Tips for porting stock heads.
02-25-2008, 07:43 PM
#16
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Location: Orange County, CA
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No stinky talk, all that is good advice: practice, start slow, read up, look at pictures. Everyone has to start somewhere. Have a spare for mistakes.
All I said is that its very involved and IMO I would spend my time/money on something else and have it professionally ported.
All I said is that its very involved and IMO I would spend my time/money on something else and have it professionally ported.
02-25-2008, 08:41 PM
#17
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Join Date: Sep 2006
Posts: 459
No stinky talk, all that is good advice: practice, start slow, read up, look at pictures. Everyone has to start somewhere. Have a spare for mistakes.
All I said is that its very involved and IMO I would spend my time/money on something else and have it professionally ported.
All I said is that its very involved and IMO I would spend my time/money on something else and have it professionally ported.
02-25-2008, 08:47 PM
#18
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Join Date: Jan 2006
Location: Fairhope AL
Posts: 487
500 is fairly cheap.
I'm gonna do mine. I'm gonna do a basic gasket match from intake to head to headers. Then clean up casting flash and smooth em up a bit.
3 angle on valve area. Put it back together
I'm gonna do mine. I'm gonna do a basic gasket match from intake to head to headers. Then clean up casting flash and smooth em up a bit.
3 angle on valve area. Put it back together
02-25-2008, 09:02 PM
#19
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Join Date: Sep 2006
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My plan is to get my extra set of heads cold tanked, cleaned up, redo the valves and valve seats, clean up some of the casting flash inside, put some 1.6, or 1.65 rockers on with better springs and get an impala head gasket
02-25-2008, 09:07 PM
#20
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Join Date: Jan 2006
Location: Fairhope AL
Posts: 487
let us/ me know how it works I have my short block now. I'm looking to do this the basic way thats proven. I have to pick up a crank scrapper/wiper. Gasket match. etc etc. I figure its all free HP waiting to be let out
02-25-2008, 09:15 PM
#21
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Join Date: Oct 2006
Location: northern indiana
Posts: 579
if you send everything out you never learn. what if someone told duntov to let someone else build that stupid looking fiberglass corvette, it will never be fast. everyone starts somewhere. just do some research first before you mess it up.. it is easy to get carried away and find a bolt or coolant passage. my first port job took almost 25 hours on cast iron and i only picked up .15 seconds. but i did it for less than 40 bucks.
good luck and look at some of the hot rod or chevy high performance tech articles
good luck and look at some of the hot rod or chevy high performance tech articles
02-25-2008, 09:20 PM
#22
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From what I've been hearing, gasket matching is not the way to go. When you increase the size of the port, the air going through it moves slower. And besides, most of the restriction is at the valve.
02-25-2008, 10:06 PM
#23
02-25-2008, 10:16 PM
#24
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02-26-2008, 12:15 PM
#25
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Location: waterford, MI - USA
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that first wikopedia one is great.
while Im no expert, Ive ported 4 sets of heads and 2 of them flow tested before, during, and after.
Id say, def. dont touch the short side radius. too tricky and easy to have neg. effects.
instead, focus on the valve guides, narrow and teardrop shape them. the rounded part is where the air is comeing from, then goes by the guide at the thinist part of the valve guide. you'll remove alot of metal doin this.
be very careful not to nick the valve seat with the cutter OR the chuck end of the die grinder. realize that will be spinning too. and when your trying to reach into the port, its easy to do. also, dont port match the edh side exactly. you need to mark where the gasket is, then leave about 1/4" of the exh. port floor intact. I have a pic of this at home I'll put up here. somebody else's pic I saved. but it clearly shows where the gasket port is way lower then the port on the head. if you try to take all that out, you'll hit coolant. that would be bad. also, be very careful when trying to gasket match the intake ports. the pushrod pinch point is pretty thin, expecially on the outer cyl.s ports. 1&7 and 2&8.
study as many pics as you can to pic up on whats been changed. dont even look at aftermarket heads port jobs wont help you at all. just look at ported stock LT1 heads for comparison's.
I'll try to dig up a website someone sent me that has reasonable price's on burr's and sandpaper cartrige rolls.
also, pay attention to cutter speed. I believe the ideal speed is 10-12K rpm. most die grinders are 18K and up speed wide open. they make cheap regulators that go inline with the air supply to slow down your tool.
yes, its VERY messy so get yourself a large area with lots of lights and a light fixture you can put directly in the port, or shine directly in the port. I use a drop light that positioned on the opposite end of the port Im working on to light up the whole port.
if I have time tonight I'll post up as many pics as I have time to do. I got tons of pics cause ive saved all the pics Ive come across of LE and AI and others port work. just for comparison and learning of my own. Ive also installed a few sets of LE, patriot, TSP, and other pro ported heads on customers cars so Ive seen what they look like as well in person.
dont expect to get the same results either as pro ported heads. only proper shaping of the ports will get the max cfm out of them. but you can reasonobly expect 60% of the improvement or better depending on how you do and how much time you put into it.
by the time you pay to have them flowtested, and have a valve job done on them, and buy materials to do the work, your gonna have a significant amount of money. unless you already have most of the tools to do it. the next time will only cost you sand paper rolls and flowbench if you want to. I spent about $60 to have mine flow tested each time.
another idea is to only port one cyl. then take that to a pro. porter and have him critic the work. give you pointers from there so you can apply that to all the rest before its too late. that will help you tremendously if you can find a cool shop to do it. I went to livernois the first time I did this and paid them to flow them. they had no problem looking at them and giving me pointers. same for another local shop that I cant remember th ename of right now when I did my dads LS1 heads.
chris
while Im no expert, Ive ported 4 sets of heads and 2 of them flow tested before, during, and after.
Id say, def. dont touch the short side radius. too tricky and easy to have neg. effects.
instead, focus on the valve guides, narrow and teardrop shape them. the rounded part is where the air is comeing from, then goes by the guide at the thinist part of the valve guide. you'll remove alot of metal doin this.
be very careful not to nick the valve seat with the cutter OR the chuck end of the die grinder. realize that will be spinning too. and when your trying to reach into the port, its easy to do. also, dont port match the edh side exactly. you need to mark where the gasket is, then leave about 1/4" of the exh. port floor intact. I have a pic of this at home I'll put up here. somebody else's pic I saved. but it clearly shows where the gasket port is way lower then the port on the head. if you try to take all that out, you'll hit coolant. that would be bad. also, be very careful when trying to gasket match the intake ports. the pushrod pinch point is pretty thin, expecially on the outer cyl.s ports. 1&7 and 2&8.
study as many pics as you can to pic up on whats been changed. dont even look at aftermarket heads port jobs wont help you at all. just look at ported stock LT1 heads for comparison's.
I'll try to dig up a website someone sent me that has reasonable price's on burr's and sandpaper cartrige rolls.
also, pay attention to cutter speed. I believe the ideal speed is 10-12K rpm. most die grinders are 18K and up speed wide open. they make cheap regulators that go inline with the air supply to slow down your tool.
yes, its VERY messy so get yourself a large area with lots of lights and a light fixture you can put directly in the port, or shine directly in the port. I use a drop light that positioned on the opposite end of the port Im working on to light up the whole port.
if I have time tonight I'll post up as many pics as I have time to do. I got tons of pics cause ive saved all the pics Ive come across of LE and AI and others port work. just for comparison and learning of my own. Ive also installed a few sets of LE, patriot, TSP, and other pro ported heads on customers cars so Ive seen what they look like as well in person.
dont expect to get the same results either as pro ported heads. only proper shaping of the ports will get the max cfm out of them. but you can reasonobly expect 60% of the improvement or better depending on how you do and how much time you put into it.
by the time you pay to have them flowtested, and have a valve job done on them, and buy materials to do the work, your gonna have a significant amount of money. unless you already have most of the tools to do it. the next time will only cost you sand paper rolls and flowbench if you want to. I spent about $60 to have mine flow tested each time.
another idea is to only port one cyl. then take that to a pro. porter and have him critic the work. give you pointers from there so you can apply that to all the rest before its too late. that will help you tremendously if you can find a cool shop to do it. I went to livernois the first time I did this and paid them to flow them. they had no problem looking at them and giving me pointers. same for another local shop that I cant remember th ename of right now when I did my dads LS1 heads.
chris
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