into longer stroke the engine speed slows down but the torque numbers go up.
if you read that article, the link is above, you will understand why honda switched to perfect cube design for their new engines. it gives high RPM red line but at the same time it gives nice torque numbers.

So if some one going to stroke A series motor with F22 crank, they will find that going with 3.74In stroke will put that engine into very slow reving engine. I would say around 5500-5700 RPM limit. the torque numbers will be great.
If you read that article you will understand that bore and stroke play a big part in the HP/TQ making but it is all about Cylinder head. If you can't move the air in and out easily, you can't make big numbers.

[ZackieDarko]

gotchya....well it was just an idea anyway

[rjudgey]

You don't need 4 valves per cylinder just bigger valves, in some ways the 3 valve is more superior, 4 valve better for turbo but for NA engine it has some good benefits, you get a much more compact chamber with three bit more room for valves to breathe, also with N/A exhaust gas getting out isn't as hard as with a turbo setup so as long as you increase your CR ratio it's not that important to have massive exhaust valves or two of them, benefits from having the 12 valves are less frictional loss from 4 less valves to push, one less camshaft to drive, smaller size head so less weight on engine, simpler maintenance, and very durable less likely to burn an exhaust valve as they are very big unlike smaller ones e.g B20A is only 28mm in size unlike A20 35mm. Also stock A20 heads can have valve sizes increased dramatically with stock seats largest maximum size is 33mm inlet and 38mm exhaust on stock seats which would give you the same kind of sizes as a stock B20A head, and probably to be honest flows better i prefer the stock shape of the inlet and exhaust ports on the A20 than the B20A, the B20A needs a lot of work to free up a very crowded in and exhaust port with all the valve guides and ramps sticking out right into the ports, once moddified it's a different story it soon catches up with the A20 and ultimately would be slightly better as the valve sizes on B20A could be increased to 35mm inlet and 30mm exhaust which is pretty big for a 2.0l engine. 33mm is still good for upto 230-240bhp though so it's not like your missing out on a great deal!! THe B20A head could have the potential for upto 250-260bhp in full race setup. Would be interesting to see which one had the best power figures and torque curves with two fully built engines i don't plan on having two of these finished untill well into next year spring at the earliest we'll see!!