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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.
JDM Civic Type R camshafts from a JDM B16AS are pretty potent and are a good upgrade. 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.
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
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.
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.
The black dry film lubricant skirt coating can identify the JDM ITR pistons. This helps reduce friction and wear. The coating is very similar to the expensive aftermarket coatings that many racers have applied to their pistons.
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.
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