Isolde

iTrader: (4)

For those of you who have had the 5.3 heads cut for 2.00" intake valves, please share your experiences. I'm trying to find a machine shop that has experience with doing a good job of it. 48 states only, please. TIA.

5.3LJimmy

iTrader: (10)

You can call Texas Speed I'm sure they would be able to help you out. I would probably ask them about doing the valve seats and running their CNC program on the ports as well, as there is not gonna be much flow gained by simply increasing the valve size. Plus for what it's gonna cost you just to ship the heads both ways(regardless of where you ship them) it would make sense to get the most you can out of them.

Some more info on the heads would help also. What are you planning on running them on? What are you trying to accomplish/what are your goals for the setup? What if anything is done to them already?

Isolde

iTrader: (4)

Thank you for taking an interest.
Actually, these heads are intake-valve limited, porting does nothing for intake flow unless larger intake valves are included. I'm fairly accomplished at porting SBC heads, so I'm gonna try my hand at these before paying for CNC porting.
TSP's PRC heads are on my list, as are TEA, but to my mind, until I see what I can do, their only advantage is consistency, ( the exact same shape in every port ).
Here's a pic of my exhaust work on these heads so far, ( no flow bench numbers YET )

5.3LJimmy

iTrader: (10)

I'm not trying to be a jerk but by your reasoning a 2.00 valve head cannot outflow a 2.04 valve head. I'm sorry but there is more than the intake valve diameter that affects the flow of the port. To say that porting does nothing for flow is just silly.

Isolde

iTrader: (4)

You're taking it wrong. These ports are already good enough to make the 1.89" valve the limiting factor. The 1.89" valves can't move as much air as these ports are already providing to the back of the 1.89" valves. There is a maximum cfm that a 1.89" valve can flow at any given lift at 28". These heads are already there.
Thus, a larger intake valve is necessary before you can get any more intake flow from these heads. And the SuperFlow 1020 proves it.
Porting does nothing for flow when the valves are the limiting factor. Porting only helps when the ports are the limiting factor.
If you don't believe me, shoot a PM to Tony Mamo, including a link to this thread. DON'T take me out of context, be fair.
Now, I have another 5.3 head, with which I went a bit farther in the exhaust ports. I got some pics of that:

I'm no photographer, I have no skills with getting the lighting right, or adjusting the exposure or the filtering.

Isolde

iTrader: (4)

I'm not happy with that port, but it's not as sharp-edged as that pic makes it look. Here's a shot from a different angle.

After I try both versions on the SF1020, I'll know what's better for my near-new-and-not-yet-ported 706 heads.

1FastBrick

iTrader: (16)

Curious why not get it done localy??? Any compatent machine shop should be able to do it. BTW are you using it on a stock 5.3 bore or for something else???

Isolde

iTrader: (4)

Hi, nice to hear from ya.
The local shop I used to use went out of business. The other shops refuse to put the seat far enough out on the valve, and they refuse to adjust the 75-degree bowl hog the way it needs to be. All I ask is the deepest possible cut that won't touch the guide, and will narrow the 60 degree cut to about 0.055" wide. They want to use big seat inserts that put the seat in the middle, but then that leaves the throat too large. They care more about not having a come-back, and less about what the air is doing.
I do currently have a stock-bore 5.3 block, but I'm on the hunt for a used set of LS6 pistons at a fair price. Preferably still on their original rods.

1FastBrick

iTrader: (16)

What a shame. My under standing is that they use the same Seat insert on the 706 heads as used on all the GenIII castings. I just dont see what the big deal is. Keep us updated on your project. For what its worth I have used Richard @ WCCH in the past. I am sure you could find some one a little closer though to accomplish your goals.

Isolde

iTrader: (4)

I hope you're still watching this thread. It seems to me I recall reading a feature in CarCraft, where they tested a 5.3, first with stock heads, then with stockers ported by Richard at WCCH, then Edelbrock Pro Ports also done by Richard. I'm pretty sure he only went to 1.95" intake valves in the stock heads, not 2.00". I'm not succeeding at recalling if it specified why.
I may call him next week.
If the stock 1.89" seats will take 2.00" valves without the seats failing, then I'd be thrilled! Plus that's mean the local shops are just trying to sell me new seats that I don't need, proving them (1) probably dishonest, and (2) definitely unworthy of any more SBC stuff from me.
I did get a PM about another shop.
Anyone else have anything?

Tony Mamo @ AFR

iTrader: (13)

How do you know they are already there??

Have you flowed them and if so what did they flow and what do you think the theoretical limit of that valve actually is?

Regarding your VJ request I would also tell you to give Richard @ WCCH a shot....he works alot with OEM castings and can certainly get you handled.

-Tony

Isolde

iTrader: (4)

Mr. Mamo,
I'm flattered and honored that you would look at my stuff, but while I have both a natural talent for porting, and extensive experience with a SuperFlow 1020 with EVERY option, there's NO way I want to risk YOU criticizing my results. You who doesn't even show us the best shape for the ports in any of the stock heads.
I didn't start this thread to debate ports or flow. I just need to find a new shop to do the machining that I'd do myself IF I still had the access to the Serdi that I used every day. Since the local shops won't cooperate, I am willing to pay shipping.
I have already finessed my intake ports to the point that the numbers stopped improving. I ruined 5 heads to get there, and my shape is staying secret. How else can I ever get rich and famous like you, Mondello and Massengill?
Do you recall back when the Vortec 350 heads were still new? Finally, one of the magazines did a long article, showing Mondello doing the Vortecs. I saved that article.
After I did my first set of Vortecs in '03, I went and found that article. My results were better, and I did it with NO trips to the flow-bench mid-porting. I just followed my instincts, then tested. That's when I knew I have a gift.
My numbers and my intake port shapes are my secret.
If it seems like I'm a bit unfriendly to you, well, that's jealousy. I could do your job, and I should have a similar job at similar pay.
Farewell.

5.3LJimmy

iTrader: (10)

The only famous massengill that comes to mind after that last post is the douche company. I now feel justified that my natural talent at identifying douches told me to stop posting here after your second response. Good luck with the heads(not that you need it obviously).

1FastBrick

iTrader: (16)

As Tony Mentioned Richard Is very knowledgeable with all the castings. He Used a 1.94 Intake with a 1.57 Exahust on the 5.3L heads your reffering to. I know Because I have a set. I also have the flow sheet from that comparison.

I dont want to get into the other part of your disscusion

Here is the latest comparison from Car Craft and I can tell you the picture of the stage 1 head is unfinished. I know because I wanted to see how much work he put into a set of heads so I took the valves out to inspect around the seat were you can not see through the intake or exahust port.

http://www.carcraft.com/techarticles...ine/index.html

Still looking for the original comparison...

1FastBrick

iTrader: (16)

Apparently it was like april 08 but I dont have that issue on hand and the artical is no longer on line either...