To add a VTEC cylinder head to an LS bottom end, you must tap and plug the VTEC oil supply hole found on the bottom left side of the head. A 1/8-inch pipe plug will work well for this. Next you must run an oil supply line from a T-fitting placed on the oil pressure sending unit boss on the block to the VTEC oil galley plug found on the intake side of the head near the distributor. To make the oil line, you need a piece of -4 braided steel line about 20-inch long, with two female A/N fittings attached (an industrial hydraulics shop can make this for you), a 3/8-inch NPT to -4A/N adapter for the head, a 1/8-inch NPT to -4 A/N adapter and a 1/8-inch NPT T-fitting with two female sides and one male side.
You must also open up the dowel pin holes on the VTEC cylinder head to 9/16-inch as the LS block has larger dowel pins to locate the head on the block. This is a pretty simple operation that can be preformed on a drill press. If you don't feel like doing this, the operation can be easily handled by any competent machine shop.
An LS head gasket is used with the appropriate VTEC ECU for your year and chassis of vehicle. A jumper wire running from the appropriate pin in the ECU to the VTEC control solenoid completes the VTEC activation. The proper VTEC ECU is the ECU for the VTEC model of your vehicle. Below is a chart with the pin locations where the wires to control the VTEC solenoid connect.
It is also critical to hook up the knock sensor or the VTEC function will not work. The engine's ECU looks for the knock sensor signal in order to activate VTEC. The B18A and B18B block has no provision for a knock sensor. In this case, or if you don't want to run a knock sensor, you can do several things. You can have a knock sensor not attached but grounded to the chassis and connected to your ECU, or Hasport has ECUs that are reprogrammed to allow VTEC operation with no knock sensor input.
Another very potent Frankenstein combination is using the B20 bottom end from the CRV mini sport utility, with a VTEC cylinder head. The B20 bottom ends that are desirable are the B20B ('97-'98 CRV) and the B20Z ('99-'01 CRV). With a big bore of 84mm and a stroke of 89mm with a whopping displacement of 1973cc, a B20 Frank has the potential to be the meanest of all the Frank engines.
Of the two B20 engines the B20Z has more compression at 10.2:1 over the B20B's lower 8.8:1. This is because the B20Z has a flatter top piston when compared with the to the B20B's deeper dish. The lower compression B20B is more desirable for a bolt on supercharger or turbocharger kit because of this. If you wanted to run high compression with a B20B/Z there are no factory pistons that can do this, but any number of quality custom forged piston makers, such as JE, Aires or Wiseco can make a piston for the B20B/Z. This piston should be made with a dome volume to give about compression ratios from 11:1 for the street to 13:1 for race gas. With 11:1 pistons and a VTEC head mildly worked over, it can be possible to have a very impressive engine for very little money.
The procedure to swap a VTEC head on the B20B is the same as the LS swap with the exception of using the B20 head gasket. A naturally aspirated, mild B20B can easily get more than 200 hp on pump gas with more than 150 lb.-ft. of stump pulling torque.
As a warning, when the VTEC head is installed, there's not a whole lot of piston-to-valve clearance as VTEC heads have larger 33mm intake valves vs. the B20 engine's 31mm valves. If you are dyno tuning, contact will occur between the piston and valves if the cam is advanced much more than 4 degrees, so be careful. In fact this is so close it's not advisable to advance the intake cam at all.
If running larger lift and duration aftermarket cams in your B20/VTEC Frank, or if the head has been modified for higher compression by milling, the piston's valve pockets should be modified and the valve-to-piston clearance confirmed before the head is final assembled to the block. Carefully grinding the piston's valve reliefs with a die grinder with carbide burrs and polishing the result with cartridge rolls can obtain additional clearance. A minimum clearance of 0.045-inch on the intake valves and 0.055-inch on the exhaust valves is advisable.
Camshafts, Valve Springs and Valves
When it comes to cams in the B-series engine, you can swap them back and forth without problems. The hot cams to get in this case are the U.S. market Type R Integra cams or the JDM (Japanese Domestic Market) Civic Type R cams.
These factory cams are quite respectable, with near racecar lift, duration and overlap on their high rpm lobes. Being VTEC, they still purr like a stock engine at idle and low speeds and will still be able to pass your local smog test.
With the exception of the Type R cams, all of the standard B-series engines have similar high rpm VTEC lobe specs. They all have 230 degrees of intake duration (measured at 1mm of checking clearance) with 10.6-10.7mm of lift. On the exhaust side, they have 227 degrees of duration and 9.4mm of lift. The cams all have about 17 degrees of overlap.
What works really well on all of these engines is to swap the cams for the Type R Integra cams or the JDM 1998 Civic Type R cams. The Integra Type R cams have 240 degrees of intake duration with 11.5mm of lift while the exhaust sports 235 degrees of duration and 10.5mm of lift. The Integra Type R cam also has 25 degrees of overlap. The JDM 1998 Civic Type R cams is slightly bigger with 243 degrees of intake duration and 28 degrees of overlap.
When installing these cams on a non-Type R VTEC B-series engine, you should install the appropriate Type R intake valve springs on the exhaust side of the head. U.S. market B engines--with the exception of the Type R--only have dual springs on the intake valve. The dual exhaust valve spring is important to help handle the extra valvetrain velocity that the much higher lift Type R exhaust cam has. The regular B-series dual intake valve spring set-up can be run with the Type R cams because they are actually stiffer than the Type R intakes. This is because the Type R valves are lighter than the regular B-series valves.
Type R cams can gain from 8-9 more top end hp--sometimes even more when the cam timing is optimized--more than the stock B-series cams and are an excellent value in streetable performance cams.
As a cost saving measure to avoid having to buy exhaust valve springs some people have success installing only the Type R intake cam. Just the intake cam alone can result in gains from 6-7 hp.
Below is a chart with the part numbers of the hot Type R cams and the valve springs needed to run them, at least on the exhaust side.
TYPE R PART US B18C5 TYPE R JDM B16B 1998 CIVIC TYPE R
Intake Cam 14111-P73-J00 14111-PCT-000
Exhaust Cam 14121-P73-J00 Same
Inner Valve Spring 14751-P73-J01 Same
Outer Valve Spring 14761-P73-J01 Same
You may also want to run the Type R valves. Although they are the same diameter as the regular B-series valves, they have an improved contour for better flow and they're lighter. A good head porter can contour the stock B-series valves to match the Type R valves, but if you need new valves, the Type R valves are preferable.
If you don't want to run the Type R cams, desiring even more top end power, excellent streetable cams are made by Toda, Spoon Sports, Skunk 2 and JUN. The big American companies like Crane and Crower are also getting into the game with their own billet offerings. Crane in fact already offers a radical profile, friction-reducing roller cam and follwer set; they aren't cheap, however. When running other cams, please note that on finger follower engines like Honda's it's critical to run near stock base circle billet cams for long life and proper true to spec valvetrain geometry. Regrind cams just don't work well with these engines. Poor peaky power bands and rapid wear can result from regrinds.
With aftermarket cams, it's also important to run the manufacturer-recommended compatible valvetrain parts, most importantly the springs and retainers with these cams.
Pistons
For an all-motor street-driven car, the factory Type R pistons are the best bet. This is the U.S. or JDM Integra Type R piston for the B18C and the LS VTEC Frank engine with the JDM Civic Type R piston for the B16A.
Type R pistons are a high-pressure die cast construction. This is the best way to make a cast piston. Since they are cast, they are not the best choice for a nitrous oxide-burning engine but they are excellent in all-motor applications. An advantage for cast pistons in a daily driver sort of car is they can use a much tighter piston-to-wall clearance. This makes for an engine that's quieter and burns less oil. Cast pistons are also easier on the cylinder walls.
The Type R pistons have a black dry film lubricant coating on the skirts for longer wear and less friction as well as additional oil holes in the ring grooves for better high rpm oil control. Type R pistons also have holes in the wrist pin bosses to improve wrist pin oiling. As an interesting and useful fact, all of the B-series engines have the same compression height, so the pistons interchange.
For a Honda street engine that will run on pump gas, the maximum compression that should be run is in the low 11:1 range. The reason why Hondas can get away with this high compression ratio with modern unleaded fuel is mostly because of their superior combustion chamber shape and small bore diameters. Higher compression than this requires racing gas to avoid detonation. With cast pistons detonation should be avoided at all costs as they are more brittle than forged pistons.
The Integra Type R piston is available in two versions, the P73-00 JDM version and the P73-A0 U.S. market version. The difference between the two is that the JDM piston has a slightly taller dome, which gives about 0.2 higher compression. The U.S. Type R A0 piston is the piston to use in the larger displacement LS Frank engine, as it will yield approximately 11:1 compression with this combo due to its lower dome. The JDM 00 piston is the piston of choice for a B18C as it will yield about 11:1 in this combo.
The JDM Civic Type R or PCT piston has the highest dome of all the Type R pistons to get 11:1 compression out of the smaller B16 engine. It's not recommended this piston be installed in a B18C or a B18B or a Frank engine as the compression ratio will end up being unstreetable, close to 12:1. This compression is good for mild race applications with racing fuel, and is in fact a popular combo for hybrid Civics raced in NASA's PTTC road racing class.
When running Type R pistons on a B16A or a B17A engine, you must remove 1mm of material on each side of the small end of the connecting rod in order to have sufficient clearance where the rod meets the piston. Any automotive machine shop can easily do this operation.
As a warning, since 11:1 is close to the limit of streetable pump gas compression and the fact these pistons have relatively high domes, it's important to verify your engine's compression ratio, valve-to-piston and piston-to-head clearance if your head was modified by milling or quench welding before final assembly. The head and piston domes should be cc'ed and the clearances checked by the clay method to insure that no interference will occur.
Intake and Exhaust Manifolds
A popular swap to gain some additional power is to run an Integra Type R manifold. The Type R manifold is a short, larger diameter, single stage manifold with a larger plenum. It lacks the dual-stage runner system of the B18C engine, and is optimized for top-end power. When doing a manifold swap, you can use either a U.S. Integra Type R or JDM Civic Type R manifold; both work equally well. The only difference is the location of one vacuum fitting on the manifold's plenum, which has absolutely no effect on anything.
The Type R manifold is good for about 6 hp at the wheels at high rpm, with perhaps a slight loss in power below 5000 rpm. The manifold is a direct bolt on the B16A cylinder head and thus works well for any B16A or any Frank engine using this head. It also fits on the rare B17A1 '92-'93 Integra GS-R engine. On the B18C, the flange of the manifold must be extensively modified for it to fit, as only the bottom manifold-to-head bolts line up. There's also a problem with the location and alignment of the coolant passage, this must be welded up and ported for the correct shape. The upper boltholes must be welded up and redrilled in the correct location and the head match-ported to the manifold. After welding, the manifold's head flange must be resurfaced so it will seal properly. After all of this mess, the injectors hang down into the airstream and disrupt flow, making this a poor way to do things.
Perhaps a better way is to cut the flange off of both manifolds and weld the B18C flange onto the Type R manifold. After welding, the manifold's runners can be cleaned up and match-ported for good flow. Fortunately, if this seems like a great deal of work, Skunk 2 has come up with a bolt-on copy of the Type R manifold that bolts right onto the B18C with no hassle. American aftermarket giant Edlebrock is also offering a direct bolt-on B-series manifold.
To do a clean install of a Type R manifold onto a B16A head, you need the following parts: a fuel rail from a '94 Integra; a '93 B16A del Sol; a '99 Civic Si, '92 or later JDM B16A or a B18C engine; an idle air control valve and 12mm mounting bolts from a '92 and later Integra, a '92 and later Civic Si or EX or a '97-'98 CRV; a throttle body gasket from an Integra Type R; and an intake manifold gasket from an Integra Type R.
A 62mm Type R throttle body to replace the stock 60mm one is a nice addition at this point, but it may be cheaper to get an aftermarket 64mm throttle body from RC engineering or JG.
On the exhaust side, a very effective upgrade is to install the JDM Integra Type R exhaust manifold. This is good for about six more wheel hp over the stock manifold. Interestingly enough the JDM manifold is a 4-1, equal length, tubular stainless steel header. The JDM Type R exhaust manifold fits all B-series engines.
Connecting Rods
The JDM Civic Type R with the B16A engine has improved connecting rods featuring steel with higher chromium content. Adding chromium to the steel greatly increases its strength, much like the chromium and molybdenum in chromoly makes it much stronger than regular steel. This steel is standard in the U.S. B18C and Integra Type R rods, but not in the U.S. B16A. The B16A still has pretty decent rods, so it's probably not worth it to go out and buy a set of JDM rods, but if you do have a choice, it's good to know the JDM B16A rods are stronger.
Any stock rod can benefit from polishing the beams and shotpeening. These operations can improve the rods fatigue strength by more than 100-percent.
It's impressive that with a well thought out combination of factory parts, good assembly and some headwork, a Honda engine can obtain very respectable horsepower and torque figures while still keeping factory-like reliability and loan-to-your-grandma driveabilty. There are not too many engine families on earth that can make this claim from any manufacturer. With Hondas, cheap and reliable power is just a call to a JDM engine importer or the dealer away.