Intake to Port question?
04-22-2015, 11:11 PM
#1
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Intake to Port question?
We've finally collected the motor having had the parts balanced and the O rings machined and sealing rings made.
Deliberating on an intake for the new motor. While I decide that, we could use the current one that was made for the last motor temporarily, but the size of the outlet at the flange end is quite a bit smaller than the ports on the new head. So if we use the current intake would it be better (or less worse) to leave it as it is or try and port the flange to open it up with a more gradual curve leading into the head. Curved or straight is the question?
Deliberating on an intake for the new motor. While I decide that, we could use the current one that was made for the last motor temporarily, but the size of the outlet at the flange end is quite a bit smaller than the ports on the new head. So if we use the current intake would it be better (or less worse) to leave it as it is or try and port the flange to open it up with a more gradual curve leading into the head. Curved or straight is the question?
04-22-2015, 11:37 PM
#3
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Yeah, the runner diameter is definitely too small. Just not really sure if opening the flange side will do much either positively or negatively. Assuming that the flow of air will slow quite a lot when it gets shot into the 'open space' of the inlet ports on the head.
04-22-2015, 11:53 PM
#4
Rainman
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i dont see much point beyond smoothing the flange to match the runner size/transition.
those runners are so straight and short that even at a smaller than ideal diameter they shouldnt pose much of a restriction to what you're running.
light clean up and just bolt it on and see where it puts you, while you contemplate making a whole new manifold.
those runners are so straight and short that even at a smaller than ideal diameter they shouldnt pose much of a restriction to what you're running.
light clean up and just bolt it on and see where it puts you, while you contemplate making a whole new manifold.
04-23-2015, 12:19 AM
#5
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Definitely like to hear Harry's input on this but I am thinking leave as is. Thinking that you want to minimize expansion at the interface to keep the speed as high as possible.
04-23-2015, 12:24 AM
#6
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dont see much point beyond smoothing the flange to match the runner size/transition
The existing one is all wrong from the get-go, it should taper continuously from the plenum to the valve face to maximize gas velocity.
04-23-2015, 12:27 AM
#7
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I wouldn't even bother with that, just make a new manifold. You could use this one for basic testing/run-in.
The existing one is all wrong from the get-go, it should taper continuously from the plenum to the valve face to maximize gas velocity at the valve face....where it counts.
The existing one is all wrong from the get-go, it should taper continuously from the plenum to the valve face to maximize gas velocity at the valve face....where it counts.
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04-23-2015, 12:40 AM
#9
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Yes, I'd be interested in Harry's or other more expert input here. It's not a deal breaker by any means but just thought we might be able to assist the setup in this potentially temp scenario.
Lucky Dave, that's the idea but until I settle on the end intake we will have this one for the time being.
Lucky Dave, that's the idea but until I settle on the end intake we will have this one for the time being.
04-23-2015, 12:42 AM
#10
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Just a comaparison against a stock one.
04-23-2015, 12:51 AM
#11
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Yes, I'd be interested in Harry's or other more expert input here.
04-23-2015, 06:30 AM
#12
Drifting
In a normally aspirated engine it could hurt flow, in a turbo not as much, just try it as is.
04-23-2015, 02:08 PM
#14
Race Car
Personally, If you are doing a new intake, I wouldn't do anything with it.
The minimal amount of turbulence it will create should hurt too much.
This way, you can either sell it or use it on another head, once its done, its done.
The minimal amount of turbulence it will create should hurt too much.
This way, you can either sell it or use it on another head, once its done, its done.
05-22-2015, 05:48 AM
#15
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Had a bit of progress. So flange, runners, plenum and T/body plate have all be made and installed.
Some might note that these aren't short runners that many would advocate for a racemotor. I had someone look at the specs of this motor and come up with some potential runner lengths. He ran them through a high end software program and gave me a couple of choices. (320mm or 260mm from bell to valve) I was initially pretty surprised how long he suggested but his research showed that with this head/cam combo not showing any signs of choking (as per the flow bench results) we could have longer runners to increase torque without losing any top end. Cake and eat it syndrome. With such big ports and cam we are still a little nervous about this motor being so different to the old one (plus we've lost almost 600cc). We will obviously lose a bit of meaty torque and on the tighter of the two tracks we go to, it might prove a bit difficult to make up how much punch we used to get out of the corners. Going to be very interesting indeed.
Some might note that these aren't short runners that many would advocate for a racemotor. I had someone look at the specs of this motor and come up with some potential runner lengths. He ran them through a high end software program and gave me a couple of choices. (320mm or 260mm from bell to valve) I was initially pretty surprised how long he suggested but his research showed that with this head/cam combo not showing any signs of choking (as per the flow bench results) we could have longer runners to increase torque without losing any top end. Cake and eat it syndrome. With such big ports and cam we are still a little nervous about this motor being so different to the old one (plus we've lost almost 600cc). We will obviously lose a bit of meaty torque and on the tighter of the two tracks we go to, it might prove a bit difficult to make up how much punch we used to get out of the corners. Going to be very interesting indeed.