Here's a shot of the finished and assembled
head |
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This is the turbo bumpstick |
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Here's the chamber, valves unshrouded and
polished. The head was cc'd and all chambers have the same volume,
yielding a final static compression ratio (with head gasket) of 8.34 to 1. |
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One of the things I needed was a way to
control the turbocharger boost pressure without spending a ton of cash.
I bought a used Turbonetics Delta-gate waste gate on ebay and then
borrowed a Hallman Boost controller to see how it worked. It is very
simple and I decided to make my own version out of AN fittings. The
benefits are twofold: the boost controller is smaller and mounts to
the wastegate, and it is much less expensive. Here's the parts: |
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The boost controller works by having a
spring hold a ball bearing against a seat, and when the boost pressure
lifts the ball off the seat, pressurized air actuates the wastegate.
So, the first thing to do is get a ball bearing and spring that will fit
into the 1/8" NPT Tee, then cut a seat into a -3 to 1/8 NPT AN
fitting |
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The spring pressure needs to be
adjustable to regulate the amount of boost that you want, so an adjuster
screw needs to be made. I used another -3 to 18" NPT AN fitting,
drilled it out and tapped it. |
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The adjuster screw would slip through the
spring without a small nail-head. Here's the parts: spring,
nail-head, drilled, tapped and cut -3 to 1/8" NPT fitting with adjuster
screw and locknut. |
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These parts with the spring/nail-head
assembly make up the whole boost control. A very small hole needs to
be drilled in the body of the 1/8" NPT Tee to release pressure from the
wastegate after the boost pressure has been reduced. If this hole
was not present, the boost controller would hold pressure due to the
one-way action of the ball and spring and this would keep the wastegate
open. |
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Here's the boost controller installed on
the wastegate. It threads right into the port and does not have to be
affixed to a firewall and plumbed to the wastegate like the Hallman unit. |
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The intake was painted a dove gray, the
only color paint I had at the time, and then bolted to the engine with a
stock intake gasket.
That's a throttle body from a Nissan 300zx with integral throttle position
sensor. |
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This shows the intake and wire connector
for the TPS hanging from the throttle body. The AN fitting on the
valve cover is a breather, it goes to the block and then dumps into the
exhaust. |
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Another view of the intake. |
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Some of the plumbing for the turbo and EFI
has been mocked up here. |
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Here's a trial fit of the exhaust manifold,
turbo, wastegate and exhaust pipe. The hole in the exhaust pipe is for the
oxygen sensor. I had to make the plate that bolts to the
turbocharger outlet and weld the reducer to it, have it surfaced by R'n'R
machine and then weld the 3" U-bend to it. |
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