Dasfinc

I mean seriously guys, WHY IS IT SO POPULAR!?

*If an admin wants to put this in the FAQ's, I think it would be a good idea*

Ok, Lemme go over the 'pros' that I'm aware of

LS/RS/SE Integras are plentiful, so you can get a B18B1 bottom end cheaply,

Head bolt pattern is shared from what I've read, so you can nearly essentially 'slap' a Vtec head onto them,

The B18 bottom end along with the Vtec head 'gives the best of both worlds' as far as torque down low, and hp up top

Here is an EXTREMELY detailed thread to a how-to guide for LS/Vtec's done CORRECTLY:
https://honda-tech.com/forums/all-motor-naturally-aspirated-44/how-build-%22reliable%22-lsvtec-b20vtec-1676914/

But the cons are MASSIVE and often over-looked information since there are so many 'noobs' asking about the LS/Vtec.


So PLEASE read carefully the following:

B18A, B18B, and the B20* Family of motors have a 6900-7200 RPM fuel-cut, and yet many people seem to believe they can safely rev this same bottom end to 9000+RPM in LS/Vtec setups.

Well, Here's the 'truth'. The 'ls' lets just call them, Family of motors have a low redline for a reason, a very simple reason "They were NEVER designed to spin THAT fast"

The rods themselves, as well as much of the rotating assembly is MUCH heavier than that of a B16/B18C motor. These motors were DESIGNED with light, precisely engineered internal components that allow for this high rate of travel *ala 7000+RPM*

Also, keep in mind, there are probably a very steep ratio of 'LS' motors to Vtec powered twin-cam motors, Meaning that they made ALOT more LS motors than any Vtec motor ever to come state-side. Please think about the 'quality' of a hand-built Cobra Mustang motor, opposed to a regular mustang, The internal components of the cobra are forged from the factory, and are all basically in direct contact with humans, now think about how many Cobra's you have heard of blowing headgasket, then think about how many 3.8 liter mustangs you've seen with their hoods up. For those of you who still don't understand, "The LS motors were DESIGNED AND BUILT to be MASS PRODUCED, while ALL DOHC Vtec motors are essentially 'performance' motors in limited run honda/acura products, which do think used more expensive components and was assembled by hand (All B18C5's were hand built for example) or under closer supervision?

This means once you have done your LS/Vtec conversion you are spinning heavy components well past their limits, and typically you do not do this conversion for MPG, so chances are you will be pushing them past their limits FREQUENTLY. This factor often leads to damaged rods, pistons, and more commonly chewed up piston rings because of the stroke of the LS motor which can in-turn wreck your block anyways.

So that addresses the first BIG con IMHO

The next issue often 'skipped' is the ECU/Compression/Tuning. I've seen CONSTANT LS/Vtec setups running B16/B18C1 ECU's and asking why they aren't running right, or are having other issues. Please please PLEASE realize that nearly ALL DOHC Vtec motors have a compression ratio above 10.0:1, while LS/Vtec's have often 9.5:1 or below depending upon the combination used. Now many noobs will ask 'what does that mean', well that means that the factory honda ECU you are trying to use in your LS/Vtec is assuming it is attached to its associated motor, not your fraken-thing, so it is trying to fuel/spark your car according to a DIFFERENT engine, with different internals, compression, and more...

So, this leads to the next 'point' "Well I put type-r pistons in my motor to bump the compression, so my ***** fast" Ok, thats great, but then we see the post a week later "My motor blew, LS/Vtec with a B18C1 ECU"

Your ECU was designed for a 10.0:1 compression ratio, while your fraken motor now has a CR of 11.5:1, so your dumb-*** probably kept feeding your motor regular fuel since it has a B18 bottom-end, and your motor detonated itself into oblivion, or even with premium and no tuning, it can/will still blow itself up, it is quite literally 'just a matter of time', and you are still running those grenades of LS Rods at 9000RPM attached to those shiny new pistons.

OK, so lets say for those few months when everything seems to be running great, and suddenly you line up with my beater LS powered coupe and I spank your ***, please realize, your transmission is most likely the same as mine, and the LS transmission was designed for the LS motor, not your franken crap. So as I wave fairwell to you while I pull away with 20-30 less HP, realize you still have $600+ ahead of you before you will be able to out pace my piece of ****. (and no, I'm not kidding, my basic bolt-on LS Swapped EJ can beat LS/Vtec powered integras, dunno how it would fair against something lighter ;-) )

Another item that was just brought to my attention (I knew I was forgetting something) was the oil squirters...
Back to the whole 'spinning at 9000RPM' thing, Factory Honda Vtec bottom ends have oil squirters in the block, that essentially spray the bottom of the pistons with oil for cooling and lubrication, a feature that the trusty LS lacks because if was not designed to spin to 9000RPM or make above its factory 142hp. This amplifies the issues with chewing up piston rings, because essentially, near red line, your motor will be struggling to keep itself fully lubricated because of this lack of oil squirters, so your shiney new rings, on your shiney new pistons will be happily destroying your side-walls internally without you even realizing it. I really have no idea if there is ANY simple 'solution' to this problem when building one correctly, but this is another factor to keep in mind, a big one that rather highlights the reliability problem with LS/Vtec builds.

SO, Cliffs notes:

If you are on a very tight budget, and feel that LS/Vtec is the route you choose to take, please keep in mind all that I have mentioned above, including the link at the top for how to CORRECTLY build one RELIABLY.

Here is a little 'cheat-sheet' for those who are budgeting:

*FROM MY EXPERIANCE*

Full LS swaps can be had for sub $800 easily, I've purchased 2 COMPLETE swaps for sub $600 in good running condition. I've found full LS motors for $250-300 all day long, and LS transmission are rarely over $400.
Full GSR swaps can be had for sub $2000, I've seen them go for as low as $1500 several times.
B16 and GSR Transmissions are typically between $500-700 depending upon condition and what all is included

So, how about an LS/Vtec?
http://swedishfa.tripod.com/nothing.html *some content borrowed from this link*

* B18a block: $160
* B16a head: $400
* Axles: $100
* ECU: $100
* B-series Mounts: $100
* CTR pistons and wrist pins: $155
* CTR rings: $86
* Block bore, clean, and rod bolt install: $185
* ARP Rod bolts: $35
* New water pump: $45
* New timing belt: $38
* Two Oil seals from Acura: $32
* Head Gasket: $45
* Rod machine and new piston install: $140
* LS/VTEC parts: $55
* Other gaskets: $35
* Main and Rod Bearings: $120

So, if you have a lowly SOHC in your car, and you want to do a half-way decent LS/Vtec, you are looking at $1800-2000 and That's not even including the transmission, and this shopping list is for a 'budget' NA build.....................

Now for kicks and giggles, My current EJ has cost me less than $1500 including my LS motor swap, and you'd better ****ing believe that $500 worth of spray in my coupe will wax an LS/Vtec powered one. Another budget comparison is my $500 motorswap with $1500 budget for a set of forged pistons/rods and a decent turbo kit would again, annihlate any LS/Vtec powered car $ for $.

Conditions in which LS/Vtec would be a GOOD idea:

1) You already have a B16 swap and want more torque and have a $500-1000 budget
2) You already have an LS swap and you have come across a B16 VERY cheaply and have a $500-1000 budget
3) You have a HUGE budget, and want to make a high compression monster without ripping apart a perfectly good GSR or ITR motor.

so Cliffs notes:

Example: If you have a stock 1993 civic DX, and are asking about LS/Vtec swaps and you are on ANY kind of budget, Get an LS swap and start there, or prepare to blow up many MANY motors.

Dasfinc

Oh, and if anyone spots something I've posted that is GENUINELY incorrect, please just U2U me, and I will correct it and make note of your user name correcting the article.

JDM_LMC_TX

nice write up man, did a good job setting a lot of things straight!

CivSteez

solid thread! good write up.

NACvicSi

I suppose numerous tuners with real world experience are all noobs and should read your thread. Anyone with half a brain can build s ls/vtec right. The others shouldn't be working on cars.

Murk 'EM

good thread.. STICKY!!

Dasfinc

There are not 'numerous tuners with real world experience' posting on these forums answering peoples questions regarding LS/Vtec builds, thats why I made this thread in hopes that it gets stuck into the FAQ's

'people with half a brain' toss in a stock ECU, or forget that the LS trans kills a high-reving motors power, or etc, etc, etc. I sat and wrote this up to clarify to everyone who is 'thinking' about doing it so they know what they are getting into. There are ALOT of things to over-look (Especially the cost and reliability) and/or screw up when building an LS/Vtec,

NACvicSi

Your post is basically saying it's a bad idea to build a ls/vtec which is wrong. If you said if you plan on building one you need to complete the build correctly or it to function properly and have longevity it would be right. Like I said anyone with half a brain could do it; unfortunately 90% of H-T does not fall into that category.

Vindicator9000

^^^I agree with this guy.

There's no reason to shy away from B18/20 vtecs. They have a lot of potential, especially the B20 vtec. You just have to research correctly and know what issues you're going to run into, and how to deal with them. And you have to be willing to spend the $$ to correct what makes the blocks not as good as a B18C block in the first place. If done right, you can have much more horsepower, reliably, and for much less than the cost of a gsr swap.

Trust me, you can do it on the cheap... I just had someone GIVE me a B20z for free. All I had to do was pull it out of his CRV. Right now, I'm just starting to research on how to actually build it right - We're doing a B20 vtec to go into my buddy's EG. Aiming for around 190whp, maybe around $1500 budget.

ltrkstr2k

i agree with the 2 above me. building a lsv or b20v takes serious research and understanding of how both series motors run. OP i am not in any way disagreeing with you and lately there has been a ton of vtec conversion questions asked by noobs and all it takes is som time and reading to find the answers. anybody can order or buy a $2300 swap but not everybody can build a lsv or b20v for half that and get better results. so far in my b20v build i have less than $100 bucks in the actual conversion itself and that includes my b16 head and arp studs. im already running a b20 w/ a gsr tranny. these motors take 2 things that alot of people on this forum dont like or have and thats patience and researching. damn this is a pain in the *** to do on a PS3 lol

NACvicSi

Haha, get a USB keyboard. I used my wireless keyboard with mine and it was a lot better. I just sold my PS3 though. Thing was nothing but a dust collector for me.

Jimmy

iTrader: (5)

I'll add this to the FAQ.

coryfenton

Very good write up! I wish I woulda done some more research when building my first LS/V set up. This will definitely help many people! Thanks bro

xsteinbachx

Wow. Amazing Writeup I'm going to bookmark this and not because I'm doing an LS/Vtec, but because it's a good read.

Dasfinc

You did not read the entire post then. Please go back, and read the ENTIRE post body.

I said EXACTLY what you just said in my post, several times.

I said it here:
I said it here:
I post ANOTHER link to a correct build here:

And I say a few conditions in which I believe it would be a good idea here:
Please read before you bash.

Thank you admin for tossing this in the FAQ's, and again, I am NOT saying "Do not do an LS/Vtec" I'm simply posting a slew of often over-looked facts about this setup, some alternatives, and how to do it correctly.

Dasfinc

I'm going to tell you flat out that you are wrong on that point.

there is NO, I repeat, NO 'franken' motor that will be more reliable than a FACTORY BUILT AND DESIGNED honda motor. The rods and block of the B18B/B20B*Z Family of engines are flat-out not designed for high RPM use. Again, YES you can build one that will last you a long time, But you will NOT find a LS/Vtec with over 100K miles, let alone even 50K miles while finding Integra's with north of 200K on their original motors is a common sight.

Yes, you can build an LS/Vtec to have lots of HP and under a budget, but it will NEVER be as reliable as a fresh B18C1 or C5.

rick_rabies

i think alot of guys especially myself in the matter have a gsr or somthing similar and decide to get more out of it and lean towards ls or b20 but like you said it can be a bad investment. when we can just build a b18c and turn the boost up on it
you get a

ltrkstr2k

i agree and also disagree. there is alot of things these motors were not designed to do but yet they do. do you think that Honda intentionally made it so every series has interchangeable parts or did somebody just figure it out? RELIABILITY IS 100% IN YOUR TUNERS HANDS! you can fully build any motor have a crappy tune and be very unreliable.

ltrkstr2k

or you can slap a turbo on your bone stock motor have a great tune and be 100% golden!

D16SiHatch

agreed, but for me i would still never go the ls/v route.

i'd rather spend less money and get a good running stock gsr. thats just me though. other people i'm sure would rather do a b20v or somethin such, and that's just fine and dandy.

nice writeup btw dasfinc

Dasfinc

Honda intentionally made it so every series has interchangeable parts so it is/was cheaper for them to manufacture and have different motors share parts, not so a tuner can make a franken motor. This reduces costs for things like headbolts, Headgaskets, and a number of other items.

Also realize that every VTEC B-series head has unique/different bolt patterns on the intake manifolds to ENSURE you can only use the correct one with it, and to USE a Vtec head on an LS block you have to add an aftermarket OIL line, so it was ESPECIALLY never designed to simply be bolted on and used like that.

and I don't mean to argue, but I just explained in deep detail WHY an LS/Vtec will NEVER be 100% reliable specifically BECAUSE of its design.

I'm in the same boat (I'd rather just have a freshly rebuilt GSR swap instead of an LS/Vtec swap) As I know I can find a GSR swap, and parts for less $ than all of the parts needed for a PROPER LS/Vtec.

I just don't RECOMMEND LS/Vtec builds for the reasons I posted above, but also as mentioned, there are several circumstances that I can picture an LS/Vtec being 'practical/affordable' such as if you have a B16 swap that is getting 'tired'

Thank you.

2redstars

just curious, doesnt the type-r crank weigh the most out of all the B-series cranks?

ltrkstr2k

im not trying to argue either lol great write up! i damn sure wouldnt do that on the Ps3 lol

Dasfinc

Crank weight is nearly irrelevant, especially in the type-R as it is hand built.

The crank in Vtec motors I'm confident went/go through a more in-depth balancing, are built out of higher quality materials, and I'm sure the whole entire rotating assembly is much more precise than the LS motors, as well as the 'cradle/girdle' design in a Vtec motor is much stronger as well as it was designed for high RPM operation yet again.

The issue with the LS motor is than again, its DESIGNED to only spin up to 7200, that's how it is built/designed/made.

Dasfinc

Thank you!

I guess my bottom line is that the people on these boards asking questions REGARDING the LS/Vtec are typically not what I'd deem 'capable' tuners, and they will not build a reliable motor regardless of the guidance spoon fed to them.