bjowett
Supporting Vendor
The 1FZ has nice loooking intake manifold... but it could use some work! Match porting and cleaning up inside the runners is not as bad as one may think. The manifold is a 2 piece design, unbolt the upper from the lower and about 75% of the interior can be reached for porting. Here's a bad picture of a partially match ported lower intake.
That leaves the upper unreachable 25% however, along with the plenum, which are probably in need of the most porting work. That equals fun time for me... time to cut! The manifold has temporarily become a 3 piecer.... The only way to reach.
Although all of the intake bells need some attention paid, the #6 runner, which is at the left of the above picture, needs the most attention. It, along with the adjacent #3, are very close to the throttle body. The air travels through the t-body and is then forced to make an extreme right or left turn to enter these runners. The inside turn in the manifold here is stepped in, too, this dosn't help. The following pic shows it a little better.
One can also see how the #6 inlet bell is oval in shape. Exterior throttle cable levers require a little clearance, so the #6 runner makes room. There is also a small bump down the runner a bit further due to a mounting boss for the EGR valve.
Speaking of the EGR... ever notice how the tube runs a good portion of the #6 runner before the exhaust is injected. Go with me on this... Cylinder 6 is where the gasket blows, I've seen several, they blow the fire ring in the same spot every time. So not only is cylinder 6 last in line to get coolant, it has a nice hot EGR cooler right behind it, not to mention a slightly restricted runner feeding it, with an extra dose of heat from the built in EGR tube. Is it really any wonder cylinder 6 slowly detonates until the fire ring goes bye bye in the same spot everytime?
More pictures as it progresses....
That leaves the upper unreachable 25% however, along with the plenum, which are probably in need of the most porting work. That equals fun time for me... time to cut! The manifold has temporarily become a 3 piecer.... The only way to reach.
Although all of the intake bells need some attention paid, the #6 runner, which is at the left of the above picture, needs the most attention. It, along with the adjacent #3, are very close to the throttle body. The air travels through the t-body and is then forced to make an extreme right or left turn to enter these runners. The inside turn in the manifold here is stepped in, too, this dosn't help. The following pic shows it a little better.
One can also see how the #6 inlet bell is oval in shape. Exterior throttle cable levers require a little clearance, so the #6 runner makes room. There is also a small bump down the runner a bit further due to a mounting boss for the EGR valve.
Speaking of the EGR... ever notice how the tube runs a good portion of the #6 runner before the exhaust is injected. Go with me on this... Cylinder 6 is where the gasket blows, I've seen several, they blow the fire ring in the same spot every time. So not only is cylinder 6 last in line to get coolant, it has a nice hot EGR cooler right behind it, not to mention a slightly restricted runner feeding it, with an extra dose of heat from the built in EGR tube. Is it really any wonder cylinder 6 slowly detonates until the fire ring goes bye bye in the same spot everytime?
More pictures as it progresses....
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