Frankenstein Fit For Freeways?I own a '96 Integra LS with a stock B18B. What would give me the most horsepower for the lowest cost: LS/VTEC with a C1 or C5 head, or a straight B16A/B18C swap? All of my research makes an LS/VTEC swap sound easy, but I'm nervous about drilling into the block for oil circulation. Is that something I can pull off myself and is it worth it? Or is it easier to just swap? The car will be a daily driver, so I need it to be reliable too.JBDaKidTempe, AZ
Can a Frankenstien motor hold up on a daily driver? I want to swap in a B20 with a VTEC head. What can I do to make sure I don't have a whole lot of trouble? Would I be better off with an LS/VTEC or is this just not good for a daily driver?Joshua SandersDaytona Beach, Florida
Just like any motor, LS/VTECs and CR/VTECs can be reliable and run for years if they're built and maintained properly. Don't psych yourself out; an LS/VTEC is nothing more then a combination of a block and head that didn't come together from the factory.
There isn't anything significantly different about these setups versus a stock VTEC motor except for the rerouting of an oil passage and opening up of the dowel pin holes. The actual machine work is something that you can do yourself, but if you're not comfortable drilling on your motor, a machine shop can do it for $100-200.
The money you save on buying just the head, instead of a whole longblock, can be used to buy some ITR cams, an intake manifold, a header and throttle body. A setup like that, tuned correctly, should easily blow doors off any stock GS-R or Type R swap.- DB
Pep TalkI'm planning a daily-driver engine build using D-series parts, but I can never get a straight answer. I'm planning on using a D16Z6 longblock with D16A1 crank, rods and pistons (from an '86-87). I've been told that the crank is exactly the same as the stock Z6 crank, except for the front side of the crank, which is a smaller diameter. Are the D16A1 rods the same size as the D16Z6 rods? I also plan to switch out the pistons to PM7 versions. Oliver YuColumbus, OH
You got the right idea and you're describing the motor we built for our D vs. B shootout in the May issue. Your best bet is to stick with the D16 crank. It's unnecessary to use the crank from the Integra because the D16A1 pistons (PG6B) and rods are identical in size to the D16Z6 units.
There are pros and cons to using the '86-87 pistons. A flat top piston with a 30mm compression height (which means zero piston-to-deck height in a D16) will enhance flame propagation drastically, meaning less timing for the same power.
On the other hand, if you plan on using a big cam (which you should) you'll need to cut the valve reliefs further into the piston. Either way, it'll end up being a pretty peppy little D- DB
Shaft Swap?I've built a B16A block with a GS-R head, which is turning about 9200 rpm for redline. I got stuck with a 2001 Integra LS transmission (S80). Are 2nd, 3rd and 4th gears interchangeable with any other years? I have all this rpm and can't use it!Richard Moss Langley, British Columbia
You're in luck. Whether they meant to or not, Honda makes swapping parts between chassis/motors easy. Your S80 case is the same kind that encases the hydraulic GS-R and Civic/Integra Type R transmissions. You can swap complete main and counter shafts between them or even individual gears.
The best part about hybridizing Honda transmissions is that the gears that we want are almost always available in OEM form. If you intend to swap complete shafts however, you probably want to look at just buying a new tranny. The internals will not cost too much less than a complete transmission and will save you the effort of cracking the cases and swapping the gears.- DB
Meet Me In The MiddleI own a 2000 Civic Si with ported head, Skunk2 stage 2 cams and valvetrain components, MSD 6A, Blaster 2 coil, CTR pistons, 65mm throttle body, DC Sports 4-2-1 header, Apexi N1 series 2.5-inch exhaust, and NGK wires and plugs. I am having a frustrating problem with VTEC engagement.
On a dyno sheet the horsepower climbs until about 5400 rpm, then suddenly plummets, losing about 25 hp. Then it begins to climb again. While driving, it is felt as a split-second pause right before VTEC kicks in. I tried yelling at the engine, but that didn't help. Could it be oil pressure or a faulty solenoid. How do I fix this?Joseph SchleifTuscaloosa, AL
This is a pretty common problem usually attributed to tuning. Basically, a normal motor will have a power curve that looks like a parabola on the dyno sheet. A VTEC motor has two of these curves, one for each cam profile.
The primary cam profile is usually made for bottom end torque and the curve will quickly fall off in the middle of the graph. The high cam profile on the other hand is just the opposite, it doesn't start picking up until that halfway point. The easiest way to fix the problem is on a dyno using a Hondata or some kind of VTEC controller.
First, set VTEC at some astronomically high activation point (like 10,000 rpm) that you're not going to hit. That way you can do a dyno pull showing only the low cam. Then reverse the process, setting the VTEC point to engage low (3,000 rpm) and do another pull. Set the two graphs over each other and the point where they cross on the graph should be your final VTEC engagement point.
When the car is tuned in this manner there will be one smooth power curve for the whole RPM range. Try to pull that off in a Toyota.