Did a search and came up with nothing. I was wondering if it was benificial to port match the Intake manifold runners to the head(using the gasket). If so I could either do this myself(with dremel and carefull hands-I have a spare intake manifold to screw around with or get a shop to do this. The reason I ask is because I am getting my engine built and the itr IM is just sitting there. Just though I would ask.

 

You could get it done fo about 100.00 or less. Unless you just want to learn and give it a go. I would say do it your self you will have fun.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TEAMGENDAI &raquo;</TD></TR><TR><TD CLASS="quote">You could get it done fo about 100.00 or less. Unless you just want to learn and give it a go. I would say do it your self you will have fun.</TD></TR></TABLE>
$100? When somebody port-matches the IM does that mean just port matching or polishing the inside also?

 

Just matching the ports. To port the whole manifold it will take hours at a time to get way inside the plenumnand be way more than a c-note!

 

It is defenetly worth it to port match all your gaskets especailly doing it yourself. Good learning expierience.

 

The port opening on the head isn't the smallest cross-section of the port and thus isn't a flow restriction, so widening will do nothing but waste time and also introduces a slight possibility of screwing up fuel atomization by changing the surface texture of the port walls where the fuel is introduced.

 

instead of portmatching, I suggested putting in an anti-reversion step as an alternative. You can pormatch if you want. The step is better than portmatching IMHO.

reversion means backwards flow...if you make a "step" increase in the diameter in the direction of flow (from small diameter to larger diameter as you move in the direction of flow) you will prevent some flow reversion when the intake valve just starts to open on the compression stroke.

we already do anti-reversion steps for the exhaust system...it's the same idea for the intake side.

No, I did not say port to the size of the gasket port. I said that was your MAXIMUM.

A headporter will know how much to increase your intake port on the head based on your cams, redline, CR, powerband location, and peak power goal. Again, the powerband location and peak power goal determines the size of the head's intake port.

once the port volume you need for your power goal is determined, usually you then compare that to the IM flange port. You add about 1mm more than the IM flange's diameter to get the anti-reversion effect as long as it is within the size specified by your power goal.

if the reversion step leads you to exceeding the gasket's size or your power goal size, then don't do it and just portmatch.

quoted by Tuan

 

More information on the anti-reversion step can be found in the archives of http://www.theoldone.com.