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Discussion Starter · #1 ·
i have a 90 ls with a b18a and i think the head gasket is going bad im getting it presure checked today. If it is i was thinking that since im going to have the engine apart i could do a vtec build up i was serching through to articles and i couldnt find anything about it i was wonder what i have to have and do to do this is it as simple as finding and buying a vtec head and tuning it if so what vtec head will fit my engine if not what do i have to do and where can i find the parts im really new to the integra world and i know you can really mess things up if you go half ****ed i appritiate all the help i can get

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3,329 Posts
90teg, there is a lot that goes with LS/VTEC. I'm sure some will be for it and some against it. the cost will be rather high. the main thing I can tell you is find a reputable machine shop with experience doing an LS/VTEc conversion. there is a ton of info out there on the internet, and a few TI'ers that have done it too. ( I am currently in the process, but I'm looking for parts)
another term is a Frankenstein motor.
If you want I'll have more to follow

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115 Posts
just FYI here's what I've gathered so far and its prices:

B16a complete head $475
CTR cams $600
ITR Pistons w/ rings $350
s.s. oil line kit $120
ITR water pump $75
ITR oil pump $75
ITR timing belt $65
p72 ECU $150
skunk2 cam gears $200
top end gasket kit $170
ls head gasket $65

still need:
p28 JUN/skunk2 chipped ECU: $250
clutch masters stage 3 clutch: $520
prelude 270cc injectors: $120
B&M fuel pump: $150
B&M fuel pressure regulator: $150
Machine shop to install & balance parts: ?

So, I wish it was as easy as "all i need is a B16/B18c head and off I go". It takes a lot of money, but hopefully in the long run, i'll be satisfied...if not then you'll see me posting up my engine for sale. haha

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21,139 Posts
Another LSVTEC question on how good is it, is it "worth it" (whatever that's supposed to mean), what parts, what's the cost, should I turbo or SC it...

some call it a RS/VTEC, GS/VTEC, or SE/VTEC...

any VTEC Bseries head can go on an LS (B18A or B18B) block... You need the proper machining (increase intake side dowel diameter holes to 14mm) to align the dowel pins and machine taper the dowel pins down to the same height as the amount of deck height you removed (actually 20 thousandths in. more than what you milled off the head deck and block deck) so that the head can seat evenly on the block. New headgasket, valve cover gaskets, and cam seals are a good idea. You also need to plug the VTEC solenoid oil duct on the head (Golden Eagle has a simple kit for this now including a headgasket). People suggest using the GSR head bolts or GSR ARP head studs, the VTEC distributor (flange bolt pattern differs from LS distributor and sits lower), and GSR water pump/timing belt (LS head & pump has too much slack). It's up to you as to whether you want to tap the block to add a knock sensor like the VTEC motors using a 10.9mm bit tapped to 12mm x 1.25mm and sealed (remove all shavings). Hondabond is your friend.

Here are the head volumes of all the VTEC Bseries heads which will affect your final static CR (the lower the head volume, the higher the CR will be) : GSR ( B18C1, 41.6 cc head volume), ITR (B18C5 head volume 42.7 cc), Si (B16A, 42.7 cc head volume)...

it's old news...

here's the story of how it all began by it's inventor , Steve Rothenbuehler (Omniman)

* B18B block
* Custom Crower Maxi-Lite connecting rods
* USDM ITR pistons
* B16A head with mild porting
* ITR valvetrain (springs, valves, lost motion assemblies)
* Crower Ti retainers
* stock B16A cams
* RS Akimoto short RAM2 intake
* JG 64 mm throttle body
* ITR intake manifold
* JDM 98 Spec R 4-1, 2.5 in. collector exhaust manifold
* Z.Speed 60 mm stainless exhaust
* B&M adjustable FPR
* RC Engineering 310 cc injectors
* Crane ignition (noisy ass crap)

how the ls-vtec came about.......

The first ls-vtec was built in denver colorado at Speed Image, i worked there from 96-98.

It all started one night in the summer of 97 when we were driving home from work. I was in my 92 GSR and hoang (the owner of speed image) was driving his cousins 92 CX hatch with a gsr motor. while we were driving home the CX died on the freeway . we towed it back to the shop, pulled the head off and found that one of the stainless steel valves had broke, taking out the entire motor. after some investigating we finally found out that one of the other cousins had over reved the motor and bent the valves but didnt want to get in trouble so he didnt tell anyone.

I felt really sorry for Tin the owner of the car. he spent a lot of money on it and now this had to happen. Tin literaly spent every penny he had getting his motor in the car and running (everyone knows how that goes).

Hoang and I looked everywhere but could not find another GSR motor. at least one that we could afford. the only thing we had at the shop was a 90k mile LS block that someone had sold us for a $100 and a GSR head.

I started comparing things, like heads, blocks, head gaskets, oil pumps, etc. it looked close enough for the most part and i decided to see if we could put the 2 together.

The first problem was the dowel pins had to be relocated to the other side of the head, no big deal. i went and bought a 9/16 drill (couldnt find a 14mm) so 14.2 would have to do. i mocked up the motor with one valve in each side of the head caddy corner so i could look through the exhaust port and see the intake valve and visa versa. with GSR cams there seemed to be just enough clearance when vtec was locked on.

after that i installed the head (all stock) and put the motor in the car. when we finally got it running it felt great but there was no vtec. so back to the drawing board.

I took the blown up motor and did some more comparing and noticed the oil hole where the vtec got its oil pressure from wasnt in the LS block. so i pulled the head off and figired if i added oil pressure to the passage it would work. of course i had to plug up the hole in the bottom of the head so it wouldnt leak.

With the head back on we took it out for test drive and it worked. not only did it work but it felt faster than any na motor we had felt. i took it to Dyno Pro (the local dyno tuning place owned by Bear Lynch) and it put down 154 whp and 125 tq

about a month went by and we saved up and bought some type-r piston from the local honda dealer. i wanted to see what would happen if i put a point of compression in it. but when i went to install them the rods were too wide and would not fit in the pistons. so i took the rods to a local maching shop and paid 50 bucks for them to shave 1mm off each side of the small end of the rods. they looked at me like i was crazy.

it was a friday night and i worked on the car till about 12:30am and finshed putting it all back together. i really just wanted to get this guys car back and running, since it was his only car. i could definately feel a power increase.

everyone took turns driving it that weekend and we all wondered how much power the pistons made. the fallowing monday i took the car back to Dyno Pro and rebaselined it. wow it made 165whp and 130 somthing tq. the car felt really good even considering it was in denver (5280 feet above sea level). the pistons picked up 11 whp.

a few weeks later i drove it to dynamic autosports for a type-r intake cam and a throttle body. aslo is was a good test to see how reliable it was, since it was an 1100 mile trip each way.

i made it no problem the motor didnt miss a beat. we installed the type-r cam and throttle body and put it on their dyno. we hit 180whp with a full exhaust, a new NA record for their dyno. but the next day some guy came in with a full race ls motor on carbs and made 182. lol , at least i had the record for a day.

after that, i drove the car back to denver and there it lives to this day. it has changed owners 2 times. it even won a burn out contest. and up until a year ago it was still running but i havent kept track of it since then.

thanks everyone for your interest. omniman

please run a search...

we milked this topic to death here already. search under LS VTEC, LS/VTEC, LSVTEC and enter that term using the phrase option under the Advanced Search...

also please check out these excellent sites:

TI thread on Golden Eagle's Oil Line & Dowel Pin Conversion Kit

itr pistons are to add compression but you need to mill the small end of the LS rod by 0.7mm on either side for them to fit. they don't reduce wear. Si pistons fit right on the LS rods without having to mill it and will bump up the static compression ratio above 11:1.

CR Calculator: Click here to see how much each piston increases the static CR with each head on an LS block.

The rod ratio (r/s) is still the same at a low 1.54 , since you still have the LS crankshaft and LS rods (same length) and so your piston sideloading and wear from the more extreme LS crank to rod angle is the same as before. This means you shouldn't scream it past 8100 rpm too often if it's a daily driver. If it's a race engine...rev it to whatever you want, since you will rebuild it sooner (eg. 1 week or 1-6 months).

Adding a block girdle (from a B18C, Z10 Engineering, or Endyn) helps the reliability of the engine, as this supports the block's mains and maintains consistent main bearing clearances.

Some people even go the extra mile and add oil block squirters to the B18a/B18b block just like on the VTEC blocks to cool the pistons & rods down for the higher revs.

LS/VTEC's are notorious for vacuum, oil, and coolant leaks,if the assembly and machine shop prepping of the head and block aren't done correctly. This re-emphasises the importance of selecting an experienced engine builder/machine shop that has put many together successfully before (proven track record of building them and they last for more than 1.5-2 years). Again, not revving as high and maintaining the engine lubrication will also prevent problems.

I would suggest definitely using ARP head studs instead of Honda head bolts here. ARP rod bolts torqued to their stretch specs are also a good idea, if you plan to freshen up the rod bearings and change out the rod bolts for higher revving (but keeping your stock rods). Checking the dowel pins for the same proper height once they're on the block so that the head seats evenly on top of the block is a good idea since a lot of the oil leaks originate there and at the head oil line tap.

If you boost it, keep the boost low, like below 8 psi due to this mismatched head to block issue. Boost just puts more stress on the mismatch because the added cylinder pressure inside will want to make the head lift off if the head fasteners (head studs or head bolts) aren't aligned and torqued down properly.

Costs without any piston change run around $2500-3500 including the head and VTEC harness and about $5000-6000 with an upgraded tranny. You can go wild and pay up if you want everything upgraded.

BTW if you already need to replace the pistons and rod bearings in your block anyway, you may then want to look at going to a junkyard and locating a B20 block. You can have 84.25mm-84.5mm bore, high compression aftermarket pistons put in, have the B20 block honed to 84.25-84.5 mm (stock B20 bore = 84mm), align hone the block's mains, add a block girdle, and then have the block prepped for a VTEC head in the same way as the LSVTEC:You would have a 2L all motor monster with 200 whp and 150 lb ft torque quite easily when properly fuel tuned (yes I have seen 170 whp B20VTECs...not tuned).

Cost out the prices for boring/honing/resurfacing the deck on your LS block, slotting the dowel pin holes so that the pins align with the VTEC head, dropping in new pistons, ( and if you want new rod bearings, and rod bolts).

Then cost out a B20 block, the cost of honing the block only, resurfacing the block deck, slotting the dowel pin holes to accept the VTEC head, dropping in pistons.

just something to consider. You'd be surprised about how close the prices are and what you get in return powerwise for each.

So everything that applies to an LS VTEC applies to the B20VTEC or CRVTEC as well.

Good Luck.

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1,652 Posts
Yeah, I have always liked the idea of a lower rod ratio and smaller port volumes (b16 head and LS block), but this is the only dyno that I have seen it the torque curve pick up at 5k. I'd like to see it with a better exhaust system. Oh well, ya learn something new every now and then.
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