Uncle Hungry

iTrader: (2)

It's a pineapple template I used on a trash housing. Let me know what you think I can take constructive critisism.

On this one for some reason the bottom edge looks wavy when it's really not

I noticed nobody seems to take the sharp bevel out of the inside of the sleeve, I did but I don't know if for some reason that's the wrong thing to do.

the top of the sleeve exit.

Let me know what you guys think!I'm more concerned with the actual geometry of the porting I did rather than a tiny dimple here or there. Am I ready to move on to my new housings or should I do my other used one first?

Captain Jean-Luc Picard

Looks very nice, but I am not a fan of that shape. I like a gradual opening and a flat closing edge.

You definitely need more bevel on the sides and especially the top. You need a 1-2mm bevel.

Uncle Hungry

iTrader: (2)

Also is it the norm to pull the sleeve and weld those egr ports shut on an emissions deleted street car??

diabolical1

iTrader: (3)

normal? i don't know. it is a good idea to do so though.

nice work, by the way. bevel the closing edge when you do them on your "real" housings. also, are you building your motor for turbo or no?

Captain Jean-Luc Picard

No, it's not normal to close those holes, and it would be a lot of work for not really any gain.

Uncle Hungry

iTrader: (2)

yes it's a rew running a t4 1.06 divided 35r and thank you .

ultimatejay

iTrader: (1)

Nice work. Take a look at a stock exhaust port and note the bevel that is used. There is 2mm all around. This is very important to do especially on the closing side. I also prefer the more square closing line like RB uses.

Uncle Hungry

iTrader: (2)

ok, now should I port to the scribed line and bevel after or leave enough so the bevel ends at the scribed line?

ultimatejay

iTrader: (1)

You can port to the scribed line and then bevel. The bevel is there to aid in apex seal smooth transistion and life longevity and is not going to effect your port timing, at least to anything measurable.

mannyvidal

iTrader: (2)

i am just and old farmer but its is to my understanding that the exhaust shape and diamater differs from boosted , all motor or laughing gas aplications in this case i think that it looks damm good to be your first exhaust port job i would do the other housing before you do your new ones remember opinoins are like belly buttons , whats works for me might not work for the next guy good luck on your build ,keep us posted

BDC

... based on the assumption that the seal will have a tendency to bow itself out like a banana as it passes over the open port...

B

Uncle Hungry

iTrader: (2)

You want bevel, you get bevel







How's that?

ultimatejay

iTrader: (1)

Perfect! Now get a good housing and to the same thing.

Uncle Hungry

iTrader: (2)

I just happen to have 2 brandy new ones right here
And thank you! Thanks for all the kind words guys I'm trying to get it right now so I don't eff up the new housings!

nathan_s

Ive never seen any porting or anything like that done but I gotta say it looks pretty badass dude. Pretty badass.

FC3Sbot

That looks really good. I hope when I do mine here in a couple months it will turn out as nice, seeing as it will also be my first attempt at porting.

crispeed

You know what they say when you assume!

It's funny because I yet to see this assumption happen on any motors even the the ones turning 10k rpm with stock seals. It's funny because it does not happen on PP intake ports.
I always thought 'bevels' on ports had something to do with flow. Oh hell what do I know!


Never knew there were differences.



Not bad for your first port job. With a little more practise you will develop better hand control so as to keep the shapes/lines more linear.

BDC

I've never seen it either, but I took it upon suggestion from Judge Ito so I adopted the same practice.

B

diabolical1

iTrader: (3)

for what it's worth ... same here!

2Lucky2tha7

iTrader: (3)

Looks pretty good except for the fact that it looks like you used the template upside-down If you flip it the other way around, then that's pretty much the way all my exhaust ports look after porting. I had bigger gains with the progressive port opening (rounded), and having the closing edge relatively flat (straight with rounded edges). My exhaust note also changed radically from having my port opening shape looking like yours, to that of what it would look like if you flipped your template around.

2Lucky2tha7

iTrader: (3)

It's also a good thing you beveled your edges (I use a dremel with a diamond tipped bit for the final bevel all around. I saw a few pics a long time ago of chewed up atkins apex seals that resulted from un-beveled ports. The engine lasted a few thousand miles or so, but eventually the seals gave out. That's all I needed to see to convince me to bevel my ports.
Also, the progressive port opening that I mentioned will help with turbo spool.

dguy

iTrader: (8)

We've done a fair bit of flow testing in the shop and we've found that a 1mm bevel nets about a 3% increase over a sharp edge, a 2mm bevel nets another 2%, and anything greater than 2mm begins to rapidly reduce flow.

Uncle Hungry

iTrader: (2)

Is is absolutely not upside down, that's the way pineapple ports are.

2Lucky2tha7

iTrader: (3)

^^that's pretty odd then, and flow-wise doesn't seem to make a whole lot of sense to me

dguy

iTrader: (8)

How so, what you're basically looking for is finding a vortex generator that creates laminar flow around the edges of the port. 2mm seems to be the magic number that creates a nice boundary layer without encroaching on the unobstructed flow areas in the center of the port.