Thinking about going ls/vtec......

but i have a couple of questions for you techies. I found an ls block today, and it is in good shape. I am currently running a b16a, but unfortunately got the automatic version. I have been missing the torque ever since my swap, and want it back, so i figure the ls/vtec is the way to go. My biggest concern is that i have heard, even if done right, is still somewhat unreliable. I have heard that the cranks on the ls block differ from that of a vtec block, where there is not one rod that operates all of them, but they are instead independently working together. I hope i have not confused anyone, but if this is true, will it still be reliable? I am not planning on taking the car over 8000 rpm’s under any circumstances, and do want a turbo for my future, but not for a few years. I really want the tourque, and figure if i can get an ls block cheap then it’s all good. Also, what do you guys think would be a good price for an ls block? I think the guy was offering me a couple hundred, which seemed reasonable, and i have a friend who does swaps all the time and he will be doing it with me. If i do the ls/vtec, i plan on building up the motor before it goes in, so i’m not worried about any parts that might need to be replaced. If you guys could help me out, it would be great, thanks.


i believe what you said regarding the crank is the main downfall. this being if it’s overeved. once over or around 8k you start to get “chatter”, or a side to side motion of the rods. this is when you see rods blown through the block. i am by no means a techie, but this what i’ve read and been told. remember, it could only take that one mis-shift to end your motor.

good luck :up:


Build the bottom to compensate for the top, so youc an safly rev it up, i personally would love to get into this but lack of funds are holding back :frowning:

that sounds great, thanks for your help. What would you recommend to “build it up” as you say? I’m not too familiar with what would help me out in this situation.

Well from what i have read the main problem with people and their ls/vtecs dying is because they just slap a vtec head on a bottom end that redlines at 6800 and just expect it to handle trips to 8k + …Things that are wrong with b20 bottom ends are the rod to stroke ratio sucks, and after revving it hard the already thin cylinder walls of the b20 start to become oval in shape…Also i would think the rods need to be replaced with better ones to handle revving higher safely. Rob bearings would need to be replaced, you will need a better oil pump. Just pretty much rebuild your bottom end, maybe balance the crank, rods, maybe re-sleeve the block…

btw im just saying what i would think needs to be done to make it run safely and reliably.

yeah, if i do it, it will definetely be a b18a/ls block. Does anyone make an aftermarket crank for that car where you can take it to 8000 safely? just wondering, thanks.

The problems associated with most lsvtec setups is the rod/stroke ratio isn’t exactly ideal and is widely believed to result in some issues with piston side-loading which in-turn causes the cylinder walls to ovalize over time. This can be combatted by having the block resleeved and/or getting .137" lengthened rods and pistons with raised wristpins. With this kind of stuff you would be talking big money and depending on the setup is often not necessary. Another problem often associated with the lsvtec build is with the stock rods. Often times people will reuse their stock rods and rod bolts. In many applications the stock rods are fine as long as you upgrade to ARP rod bolts. If your rods have a ton of mileage on them or you’re going with a “wild” build then you may want a set of forged rods which will come with ARP rod bolts. One of the most overlooked issues is tuning. This is not a factory motor but you will find that many people will try to run it untuned off of a stock ecu. This can lead to detonation issues from lack of fuel at high rpm’s and/or improper ignition timing. Another major cause is revving the motor too high. You need to have an understanding of your motor’s capabilities. Depending on the lengths taken to strengthen the bottom end as well at what rpm’s it makes power is where you need to shift when racing. Revving past this point (which depends on your specific setup) is a common cause for failed lsvtecs.

The lsvtec has it’s drawbacks. Having one that is reliable depends on a combination of how it’s built and how well the driver knows the limitations of that specific build. There are a lot of guys out there that are using stock rods with ARP rod bolts on a balanced bottom end and have had great reliability out of it.

Take your time to research and check out other people’s setups and see for yourself what works and what doesn’t. Then come up with a plan that meets your expectations as best as possible (I throw that phrase in because an engine build is a series of compromises). You can have a reasonably reliable motor out of it.

things to do to insure bottom end reliability:

-good cylinder hone
-hastings or OEM piston rings
-arp rod bolts
-resize big end of rods to compensate for rod bolts
-shot peen rods to decrease fatigue and restrengthen
-run ACL or pr3 (b16) main and rod bearings OR notch rods to accept b18c p72 rod bearings. (b18a bearings are bi-metal while vtec motors and ACL are tri-metal)
-balance complete bottom end
-polish crankshaft
-gs-r water pump
-gs-r oil pump
-gs-r timing belt, new tensioner
-new gaskets and seals
-gs-r headbolts
-golden eagle dowel pins, OR golden eagle ls/vtec conversion kit

most important… a GOOD BUILDER. put together right, that should get you to 8000-8400 rpm pretty good.

the dude that just posted above me listed way too much shit… there is no way you need all of that to rev to 8k… all i have are arp bolts and i rev to 8k once in a while when i race, and ive had my engine find for 1.5 years… all the shit he listed 9k :rant: rpms

better safe than sorry

Yea… U need that stuff to rev high… My personal opinion on the whole resizing rods, shot-peening, oil squirters, yadda yadda is just get beefy aftermarket piston/rod combo… They come with ARP rod bolts, no need for oil squirters… may be more expensive, but u can tell all your friends u have JE pistons. LOL. U definitely need the stuff like VTEC oil pump, GSR head bolts, etc.

Wow guys, thanks alot for all the great info. I have been a member of a few honda sites, and next to, this is the most friendly site for getting help. Thanks again for all the tips.

Correct me if I’m wrong, but people always talk about how reliable the LS motor is but how UNreliable the LS/VTEC is. My question is, the only difference is the head so as long as you don’t rev much over the stock LS block’s redline then wouldn’t the LS/VTEC have the exact same reliability as the LS? I’m sure there is a answer to this that I’ve missed somewhere but it just seems like the only problem people have with their LS/VTECs is trying to rev like a B16 when they have an LS block.

LS/VTEC becomes unreliable only when you don’t build it right. Bottom line. End of Story. I have an LS/VTEC that saw the track 2-3 times a month (I shift at 9000rpms) for the past 3 years and ran great before I got rid of it… So I could build another LS/VTEC setup.

The keys are: Rods and rod bolts, Oil pump, and either good machining of the head, or get the GE kit so u plug up all the holes that need plugged and u have adequate oil supply to the head.


I’ve had my ls/vtec for about a year now, and its very reliable, i even drove it to texas and back without a problem, this was a stock vtec head and stock block. Now i’ve upgraded my pistons to pr3s and i’m loving it. It all depends on the owner, if your building your car to be race prep, then i suggest getting it built, but if your a weekend racer, going gettho wouldnt hurt your motor that much. I never worried about it because i have a spare block to work with. My ls block has 140XXX on it. 135,XXX when i did ls/vtec.

Thanks for the info, I’m pretty sure on going LS/VTEC. What kind of heads are you guys running? I’m thinknig a B16 head because it would b cheaper or would a GSR head be a better choice?

b16’s are suppose to have a little better airflow or something… there is a thread somewhere that has both of them matched up… i think the gsr had 1 more top whp but the b16 beat it most of the way… anyways b16head=typeR head - some porting and parts

← Running B16 head with ITR valvesprings/retainers… Next month I should get the new head back though… B16 head P&P… Then, cashflow permitting, I wanna give it the rocket motorsports makeover w/ some m24x’s.


wanna do an ls/vtec?

i posted that up. it was on the alaniz technologies website but he’s updating it right now. ALANIZ TECHNOLOGIES

the ls/vtec issue has been covered many times on here, i suggest you do a search on it, my thing on ls,b20/vtec is that they are reliable if you build it right. regard less of what you put in it. and to all those who dont recomend it…dont knock it if you havent tried it. ive commuted about 100 miles a day for a few years on an LS/VTEC back in the day.
ive been building LS,B20/vtecs since 1999 and will keep on building them.
my DA street car has a B20/vtec on a 100 direct port with a ported b16head
my ALLMOTOR race car has a RS machine built block stroked b18 to 2.2L with a B16 head with competition ports by alaniz.

“An open mind is more useful than an open mouth.”
EFI 101 certified

hybrid what kind of work you do? i need to build my shit… its just stock b20b and stock b16 head… but i got about two g’s to toss into it