sohc intake manifold
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06-27-2005 | 01:53 PM
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06-28-2005 | 09:29 AM
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From:
RE: sohc intake manifold
Auto or MTX makes no difference on the manifolds, only SOHC and DOHC.
The ports don't line up.
The ports are different shapes.
The SOHC manifold does not have provisions for coolant flow.
Nope, not a direct swap. With enough machining, anything can be done though... Frankly, the split-case style of the DOHC manifold makes it much easier to do port/polish work. You can increase plenum volume for a few ponies using Vitor's spacer (www.neongoodies.net). I have seen a few hacked DOHC manifolds used on SOHC heads, but it took a lot of work.
The differences betweeen the atx and mtx TB's is that the mtx necks down from 52mm to 49mm and back out in a venturi shape, the atx has a weaker return spring, and the throttle shaft cam is more agressive (butterfly opens more for the same pedal travel, so somewhat better throttle response). The inlet, outlet, and butterfly are all identical sizes (as is the opening on the manifolds). They don't come port matched from the factory though, so a little time with a Sharpie and a Dremel can help some. Still, the opening where the "neck" meets the plenum is less than 52mm, which makes it the choke point. You can bore it out some with the Dremel, but you're likely to make yourself a new hole in the neck... JB Weld comes in handy...
Best of luck!
The ports don't line up.
The ports are different shapes.
The SOHC manifold does not have provisions for coolant flow.
Nope, not a direct swap. With enough machining, anything can be done though... Frankly, the split-case style of the DOHC manifold makes it much easier to do port/polish work. You can increase plenum volume for a few ponies using Vitor's spacer (www.neongoodies.net). I have seen a few hacked DOHC manifolds used on SOHC heads, but it took a lot of work.
The differences betweeen the atx and mtx TB's is that the mtx necks down from 52mm to 49mm and back out in a venturi shape, the atx has a weaker return spring, and the throttle shaft cam is more agressive (butterfly opens more for the same pedal travel, so somewhat better throttle response). The inlet, outlet, and butterfly are all identical sizes (as is the opening on the manifolds). They don't come port matched from the factory though, so a little time with a Sharpie and a Dremel can help some. Still, the opening where the "neck" meets the plenum is less than 52mm, which makes it the choke point. You can bore it out some with the Dremel, but you're likely to make yourself a new hole in the neck... JB Weld comes in handy...
Best of luck!