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View Full Version : My first streetport in progress


Ender
03-23-2008, 04:28 PM
First off, I got two junked front irons to practice on, so all these pictures in this post are on a practice iron. I'm using the Racing Beat streetport template to at least start out with, I may make a copy then modify the copy, I would probably only do so for the secondaries.

I'm looking for pointers and discussion, and I have a few questions to get things rolling.

Template over the primary then secondary ports:
http://img217.imageshack.us/img217/4872/overprimaryqo2.th.jpg (http://img217.imageshack.us/my.php?image=overprimaryqo2.jpg)http://img148.imageshack.us/img148/121/oversecondaryjt3.th.jpg (http://img148.imageshack.us/my.php?image=oversecondaryjt3.jpg)

Dyed:
http://img217.imageshack.us/img217/610/dyed0xr2.th.jpg (http://img217.imageshack.us/my.php?image=dyed0xr2.jpg)http://img217.imageshack.us/img217/1935/dyed1gt4.th.jpg (http://img217.imageshack.us/my.php?image=dyed1gt4.jpg)

Scribed:
http://img227.imageshack.us/img227/7963/scribedlc5.th.jpg (http://img227.imageshack.us/my.php?image=scribedlc5.jpg)

Rough cut:
http://img217.imageshack.us/img217/1391/rough90tr4.th.jpg (http://img217.imageshack.us/my.php?image=rough90tr4.jpg)http://img148.imageshack.us/img148/2371/rough90blurrp4.th.jpg (http://img148.imageshack.us/my.php?image=rough90blurrp4.jpg)http://img148.imageshack.us/img148/4563/roughaerialgd2.th.jpg (http://img148.imageshack.us/my.php?image=roughaerialgd2.jpg)http://img217.imageshack.us/img217/4223/roughaerialblurci0.th.jpg (http://img217.imageshack.us/my.php?image=roughaerialblurci0.jpg)http://img148.imageshack.us/img148/9184/roughtoptf7.th.jpg (http://img148.imageshack.us/my.php?image=roughtoptf7.jpg)http://img148.imageshack.us/img148/4333/rough90templatebs7.th.jpg (http://img148.imageshack.us/my.php?image=rough90templatebs7.jpg)http://img217.imageshack.us/img217/3954/roughendco5.th.jpg (http://img217.imageshack.us/my.php?image=roughendco5.jpg)http://img148.imageshack.us/img148/6089/rough90blur2ck5.th.jpg (http://img148.imageshack.us/my.php?image=rough90blur2ck5.jpg)http://img80.imageshack.us/img80/5878/runnerrough0em1.th.jpg (http://img80.imageshack.us/my.php?image=runnerrough0em1.jpg)http://img217.imageshack.us/img217/3095/runnerrough1vq0.th.jpg (http://img217.imageshack.us/my.php?image=runnerrough1vq0.jpg)http://img217.imageshack.us/img217/9789/littop0oz2.th.jpg (http://img217.imageshack.us/my.php?image=littop0oz2.jpg)http://img148.imageshack.us/img148/2748/littop1mb2.th.jpg (http://img148.imageshack.us/my.php?image=littop1mb2.jpg)http://img148.imageshack.us/img148/6175/lit90wa9.th.jpg (http://img148.imageshack.us/my.php?image=lit90wa9.jpg)http://img219.imageshack.us/img219/3568/endangle90ia8.th.jpg (http://img219.imageshack.us/my.php?image=endangle90ia8.jpg)

Here's a comparison for the size of my grinding bit, which I think is too big for some spots.... I have two carbide cutting bits, the smaller one is the one I used for this work and works pretty well (it is also smaller than this grinding bit).
http://img217.imageshack.us/img217/8152/showgrindbitsizeph1.th.jpg (http://img217.imageshack.us/my.php?image=showgrindbitsizeph1.jpg)

Ender
03-23-2008, 04:30 PM
Questions:

-I cut maybe .5mm past the outer edge near the opening edge, it happened when I was blending the stock port into where the template mark ended (template isn't as long as the stock secondary port). Is that a problem? Could I actually extend it out that much the whole way? Would I want to? That is where the side seal/corner seals ride, right?

I know, I should get my e-shaft and a rotor out there to check things out that way. I probably will before too long. I won't be able to do much else today though.

-Should I cut deeper at the closing edge? I only angled the opening to the template line. I've seen some ports go very deep there, and from what I've read I don't want to really do that, BUT I suspect I may benefit from ending the slope (meeting the stock opening) about 5mm lower.

-I also want to know if I should cut the template just to the line or cut the line as well.

I know I can also cut a little into the control ring area, but I would prefer not to do that with this motor. Although I guess if I cut the template out like that then that a little control ring surface would be removed...

classicauto
03-24-2008, 07:59 AM
1: You could go out a little further by the looks of it, but you'd need to mock a rotor/shaft up and spin it just to make sure the side seal and corner seals are supported because yes, thats where they ride.

2: I don't understand this question. Are you talking about closing the port later, or changing the angle of the bowl at the closing edge?

3: Thats up to you and your plans for the engine. I'd go until the port is flush with the template 2D wise.

4: Again depends on your purpose for the engine. If the template laspes into the oil control ring area, I personally wouldn't go there on a street engine, but some say you can without many negatives (which is cutting into the first edge slightly) but I wouldn't.

looks pretty good though. Bowl and backcutting also seem decent!

Ender
03-24-2008, 02:59 PM
1: You could go out a little further by the looks of it, but you'd need to mock a rotor/shaft up and spin it just to make sure the side seal and corner seals are supported because yes, thats where they ride.Will do.

2: I don't understand this question. Are you talking about closing the port later, or changing the angle of the bowl at the closing edge?I mean cutting down (if the iron is laid flat on a bench). However cutting down more will necessitate changing the angle of the bowl at the closing edge. I want to know what ought to be ideal. I will state my intentions with the motor soon, as I now realize that's important to this discussion.

3: Thats up to you and your plans for the engine. I'd go until the port is flush with the template 2D wise.I have been doing that. There's a thin scribe mark on the template, and you can still see it on the template. I'm asking if I should cut off the tiny bit of metal that makes up that scribe mark all around the port outline on the template.

4: Again depends on your purpose for the engine. If the template laspes into the oil control ring area, I personally wouldn't go there on a street engine, but some say you can without many negatives (which is cutting into the first edge slightly) but I wouldn't.

looks pretty good though. Bowl and backcutting also seem decent!

Yeah, I'd prefer to leave the control ring area alone. This is intended to be a mild streetport with the potential to make 300+hp to the wheels later on. I'm going to run the stock turbo for a while, probably more than a year after the motor is installed, but once I have the means I will want to upgrade my turbo (and probably go standalone) and head for the mid 300's. I want it to be efficient, as economical as possible with regard to fuel for commuting, and make good power. I have all new seals/gaskets and good quality used housings, irons, and I think my rotors and e-shaft are in good shape. I'd like to have the rotors trimmed/bevelled/port phasing (there are a number of names for it I guess), but I doubt I'll get to that point. I will be running the stock ECU except for having the Rtek 1.7 chip (so I also have 720cc secondaries), I already have an SAFC-II set up running the throttle off the boost signal. I'm working on scrounging up the money for a zeitronix wideband, but idk when that will happen...