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Discussion Starter · #1 ·
I know this may have been asked before, but why is the b16 50+ hp more powerful than the d16? I know it has vtec and all, but it just feels as though a 52 hp difference between the d16a6 and the b16 if pretty significant. How did Honda manage to build a 1.6 motor with 50 more HP around the same time as building the d16a6? I just make the d16 seem much less efficient.
 

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The difference can be summed up in one term......

Volumetric efficiancy.

It is MUCH more efficient at air flow in the head than the D.
It also doesn't have the self desroying rod stroke ratio of the D.
And even though its overplayed....it has Vtec with TWO cams instead of one, alowing for a much greater tunable rev range.
 

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right, look at a z6 vs a a6.....they got another 20hp from head design.....

build a z6 with a better cam and valvetrain, tune it right and run it to 8k and bam, youve got yourself a single cam b16 level of power.

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ANYTHING above 7200 on ANY D engine, is risking internal bottom end damage unless you have put some serious work into it.

The rod stroke ratio is crap, these motors are built to run to 7200. not above.
Honda puts redlines on their motors for a reason, just like every other manufacturer does as well, Honda is no different. Just because some oil junkie makes his B16 or GSR rev to the moon, doesn't mean your D will handle it as well, no matter how much you want it to. :rolleyes1:
 

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i wouldnt call 8000 rpm to the moon. with a proper head and valvetrain, I would rev the car till it didnt make any more power. on my old single cam setup I revved it to 7400 daily with no issue on a fresh stock bottom end and a mildly worked over head.

If I had had a cammed out, upgraded valvetrain, pnpd uber head you bet idve been revving it higher.

once the head is up to par, the only thing holding back the d is indeeed the rod/stroke ratio and theres not a whole lot you can do about it.

the good part is bottom ends are cheap!

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Spoken like a true "I build my engine every year" kinda guy.

Ive got 171,000 miles on my car for a reason, NO OVER REVVING!

Get your car to a dyno and you will see what Im talking about, you dont need to rev the piss out of a motor, you only need to rev it ENOUGH, to get the useable powerband.

So many people, on so many car forums (especially honda) need to go to an engine building 101 course, and learn the physics of the whole thing. It would seriously enlighten some of us out here.
Honda teck is the worst for this mentality.
 

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I don't think this is to far off topic so I will ask.

Is there any reason to change the redline on a stock engine. The way I have always looked at it would make no sense to increase the RPM without rebuilding an engine to make power at that high RPM. Example taking a stock D16 and change the rev limit to 8500. That would not make any more power, right? The engine is just revving higher (It's not going to last as long) and not make any more power than if you left the rev limiter at 7200.
 

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Discussion Starter · #15 ·
exactly. I believe d16s make peak power a little before the redline. Thats the whole idea behind transmissions. Its to allow the car to perform in its own unique powerband. If your redline is 6500, your engine was made to produce power up untill 6500.
 

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Holy cow, two people who basicaly understand!

7200 is the ablolute max a D should be revved to. D15B vtec excluded.

The D16 bottom end is just not gonna be efficient or reliable above stock redline. Its there for a reason.
Make power, and mod your engine by all means, but mod it to make power in the useable powerband that it was made with.
Increase tolerances for boost on all applicable parts, but don't rev any higher anyway, the turbo will allow for more power at higher revs, but thats what turbos will do, they spin, there is no stop motion like a piston and rod.
Just cause the turbo will produce more boost, doesn't mean the motor will take it.
 

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I disagree that the bottom end can't hold more than redline. Like I said, the ZC will rev to 7800, and uses the same bottom end as an Si, minus the pistons. (OK, I have heard speculation about different rods, supposedly the ZC rods are thicker, which I didn't find to be true measuring with dial calipers) When I rebuilt mine, it was using a standard Si bottom end kit. I think the bottom end can hold more abuse than we give credit.

I would assume a rev limit is there to keep morons from winding their engine as high as it can go, and then bring it back to get a new engine under warranty. It is set where it is because the engines acheive peak power I'd assume a given percentage before the limiter.
 

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well, since i have personally seen d motors that make power past 7200 (7600 iirc was the peak hp) i can see some reasons to rev past 7200

the stock redline there for a reason, thats fine and dandy, but we are modifying motors here. if you want stock reliability then roll around with a stock motor, thats fine by me.

even imagine you make peak power at like 7000 rpm flat, you wouldnt want to shift there, youd want to shift some point past that to be in a sweet part of the powerband in the next gear.

you are only going to get so much power by modding a D motor NA with a stock rev limit....after that point you need to start making changes that will require you to rev higher, or be satisifeid with the power you have.

as for turbo cars, wherever that came from, i had my rev limit at 7200 rpm on my turbo z6 because i had a stock (minus turbo cam) head so there was no point to rev higher.

its not like im sitting here tellin people to change there d16a6 rev limit to 8000 and rev the piss out of it, far from that.

<--built my own na z6/y8 hybrid, built my own turbo z6, built my own c1

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