241 heads worth porting myself... Pics added
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241 heads worth porting myself... Pics added
Would I see enough of a gain in porting my 241 heads myself to make it worth the price of the head gaskets and head bolts etc... Is it necessary to replace the head bolts? The motor is stock with a 600 lift hydraulic roller cam, long tube headers, and a 3600 stall. Like I said it is very basic and not sure if it would be worth the time so I thought I might ask you guys. I have gasket matched a few sets of heads in the past one set for a grand national that I had and a few sets of small and big block chevrolets. Any thin areas that I would need to look out for?
Last edited by JUICED98Z; 10-28-2010 at 09:46 PM.
#2
if that is all your planning to do is port stock heads then def not worth it. You may see 10 hp on a dyno? Yes you have to replace the bolts and gaskets and everything..... so i dont see spending the money on just those parts alone for barley a gain
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If done correctly they could really make a difference. A valve job would add even more. Advanced induction has ported 241's making around 450rwhp.
Somebody flow tested their hand ported 241's on here and it went from 223cfm at .500 lift to 270cfm+
The bump in the exhaust shouldn't be removed all of the way though because that is a thin area, there are also cutaway pictures on here of the 241's. If you want to skip the aggrevation and time spend on them, I have freshly ported 241's in the FS section.
Somebody flow tested their hand ported 241's on here and it went from 223cfm at .500 lift to 270cfm+
The bump in the exhaust shouldn't be removed all of the way though because that is a thin area, there are also cutaway pictures on here of the 241's. If you want to skip the aggrevation and time spend on them, I have freshly ported 241's in the FS section.
#6
Do some searches and find all the porting threads on here. You really don't have to open up the intake port much to make it flow very good. Porting your heads is probably the best bang for the buck other than buying 243s and porting those.
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If done correctly they could really make a difference. A valve job would add even more. Advanced induction has ported 241's making around 450rwhp.
Somebody flow tested their hand ported 241's on here and it went from 223cfm at .500 lift to 270cfm+
The bump in the exhaust shouldn't be removed all of the way though because that is a thin area, there are also cutaway pictures on here of the 241's. If you want to skip the aggrevation and time spend on them, I have freshly ported 241's in the FS section.
Somebody flow tested their hand ported 241's on here and it went from 223cfm at .500 lift to 270cfm+
The bump in the exhaust shouldn't be removed all of the way though because that is a thin area, there are also cutaway pictures on here of the 241's. If you want to skip the aggrevation and time spend on them, I have freshly ported 241's in the FS section.
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If you want to stay on a budget.. I would personally grab some 5.3L heads.
According to the flow charts on here, the 5.3L heads flow as well as 853/241's do with a smaller Intake valve. Take the 2.00 intake from your current 241's and have them cut into the 5.3L heads along with a valve job. Then mildly port them to your liking.
I could never find the cutaway picture that camz28arro is talking about, but I do have this http://i29.photobucket.com/albums/c2...g?t=1287976309 which is what I used to guide myself.
If your really on a budget, just leave the 1.89's on there, but if your getting a valve job, I would throw in having the valves cut as well.
If your gonna have the heads on and off a lot, get some ARP's. If your not, get stock replacement head bolts. Stock are TTY(Torque to Yield) and are one time use only. ARP can be reused but are 2-3x as expensive.
According to the calculator I used, and hoping I didn't mess it up (LOL) I am at 10.9 with the graphite gasket used for the 98-00's with notched heads. (0.051 compressed) and .010 milled off the bottom to bring the chamber to 59.6 CC.
According to the flow charts on here, the 5.3L heads flow as well as 853/241's do with a smaller Intake valve. Take the 2.00 intake from your current 241's and have them cut into the 5.3L heads along with a valve job. Then mildly port them to your liking.
I could never find the cutaway picture that camz28arro is talking about, but I do have this http://i29.photobucket.com/albums/c2...g?t=1287976309 which is what I used to guide myself.
If your really on a budget, just leave the 1.89's on there, but if your getting a valve job, I would throw in having the valves cut as well.
If your gonna have the heads on and off a lot, get some ARP's. If your not, get stock replacement head bolts. Stock are TTY(Torque to Yield) and are one time use only. ARP can be reused but are 2-3x as expensive.
According to the calculator I used, and hoping I didn't mess it up (LOL) I am at 10.9 with the graphite gasket used for the 98-00's with notched heads. (0.051 compressed) and .010 milled off the bottom to bring the chamber to 59.6 CC.
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If you want to stay on a budget.. I would personally grab some 5.3L heads.
According to the flow charts on here, the 5.3L heads flow as well as 853/241's do with a smaller Intake valve. Take the 2.00 intake from your current 241's and have them cut into the 5.3L heads along with a valve job. Then mildly port them to your liking.
I could never find the cutaway picture that camz28arro is talking about, but I do have this http://i29.photobucket.com/albums/c2...g?t=1287976309 which is what I used to guide myself.
If your really on a budget, just leave the 1.89's on there, but if your getting a valve job, I would throw in having the valves cut as well.
If your gonna have the heads on and off a lot, get some ARP's. If your not, get stock replacement head bolts. Stock are TTY(Torque to Yield) and are one time use only. ARP can be reused but are 2-3x as expensive.
According to the calculator I used, and hoping I didn't mess it up (LOL) I am at 10.9 with the graphite gasket used for the 98-00's with notched heads. (0.051 compressed) and .010 milled off the bottom to bring the chamber to 59.6 CC.
According to the flow charts on here, the 5.3L heads flow as well as 853/241's do with a smaller Intake valve. Take the 2.00 intake from your current 241's and have them cut into the 5.3L heads along with a valve job. Then mildly port them to your liking.
I could never find the cutaway picture that camz28arro is talking about, but I do have this http://i29.photobucket.com/albums/c2...g?t=1287976309 which is what I used to guide myself.
If your really on a budget, just leave the 1.89's on there, but if your getting a valve job, I would throw in having the valves cut as well.
If your gonna have the heads on and off a lot, get some ARP's. If your not, get stock replacement head bolts. Stock are TTY(Torque to Yield) and are one time use only. ARP can be reused but are 2-3x as expensive.
According to the calculator I used, and hoping I didn't mess it up (LOL) I am at 10.9 with the graphite gasket used for the 98-00's with notched heads. (0.051 compressed) and .010 milled off the bottom to bring the chamber to 59.6 CC.
#10
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if done correctly your ported 241s will make great power and knock some time off your ets. This is what they use to do back in the day circa 1998-2002 to the fbodys with there giant of the day 228-234 duration cams and make like 420 rwhp and run on the brink of 9s with a th400 swap and some juice. Its a tried and true recipe for a fast car. Good luck if you decide to port them bad boys keep us posted!
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I ported mine at home. Along with a .040 mill and some flycuts (11:1 compression) I went from roughly 405 to 430 HP. I also gained a ton of off idle response. Cam only, the motor felt soft driving around. After the added compression, it came to life. If its your first time porting, it may be worth buying a trashed head to practice on first.
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Dont go with a dremel. Use a 1/4" die grinder and a compressor if at all possible. Or use an electric die grinder with a speed control. Start with 6" long carbide burrs and do most of the work that way. Then finish with cartridge rolls (sand paper) to get a smooth and consistent finish. Leave the intake ports finished with 80 grit, but polish the exhaust ports. You can get all the necessary tools from mcmaster carr (mcmaster.com).
If I recall, I bought:
1/4" shaft 6" long 3/8" round carbide burr
1/4" shaft 6" long 5/16" flame shape carbide burr
1/4" shaft 6" long to 1/8" cartridge roll arbor
varying cartridge rolls in all shapes and sizes and tapers from 40 grit to 400 grit.
Here's how mine came out. Sadly no pics after milling and cleaning up the heads.
http://picasaweb.google.com/GuitsBoy...PolishedHeads#
If I recall, I bought:
1/4" shaft 6" long 3/8" round carbide burr
1/4" shaft 6" long 5/16" flame shape carbide burr
1/4" shaft 6" long to 1/8" cartridge roll arbor
varying cartridge rolls in all shapes and sizes and tapers from 40 grit to 400 grit.
Here's how mine came out. Sadly no pics after milling and cleaning up the heads.
http://picasaweb.google.com/GuitsBoy...PolishedHeads#
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juiced nice job. smart leaving the swirl ramp to keep the mid range for that heavier chevelle.
i cant understand the people on this board saying not to PP your own heads. as long as you don't go crazy and follow the good homeporting pics on this board your fine. this guy did a great job and according to the info on this board at least picked up 15 solid hp. i would be able to add my results but TTP closed down here in jersey so i lost my baseline comparison. maybe ill go to the strip tonight untuned...
i cant understand the people on this board saying not to PP your own heads. as long as you don't go crazy and follow the good homeporting pics on this board your fine. this guy did a great job and according to the info on this board at least picked up 15 solid hp. i would be able to add my results but TTP closed down here in jersey so i lost my baseline comparison. maybe ill go to the strip tonight untuned...
Last edited by disc0monkey; 10-29-2010 at 07:59 AM.