Mi16 Porting Ridge Above Inlet Seat

[Guest davebxgt]

Hi Guys,

 

Have had my mi16 head blasted clean and have found it has huge ridges above the valve seat. I'm reco'ing the head with std valves, but with 3 angle seats (which it seems to already have 3 angle as std).

 

I know this has been discussed in the past but what is the conclusion as to whether this ridge should be removed or not, to remove it completely on my head it looks like I would have to grind into the seat insert a little.

 

Any tips would be appreciated.

 

http://members.optusnet.com.au/davez0r/seat.jpg

 

Dave

[Dom9 2]

I understand when people say that it was put there deliberately to indiuce some turbulence to the mixture... But I don't actually believe it! If it was my head I would remove them... Try asking some of the guys who have had heads from respected tuners and ask them what they did - Maybe ask Mattsav as he has been doing a lot of work for Shevy I believe, especially with respect to porting and inlet shapes.

[B1ack_Mi16 67]

I have had several Mi16 heads over the years and I have found them all to be like that, apart from one very early BX 16v head I got my hands on. It was from a 1987 model BX 16v and looked like it had factory machined ports to remove those ridges.

 

http://cortex.fa-s.ntnu.no/~kristian/jenvey/difference.jpg

[bennett418 1 1 Cars]

anything you remove from the chamber will lower compression, i would leave alone for the increase (if any) that you will get its not worth it

[Guest davebxgt]

anything you remove from the chamber will lower compression, i would leave alone for the increase (if any) that you will get its not worth it

I'm referring to the ridge in the port (below the seat in that pic) - not anything in the combustion chamber.

 

Here are a couple of photos looking through the inlet at the ridges:

 

http://members.optusnet.com.au/davez0r/16v/2.jpg

 

http://members.optusnet.com.au/davez0r/16v/4.jpg

 

Some are worse than others,

 

Dave

[Guest davebxgt]

I just checked on Aussiefrogs and I have a reply from Peter saying there is probably no point on a street engine, which is fair enough. For interests sake though I would still like to know what people think is best for pure flow. What have the pro's done to your heads when you have had them ported?

 

Dave

[petert 587]

I understand when people say that it was put there deliberately to indiuce some turbulence to the mixture... But I don't actually believe it!

 

I don't either. It's a crock of s**t. The most important part to get right is the seat area and the vertical drop. There needs to be at least 3-4mm of vertical under the bottom cut before it enters the bowl. They obviously got this part correct! They're certainly good looking 3 angle OEM seats, rarely seen on the Peugeot heads.

[Guest davebxgt]

I don't either. It's a crock of s**t. The most important part to get right is the seat area and the vertical drop. There needs to be at least 3-4mm of vertical under the bottom cut before it enters the bowl. They obviously got this part correct! They're certainly good looking 3 angle OEM seats, rarely seen on the Peugeot heads.

 

Since I have a die grinder and all the bits required have I got anything to lose by blending this ridge out where possible? Where the port is badly aligned with the seat insert don't think I can remove it completely, but probably most of it, is it bad to grind into the insert a little for the sake of blending out the ridge?

 

Cheers,

 

Dave

[bennett418 1 1 Cars]

ahhh got ya!! yeah i would get rid of em def, just watch you dont catch the seat...

[Martin@PRD 0]

Here are some interesting pis for you, I cut this last year to look for wall weaknesses.

 

 

 

 

If you do die grind them out, remmber to use WD40 or your burr tree will clog

 

Have fun!!!

[309PUG 2 1 Cars]

Only one bit of advice is to make sure it is absolutely free from whatever blasting medium you used, those bits get everywhere, to skip on the cleaning/flushing out at your peril.

 

Chris

[James_R 3]

My heads off being flowed at the moment, as when speaking to the guy about it, he was intending to remove lip as best he could as there doesn't see to be too much room for manouvre in the the port. Will post pics in a few weeks when I get it back.