Ls/vtec

[civic31g]

Anyway, I suggest you check out these sites:

http://www.c-speedracing.com/howto/lsvtec/lsvtec.html

http://www.angelfire.com/sc/thuspeed/lsvtec.html

http://www.geocities.com/MotorCity/...437/lsvtec.html

the c-speedracing site goes through most of the salient points about the process of putting the combination together.

the key to this setup is WHO does it ....not the parts you should get which is what most novices focus on only, not realizing the impending headache they will face from an improper install.

you need to find a very good machine shop locally who is precise and has a good rep for doing things to spec dead-on (like blueprinting) with aluminum heads and blocks (not just iron domestic blocks). You have to
plug the VTEC oil passage in the VTEC head (usually welding the plug in is better than just using a bolt plug) and then machine the plug down flush with the cylinder head's deck surface. Secondly, since the LS block dowel pins and the VTEC head's dowel pin holes are not aligned, the machine shop must redo the dowel pin holes by slotting them to line things up properly.

The main problem with this setup is, if machining & installing are done improperly by an inexperienced or incompetent shop, you will end up with oil leaks and coolant leaks, since the ducts for oil and coolant in the
head and block are not aligned up...they were never meant to be put together at the factory in the first place and they have to "make" them fit with adjustments at the machine shop.

I always tell LS owners that you can get much more power reliably ,if you invest in a turbo and getting the correct anti-detonation parts , instead of running an LS VTEC.

To run faster than a GSR or ITR with i/h/e, you must upgrade the pistons for higher compression in the LS block. My friend Chistian Gaines runs an LS VTEC with 11:1 CR and makes over 185 peak whp with Type R cams. Chris used to visit us over at Superhonda and gave me good advice.



Most beginners mistakenly think the VTEC head allows them to rev higher.

The rod ratio in the LS VTEC is still the same as the LS...a low 1.54. This does not help your cause in revving higher. I explain why elsewhere, if you do not know what rod ratio means and it's implications on the redline. Beginners often think that the head and VTEC gives them a license to rev higher, when in fact, the rod ratio is what allows you to rev higher safely and reliably. The head just breathes better and VTEC allows variable valve lift/duration to get a peaky powerband in a 4 cylinder engine and at the same time, get decent driveability in the low-mid rpms....that's all...having VTEC is only one part of being able to rev higher...NOT the entire reason.

These concepts don't just apply to the 1.8L LS VTEC . You can apply them to a B20 VTEC which is a CRV bottom end or block (also has the exact same rod length & stroke as the LS!) with any Bseries VTEC head (it also needs the rear dowel pins aligned and the head oil duct shut by a machine shop). You don't rev a stock block 2L B20 VTEC past 8000 rpm either.


If you know of a good local shop then you may still want to look into
doing it...I also recommend www.drtracing.com who has done several of these reliably

[civic31g]

the LS bottom end has a lower rod ratio than the GSR or ITR bottom end.

as the rod ratio on a naturally aspirated (i.e. No Boost) engine becomes lower or shorter, low-mid rpm hauling power increases.

you see the peak torque shift to a lower and lower rpm, as the rod ratio drops. This is probably why Honda chose a shorter rod ratio with a higher displacement on the integras compared to the civics.

As you decrease displacement to 1.6L on a civic , peak torque , as an absolute value, becomes smaller and you have to rely upon higher rpms to generate horsepower, instead of depending on torque. So the civic gets a longer rod ratio because of where it's powerband will be located (in the higher rpms).

The 1.8L , with more displacement, makes more torque and has a lower "hauling" or "pulling" powerband. It gets a lower rod ratio.

Please be careful about making statements about the 1.8L LS VTEC peak torque compared to the 1.8L VTEC peak torque. You hear this statement that the 1.8L LS VTEC makes more torque (assuming the same cams , redline, header/ cat/exhaust, and static compression ratio in both engines). In most cases, unlike this myth of more torque in an LSVTEC, the B18C actually makes as much or more peak torque..BUT AT A HIGHER RPM: it's rod ratio is higher or longer than the LS VTEC's. The key here is: the VTEC engine with a better rod ratio can happily rev all day at a higher rpm than the LS VTEC over the years. You can push a stock B18C bottom end to 9000 rpm as long as the valvesprings are upgraded. You can't go to 9000 rpm on a stock LS block's rod ratio.

[civic31g]

A low rod ratio motor likes a certain intake manifold runner length / diameter , intake port shape and size in headporting, cam spec, header length/diameter, exhaust diameter. A short rod ratio motor likes a totally different set of parts with different design characteristics. And with these packages, the powerband (which is about 2000-3000 rpm in width if you are a good tuner) can be moved up or down the rpm range to your liking. Where it is placed dictates your tranny gear ratios. The narrower and peakier the powerband, the more gears you will need. You want your shifts to fall to an rpm just below peak torque to get the most acceleration.

It all ties together. Buying a part without overseeing how it fits in the whole thing makes for a disappointing result both at the dyno and more importantly, at the track...it's a lousy feeling not getting what you expected based on how much you worked hard for, saved, and spent...all because you don't understand engine package, powerband locating, and gearing. Trust me, I've been there. I eventually learned from pretty smart generous people. Hope this helps you guys think it through better and avoid the future letdowns.

As far as costs go, converting an LS to an LS VTEC can vary from $2000 to $10,000: the bare basics with a stock LS block and no change in the bottom end internals will run you $2500 for the head (legitimately obtained and not stolen of course), machine prepping of the head ducts and dowel pin alignment, VTEC ECU & wiring harness, and proper install. Some people, like importbuilders.com for instance, charge as much as $8000 for the whole shabang with a lot more upgrading on the cams,valvetrain/cam gear, and bottom end.

As I said, most people move the CR up and keep the revs at 8000 rpm max. Please look at Chris' dyno above again. In an LS VTEC with an 11:1 CR and ITR cams: over 185 whp and a well-tuned flat torque curve from 6000-7500 rpm sitting at peak torque for that powerband (6000-7500 rpm)...and a nice safe 8000 rpm redline. That's all you need to run low 14's-high 13's et (assuming decent tires, engine mounts, and springs), all day, every day without going kaboom IMHO. If you want more than this by having 11.8-12:1 CR and cams with 12-12.5mm lift, 255-260 duration in an all motor setup, that's your business.

I suggest at least talking to people like drtracing.com or c-speedracing.com for their advice and experience , if you are thinking of doing this. They don't charge $8000-$10,000 for an LS VTEC build up.The oil/coolant leak thing and lower revs than a VTEC block are huge issues to remember for the LS VTEC reliability.



cheers"

as posted by user TUAN on automotivetech.org

http://www.automotivetech.org/forum...=&threadid=3854

also go here

http://www.theoldone.com/articles/badtothebone/

[civic31g]

some other general information

http://www.hondaswap.com/forums/index.php?showtopic=11

here is a kit made by eagle, it looks quality and i have heard good things about it so far

http://www.robearracing.com/pd_gold...e_full_vtec.cfm

here is whats included for the lazy people who don't want to go look

"FULL VTEC CONVERSION SYSTEM

- We now have a Full Vtec Conversion System for people that want to use an LS/VTEC or B20/VTEC set-up.
- This kit is the easiest and most complete way to supply oil to the head without any machining required and is very clean and reliable.

The kit includes:
- 1. Golden Eagle Vtec Conversion Sandwich Plate with a -6AN fitting for the plate and head.
- 2. -6AN steel braided teflon hose for oil supply
- 3. Golden Eagle Vtec Conversion Dowels for proper alignment of the head and block without machining
- 4. 1/8 NPT tap and plug for the oil port in the head
- 5. Golden Eagle worked factory head gasket with any bore size and dowel holes opened for any application

-When we say " NO Machining " we mean that there is no reason that anyone cannot do this kit in their own garage. - The only thing that must be done is tapping the head for the plug .
- The VTEC line and fitting all use existing ports with no need to do anything else.
- Sold as a kit with full instructions.
- Individual parts can be purchased separately."

[civic31g]

dynos of the ls/vtec










go here for more dyno's of 1.8L engines

http://www.importreview.com/d_1.8.html

[civic31g]

"Subject: LS/VTEC with GSR head VS B16A head similar mods.



This is a VERY good comparison to look at...

Question: What is the best head to put on my LS/VTEC, GS-R or B16A?

Answer: In the opinion of Atomic and myself, I have to go with a GS-R head.

Look at the graph...here is the 2 motors..

On 1 side we have the LS/VTEC B16A head...coming in at 180 HP...
The bottom end is EXACTLY the same as the GS-R LS/VTEC...exactly...
so it makes for a good comparison.

B16A has:
port flow port/polish (mild)
Civic Type-R intake cam
ITR exhaust cam
Comp valve springs/retainers
Type-R intake manifold

GS-R head has:
Stock head
Stock valvetrain
Stock intake manifold
ITR cams, intake and exhaust.
and it made a little more power, as you can see by chart.
With the GS-R head, you also will definitely get more torque.

For the money though, B16A head is a good choice.
Remember, this is not a perfect test, it just shows a pattern....

Jeff"

go here for more comparison info

http://www.importreview.com/performance.html

[cynosurecivic]

is that vtec conversion kit for real? cuz if so i want to do a b20 vtec. i already got a b16a. so with this kit, all i would need is the b20 block and this conversion kit? hmm, how much for a block?

[civic31g]

Originally posted by cynosurecivic@Jan 20 2004, 11:24 PM
is that vtec conversion kit for real? cuz if so i want to do a b20 vtec. i already got a b16a. so with this kit, all i would need is the b20 block and this conversion kit? hmm, how much for a block?

yes the kit is real. i think i put up the site were you can go to get one. not sure on how much the b20 block is. but you need to read everything before you decide to do this, cuz imo this is not worth all the trouble you are going/might run into. better to just go with the b16 or b18. but like i said just my .02

[cynosurecivic]

well i already got the b16a in my car and am currently saving up to buy a turbo kit. theres just something about the b20. it has a ring to it. if i had my way, i would do the b20 and boost that. but i dunno if i can afford that. think i'd be better off just boostin the b16?

[civic31g]

Originally posted by cynosurecivic@Jan 20 2004, 11:28 PM
well i already got the b16a in my car and am currently saving up to buy a turbo kit. theres just something about the b20. it has a ring to it. if i had my way, i would do the b20 and boost that. but i dunno if i can afford that. think i'd be better off just boostin the b16?

i would save up and rebuild the b16 and boost this sh*t out of it. you will see much more gains with that. The b20/vtec switch can cost an arm and leg if you dont do it just right. anf if you get this to work for $2,000 then you could have done an almost complte rebild of ur b16 and got to boost it to like 20 psi. and tell me which car would win? a n/a b20/vtec or a 20psi b16? i think you get the point.