Why does a B20 shortblock command such a high premium over a B18B? You can find B18B's for $50-100, but B20's go for upwards of $800! Do the B20's have different bore centers or something? I thought the bore centers would be the same as a B18 (afterall, the heads are interchangeable on them).

I mean why pay $800-1100 for a B20 when you can almost get somebody to pay you to take their LS block, and then for $600 or so you can get it sleeved by Golden Eagle to 85-87mm and end up with a block that's bomb proof for way less than the cost of a stock B20. How big of an overbore can you go with a B20? I think it's the same as a B18 isn't it? Same bore centers, etc?

 

Are you sure you can get a b18b bare block for $50-100?..

 

haha, alot of [performance] shops around here charge upwards of $1400 just for the B20 shortblock. Probably two reasons here, first and foremost poeple can say they have a B20, and also because you don't have any extra downtime by getting the B20. Although your right a B18B with resleeve and 84mm+ pistons would be nicer.

 

This is why. Torque! BTW, stock Honda sleeves are underrated.

Also, just because its Iron sleeve does not mean its bomb proof. I have seen Iron sleeves crack.


[Modified by CRV Monster, 6:16 PM 9/13/2002]

 

The larger bore of the b20 gives it way more low end torque than any other b-series engine as CRV Monster has shown on the dyno printout. It is hands down the best "stock" engine swap if you want a torque monster that kicks *** for purely street (sub-5k rpm) driving.

Other than that, the b20 has a one-piece sleeve. This would make it stronger than the separate sleeves on the other b-series engines (stock vs. stock), but yeah, an aftermarket sleeve in any b-series would definitely be the strongest way to go.

 

WAY more as compared to what? If you had a B18 and B20 wit the exact same mods, it might have ~9% more torque... I have experienced both displacements in my Civic, and the difference was hardly noticeable. Now, compared to a B16, which I have now, there MUCH more bottom end with a B20B.

 

That's an impressive dyno slip! But still, I question the rationale behind spending $800 more for a B20 block. Max overbore for B18 = Max overbore for B20. Hmm, $100 block + $600 87mm overbore job. Or $800-1100 block + $600 87mm overbore job. It seems such a simple choice it makes me wonder if I'm missing something. Does the B20 have a different stroke or something?


[Modified by CheezeFrog, 10:36 PM 9/13/2002]

 

Nope, same stroke as the B18, just a 3 mm wider bore.

B18B Dyno... but this block wasnt stock, it had Rods and Pistons

 

Just imagine this engine with the 62402T's! 200+ ft-lbs of TQ, it could easily be in the 275HP range!

 

You're completely modifying my original argument to suit your agenda. For starters, I was talking about low-end torque (the kind to get rolling in daily traffic) and stock (not modded as you want for your comparison) setups.

Another important consideration which you didn't mention is what rpm does the additional 9% more torque come in the b18b vs. the b20 in your hypothetical "exact same mods" comparison? If you look at peak torque, the b20 hits its mark about 700rpm lower than the b18b. If you're running down the quarter mile this doesn't mean much, but for street purposes (which is what I was originally talking about) this is very significant.

I don't know about you, but the idea of being able to shift at only 2.5k and still be able to keep up with similarly-paced 6 and 8 cylinder cars next to me is very appealing for a daily driver.


And CHEESEFROG : here's an interesting discussion on the engineering which went into converting the b-series block to accomodate 2L...take a look:

http://dwolsten.tripod.com/articles/jan96a.html


[Modified by GB, 11:11 AM 9/14/2002]

 

Damn, $800 for a shortblock now? I bought my longblock like 3yrs ago for $650. You can't overbore a stock B18 to the same as a B20. The sleeves are different. Max you could go on a B18 is 82mm with stock sleeves. B20 will easily goto 85mm stock. Remember the B18 starts with 81mm vs the B20's 84mm. Same stroke, but the B20 sleeves are all one unit, like a chunk of iron with 4 holes cut in it. If your gonna sleeve it, I agree, get the cheapest block you can find.

 

Another pojnt of the benefit of a larger bore is the breathing increase that the valves have when the combustion chamber is enlarged to the same bore as the cylinder.

Torque? Yes, the torque increase is neglidgeable, but it is rewarding, every little bit helps, with the increased displlacement, beyond torque, it means a slight decrease in spool time of the same turbo.

Yes stock B20 sleeves are quite strong, but not as strong as most people think, those that you see running high boost applications on stock sleeves for sustained periods of time do two things, tune their cars dead nutz on, and take good care of their cars. Tuning is the biggest factor in how much pressure the stock sleeves can handle.

GB if your gonna keep either bottom end "stock" then keep in mind that the B20B compression is 8.8:1, quite low if your not adding boost.

The compression drop between the B18B and the B20B could account for the lack of "feeling the torque" with the B20B block.

That was a good article on the B20B by the way

About the dyno charts, internal engine upgrades do little for power increases if spec is kept at stock. Upgraded internals at stock spec is for piece of mind more htan it is for power increase.

 

I just started with a B20 because I bought the entire longblock for 500 bucks.

 

i got complete LS motors, head and block, for 650. and u can sell all theparts, and make copule hundred back. then u can bore your b18. my b18 cost 3000 to get prepped and built. 11.5 CR 84 mm bore and sleeve, eagle rods,

 

GSRswapandslow , Stroke aids in torque that is felt primarily because the piston speed is raised, aloowing for higher velocity through the intake ports. Bore increases torque out of displacement only, but the added breathing of the valve to cylinder wall clerance really comes into play when the combustion chamber is opened up.

Another point about sleeving a B18B to 84-85 mm is that the cooling jacket space is compromised.

 

The difference in displacement hardly noticeable? Where did you get your motors? I felt a HUGE difference between the two. The B20 pulls WAYY harder. It also can climb hills in fifth that required a downshift with the LS. And quarter mile times dropped by .3-.5 second! There is definitely a HUGE difference between the two motors.

As for the reason why people buy a B20 rather than sleeving a B18A/B18B, the reason is simple: cost. Even if you can get a B18A/B18B for $50-$100 (and I have yet to see one this cheap!) and sleeve it for $600, you still need to buy pistons. This will cost an extra $500 or so. Add to this the cost of machining to fit the pistons and miscellaneous gaskets and seals and you come out of it well ahead of the cost of a complete B20 longblock. And I am assuming that you do all the work yourself. If you actually have to pay someone to build the bottom end, you can add several hundred dollars to the price. So for many people, it makes sense to pay less and have a motor that is ready to go.

 

Yeah, it was hardly noticeable. I'm at 5300 ft altitude. about 15% less power than at sealevel.

 

i've had both swaps. The Ls/vtec and the B20/vtec, the b20 really does pulls a lot harder but for some reason i think the ls/vtec pulls better after 120 mph, thats just me though, your listening to a guy thats been through 2 ls blocks and one stock b20 block and another b20 block that was built,but not sleeved, pushed it at 12 psi and cracked the sleeves. good luck.

 

1. The thread was about Non Vtec motors.
2. never cracked any sleeves, just for the record.

 

wow, goood thread.

My question is, if your going to sleave both the ls and b20 bottom, then which is better? The thing here is, can the b20 be bored out to larger then the ls(that is being resleaved)?

Because like if you can resleave both the ls and b20 bottom end and still obtain the same maximun bored, then why not just go with the ls, resleave it and bore it out. For cheaper... Every one knows that the b20 is hands down superior to the ls stock durhh

 

As I said, people prefer to buy the B20 block because it is cheaper. For a resleeved LS, you must buy the block (I have never seen one for $50-$100), get it sleeved (about $600-$800), buy pistons ($500), rings ($150), and pay for miscellaneous gaskets and machine work (can be several hundred dollars). If you look at the total cost and not just resleeving, you see that it greatly exceeds the cost of a B20 longblock. And if you are just going for a fairly basic 2.0 liter setup, the B20 is cheaper. But if you want a built motor, the resleeved LS is a better wy to go.

As for boring, I would say you can go bigger on a B20. The limiting factor is the bore spacing (90mm for both motors). This means that with an 84mm bore, you only have 6mm of wall thickness between the bores. This is less of a problem with the B20 since the sleeves are one piece. But since sleeves are inevitably separate, you actually only have two three mm walls between cylinders.

 

ok i know what i want now.......damn i cant wait to get a job

 

CRVTEC is no fun on the street, no traction till 3rd gear.. but it's all good at the track with Bogart Pro 4's and M&H Racemaster 22x9.5x13 then you hook up in second.

 

OK I am planning on picking up a b18b off of my friend for $350, and they are telling me to bore it out to a 2.0. Will it perform like a B20? Like identically, or is it one of those almost but not really things? What should I change on the motor before I install it, to ensure the life of the motor. Like basically anything to get at least a good 100,000 miles out of it. This will be a daily driver, and will spend a good amount of time on weekends in the mountains, not dragging...so I am more interested in torque than top speed...should I just wait and pick up a b20? Also it is a USDM motor, and I can get it registered cause it has all the papers

 

You can't bore a stock B18B to 84mm, unless you want to re-sleeve it. If its old and being rebuilt, replace all seals, gaskets, oil pump, waterpump, and bearings. If your not gonna build it, look for a low milage B20Z.