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HELP need head porting advise
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From: >>>_FRISCO_MUSCLE_<<<
HELP need head porting advise My friend goin to send out his 241 stock head to a local machine shop for some port work. Since my friend don't know ****, so I've to give the machine shop spec and area to work with. What you guys suggest to be done to the head? It'll goes with a Comp cam 228/232 custom grind.
Here's what I can think of:
3-5 angle valve job
Cut down valve seat?
Smooth out the combustion chamber
Smooth out exhaust inlet and outlet
Enlarge exhaust outlet port to 1 1/2 to 1 5/8 (1 3/4 header used)
Mill down 0.020
Any input is welcome and those head will start working on Monday.
Here's what I can think of:
3-5 angle valve job
Cut down valve seat?
Smooth out the combustion chamber
Smooth out exhaust inlet and outlet
Enlarge exhaust outlet port to 1 1/2 to 1 5/8 (1 3/4 header used)
Mill down 0.020
Any input is welcome and those head will start working on Monday.
Last edited by darknessxyz; May 2, 2009 at 04:51 AM.
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From: >>>_FRISCO_MUSCLE_<<<
Don't get me wrong the shop has experience. They just ask me the spec like how much I want to mill and how big I want to open up the exhaust port. They can do anything I want but they're not really a speed shop that do high performance stuff.
That machine shop has been around for over 20yrs. They do crankshaft, head work and build all kinds of engine (From 4 banger to freightliner). So I'm pretty confident with them.
That machine shop has been around for over 20yrs. They do crankshaft, head work and build all kinds of engine (From 4 banger to freightliner). So I'm pretty confident with them.
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From: >>>_FRISCO_MUSCLE_<<<
The shop actually suggested and will perform this:
3-5 angle valve job
Smooth out the combustion chamber
Smooth out exhaust inlet and outlet
Port work done to intake and exhaust port
This is what I ask them to do:
Cut down valve seat
Enlarge exhaust outlet port to 1 1/2 to 1 5/8 (1 3/4 header used)
Mill down 0.020
What else I should tell them to do aside from the above?
3-5 angle valve job
Smooth out the combustion chamber
Smooth out exhaust inlet and outlet
Port work done to intake and exhaust port
This is what I ask them to do:
Cut down valve seat
Enlarge exhaust outlet port to 1 1/2 to 1 5/8 (1 3/4 header used)
Mill down 0.020
What else I should tell them to do aside from the above?
I suggest if you don't know what you're doing don't give any advice. Hell, I've been studying port design specificly for over a year now and I'm just now cutting into my own set of heads!
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You can tell them what size CC you want. They should be able to cut it to that. Most of the gain on a light port job is going to be found within the first 2 inches up from the valve. VJ + blend, pocket porting, minor SSR work.. the runners themselves aren't going to limit you until that stuff is taken care of. Of course, going beyond that, make sure the runner walls are straight.. do you want to bias the runner? There are a lot of things to consider when changing a port shape. I mean, do you know what an ideal port shape for the head is? What is going to limit you from creating it? How will that affect your flow? How do you adjust to that? When changing the CSA taper, do you want to raise the roof or lower the floor? or do you want to make the port wider? It's really an art form and it seems every porter is a little different in their approach.
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From: >>>_FRISCO_MUSCLE_<<<
Thanx for the input, Paint It Black. We (me and the shop) have consider some of the area you mentioned. Then the shop ask me how far I wanna go for that port work. Cuz that'll take alot more time also maybe more $$. That's why I wanna get more ideas. I'll take that into consideration maybe PM you for the info
Quick question, can the exhaust outlet port be open up to 1 1/2 to 1 5/8 to match the 1 3/4 header?
Quick question, can the exhaust outlet port be open up to 1 1/2 to 1 5/8 to match the 1 3/4 header?
Thanx for the input, Paint It Black. We (me and the shop) have consider some of the area you mentioned. Then the shop ask me how far I wanna go for that port work. Cuz that'll take alot more time also maybe more $$. That's why I wanna get more ideas. I'll take that into consideration maybe PM you for the info
Quick question, can the exhaust outlet port be open up to 1 1/2 to 1 5/8 to match the 1 3/4 header?
Quick question, can the exhaust outlet port be open up to 1 1/2 to 1 5/8 to match the 1 3/4 header?
Good luck with the build!
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From: >>>_FRISCO_MUSCLE_<<<
That means port out the exhuast exit to 1 1/2 should be ok, right? The header's primary is 1 3/4, those are Pacesetter Headers.
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From: >>>_FRISCO_MUSCLE_<<<
Can the same porting theory apply to STOCK 5.3L head? Aside from the smaller intake valve, which I'll replace with stock 2.00 valve, the runner and stuff are the same in 706, 862, 853, 241 casting head. Is that means I can apply the same port work from my friend's 241 head to MY 862 head? Those 5.3L will be next to send to that shop.
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From: >>>_FRISCO_MUSCLE_<<<
I got hook up on head porting, very good price. PM me if you wanna know details.
Haven't take out that god damn lifter yet, rain ruin our schedule. Also need to wait on the port work. They take like 4 days to finish two head.
Haven't take out that god damn lifter yet, rain ruin our schedule. Also need to wait on the port work. They take like 4 days to finish two head.
LOL you better get started on pulling the kmember out that is a BITCH! You've got bigger fish to fry then ported heads lol
