porting tips for LS1 heads
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Staging Lane
Joined: Aug 2002
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From: Wake Village, TX
Re: porting tips for LS1 heads dont do it...pay a professional...ive see too many screwed up heads at our shop...porting is difficult to begin with and porting ls1's is completly different than porting a plain old 350 head
Re: porting tips for LS1 heads thanks for the advice but i can remember some one here on this ls1tech board said that he ported his own LS1 heads with the help from a professional and he got excellent flow numbers and i guess excellent rwhp numbers but i can't remember his name.
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Re: porting tips for LS1 heads I just did it but would like to know more. I concetrated on obvious things like valve guide supports, rocker arm bolt bosses, smoothing here and there, kept swirl ramps and didn't open ports as RPM band will be fairly low with my 212/218. The engine is still in pieces.
Re: porting tips for LS1 heads My attitude with porting is that if a shop can do it, why can't I? They're probably just paying somem pimple faced 21 year old to do it... If you know where to take the material off, then might as well do it yourself!
Re: porting tips for LS1 heads I've just finished my second set. I don't expect them to make huge numbers, and never did. I tried not to remove much material, just enough to rid the runners of all casting material. I cut down the valve guides some, and really made a nice smooth transition from the seat to the runners. I left the chambers alone.
I have the tools and time to port them, so I figured "why not". Even if its only 10 hp, it was worth my time. I won't have before and after numbers because these will go on a new motor.
I have the tools and time to port them, so I figured "why not". Even if its only 10 hp, it was worth my time. I won't have before and after numbers because these will go on a new motor.
Re: porting tips for LS1 heads It's not easy lets put it that way. You can't just port them and expect good results. You can port and port all you want in alot of areas and do nothing but bad. You really need a flow bench to dial in the critical areas. You can get lucky or you can get smart and pay to have a professional do it. I used to say GO FOR IT, but I have enough time on the bench to know it'll be real hit and miss and mostly miss with the LS1 heads. They're tough!
There are plenty of LS1 head porters like myself that offer great results without the huge prices.
There are plenty of LS1 head porters like myself that offer great results without the huge prices.
Re: porting tips for LS1 heads so what areas requires touching up and porting, and what areas to be avoided with the carbide bit? <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> . thanks.
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From: New Jersey
Re: porting tips for LS1 heads Here is a funny story of a home port gone arye, Local guy comes into my shop, gets a Comp 216 cam installed, dynoed the best of 345 RWH 340 RWT through manifolds and stock cats, gets an eyefull of what I'm doing on the flow bench and see's the runner/bowl designs I use, he seemed some what mechanically inclined and asked lots of flow questions. 2 weeks later, he ordered a set of Mac headers with an ORP from me, he picked them up and mentioned he ported his own heads and that he installed the same Ferrea valves I use because that's the brand name he read on the boxes around my porting area, 2.02's and 1.50's, so after his heads and header install, I meet him back at the dyno and he pulled the best of 352RWH @ 6,300 and 330 RWT @ 5,000 at 13.0 on the WB with a terribly erratic torque line. I am not deterring anyone from trying, but you can't port by line of sight just from looking at another ported runner period. long story short, I sold him a set of S2's and he went on to dyno 390 RWH @ 6,000 384RWT @ 4,600 with the same cam and headers, so... you can hurt them as quick as your trying to help them. I inspected his porting, it looked very nice but stalled there asses off all over the lift range, he mirror polished the intake runners for some reason also.. looked nice though! Now on the other hand, I have seen about 3 examples of home ports that have been in the 400 RWH range but they had a flow bench at there disposal. The LSX runners are very sensitive to port flow changes, take a little out where you shouldn't and 20 cfm's go right out the window, port them where it matters and they will flow great.
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Staging Lane
Joined: Aug 2002
Posts: 65
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From: Wake Village, TX
Re: porting tips for LS1 heads This winter I had a customer with a blown 382 that was dynoing down real bad...after pulling the heads we found why...the person who ported these heads cut the ramp out of them and install 2.02/1.60 SBC (11/32 guide) valves...threw them on the flow bench and they flowed 3cfm better on the intake and 2cfm worse on the exhaust than a STOCK UNPORTED head...if you are going to port at home, practice first...have someone who knows what they are doing help...and get access to a flow bench...dont want to bolt something on that flows worse than stock!...good luck
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From: KS
Re: porting tips for LS1 heads Since I am also a flow bench owner and experienced with the LSX series heads, I would like to say "you are flirting with disaster" porting on an LSX head. You can't just know where to port from looking at it. I can take .050" of material off in certain areas and pick up 5 cfm of flow across the board. And like JPR says, you can take off the same amount in the wrong area and all but ruin the heads.
Don't skimp on heads. You guys just need to scrape up the money and pay someone with a flow bench who knows what they are doing. And make sure when you are shopping for a porter they have a worthy flow bench. Not a home made job. They might work, but they have no calibration certificate which means their numbers mean nothing. Those of us who spent the thousands that we did on flow benchs are SERIOUS head porters. Not someone who guesses. Although I've seen some BS numbers from some of the people who sell heads. That's another thread though. <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />
Don't skimp on heads. You guys just need to scrape up the money and pay someone with a flow bench who knows what they are doing. And make sure when you are shopping for a porter they have a worthy flow bench. Not a home made job. They might work, but they have no calibration certificate which means their numbers mean nothing. Those of us who spent the thousands that we did on flow benchs are SERIOUS head porters. Not someone who guesses. Although I've seen some BS numbers from some of the people who sell heads. That's another thread though. <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />
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Re: porting tips for LS1 heads </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Jantzer98SS:
<strong> It's not easy lets put it that way. You can't just port them and expect good results. You can port and port all you want in alot of areas and do nothing but bad. You really need a flow bench to dial in the critical areas. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I believe that. That's why I concentrated on small things which should be ok with a small cam. Let's see... I mainly didn't want to start ordering these internationally right now.
<strong> It's not easy lets put it that way. You can't just port them and expect good results. You can port and port all you want in alot of areas and do nothing but bad. You really need a flow bench to dial in the critical areas. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I believe that. That's why I concentrated on small things which should be ok with a small cam. Let's see... I mainly didn't want to start ordering these internationally right now.
porting tips for LS1 heads any one has porting tips for LS1 heads similar to these for porting LT1 heads :
http://members.***.net/gmarengo/Head...eadPorting.htm
thanks
Abdullah
<small>[ March 16, 2003, 12:02 PM: Message edited by: Abdullah ]</small>
http://members.***.net/gmarengo/Head...eadPorting.htm
thanks
Abdullah
<small>[ March 16, 2003, 12:02 PM: Message edited by: Abdullah ]</small>
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From: Houston, Texas
Re: porting tips for LS1 heads It is on the intake port if you look at the stock heads next to the valve guide one part is raised the other is not. It is to induce swirl into the chamber to suspend fuel before combustion.
Re: porting tips for LS1 heads I guess the thing that I can't seem to understand is the pricing some of the shops are charging. The advent of CNC technology was, to reduce costs, keep quality consistent from one part to the next. All you do, if you have CNC to begin with, is enter your measurments in a tape. Yet you guys are charging out the *** for basic cylinder head work. Maybe someone could clarify this, because I don't pay that kind of money for head work on my damn cirlce track motors. 
Re: porting tips for LS1 heads
I guess the thing that I can't seem to understand is the pricing some of the shops are charging. The advent of CNC technology was, to reduce costs, keep quality consistent from one part to the next. All you do, if you have CNC to begin with, is enter your measurments in a tape. Yet you guys are charging out the *** for basic cylinder head work. Maybe someone could clarify this, because I don't pay that kind of money for head work on my damn cirlce track motors.
As far as DIY head porters, I know there's some on here that haven't responded, but they might be avoiding threads like this due to all the questions they would be hammered with.
Re: porting tips for LS1 heads I've home ported my LS1 heads, and believe that a very good job can be completed so long as all contours are completely retained. Remove only enough material to smooth out rough surfaces. Removing extra material(other than rough surface) around the valve guide/inner radius is asking for trouble without a flow bench to verify your work. This is where a funnel effect takes place, and where small differences(cylinder to cylinder) in porting cause big differences in mix and velocity.
It took me over 50 hours to complete what I would call a "stage 1" port. This was done with a Dremel, die grinder, and lots of 150 grit emery paper. I can understand why the cost of a professional job is what it is.
It took me over 50 hours to complete what I would call a "stage 1" port. This was done with a Dremel, die grinder, and lots of 150 grit emery paper. I can understand why the cost of a professional job is what it is.
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From: RainbowCity,Alabama
Re: porting tips for LS1 heads
I guess the thing that I can't seem to understand is the pricing some of the shops are charging. The advent of CNC technology was, to reduce costs, keep quality consistent from one part to the next. All you do, if you have CNC to begin with, is enter your measurments in a tape. Yet you guys are charging out the *** for basic cylinder head work. Maybe someone could clarify this, because I don't pay that kind of money for head work on my damn cirlce track motors.