what do you guys thing of these exhaust ports?

 

looks pretty damn big, i havent seen to many pics of ports.
what spec is that?
my car is currentl getting a race port at gotham.

 

good lord

 

well i bought them in ebay (separately) for my rebuild and i didnt notice the difference til 2 days ago. the one that's not ported is a tII rear housing and the other is a n/a front housing w/o a sleeve. it looks like it opens really early and closes a lil late. will i lose torque in the low end? to me it looks like an aggresive streetport but i'm just a noob. what do you guys think?

 

Pretty freaking huge... and I really don't advise running a giant exhaust port with no exhaust sleeve if that was your intent. Too many downsides and not enough plausible gains. But to each their own.

The shape looks fairly well done, however. Possibly a tad smaller and retaining the exhaust sleeve would be optimal. But that is definitely gigantic. Moves WAY up and down, pretty extreme. Is this for turbo or n/a application? If it's turbo, I also don't advise moving the exhaust port UP that high, the lower part is fine but eh... its just too big in my opinion.

EDIT
Also bevel that port if you're going to use it, don't want your apex seals getting eaten by sharp edges.

 

I second that.

 

Those are so huge...

 

Those are so huge... I don't think there's any type of streetable application that would call for ports that mon'strous. PP/full BP?

 

i'm looking for a tII sleeve for that. but this will be for my turbo'ed n/a project. when you mean bevel do you mean square off the lower ends? i'm not gonna touch the already ported one but i will have to match the unported (or less ported) one.

 

...or save some more money for more housings....DAMMIT!!

 

By bevel he means; on the 'top' of the port there should be an angle like ---> \ To make the transition easier on the apex seal as it passes over the 'empty' space of the port back onto the flat surface of the housing... Make sense?

Like, with such a big port, the apex seal might 'flex' INTO the port (hole) and have a hard time 'coming out' with no (or little) transitional bevel...

It looks as if there is a small transitional bevel on the modified port, but it might be a good idea to make it more pronounced. Normally, it should look like the top-half of a stock port (with a 2mm bevel) but it might be safer to go a little more on such a large port.

 

BTW, your car will be LOUD.

 

Bevel http://www.nopistons.com/forums/inde...howtopic=31895

 

ditto what dDub already said. that is a bit of overkill unless you are running a PP or J port.

 

thanks for the infor ddub. it looks i may have to bevel both ports.


[QUOTE=eriksseven]BTW, your car will be LOUD.

i can't wait. tee hee

 

erik mentioned that i should pronounce the bevel a lil more. so instead of the 45* angle the link recommended should i bevel it a lil steeper like say between 50-60* and keep it 2mm wide?

 

damn son, i would love to go for a ride in that mad machine if u ever get it going w/ those ports, as for the angle, beats the **** outta me...sorry just had to say something

 

Seems like 45 should work fine but I've never really seen the port that big so who knows. Looks like someone just got excited and kept going and ended up having to sell them.

 

i do a double angle, 45 and then a steep 20 degree or so and then go over it with a flapper wheel to smooth it out even more.

i only do about a 1.5mm wide bevel, it doesn't need to be quite as large as the factory bevel.

 

so i start out with a 2mm 45* angle bevel and then a 20* bevel on the lower half of it correct?

 

what you want is a sweeping curve so the apex seal won't catch the edge on the upper edge of the port(closing edge), the bottom edge does not need to be beveled.

i'll get you some pics later this evening for reference.

 

greatly appreciated

 

sorry for the crappy quality, i forgot my camera at home today so i couldn't take some fresh pics. this is one of my earlier mild street ports, the bevel is shiny so you get an idea of how large it needs to be.



to get the final 20 degree bevel i just lay my dremel extension on the housing and run my sanding wheel down the edge of the bevel until it is around 1.5-2mm tapering down as it meets the leading edge of the port(bottom of the port) then i finally finish it with a fine grit flapper wheel to polish the bevel so there is no burrs. this ensures the apex seal, if it happens to flex out under high RPMs it will not catch the surface of the port rather it will hit the bevel and be forced back into place in the rotor rather than taking chunks out of the seal and housing virtually destroying both eventually and causing low compression.

 

[QUOTE=TitosToy]Give it a week...

 

Week? Took me about 2 minutes after my car started up to know even mine was too loud (for me, who is very tolerable of loud exhaust).

I need 3" anyways, so I guess I'll be redoing it and going to something quieter... hopefully.