Ok, since my buddy (Drew778) screwed up his heads (casting #241) I am getting a really good deal on them, most likely trade for LABOR, right Andrew?
I am running the TR 224 cam, may jump up to a bit larger cam, not sure.

1) valve size, is 2.02/1.57 best, or stay stock for this cam?

2) valve make, Fererra over Manley or v/v?

3) Any good info on * of valve job, 3 angle, 5 etc...

4) milled 5.7L .030" = 11:1 compression correct?

5) would it be beneficial to work on maximizing flow under .600 as I will most likely not go any cams over .600 lift? And if so, whats the best way to do it, work the floor or roof of the runners etc..???

Any info for the runner volume, etc...is greatly appreciated, and yes this will be my first pair heads i will to port.

 

I would have to say 2.08"/1.60" would be best

Who's heads

 

ttt

 

Noone wants to help a begining porter???

 

Well, if you keep asking somebody will soon jump in to say you shouldn't do that. Anyway, if you're changing valve sizes you're making major changes to the flow and won't come out good without a flowbench. If you stick to stock valve size you can safely do some obvious improvements and smoothing here and there but again making significant changes to port shape requires experimentation. You can find info on port volumes by searching and some porters like Absolute lists them on their web site.

 

pekkaz, thanks. I just kinda figured I could get some pointers and such from other people that have been doing them. Bode, a local shop owner ports LS1 heads and is going to help me, but I would like to use as much knowledge from as many sources as possible as it makes for good learning.

 

The flowbench would be nice to have for doing this. A friend of mine did his own and used the stock valves and just smoothed things out. Heads didn't turn out too bad. He wishes now that he would have taken more material out after seeing a set of stage 2 heads and how much they were ported.

Jordan

 

I have ported several sets of heads (from various engines), and here are some general guidelines that work well for me:

Start at the throat area (the area just behind the valve). Open up the throat to 85%-90% of the size of the valve seat.

With the throat complete, blend it back into the bowl. You can open up the bowl slightly and make it smooth.

With the bowl complete, focus on the window area. This is where the port transitions from being rectangular to round. Widen the window area by removing material from the sides of the port. Raise the roof of the port by removing material from the top of the port. Blend the window into the bowl area.

The shape of the short turn radius (where the floor of the port turns down to the valve) is critical. Proper shape is a matter of geometry, and I find that it's best to make a template. As for the geometry, the short turn should be approximately 1/4 of the radius of the completed throat area. To make a template, measure the completed throat area. Let's assume it's 1.818" (90% of 2.02"). Use a protractor to draw a 1.818" (or whatever is appropriate for your heads) circle on a piece of cardboard, sheet of aluminum, steel, or ?? Cut out 1/4 of the outside arc for your template. You can slide this into the port from the valve area to see where material must be removed.

Gasket match the opening of the port, and blend the opening back into the completed window area.

I would find a scrap head to experiment on, before starting on good cores.

Don't go wild with removing material. If the port is too large, it may produce good flow #'s on a bench, but the performance will be terrible. Huge ports = slow air speed and lost low end torque.

I hope this helps

 

This info does help. Cant remember with the LS1 heads but I thought I was told to leave the roof alone and work the floors, or am I backwards here?

Thanks HumanoidZ06.

 

His name isnt Humanoid. There is only one pimp named Humanoid around here and that is me!

 

Ok, edited that part so your undies can creep out of your asscheeks whenever your ready. I used to have a dashplaque that read similar to your avatar Humanoid! Nice.

 

I'm not sure what other porters are doing, but when you lower the floor it changes the ramp leading up to the short turn. You need to leave enough material to have the proper angle for the short turn radius. If the turn falls too short, the air will blast down the floor and skip over the back of the valve. Tumbling will occur when it hits the air from the roof that is trying to exit out that side of the valve. On some heads I have actually added epoxy to the floor and raised the roof. This provides a straigher shot to the valve seat. The techniques are infinite, and will vary by porter. These are the things that have worked well for me.

 

Ok, so take away from the roof and leave the floor alone as much as possible. And as for gasket matching, obviously scribe the size and slowly go at it, making much like the opening of a tuba or trumpet right? Where it is wider/taller etc..and then smoothly tapers back into the "final port size/shape". Blend the valve guide boss (?) so it is like a knife edge on the port side and leave the backside alone? How about when shaping the guide, is there a rule as to taper the guide to be shapely as it meets the valave, or more blunt? I have seen some heads, SBC AFRs and others that the Bronze guide inside the guide boss is barely visible where it meets the valve...any benefit to this or leave it? How do I massage the bowls for a good swirl, or do I wanna just make them smooth as hell?

Speaking off roofs, now I remember...All the people posting up about jacked up heads from a sponsor cause the roof went so far it opened up the rocker boss! The solution was to fill it with epoxy and grind on! Damn, thats a lotta grinding!