Ball milling reamer??

[flyin ryan]

Originally Posted by tpepmeie

One of those guys you mentioned is taking my LT5 heads to the next level! A long R&D project, which hopefully is nearing completion.

Curtis will do a good job for you. anything worthwhile takes time.

[flyin ryan]

Originally Posted by XfireZ51

FR,

Given that our manifolds are dry, how does that change the principles of
porting? Or does it? What's your view on direct injection and any
modification it suggests for porting?

No it really doesn't change anything. when we say 'Dry', it only starts out that way. on a running engine nothing is dry, it's like a tornado inside the intake. you want the intake tract as rough as possible so fuel won't stick to it. if it's rough air can get behind the sticking fuel & peel it off the walls. look at glass, water crawls off it, right? thats because it has TOO much friction. guys think smooth is the way to go & everything will slide off, well it's the opposite. glass, for example, has like 100% friction coeficiant, no good for an intake. i'll give you another one. remember the old blue Penske Trans-Am cars? one day the Tech guys were all over Penske's car because he showed up with a vinyl roof. acid dipping was a big thing to cheat back then & Tech thought his roof was paper thin & he was trying to hide it. truth was that the vinyl roof created tiny vorticies, at speed, & helped deter the boundry layer that builds with speed. the car was 'slicker' with the vinyl roof than anything else going. rumor was Roger, always one step ahead, would take wax/polish from a company he was involved with & go up & down pit lane giving out the stuff to 'Promote' the wax. he was only trying to slow them down, guys a smart dude. now, as it turns out the gains we are talking about are miniscule but nobody knew that in the 60's. they were chasing whatever they could.

[flyin ryan]

Originally Posted by LGAFF

I did my own intake and got 391 rwhp without even tunng the car yet, I'm not a pro but I am $1200-$2400 richer than if I sent it out. I also did an intake which I sold to Hans(CCMANO) and will be interested how his car does with the port job.....have another intake that I bought and am working on it now. There is a learning curve with it but as with anything to me there is a diminishing return on everything......how much extra time, cash etc to pick up a few more ponies.... I was also able to recreate the smooth finish of the extrude hone with lots of WD40 and 800, 1000, 1200 grit paper but what is it really worth?????? I did it on my intake but would not do it again.

LGAFF
"carbide cowboy"
LT-5 hack
92 ZR1
#234

don't take it personally Lee, i don't see you on here telling everyone how to do this or that. that's what i'm not a fan of. guys doing/trying things on their own is what it's all about, to me. gotta start somewhere. the guys that do one set of heads & are pros all of a sudden.

[flyin ryan]

Originally Posted by tpepmeie

I found the reference. Here is a very good article by Darin on the subject.
http://www.competitionplus.com/2006_...der_heads.html

That's a good article, never seen that one before. Darin's no dummy. hope everyone on here takes a peak at it.

[-=Jeff=-]

I did the 'Poor Man's" port job..

I bought later model IH and Plenum and bolted them on..

I Will be installing Headers in the spring and maybe cats and then just enjoy the car..

[LGAFF]

Just joking around Ryan, I started with a friggin dremel.....then finally after about 50hrs of work moved to the grinder



LGAFF
92 ZR1
#234

[flyin ryan]

Originally Posted by LGAFF

Just joking around Ryan, I started with a friggin dremel.....then finally after about 50hrs of work moved to the grinder



LGAFF
92 ZR1
#234

i'm shocked the dremel lasted 5 Hrs., let alone 50. i had one years ago, honestly i don't think it lasted 50 minutes, junk. first & last one i ever owned.

[XfireZ51]

I used the Extrude Hone process on my 84 Xfire. Using a Xfire manifold(and if you've ever worked on one you know what the issues are), the motor made close to 300 rwhp and 340rwtq. That's about 75hp more than what GM rated the stock motor at the crank. Nothing was done to increase the x-section of the runner itself. The manifold was port matched(by me) to the TFS 23d heads. It ran a consistent ~105mph trap. Wasn't cheap and I'm not here to be an ad for EH. However, I thought I would discuss a few notions about EH based on my experience with it and expressing my opinion about it. If I understand FR and the others, velocity is a significant contributor to making power. On the Xfire, that was important not just in the runners but even through the TB venturi. The Xfire is a wet manifold ( fuel travels in suspension in the air and through the runners). Its also important to have the air velocity high in order to "shear" the fuel from the TB venturi walls (2.13" dia.) where the injector would spray it. The higher the velocity, the better the atomization, the less likely fuel would fall out of suspension. Fuel falling out of suspension is an issue with the path the A/F mixture travelled thru Xfire manifold from the TB to the head/manifold interface. So anything you could do to maintain velocity was a plus. EH isn't a mirror finish and it isn't something you replicate with sanding rolls. The aluminum (in the case of my manifold) appeared as if it was "re-flowed". The value of EH is how the micro abrasion contours all 4 walls of the runners. Runner walls end up with "strakes" that run longitudinally. These act in much the same way airfoils act on the wing of a jet. They direct the airflow minimizing turbulence which would otherwise rob a runner of its "efficiency" or capacity to move air. You can increase capacity in a pipe by either increasing cross section or velocity. Again, IMO, EH allowed more air to move through the same x-section than would normally be possible. And it did this by enhancing the velocity.
I do not believe EH is a substitute for a porting job that increases overall capacity.

[Locobob]

There really aren't any shortcuts unless you have access to a CNC machine and programming.

From my experience doing LT-5 intakes here are a few basics:

Always start with the port match between the plenum and injector housings. This will help guide you as to where to remove material. On every single one I've done the ports have been skewed to one side. To do a good job you'll need positive alignment. I usually use aluminum tubing to tighten the tolerances of the four corner bolts to accomplish this, I have also on occasion drilled holes for alignment pins.

When you have a choice remove material from the inside radius of a curve rather than the outside radius. You want to straighten out the curves as much as possible.

Either maintain a constant port diameter or slowly neck down the ports toward the heads - like a moderate funnel. You don't want enlarged areas downstream creating dead spots - you want to keep air velocity up. I prefer the funnel design as LT-5's seem to respond well to some extra air volume in the plenum and partway into the injector housings.

Be careful working around the gasket surfaces, it's easy to get a bit too much angle on your tool and/or gouge the metal with a burr.

1in wide by 1/2in tall course grit drum sanders work very well for material removal and help keep port shape consistent. I also make extensive use of a 1in diameter ball burr. I find alternating between the two works best. Flap wheels are pretty much a finishing tool, if you rely on them for material removal you'll make slow progress and spend a lot more.

[USAFPILOT]

I heard you wanted a rough intake to cause turbulence in the intake in order to atomize the fuel etc. But as far as a rough surface being better for aero I am not so sure. None of the 737's I've ever piloted had anything other than smooth surfaces. On the wing you dont want boundary layer separation because you would lose lift, but all along the fuselage it would be a good idea right, to reduce parasitic drag/ save fuel etc. Adding vinyl would increase weight and negate any positive aspects of the surface, but if it was a good idea, the aluminum skin could be manufactured in such a way, just like the inside of the plenum. They are not. You want it smoooooooth. That nascar guy probably didn't help himself much.