Best choice for 00' Civic Si engine swap(replacement)

We may earn a small commission from affiliate links and paid advertisements. Terms

I've searched extensively and haven't found an intelligent discussion that speaks to the merits of the motors beyond obvious HP, TQ and displacement differences, and doesn't quickly degenerate into a pissing contest amongst the many fanatical b series factions.

My Si engine is shot and needs replacing, burning oil. I'm deciding between b16b (ctr), b18c (gsr), and b18c (itr), all JDM. I just need the longblock.

I want fun (and a bit more perf. than my current motor), but reliable and relatively stock. I'm not going to build it or go FI, this is a set it and forget it, aside from some well chosen bolt ons.

Here's what I'm hung up on: The GSR is the cheapest (1700) and gives low end torque and nice HP to boot (180), on paper it's the best bang for the buck. The ITR is the king so to speak, but is significantly more money (2500). The B16b is in the middle (2100), and gives a bit at the top end over my current motor. I know the B18's will beat the B16 on raw performance, why I like the B16b is the 1.86 R/S ratio, type r internals and balancing, I feel it will be the most reliable and smooth, plus it's an 00 so it's the proper disp. and model year for my chassis and thus legal. I worry that the GSR and Type r revving to 8k or more with a R/S of 1.6 will be prone to premature wear and oil consumption due to the higher stress, which is the reason I'm swapping in the first place. Any one who can speak from experience on the performance merits weighed against the reliability of these motors, your input is greatly appreciated.

Thanks,

J
 
GSR will be fine

the only thing the B16B is good for is bling factor
 
A GSR in your Si will be pretty quick. I wouldn't even bother spending money on any modifications to it if it's just your dd.
 
I agree with the GSR its cheaper and it will be quick enough for what you want...
 
A GSR motor will be great.Get a 00-01 GSR long block and get a Blox or Skunk2 intake manifold and you will not have to worry wiring in the GSR mani. Your B16 harness will all plug in. Use the needed mount brackets off you B16 and use the shorter geared B16 trans. Oh and get a header for a 94-01 B18B1 the header for a GSR is to short(wont bolt up to your cat) and does not have an O2 fitting. Not sure but I think B16 header is also to short in a different way, the B16 block is shorter so a B16 header may hit the oil pan on a B18. Even your B16 ECU will run the motor and Vtec(if you use a Blox or Skunk2 intake mani) just fine but tuning will get the most out of the larger 1.8L motor and any bolts ons.
 
A little more info, clarification

Thanks guys, I agree, with everything said so far. I was initially leaning GSR, it has better torque from 0-6k than even the ITR, which is where the engine spends most of its time, and the b16b is more money for less performance at the wheels. All the swaps are effectively equally easy, wiring in the secondaries is not a big deal and I'll run the ECU for that engine. Trying to do this somewhat cheap, and chipping plus tuning climbs to $1k pretty quick.

The main reason I am considering the b16b are the intangibles of the build quality and engineering. Of the 3 it's the best in terms of design, with same parts as an ITR and an R/S approaching F1 ratios. F1 engines are above 2 (think sportbikes are too) so they can rev to 14k without tearing themselves apart over time. You can build any engine to rev to 10k (ITR, GSR, CTR), but if the R/S is low, over time the side wall stress will wear the bores quicker and I'm back to needing to rebuild/replace. Any thoughts specifically about the 1.59 R/S of the B18s vs the 1.86 R/S of the B16b?
 
My B20 block was rebuilt with OEM bearings and forged rods/pistons. I revved it out to 8000rpm all day long for 45k miles, and the bores (except for the one piston I killed on an over-rev) and the bearings looked practically new on disassembly. I really wouldn't worry about a 1.58:1 rod ratio- there are a lot more factors than just geometry that dictate how well an engine will survive at high rpms.

Considering that Honda designs pretty much all their engines to survive at high rev speeds for long periods of time, and that they release them into the wild to be driven by the average consumer who doesn't take care of cars as well as most of the people who are "IN" to cars, I think you'll be ok. I wouldn't hesitate to daily drive a GSR block and run it off the rev limiter all day long.
 
In terms of rod ratios and longevity with high revs....aren't we comparing oranges to tangerines? GSR 8K rev'ing and B16B 9K Rev'ing?
 
Ha! Yes and no

The CTR is basically (a couple minor diffs) a destroked ITR. Because of this at a given rpm the max piston velocity is lower and the R/S results in less side loading, and is more efficient in theory. There are two main failure modes for a high perf. engine like these. Failure of the moving/connecting parts (rods, crank, springs, valves, etc.), this is solved by lightening, strengthening, balancing. Then there's the block wear from normal operation. I'm confident that Honda built all these engines to hold together at the extremes and then some. What I'm asking is a more subtle question whether the 1.59 R/S of the 1.8s will be prone to wear and oil burning vs the 16b. They're really all 1.8s at the end of the day. Maybe I'm splitting hairs here, I'm not an expert mechanic. I'm coming at this as a relatively handy physicist whose naive analysis makes me tend toward the 16b, despite its difficiencies (price, TQ). I'm hoping to have someone with insight on the 16b and 18c's chime in.
 
I got my full OBD2 to OBD1 conversion, P28 ECU, Hondata S100 and tuning for $460 out the door. A GSR can rev to 9k stock no problem, tune to raise rev limit. Dont worry about the 1.8l R/S they are balanced well and are made to sit at higher revs. The GSR makes all that extra tq in the mid range because of the intake mani and the butterflies. A great stock mani for mid range power. Yep it is simple to wire in I would always go with a B18 over any B16 more displacement.
 
Last edited:
I like that you are thinking very different than I am used to reading about. Its intriguing but I might say that its over thought and I would like to interject another train of thought.......the "Butt Fell" Theory.....lol

I would have to say that the B16B being "BliNg" is something I have read a few times....I have also been told by some tuners (just their opinion) and they have said that it doesn't really show up to the track like you think/hope it would in my shell and your car is heavier.....

So as I give you my opinion.....I think of it in terms of it being a street car that is driven lower than 6K most of the time (like you stated before)....the B16B isn't as satisfying of a pull. I had an LS swap which was very fun when driven in the city and currently have a B16A which is only fun a high revs....drove two GSR swaps (all inside EGgs). I have NOT driven a B16B so my opinion looses its luster.....the best from my recollections (sadly...these experiences are spanned over 12 years) and the "butt feel"....I enjoyed the GSR swaps the most. And lastly....logic tells me to look towards my B16A to tell you that the street driving will not be fun.

P.S. Any glance to find that 5hp more out of that B16B......ain't gonna be until 7K+ and getting to that hp output....AKA Torque.....I say it's a rap! GSR.....right out of the box.....it just what the doctor ordered! lol

I want a B18C bottom with LS Crank/Rods and P30 Pistons and just use my B16A head but that's when I find a good deal and/or after I rev the crap out of the B16 cuz my car is getting non-op'd and tracked only soon!
 
A GSR can rev to 9k stock no problem, tune to raise rev limit. Dont worry about the 1.8l R/S they are balanced well and are made to sit at higher revs.
No its not that safe. Not to say you "couldn't" but even the sun shines on a dogs as sometimes. To get all nerdy...Catastrophic failure probability increases......and I think the top end (Valve Springs) would go first...not the bottom but its still taking it above and beyond what Honda wanted so....in some Latin I don't know....Buyer Beware lol

The GSR makes all that extra tq in the mid range because of the intake mani and the butterflies. A great stock mani for mid range power.
The Butterflies (IAB's) might have some slight alteration of pressure to help with torque but IMO...it is not the justifying torque difference....its the displacement gain with the B18C
 
Cafrog yes it is true that the larger displacement from the 1.8L helps a lot with the torque compared to a 1.6l. Honda designed the B18C1 intake for extra mid range tq. The IABs stay closed at lower rpms making the runners longer, then they open at higher rpms shortening the runners for higher rpm flow. This how my tuner explained it to me.
Upgraded valve springs are always a good idea when reving a motor higher than stock and are a must when upgrading cams. But with stock cams a GSR will rev to 9k just fine, 9k is only 800 rpms more that the stock rev limit. A cheap valve spring upgrade is to get Type R intake springs and move the stock intakes to the exhaust valves.
 
why the hell would you rev to 9k on cams that only make power to about 7600 RPM????
thats 1400 RPMs of pointless engine abuse
its just stupid
 
why the hell would you rev to 9k on cams that only make power to about 7600 RPM????
thats 1400 RPMs of pointless engine abuse
its just stupid

Yes.....this is what his tuner didn't tell him. Well.....I think 7400 is a little low but no way in hell he's making power past stock rev limit with sock cams.

And how do the runners get lengthened with IAB's closed....I think he has it backwards.
 
@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0in 0in 10pt; font-size: 12pt; font-family: "Times New Roman"; }a:link, span.MsoHyperlink { color: blue; text-decoration: underline; }a:visited, span.MsoHyperlinkFollowed { color: purple; text-decoration: underline; }div.Section1 { page: Section1; } OK, here's the deal with the IAB, VTEC kicks in around 4500rpm. High flow intakes aren't ideal at lower RPM, more turbulence, lower velocity into the cylinder chamber and stuff. GSR intake basically gives you 2 IM's in one. The secondaries open up at 5500rpm shortening and widening the air path for high flow at high rpm. That's why the GSR is stronger than ITR at low rpm. The single stage ITR is designed for high rpm function. Your lungs work the same, it's actually more efficient to breath through your nose at low aerobic load, i.e. just sitting. Even at a jog elite runners are taught not to let their mouths gape open.

As for reving a GSR past 8k, you can rev anything past it's redline, but the GSR cam makes no power past that point, if you look at dyno curves HP is actually starting to go down around 8k (peak is like 7600-7800), which means TQ is really falling off since HP=TQ*rpm.

As for the 1.6L. My B16A which I have now is identical to the B16B in terms of output below VTEC. A friend had a GSR (USDM) and he was always gapping me from a stand still at lights, but I could almost catch him when merging onto highways b/c I had better gearing. The GSR with my gearing would be even quicker great discussion at club integra. The debate I'm having with myself is not the typical one I find out there, which is why I posted. From a "butt dyno" point of view the GSR wins in my book at 2/3 the cost of an ITR, and faster than the CTR. The B16b offers not bling in my opinion, but rather probably the best build quality and design of the 3, even if it doesn't offer the raw performance, plus it's a little greener being lower disp. (half joking).
 
Well.....after filtering what you said.....sounds like you made your mind up. GSR it is!

And I need a picture to understand the IAB short when open and long when closed situation. It just seems backwards until I can visualize it
 
The long (primary runners) curl around in a semicircle, with the butterflies and secondary runners inside the semicircle. When they open up they provide a straight line shortcut to the primaries' more circuitous path. If that makes sense. If you google it there are diagrams. Yeah, I'll probably throw the GSR in, but the CTR keeps pulling at the engineer in me.
 
I'm simply going to quote my high school AP Bio teacher. "You're over thinking this."

People who don't take care of their cars as well as, I assume, you do beat on GSRs every day. Honda motors in general are built to withstand abuse.

I wish I could find the video of some guys trying to blow a Honda D-series. They drained the oil and were just beating on it and it wouldn't give in. Finally they filled it with water and it still took a good amount of abuse before it let go.
 
Back
Top