Thread: so, how balanced are SR20's?

I haven't had any experience with honda engines, but I think they are likely more durable OEM vs OEM (this is just from my observations of course). I constantly see them with a lot of miles still going strong without problems. SR's too, but not as much. When it comes to modding though, I think the SR20 is going to outlive it.

I definitely know and agree with this. the closed deck design makes it boost friendly whereas the Honda guys have to spend a little $$ on a block guard or sleeving the block. I understand the SR's strong points(which is why I have one), I'm just comparing it high rev capability and refinement compared to other cars. don't get me wrong...I still rev the piss out of it, but that's not to say it doesn't make me a lil more nervous than revving other 4 cyls out.

I'll field this question. The answer: "the owners". They either forget to change the oil (leave non-synthetic in over 20k miles), let the oil level get dangerously low (usually due to oil leak), or they rev the crap out of a cold motor. All of these things will result in accelerated rod bearing failure. When you get oil to the bearings they are fine. Do something to prevent proper lubrication and you have trouble.

I guess it would be stupid to assume Honda drivers are more diligent than SR20 drivers when it comes to proper lubrication. This makes me think Honda's general engine lubrication design is probably a step above what the SR20 has. Maybe their oil pick-up and scavenging is better, maybe their oil pressure operation is more stable under cold temps, etc.

When treated properly, the SR20 is as reliable. Maybe it doesn't take abuse as gracefully as a Honda motor.

About the revving though. I'll say it again. The SR20 isn't as smooth as the other engines you mentioned. If you're that sensitive to engine vibration, I would say there's nothing wrong with your engine, or engine mounts. Be happy with what you have, and enjoy the fun.


If you're not overly sensitive to engine vibrations and you still feel like there's a problem, it wouldn't be a rod bearing or balance problem. Rod bearing failure is heard, not felt. I don't think an out of spec, unbalanced motor would last more than a couple thousand miles of spirited driving. You say you have over 200k miles on this engine? You're fine.

The only other thing would be engine/transmission mounts. These could easily be on their way out, or way past dead. I would inspect all four of them.

This is a great thread. I'm learning so much more from this thread. You sr20 guru's/veterans know your chit.

I thank myself I own a SR20 and not a pos honduh. My p11 is my 1st n/a sr20(since 2005) and redline it once to 3 times a day. But when I hit the canyons the motor always hits redline. My motor has never been through a rebuild or swap and its 116xxx miles strong.

Another reason why our engines are more durable because were chain driven, unlike honda's are belt driven, which tear apart.

Since you guys talked about how torqueless the B series motors are, I agree with ya. How about the D series, and H series. compared to our beloved sr20's.

I walked all over my friends D16Z6 '95 del sol. twice without cams and Once with bc stg2 cams.

here is a good saying we can all use

"A redline a day keeps the rebuild away"

Now, this is what I'm curious about. How much difference did it make(if any) in the high rev refinement of the motor after the lightening, balancing, blueprinting, etc..
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well lmy sr20det lightening up the assembly definitly made the rotation assembly rev much easier and faster, then add in the lighter flywheel (8lbs) then add in unorthadox 4 piece pulley kit, and the results of that is DEFINITLY noticed, very fast rev to redline and in my application i feel all of that is aiding in seeing full boost faster. the engine really revs like a bike lol really really smooth, fast

i seen ful boost on my application at 3600rpm with the gt2871r and running a large .86AR and i think too that the fast reving lighter counterparts my engine is using is the reason that i seen really fast full boost, BUT i will also say there are other counterparts on my engine that make it see full boost that fast too, but WITH turbo you depending on your appication its good to have real fast reving, at least with what i have expierneced

i will point out another design flaw of the d/b/h series engines that honda corrected on the K series engines, and this is one flaw of design that makes the SR20DE superior over the B/D/H series and makes it par with K series, ISSSSSSSS belt driven powertrain, with hondas HIGH reving and belt driven powertrains, they have been known to stretch out,snap, or most importantly jump timing KILLING the interface honda engines, where are K series and the SR20DE is chain driven, obviously this is a more superior design as nissan has been using it for years and honda has been using a accident prone belt belt driven powertrain since forever and then come the k20 they chose the chain driven powertrain to drive the power train which shows you that nissan has been using a superior form of powtrain drive, over hondas high revining, belt drive, really that combo is real bad for obvious reasons

the open deck design is probably oe of the worest things that honda has came up with, on the b series b20 the cylinder walls are thinner making it prone to cracking if the see alot of stress either on higher compression applcations or boost applications. all open deck blocks from honda D series B series are really a bad design, WITH exception of the K20A their ope block design is VERY serperior, i have seen ppl with over 500whp on stock block...again the d series,b series, they are all geared towards NA so really having open deck design is good for NA but then come BOOST and that design has much flaws whereas nissans sr20de is NA to start but has great ability to be boosted too without haivng to tear apart the engine for rebuilding.

i would also like to point out, with hondas even if you do get the block resleeved for a extremely high NA hp car or BOOST becuase the honda blocks are designed for open deck cooling, when you close that deck, you can get cooling passages problems with the block and head and that is where you start to see that the engine wasnt built for closed deck application, causigs you all kinds of cooling issues which is obiously not good for any application, however there are a few companies that DO offer open deck sleeving, which is kinda the fix for the closed deck cooling issues, and again its not a problem 100% of the time with the closed deck honda block sleeving, but it has been known to be a issue

as far as honda owners making their d or b series engines more stout, a block guard isnt going to change the integrity of the cylinder sleeves, block guards have been known to egg shell the cylinders (make thecylinders out of round) really he only way to make a d,b series engine more stour for boosted application is to ductile iron sleeve the block which ISNT cheap i have done it a few times both cost over 1k to make it solid deck.

i was into hondas for A WHILE and i have seen my fair share of ppl overreving the engine causing bearing damages, i have seen my fair share of ppl who had engine bearing failure from oil passages problems, or oil starvation problems, so honda dont, not get oil failure problems or bearing failure just like every other engine, i really feel that maintence is really key on keeoing your engine from oil/bearing failure, oil pump replacement,keeping your oil pikups clean, making sure your oil pan isnt dented ect all of those can keep you from getting bearing failure.

sorry i touched base on ALOT of different areas which i feel are rellivent becuase we are talking about reving and reving doesnt just mean high rpm, there are alot of different variations of reving problems you will see, or like we are comparing sr2de design to honda design, and the differences the engines have that makes them inferior or superior. just didnt want you guys to think i am going on a tangent, i hve alotof expierence in hondas and know basicly everything about them as i have built a NA honda engine and 650WHP turbo b16 engine (altho it was sleeved to 2.0) so i know a bit about both na and turbo on honda, then i know about nissan as well,and my turbo knowledge spans throughout.

d series are really inferior to the B series as they have SINGLE camshaft 16v 75mm bore vtec even a FULLY built NA d16z6 you would be VERY lucky to see anythnig NEAR 200whp and again thats with a 1.6L single camshaft design which is very inferior to the B series

the H series is closed deck design, BUT with compression ratio of 10:1 and 10:6:1 from japan the numbers are good for NA but again with closed deck design and too high ofcompression boosted aplications arent to great asthe compression really limits the ammount of boost able to run, BUT at least honda gave it a closed deck design.

neither of the D series or B series make any torque, not even if you take a stock trim block reinforce the pistons, and turbo it, doesnt it make any power, 1.6L is the flaw with both b16and d16.

only when you get the b16 and sleeve it and bore it to 2.0L then will you start to see simular numbers as the sr20det, but again JUST to get the honda block to be able to support any kind of boost its going to cost you more than a sr20det and thats just to sleeve it.

thats just my take

my SR sees 9k all the time

gt2871rblubird, you hit it right on the money. Honda did the chain drive with both the F20 S2000 motor which is a very very good designed motor making alot of power and the K series, they finally got that part right, and from what ive seen the open deck on the k series has bracing in between the cylinder walls which makes for a decent design, now the other open decks you sit there and sleeve it and you get the overheating issue which happened to my buddies D series block that he put darton sleeves into, he kept overheating it when he would get on it, he was running boost on it, kept blowing headgaskets also. So yeah the SR comes really well built from the factory, i mean look how long its been around and they are still using it in some contries. So i mean come on, rev the piss out of your SR and i guarantee you it will take it all day long, keep up on the maintenance like the timing chain tensioner and seals and you have a long long lasting motor. Dont take care of it and it will be just like any other motor out there and fail on you.

Manufactures dont just set redlines high for no reason, The SR20 is obviously a well balanced motor thats meant to be reved being nissan gave it a 7750 rev limiter. I mean what more do you want, Manufactures set redlines on motors where they know its safe and will maintain reliability even when that limit is hit again and again and along with where the motor makes peak power. The SR tends to make peak hp up around 6800 in NA trim, with cams in there and other boltons the peak power is raised, my S3's made peak power at around the same but the thing is it held that power all the way to 7750 with no drop off. So this is what you have to keep in mind. Dont be afraid of the vibration, its just the power of the SR your feeling. haha

i can remember my old bolt-on, S3 cammed de at the strip. when approaching the lights in 3rd gear @ ~90-93 mph (7500-7800 rpm indicated) the engine sounded AND felt like it was gonna blow. it was really POUNDING! in contrast, my ve is MUCH smoother up to 8k. i'm not sure if it's a 4cw vs 8cw thing or not, but the ve feels better balanced. still running the same es insert's in the stock 200k mounts. ymmv