Also, please be aware that the procedures, techniques, and other material on this page, as well as answers to your engine questions, may not work for your particular application, and in some instances, may be hazardous. It is up to you to use your own judgment as to whether information you find here will work for you. With that said, lets get to this months article.
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Part 2
Lets take a quick review of what has been done so far. The book work has been done to determine what new parts need to be ordered. A good machine shop has been found to do the necessary machine work. Parts have been located, ordered, and received. The engine components have been cleaned a second time. The parts that will be painted have been prepped and painted. The pistons, rings, and rods have been installed, along with the crankshaft. The cam has been installed and timed.
Next comes the heads. I had Gregg Spreen, the machinist
that did the block and rotating mass, rebuild my heads. Before the heads
were taken to his shop, I did some clean up work on the ports, paying special
attention to the bowl area. I used a die grinder with a sanding roll to
smooth the port runners, and to clean up the bowl area, paying particular
attention to the area around the valve guide. While Greg had the heads,
I asked him to install bigger valves and seats to let the engine breathe
better. Greg installed a 2.11 intake valve, and a 1.83 exhaust, both 
being
a stainless steel, heavy duty valve. Before installing the valves, Greg
un-shrouded the exhaust valves. Un-shrouding a valve is simply removing
material from the combustion chamber where the valve comes closest to the
side of the chamber. This can give a great boost in performance, and is
well worth any added expense. Greg also spent time blending the seats into
the combustion chamber. A triple angle valve job was done, since this engine
won't be used for constant racing. Next, he installed new valve seals,
with the intake
seals having a spring to keep close contact with the stem, then he installed
the new spring set I supplied, and set the spring pressure with the
valve in the fully closed and open position. One other thing he checked
for, was coil bind. This is something to watch for when using a high lift
cam, and with an exhaust lift of .600, this could have been an issue with
my engine. One other thing to watch for is too large an intake valve. Bigger
is not always better when it comes to valves. A bigger valve could have
been installed in my heads, but it would have interfered with the air flow
into the cylinders. Remember that a bigger valve presents a lot more area
for the air to run into as it comes down the intake port and into the cylinder.
The intake valves need to be matched to the size of the port runners to
insure good performance. Now that the heads are done, its time to finish
the engine.
With the heads back at my friend's shop, it was
time to do a mock up. This is to ensure proper valve to piston clearance.
The first thing to do, is to put a small amount of modeling 
clay
into the valve relief area of the piston. Use only enough clay to fill
the valve relief pockets to the top of the piston. We then bolted one of
the heads in place with a couple of head bolts, and no gasket. The bolts
don't need to be very tight, so don't torque them down. Next, the rocker
arms are installed, and adjusted to the point that the lifter is completely
collapsed. This should give a close approximation of the valve travel when
the lifters are later full of oil. We then rotated the engine through two
full cycles (four turns of the 
crankshaft).
The rockers and head were removed, and the pistons with the modeling clay
were brought up to the top. The modeling clay was removed, and a slice
through it was made where the exhaust valve had made the deepest impression.
This allows for measurement in the cross sectional area of the impression
to determine valve to piston clearance. Engines will vary in how much clearance
is needed for a particular application, and for my engine, .010 was needed.
After measuring the clay, I determined that I had more than adequate clearance.
Now I could proceed with finishing the engine.
Bolting down the heads came next, but before installing them, I gave the cylinders one last cleaning, and lightly oiled the bores. In case of something not working properly, the oil on the walls of the cylinders will protect them from corrosion while waiting for new parts to arrive. I then carefully cleaned the deck and head mating areas one last time before installing the gaskets and heads. The heads were torqued down using the factory pattern and using the torque values specified by ARP, since I am using they're head bolts. This is one area where you might want to check the torque at least three times. Next comes closing up the bottom of the engine.
After the heads were installed, I concentrated
on installing the oil pan and windage tray. This is where things got a
little difficult. I had decided to enlarge the oil capacity of my engine
by enlarging my oil pan. To do this, I bought a second oil pan from a local
salvage yard, and cut the sump area out of it with a jig saw. Next, I cut
the back of the sump area, and part of the 
area
behind the sump, out of my original pan, using the previously cut out sump
as a template. The piece from the second oil pan was then shaped to fit
the opening in my old pan and TIG welded into place by my friend Bart.
While I could have bought a deep sump pan from one of the mail order companies,
I decided to build one myself, just for the enjoyment and practice. I don't
recommend this unless you have access to the proper equipment for doing
such a project, and you have a good friend who won't charge labor to help.
Next the pan was fitted to the engine, and a problem was noticed right
away. The main 
studs
that I had installed, were hitting the pan at the rear main area. The original
bolts that were used to bolt the cap into place normally sit lower in an
area machined into the main cap. The stud, on the other hand, sticks up
well above this machined area, and interferes with the oil pan. To correct
this problem, the 
pan
was heated and two areas were hammered outwards away from where the studs
were contacting the pan. After welding and hammering, the pan was heated
to anneal the metal in the welds to prevent cracking. Again, this is not
for the average person to attempt without the proper equipment. Once the
pan came out of the oven, it was cleaned and checked for any pin hole leaks
by filling it with Varsol. Any good solvent will come right through a small
hole and show up as a wet spot on the pan where the leak is.
Then came checking the fit of the windage tray
after the pan was modified to clear the main studs. Again, there was a
clearance problem that had to be corrected. A die grinder was used to notch
the windage tray where contact with the studs was occurring. With that
done, the timing 
chain
cover was installed, and then the windage tray and oil pan. Again, if you
are using silicone to seal the gaskets, use only a small amount. The oil
pan is an area where excess silicone can come loose and get into the oil
pump. Finally, the water pump was installed, and the engine was now ready
to be put back into the hull.
The engine was mated to the transmission, and then
lifted back into the hull. Next came installing the intake manifold, headers,
push rods, and rocker arm stands. Once all the auxillary 
systems
were hooked up, water lines, cables, etc., the engine was pre oiled. Using
a drill, a socket on a long extension was inserted into the distributor
hole in the manifold, and slipped over the oil pump drive. Using the drill,
oil was pumped for a couple of minutes after the oil pressure guage showed
positive pressure. Then came installing the distributor and setting the
initial timing. Here there are several ways to go about it. You can connect
a volt ohm meter to the coil after setting the timing mark of the crankshaft
on the desired degree marking. Then, with the distributor rotor on the
proper cylinder, turn the distributor until the meter shows no current
flow. Turn the distributor back until the current flow starts again. This
should be very close to the desired initial setting. With everything closed
up, a second check was made to see if anything looked out of place, or
wasn't properly installed.
Now came the most tense time. Time to start it and run it for the first time. This is the most critical time for a new engine, for several reasons. Most important, this is when the camshaft is going to break in. A new cam needs to be run for at least thirty minutes at 2000 RPM or above. If its not broken in properly, its going to fail rapidly, and lead to a complete rebuild again. With the boat moved outside the shop, a water hose was hooked up as well as a battery charger. Its always a good idea to have a battery charger hooked up to give some extra power for starting, since a new engine is very tight, and may be hard to turn over. The fuel system was then primed, and the water turned on. With Bart holding a fire extinguisher, the engine was cranked, and it fired immediatly, but then died. It took two more attempts before it continued to run. This had me a little nervous, since I had decided on only three short starter attempts before I would have to re-lube the cam with assembly lube. If a new engine doesn't fire up after a few tries, it may be necessarry to re-lube the cam, since the lifters will wipe away the first application of the assembly lube, causing cam damage if the cam is run dry.
After about five minutes of run time, a problem was noticed. There was an excessive amount of water on the floor of the hull. At first I thought it was due to the water injection valve on my headers sticking open. I was wrong. Bart quickly spotted the problem, a missing 3/8" drain plug, and corrected it. I had overlooked the drain plug on the side of the block during assembly, and it was dumping a good deal of water into the hull. Then disaster struck 25 minutes into the breakin run. Three cylinders began to loose power, and excessive lifter clatter was heard. The engine was shut down, and an inspection of the valve train was made.
Several rocker arms were damaged, and there were aluminum particles on top of the heads. Some of the rocker arm adjuster nuts were loose, and had allowed the adjusters to back out. In trying to determine what had happened, several pushrods were noticed to have scuffed the intake manifold. On closer examination, it was determined that the rocker arms were not machined properly. The adjusting bolts were not aligned properly in the rocker arm, and had led to the problem, one I could have corrected with more attention during the rebuild. I had thought the pushrods came very close to the intake during the assembly, but felt there was enough clearance. There wasn't once the lifters had filled with oil, and pumped up to the proper operating length. Although I am a little upset about the rocker arms not being built properly, I have no one to blame but myself. Like I said in the begining, check, check, and double check. One good thing is that the metal was aluminum, and not cast iron. And after checking the oil filter, it looks as if the larger particles were trapped in the filter.
After removing the pan, one of the main caps was removed, and showed no damage, or aluminum particles embeded in it. It now looks as if the engine will be OK, and just needs the oil pan, and pump cleaned. I did this while the engine was still in the hull, by lifting only the front of the engine with a hoist. This raised the engine up enough to get to the oil pan bolts and remove it for cleaning. I also removed the oil pump and inspected it for internal damage, but found none. The worst part of the whole ordeal was installing the windage tray and oil pan. Lining up the pan, tray, and two gaskets, was a tough job while the engine was in this position.
With the bottom end cleaned out, it was time to
install the replacement rocker arms. I have 
to
thank Jeg's for exchanging the rockers as quickly as they did, and for
replacing them with a better rocker arm. There were no more rockers of
the type that I had first used, so Jeg's replaced them with Harland Sharp
rocker arms at no additional cost. 
These
rocker arms turned out to be much better than the ones I had first used.
They have much larger rollers, and also have bronze bushings. Next, the
intake manifold was put back on, followed by installing the pushrods and
rocker arms. The arms were again adjusted to the proper pre-load, and the
valve covers installed. Finally, the distributor was installed and timed,
and the cables and hoses hooked up.
The engine was again pre oiled before starting, and one final check was made. With crossed fingers, the engine was started again. This time, the engine ran like a dream. A few more adjustments had to be made, like synchronizing the throttle plates, adjusting the idle mixture, and re-tuning the main jet, and secondary by pass in the fuel injection, but once this was done, it was ready for the water.
A few days later, the boat was launched at the local lake. Although this lake is not long enough to let the engine get over 5,000 rpm before having to stop, I must say I was very happy with the performance. One thing I noticed right away, is that I need more prop.
Check back soon for the next engine build, when
we will feature the build up of Bart's BB Chevy, for his Curtis runner
bottom.