| Finally, my Civic
Type-R cams arrived from Japan (thanks to Eric) and I was eager to see how
much of a difference they made. Eric, too had a set for himself and was
itching to do the same. So, armed with the right tools we set out to do both
cars.
But first, there are some issues to clarify.
According to Spoon's race engineers, the valve springs need not be swapped
out for the Type-R dual springs if (and only if) the rev-limiter is not
raised above that of stock. Well, good for us. We had absolutely no
intention to raise our rev-limits any time soon or in the future.
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| According to the specs, the
Civic-R camshafts are slightly different from the Integra Type-R camshafts.
Actually the difference is only on the intake side. The VTEC lobe on the
intake side has slightly more duration (3 degrees more compared to the
Integra Type-R) and the cam profile was bigger and broader. The exhaust cams
are exactly the same as the Integra Type-R.
The Civic Type-R cams would be the cams of
choice as they will allow the engine to breathe much better. In addition,
the increased duration on the intake side will allow for better exhaust
scavenging.
Tools Required
Before you start, make sure you have the
right tools. You will need the following:
- Ratchet and breaker bar
- Socket extensions
- 19mm socket
- 14mm socket
- 12mm socket
- 10mm socket
- 10mm combination wrench or Honda's tappet
adjustment tool.
- Feeler gauges (0.05"/0.125mm thinnest)
- High-temp silicone sealant
- Timing light
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IN cams: B16A, B18C1, B16B
EX cams: B16A, B18C1, B16B
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Preparation
Logically, the first step of the process it
to remove the old cams from the engine. So, remove all attachments to the
valve cover. This includes the grounding points, the PCV return hose and the
spark plug wires. The nuts that hold down the valve cover are then removed.
Using a screwdriver, remove the metal/rubber seats from where the nuts were.
You don't want them to fly out when you remove the valve cover. The valve
cove should be ready to be removed. Using a thick putty knife to scraper,
gently pry the valve cover off along the edge, while taking care not to
damage the rubber seal.
Go over to the side of the engine and undo
the bolts holding down the timing belt cover and remove the top piece of the
timing belt cover. Then check to make sure that the timing belt tensioner is
locked down (tight) by checking the tensioner bolt. If everything checks
out, loosen the bolt that holds down the cam pulley. To do this, press down
hard on the cam pulley while breaking the bolt loose (don't remove it , only
loosen). It can be pretty tight and an extra pair of hands will come in
handy here.
Next, disconnect the two plugs that are
connected to the distributor. Then undo the three bolts holding the
distributor in and remove the distributor by pulling it off. Put the
distributor in a safe place, don't want to damage it unnecessarily. Last,
loosen all the spark plugs (but don't remove them) so that it will be easier
to turn the crank by hand.
If you have been following thus far, the
valve cover should be off and the camshafts should be ready for removal.
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Camshaft Removal
With everything removed, the next step will
be to remove the camshaft holders. Undo (loosen by 2-3mm) the bolts that
hold the two oil spray rails and the cam holders. Next, undo remove the two
front(timing belt side) bolts that hold the camshaft seals down. Next,
remove the outermost camshaft holder bolts (the ones forming the distributor
bracket and next to the VTEC solenoid. |
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Next, completely remove the oil
spray rails and the three camshaft holders in the middle. Be very careful
when removing the middle one as there is an oil channel guide (small metal
tube) that fits in the middle of that piece. Take note of which guide came
from where and also the orientation and set everything aside in a clean
area. Then finally remove the four small camshaft holders .
Once everything is out, the far end of the
cams should hang loose like the picture on the left.
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Now, before removing the cams,
you have to release the timing belt. Lift the camshaft at the free end and
slide the timing belt off the cam pulley as the belt tension is released.
Next, undo the cam belt pulley bolts and CAREFULLY pull out the cam pulley.
Make sure you don't lose the tiny Woodruff key that keys the pulley to the
cam. Again put everything in a proper place so you don't lose anything.
Finally, lift the cam out by the far end and remove it from the cylinder
head.
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Putting it all Back
At this stage, everything is almost ready to
be put back together. Using the 19mm socket on 3 extensions, turn the engine
over by the crank pulley bolt until the TDC (white) mark on the crank pulley
lines up with the timing mark on the lower timing belt cover.
Apply an even layer of oil all over the
camshafts, except the end where the timing belt pulleys bolt on. After
identifying which cam is which (the intake cam has a slot cut on the far end
for the distributor) put the new cams into position. The slot for the
woodruff key should be pointing upwards. Next, carefully reinstall the cam
pulleys with the keys in the right place (again, don't drop the key down the
timing belt cover, a tiny bit of grease helps to hold it in place) and
replace the cam pulley bolts (hand tight). If everything is correct, the
"up" arrows on the cam pulleys should be pointing upwards.
The next step it to put back the timing belt.
Making sure that the TDC mark on the crank pulley is still aligned, pull
both sides of the timing belt is taut. Keeping the timing belt taut, pull up
the far end of both cams and slip the pulley under the timing belt. Putting
down the end of the cams should tighten the belt up. If you have done this
correctly, the front side of the timing belt (side towards the front of the
car) should be completely taut. The crank timing mark should still be
aligned and the UP arrows on the cam pulleys should be pointing up while the
timing marks on the pulleys (small tick marks on the edge of the pulleys)
should line up straight across both pulleys.
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| The cam holders can now be
reinstalled. Making sure you have the cam holders in the right order, put
them all back, followed by the oil spray rails. Remember to apply a small
amount (not a huge glob) of high-temp sealant on the mating faces of the end
camshaft seal hole. The same goes for the opposite end. Finally torque the
12mm bolts down to 2.0-2.4kg-m and the 10mm bolts to 0.8-1.4kg-m.
Re-install the distributor and then double
check that all the timing marks are correct before proceeding to the final
stage.
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Finishing Up - Valve Clearances
Before the engine can even be started, the
valve clearances have to be checked to make sure that they are within specs.
To make this process easier, remember to loosen the spark plugs so that it
is easier to turn the crank by hand. Remember that valve clearances on a
Honda have to be done when the engine is cold so only do this if the engine
has had ample time to cool down (3 hours at least).
If you have just replaced your cams, it's
time to re-tension the timing belt. Loosen the 14mm tensioner bolt and turn
the crank counter-clockwise two turns. The timing belt should be at the
right tension at this point of time so go ahead and tighten the tensioner
bolt.
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| Using a 19mm socket on the
appropriate number of socket extensions, continue turning the crankshaft
counter-clockwise until the engine is TDC at cylinder 1 (remember the up
arrows and the tick marks?)
With cylinder 1 at TDC, you can now proceed
to do the valve clearances. The valve clearance specs (for any DOHC VTEC
engine) are as follows:
- IN - 0.15~0.19mm
- EX - 0.17~0.21mm
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| Slip the appropriate
sized feeler gauge (I use the smallest one) between the intake side rocker
arm and the cam lobe. The gauge should slip in easily. If it does not slip
in, don't force it. Release the 10mm lock nut on the adjustment screw and
loosen the adjustment screw with a screwdriver to get more clearance.
Next, try sliding the gauge around between
the space. There should be a slight amount of drag but the feeler gauge
should slide freely, without any resistance. Loosen or tighten the
adjustment screw accordingly and once you are happy with it, hold the
adjustment screw stationary and tighten the 10mm locknut. This task is
difficult with regular tools so I'd recommend you spend $40 on the correct
valve adjustment tool available from Honda or Snap-On (what I use). Once
this is done, double check by testing the gap again with the feeler gauge,
followed by the next bigger size, which should NOT fit.
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| Once you are done with both the
intake valves, move on to the exhaust valves and do the same. Remember to
switch to the correct sized gauge. Assuming you have done this properly, you
are now ready to move on to the next cylinder.
Turn the crankshaft counter-clockwise by 180
degrees (the cam pulleys will turn by 90 degrees) to bring cylinder 3 to TDC.
Proceed to adjust the clearances for cylinder 3, before moving on to
cylinder 4, then finally cylinder 2, turning the crank by the same amount
(180 degrees) before you switch cylinders.
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Finally...
The final stage of this procedure is to
reassemble the last bits and pieces. Apply a small amount of sealant to the
sharp corners of camshaft end holders before putting the valve cover back
on. Carefully replace the valve cover without cinching the seal and replace
all the retainers and nuts that hod the valve cover and finally torque it
back into place. Before you forget, re-torque the spark plugs and re-install
the plug wires.
It's almost ready. Loosen the three
distributor mount bolts (just enough to hold the distributor in place) and
turn the top side of the distributor towards the front of the car to fully
retard the engine timing. Locate the system test plug (usually a green
rubber plug close to the ECU in 5G Civics or in the engine compartment for
the 4G Civic/CRX) and short out the 2-pin connector with a paperclip.
Double check that everything else is
connected correctly then start the engine. Leave the engine to run until it
warms up to operating temperature (the fan should come on at least once). In
the meantime, hook up the timing light according to the manufacturer's
instructions.
Once the engine is warmed up, aim and shoot
the timing light at the crank pulley and check that the timing mark (middle
red mark of the 3 timing marks) lines up with the timing pointer on the
timing belt cover. If it falls in front of the pointer, rotate the
distributor's top side towards the rear of the car. This should bring the
three timing marks closer to the pointer. Keep rotating the distributor
accordingly such that the timing marks line up properly. For the more
advanced HP'er, you can go ahead and advance the timing up to 2 degrees
ahead of the red mark to optimize power.
Once the timing is set, tighten down the
distributor and double check the timing again. Finally, stop the engine,
remove the jumper wire on the test plug and (optionally) replace the spark
plug wire cover.
You are now ready for a test drive. Remember
to let the new cam seat properly so don't run at constant or excessively
revs for extended periods. Let the engine run through a varied range of
RPM's below 6000 RPM for about 100+ miles.
Just don't get a ticket.
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Performance Insights
How do they perform?
The difference is like night and day. Unlike
the stock cams, the power doesn't taper off as you approach 8000rpm.
Instead, the power just keeps coming, especially after 6000rpm. The first
time I took it out and floored it on 1st, I hit the rev limiter in a flash!
That was even before I put the shorter Type-R FD in (watch for another
upcoming tech article).
Driving around with the broken in cams, the
car exhibits awesome and unbelievable acceleration on the high end (yes,
that's how I drive, VTEC on all day) but the low end cam lobes seem to give
improved performance too, but I cannot substantiate this with my butt.
Coupled with the shorter ratio 98 Type-R FD,
highway onramps and offramps have become extremely entertaining.
These cams are the probably best $450 I've
spent, short of the $500 spent on the shorter 98 JDM Integra Type-R FD.
...I wonder what Eric Bauer has to say about
his Civic-R cams. |