DIY LS1 Head Porting at home can Help
#62
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Yeah we need a head porting sticky!!
And to agearheadlife- great info and its awesome somebody took the time to do this! Im no expert but somebody might have said this but ive also been told you do not want to slow the velocity of the air down by porting to flow more cfm. And the gmhtp article is a perfect guide!
And to agearheadlife- great info and its awesome somebody took the time to do this! Im no expert but somebody might have said this but ive also been told you do not want to slow the velocity of the air down by porting to flow more cfm. And the gmhtp article is a perfect guide!
You're right. I try not to lose velocity. I try not to enlarge the ports, beside the lumps that I remove.
Too keep it simple, all I mainly do at this time is remove the two lumps and then blend and smooth the rest.
In my opinion, that article in GMHT on porting was great to start out with when researching. But for good detail that I was looking for, wasnt there. Seemed a little bland to me. Maybe because I'm already playing with them and look for more. IDK Wish that article had come out before I started researching. It probably would have been helpful to me.
I'm thankful for the information I found scattered across threads on this forum and from Mikey97z and BoWhite for taking the time to answer my questions.
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You're pumping up my 15 mins of fame again!! WoooHooo! If you check that, then you might like to check out my interview with Holley as well for winning the Presidents pick at Holley LS Fest 2012
Dont make fun of my wording. It was awkward trying to think of things to speak of for them.
Dont make fun of my wording. It was awkward trying to think of things to speak of for them.
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You're pumping up my 15 mins of fame again!! WoooHooo! If you check that, then you might like to check out my interview with Holley as well for winning the Presidents pick at Holley LS Fest 2012
Dont make fun of my wording. It was awkward trying to think of things to speak of for them.
http://www.youtube.com/watch?v=xewHJ88EOfw
Dont make fun of my wording. It was awkward trying to think of things to speak of for them.
http://www.youtube.com/watch?v=xewHJ88EOfw
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LS Fest was a blast! Nah wasn't worried about the rain. I'm kinda a survivalist and being military, the rain was no problem. Actually I was very thankful for it, because Friday was extremely hot and I was headed to bed with sweat dripping off my head. Then the rain came and cooled everything off.
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I've come up with some more info to share. I'm really tired and hopefully didn't miss anything. I attempted to learn how to make a graph with excel. I put the before and after dyno numbers on it to compare.
See attachment.
It looks like I lost a lot of torque below 3k rpm. 100ft lb of torque. If this is so it could be because I took a little material off of the short turn radius. I will leave the short turn alone next time (besides smoothing).
I don't know. Cant think straight. going to bed....
Good night LS1Tech!
See attachment.
It looks like I lost a lot of torque below 3k rpm. 100ft lb of torque. If this is so it could be because I took a little material off of the short turn radius. I will leave the short turn alone next time (besides smoothing).
I don't know. Cant think straight. going to bed....
Good night LS1Tech!
#68
I watched your diy videos on you tube.I feel a little squemish about taking a good set of
243 's and porting them. Should i try to do it first on a set of 853's that are sitting around in my garage first to practice on?How hard was it to do your first set of heads?
243 's and porting them. Should i try to do it first on a set of 853's that are sitting around in my garage first to practice on?How hard was it to do your first set of heads?
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The hardest part of the first pair I did was finding information on how to do them. lol So you've got that part knocked out! haha It is very time consuming though. Especially on your first pair.
#72
I've come up with some more info to share. I'm really tired and hopefully didn't miss anything. I attempted to learn how to make a graph with excel. I put the before and after dyno numbers on it to compare.
See attachment.
It looks like I lost a lot of torque below 3k rpm. 100ft lb of torque. If this is so it could be because I took a little material off of the short turn radius. I will leave the short turn alone next time (besides smoothing).
I don't know. Cant think straight. going to bed....
Good night LS1Tech!
See attachment.
It looks like I lost a lot of torque below 3k rpm. 100ft lb of torque. If this is so it could be because I took a little material off of the short turn radius. I will leave the short turn alone next time (besides smoothing).
I don't know. Cant think straight. going to bed....
Good night LS1Tech!
As for the short turn you have to watch what you do there and it always helps to know what your looking for on the flowbench when grinding it.
It is the easiest spot usually to make great gains or put the head in the toilet.
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Cam timing and port design go hand in hand... you could swap the cam for something that works with the new port design and pick the bottom back up while keeping most if not all your gains in the top end.
As for the short turn you have to watch what you do there and it always helps to know what your looking for on the flowbench when grinding it.
It is the easiest spot usually to make great gains or put the head in the toilet.
As for the short turn you have to watch what you do there and it always helps to know what your looking for on the flowbench when grinding it.
It is the easiest spot usually to make great gains or put the head in the toilet.
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Hey guys ive never posted here i need some help. seems like youve got some things figured out with the ls heads.. i have a question to thicken the plot. i have a 5.3 aluminum block with the 799 head castings which ive read are basically 243. so they flow good. cool. i dont however have the valves for that engine.. but i have a set of dart valves from iron eagle platinums that would be a great valve for that head. theyre swirl polished valves that already have a 30 degree cut back and measure 2.02/1.60 the heads i have should be 2.0 and 1.55 also theyre a .342 stem diameter. so my plan was to o.d. the valve to the correct sizes and then regrind the seat into them. my issue is with the valve guides. can i just ream them out to accept the larger diameter stem and also my 600 lift springs from sbc i know theyd work i just dont know exactly how...i can lathe a spacer easily to raise the spring height from the pockets since the stock beehives are slightly taller. anyone ever done this or does this seem crazy. im a machinist so i see damn near everything as possible. even if its not.
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Hey guys ive never posted here i need some help. seems like youve got some things figured out with the ls heads.. i have a question to thicken the plot. i have a 5.3 aluminum block with the 799 head castings which ive read are basically 243. so they flow good. cool. i dont however have the valves for that engine.. but i have a set of dart valves from iron eagle platinums that would be a great valve for that head. theyre swirl polished valves that already have a 30 degree cut back and measure 2.02/1.60 the heads i have should be 2.0 and 1.55 also theyre a .342 stem diameter. so my plan was to o.d. the valve to the correct sizes and then regrind the seat into them. my issue is with the valve guides. can i just ream them out to accept the larger diameter stem and also my 600 lift springs from sbc i know theyd work i just dont know exactly how...i can lathe a spacer easily to raise the spring height from the pockets since the stock beehives are slightly taller. anyone ever done this or does this seem crazy. im a machinist so i see damn near everything as possible. even if its not.
Problem is that I think the old SBC valves are shorter. I researched putting LS1 valves into an old SBC head once and I remember someone stating that the valves are longer and the locks are different. But this gets out of my area of experience/knowledge. Maybe another machinist will chime in.
I do know these heads would like a set of 2.02/1.60's!