I'm curious about B16A's that have been built to run up to 10,000 rpm. What head work did you do? (Cams, cam gears, valves, valve springs, retainers and such). What internals? (Pistons, rods and such). I've heard several takes on needing a girdle or not. What is the integrity of a B16A to need or not need a girdle under conditions of 10,000 rpm?
Please keep your opinions to yourself. Just because you don't have or understand why one would need or want a B16A to rev to 10,000 rpm, doesn't mean there isn't an application for it. Thanx for your help and respect in advance.
Just did some googling so these are not my thoughts.
"If u use arp rod bolts you could go up to 8000-8500. If you have forged rods, pistons and a girdle you could go to what ever your cams make power to. The factory rod bolts are the weakest part of the block and could break shortly after factory rev limit for the block. Untuned i wouldnt go over the factory limit or give it all as it will have wrong fuelling and timing."
also
"Yeah a B16A or B16B would be a decent motor choice to do this. Honestly I would just make a motor make power at 8500-9100 rpm, as this has been proven to be safe and reliable.
But if you want to make an all out race motor, plan on spending a lot. All new valve train is needed; this includes new valves, springs, retainers, guides, seats and cams. Look into Wicked Industries cams, Rocket cams, or some crazy custom grind that will suit your setup. You will need a really good port and polish to bring in a buttload of air at those RPMs. Look into some sort of ITB or high flowing intake manifold set up. You are going to need a good fuel management system and ignition system to maintain what you are doing.
Then you will need a sleeved block, I do not care what anyone else says, honda open deck sleeves cannot take the abuse of 10,000rpms for very long. You will want a well worked over crank, that has been knife edged. Strong Rods and rod studs are key too, along with forged pistons. A light balanced bottom end is going to be key on a high reving application.
Then comes your transmission, either spend a lot of money on aftermarket gears, or go through transmissions every couple of times you race. That is just how it is."
Thanx. I saw that same post. My engine stock goes up to 8200 rpm. I more was curious of someone's exact setup especially the weakest points like u said the rod bolts. Appreciate the input.
Tom Downes would be another good person to talk to. He built a B17 several years ago and had it revving to 10k. He is the owner at WPG (see signature) and is a member (downest) here. It's not a trivial task to rev that high reliably and make decent power.
The Crx that I purchased with a B20V redlines at 10k, I've had it there maybe twice in like 3 years though lol...
I forget one that internals are because I didn't build it myself. ARP everything, CP Pistons, Buddy Club Cam Shaft, I think supertech or something retainers? I'm really just spreading thin trying to remember this stuff...
I don't know which rods, the builder told me once and is local but I've forgotten.
Thanks very much for the input. Yes it's definitely a time consuming and costly endeavor. I've built a few engines but nothing this precision. Blue printing and balancing I assume is a must. I've been looking into sending the engine out. But I've also seen some blueprinted high compression kits from toda that come with everything from the crank up to the pistons. $5,000 for the kits only. Obviously for this type of build that's the minimum price as a starting point. Would it be more economical to buy a kit like that and get sleeve and send it all to a reliable shop for this type of work or as previously stated just send it all out to get built? The head is simple enough to get figured for this kind of application. More costly than precise. Not that I don't want it done right of course. But the precision of the bottom end I feel would need to be exact to last any reasonable amount of time.
A bunch of the internal components "needed to replace" are all for higher HP applications, not necessarily high rev applications. For heavy racing, you want both; things like autocross doesn't really need the 600 HP. Stock rods and piston heads last very well up to 250 HP.
Higher rpm's is all about valvetrain. At high speeds, you run into spring resonations where they continue to bounce up and down during valve closing. You reach a problem called "valve float" where the valves can't seat fast enough before the piston head smashes into it. Yeah, mean piston speed is important, but you can't change it without altering the rod/stroke ratio. Generally you go for heavier valve springs, but you eventually reach a spring constant that wears at the valve seat. Most people run dual or triple spring sets to prevent resonation. The problem is finding a strong set that actually works up to 10k rpms.
You don't have to visit Wicked Performance, just call and ask what they did on their engines.
Also, I personally think a lot of the work (like sleeving) that people put into Honda engines is silly and wasteful. You really only need to replace the pistons and find a good tuner. It's about preventing detonation, not compensating for it. It you're going to spend more than $2k, just buy K or H series and work on that.
Solid posts, I just want to point out that rod length is not a factor in piston speed. The B16B is a study on why the r/s ratio is still important though, to limit lateral loading on the cylinder walls at high RPM.
Thanx again for all the input. Yes I've already got the parts list put together for dual titanium valve Springs and associate components and with machining I'm in the ball park of $2000 for the head. While I do want bigger numbers, the point I'm shooting for with high rpms isn't for a power gain. More of a power maintainer. I'm running a jdm B16A from a crx sir. That block is 26 years old. The point of Sleeving in this case is more of a block maintenance.and going oversized, high compression with the extra heat from higher rpms, I figured its the least I could do to insure the blocks general integrity. On general integrity wouldn't one want finer, balanced clearances from all bottom end components to ensure maximum longevity and less rotational friction? Toda has a very nice very expensive bottomed end striker kit I found that from Wut I've gathered cam serve both purposes. Thoughts? I agree, floating valves is no good but oddly enough the head is the one part of this I've got a solid idea about wut to do. When I'm more familiar with building bottom ends. But yes by the time I'm done with this projects it's not going to have just a bit of this and that. Tune is common sense here, there's no project without it. Plus fuel, toda cams, distributor replaced with a cop delete kit. And accessories to help keep up with the new loads, oil pump and such. Thanx again for all the input. Great posts!
I won't recommend a stroker kit for a B16, especially if high RPM is your goal. The r/s ratio gets rather out of hand on the short B16 block.
Honda cranks are really good. Factory forged and balanced. They're the strong point of Honda engines. Plus several stroke options are available in other B-series cranks (B17, B18C, B18A/B/B20, B21) that are drop-in fits for any B-series. It only makes sense to go with an aftermarket crank when you want a specific stroke that Honda didn't offer, or if you're seeking 800+ HP.
If you have the cash to burn, consider instead a tall deck block like a Dart. Then you can use a longer rod and really rev the pants out of it. Or find a B18C block and build a B16B in all but name.
I wanted to add that CNC Werx does a precision machined block guard application that far exceeds sleeving.
To date, a CNC Werx block has NEVER failed. ( not that i know of )
If i was going to build a massive motor , i'd start with a CNC Werx block.
The only real thing that damages Honda factory sleeves is detonation; they last for freakin forever stock. You should only sleeve a block if you're planning on a much larger over-bore or if there's already a crack in yours.
jfrolang said:
Myriad said:
mean piston speed is important, but you can't change it without altering the rod/stroke ratio.
Solid posts, I just want to point out that rod length is not a factor in piston speed. The B16B is a study on why the r/s ratio is still important though, to limit lateral loading on the cylinder walls at high RPM.
I almost wrote "rod length", but caught it before I actually posted. You are correct: it is actually the stroke length that determines Mean Piston Speed; alas though, you change the r/s ratio when you change the stroke length. :twisted:
Another thing to note for the OP, the B16's strokes are as small as honda made them. If you'd want to go with a higher r/s ratio, you need a taller deck block for longer rods.
I came across this thread and decided to register to the forum. I was looking into the piston speed and max safe rpm limits for my B16B. So far, there is no real answer yet that I've found to clarify my thoughts on revving past my current rev limit of 9500rpm. However, there is one concern that I've discovered throughout my research, which is the factory rod bolts that I've read up on how they could stretch at high rpms. But how high at what piston speeds? And are the factory rod bolts on the B16B different to the B16a?
I built this motor 3-4 years ago. It has a complete stock bottom end, slight raised compression with thinner Toda gasket and slight skim on the head. Toda valve train, cams etc the whole lot. 193hp at the hubs.
The graph I took at the time scaled to 9000rpms which cut off the rest of the graph. Peak power was at 9300ish or more from memory. This was 3-4 years ago. The car has been dormant for a while in the last year or 2 due to life and other projects.
I've picked up again from where I left off and giving it the attention it deserves
With a couple of tweeks and mods, my target is 200whp and 10,000rpms. I'm just trying to find some assurance on this move by getting down some physical facts and what not. Can anyone shed some light?
Rod bolt stretching usually only happens with higher power and, just like with head-bolts, isn't as big an issue until they are loosened. From the engine teardowns I've seen where a bearing spun, I can't recall any that were caused by a rod bolt.
Also another thing I forgot about until I saw your pics was the distributors/coil-on-plugs. COP's help so much with higher-revs for the spark-timing and spark strength. I'd venture to say they are required for any decent power above 8k rpms.
So lets say I make power between 9500-10000rpm. Which part of the B16B would likely to suffer in the case of high rpm(10000)? I've gathered some physical information on other motors in contrast.
B16B
- Same stroke and bore as b16a(81.00mmx77.4mm), but longer rods(142.42mm), taller block(Type R), heavier pistons, all B18C type R hardware.
- Piston weight, B16B = 324g, F20C = 355g, B16A = 295g, B18C = 306g,
- Rod/stroke ratio B16B = 1.85:1, F20C = 1.82:1, B16A = 1.73:1, B18C = 1.58:1
Since the F20C revs to 9000rpm from factory with similar rod/stroke ratio and heavier pistons. Wouldn't the B16B do the same thing with more ease?
Yes I found the COP essential with high rpm. There's no way the old dizzy system would keep up past 9000rpm without failure.
I've always believed the B series were overboosted engines, especially the B16B. I didn't want to touch the bottom end so I could gauge the limitations and work my way from there. It's difficult finding any information on real world results with the B16B on the internet, with most info being b16a and b18s and b20s.
I wanted to do something different and resist the temptation of stroking the motor for power - not so cost effective but rewarding in a way. I've also built a k24 250whp on my DC5R that has gone to a happy home. So even more reason to leave the B16B at 1600cc.
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