Custom B16B Rods


oifovo

oifovo

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Jan 11, 2011
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Right lads and gals,

Bear with me this might be a bit long :)
This at this stage is definitely more of a brain exercise rather than something that's about to happen anytime soon, but since I have a spare B16B block, crank, rods & pistons just lying here I can't help but think what I could do with them. I have no interest in high power figures, turbo or stroking are out of question as it's not what I want plus everyone seems to go that way these days. What I want is a high revving N/A screamer, for which the B16B would seem like an ideal motor. Except it isn't, because there are no off the shelf pistons or rods available. As far as I know B16A and B16B pistons have different wrist pin height, which is why PCT pistons produce fairly high compression in B16A engines (negative piston to deck height)? Assuming that's correct then if I used B16A forged pistons I would end up with too high positive piston to deck clearance and too low compression - no good. So I've been thinking about custom forged pistons that would mate with stock rods (not ideal), and then I realized I don't need custom pistons at all - I can use any forged B16 pistons I like as long as I get custom rods made up to account for the difference between the length of the standard B16B rod and the different wrist pin height? That would mean even higher (if only slightly) Rod/Stroke ratio, which would be perfect for a high revving N/A motor! Obviously I would need to figure out exactly how long would the rods need to be (I think I'd actually buy B16A piston, put it on my B16B rod and physically measure the piston to deck height as I've found so many different figures for rod lengths online that I simply wouldn't trust them)
Now, are these assumptions correct or am I missing something here?

Discuss :)
 
I'm quite rusty with this, but have you looked into the details of the B16b that Spoon Sports built years ago specifically to make power at high revs? It had a beefy block brace installed that they made for the B-series. It could safely and consistently go well over 10,000rpm but didn't exactly make the best power above 9,300rpm (according to test driver Tsuchiya). So it had a much longer powerband than the stock B16b and if you needed to stay in a gear longer for certain turns, you had that advantage without shifting.

And what is your definition of high revs? Like 10,500? 9500? Do you want to make good power at these levels or just not blow up? To make a reliable motor that revs this high will take careful planning, lots of know how, and a good amount of money because you have to change/modify/add a lot of things to the motor. Spoon's motor made 200hp, and was slightly faster than the stock EK9. It made for a better drive because it was more powerful, revved more freely, along with the things I mentioned above. But if you're not going for power, they certainly were, and they didn't get that much faster than stock.
I don't know what your exact goals are but I would think having a working B16 that revs a bit a more than stock and can make slightly more power would be a great result from stuff you just have lying around.

Larry Widmer of Endyn is (was?) also very good at building very powerful B motors that revved really high, but as a necessity for the power numbers he was going for. I would just spend time on that site and read the whole thing before I wanted to build a motor myself. He offers a few special parts as a necessity for a reliable high RPM B-series build. A lot of the stuff on this site is old, but that doesn't matter. So are these motors.
http://www.theoldone.com/articles/badtothebone/
http://www.theoldone.com/articles/Larryscivic/Larrys_Civic.htm
http://www.theoldone.com/articles/default.asp
 
I believe that the Best thing you can do with that spare b16b is wrap everything nicely, put it on a pallet and send it to me ahahahah Sorry for not be an help, but let me warn you that if you wanna do high rpm you 'll spend some good and don't forget your cams choice, that will dictate till when you' ll keep making power. .....
 
Company in Australia make forged b16b rods.
Can't remember the name which is useless but they are out there!
Then just a high comp b series piston on top?
 
Dino: It goes without saying that the head would have to be build to match the bottom end. Forged hi comp valves, titanium retainers, springs the works if I wanted it to work. Somehow 10k rpm is like a sort of magical number to me that I'd like to reach but even 9.5 would be nice. When I say I'm not interested in power I mean it is not my primary goal - if it was I would not even be thinking about this, turbo would be cheaper and produce more power. If I wanted a fast car I wouldn't have bought an EK9 in the first place, there are loads of faster cars for the same money out there. I really like high revving engines for some reason, which is also why I'm set on the B16B. I've seen the Spoon motor obviously, they used their own girdle/sump setup on that engine, but we don't know what rods or pistons they used, if they used stock then that would limit the high rpm performance as PCT pistons are imho too heavy for serious high rpm work.

Jesse: I'll look into it however I still think custom rods would be better. The reason is that I would still need custom pistons and custom rods are likely to be slightly cheaper. Also longer rods = even higher r/s ratio! I know there are also B18 pistons available for use with longer B18 rods ( the wrist pin is even higher on those) which would allow to get the r/s ratio closer to 1.9 which would be awesome for a high revving motor. Obviously I'd then need to research things like piston dwell time to make sure there are no clearance issues but I'm sure it could be done! If I ever do it will most likely be like my current EK9 build - a slow process of hoarding parts which I buy as they become available rather than taking ££££ and just throwing it at it. That should bring the cost down a bit and will also spread it over time.
 
^excellent, I did wonder was it actually New Zealand, you all the same anyway...
Right? ;)
 
Thanks NZRacerX that's perfect! I will email them to see if they have a matching piston, as I still think B18C pistons would not yield enough compression due to the different comp height of B16B piston. Maybe they made the B16B rod that little bit longer to accommodate for this, that would be ideal. I did some rough calculations today, stock vs stock B16B has roughly the same piston speed at 9100 rpm as B18C at 8400 (There are small differences in mean speed and maximum piston acceleration but for our intends and purposes they are pretty much equal in both) Now thanks to higher r/s ratio I'd imagine there will be less side load on the cylinder walls in B16B at 9100 rpm than at 8400 in B18C! Considering how many people rev stock B18Cs to 8400s without any major consequences I think it should not be difficult to get B16B rev to 10k if one used lighter and stronger rods and pistons! Wonder if @Vtec6000 has to say anything about this? :) I think you should be encouraging me to do it Aonghus since if I build it you'd be the first person to take it to the magical 10K rpm lol
 
Speedfactor (selling the B16B rods linked above) have plenty of experience with the B16B in both street and race guise, including in championship-winning 10,000rpm spec. They know their stuff with performance Honda's (amongst other things), and are awesome people to deal with.

I have their billet rods in my B16B (albeit some earlier ones they commissioned, before their relationship with Molnar), along with CP SC7116X pistons. Combined with a bit of head/deck skimming, I believe it's around a 12:1 compression ratio. There are plenty of other piston choices... just comes down to personal preference for brand, design (domed, flat etc), and the CR you're looking for.

I like where you're heading to with this build; I share your appreciation for a high-revving B16B. :cool: I'd like to think/dream that my build would be capable of the magic 10,000rpm mark too, but I don't think I'll ever find out. Cam choice plays a huge part, and mine don't really support any benefit from revving that high. Keen to see how your build goes!
 
NZRacerX said:
I'd like to think/dream that my build would be capable of the magic 10,000rpm mark too, but I don't think I'll ever find out. Cam choice plays a huge part, and mine don't really support any benefit from revving that high. Keen to see how your build goes!
Click to expand...

Thanks bud! I'm kinda busy to do much with this right now but it is something I've always wanted to do and with a new job on the horizon might have the means to do it! I agree the cams will dictate how high will it make sense to rev the engine, and TBH that's what I would be starting with - identifying cams that will be able to feed the engine at 9000+ RPM. Another issue will be compression, I want to stick with Shell V Power (99 octane) pump fuel as venturing into the race fuel world would make running the car too expensive. It is a track car and a toy and streetability is not something I'm too concerned about, so I'd be happy with a peaky motor with big cams that would bring the dynamic CR down into some useable territory at high RPM. I'm not an engine building expert but I like to do my research and I'd make a plan of what I'd need to achieve my goals and would also check whether they are actually achievable on pump fuel.
 
Engine building is out of my expertise, but I do know that Larry at Endyn was getting great reliable power at 9500rpm with 92 octane US gas. So you should be fine with that 99 you guys are blessed with.
Would it be absolutely nuts to contact Spoon for their specs on that b16b, pretending to be an interested buyer?
You could also get in touch with Larry at Endyn somehow. Might be a bit easier and he's as good of an engine builder as there ever was.
 
The US and UK gas (or as we call it petrol :p) octane rating is calculated differently (google AKI vs RON) so 97 octane fuel in UK is roughly equivalent to 92 in the US I believe
 
As above, the numbers are different
 
Oh cool I never knew that! Fun fact for you guys, some parts of the US like where I live in the Northeast have our best "premium" gas as 93 octane, but the car nuts in California are stuck with 91 as their maximum octane at most stations. I literally have no idea geographically where that changes though.
 
Hey,

Im back from the dead!

Doing a bit of research on revving to 10k rpm for my Ek9 and stumbled across this. I actually have the same goal as the OT now that ive sold my K24 DC5R beast.

You can certainly rev the b16b to 10k rpm so long as your peak power is somewhere around 9500rpm like mine has achieved (193whp @ 9400).

People instantly assume you need insane mods to reach this goal and upgrade every part they can find that is bigger. However, its not as simple as this, infact most people result in mission abort.

My goal is 10k rpm redline and 200whp on stock b16b block. I will defintely post my write up when I achieve this. Whole car is undergoing a refurbishment to make it up to modern standards (lots of money, effort and Labor). All mods on my car are done in my professional garage.

Seeya!
 
The drag race guys are pulling 2L bottom ends out to 10500rpm. I guess they don't care about how long the engine lasts and the turbos being so large keep the power going at that kind of rpm.

I'd be looking more into the valve train and cylinder head than the bottom end for alot of revs.
 
Those high revving b20s would have completely custom stroke lengths, rods and sleeves etc. Very similar to those K24s revving to 10500 easy.

Tuning the B16b needs a different approach compared to B18, and a slightly different to approach to b16a. I can say I havent touched my head 'ports' and that it makes 55whp more than a mild tuned b16a on same dyno/day/tuner.
 
Sounds interesting. What we got going on then?
 
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