Custom LS1 Head Porting trouble
I recently purchased heads/cam from a local area guy who got the heads from a company called Precision Motorsports.
After I purchased heads/cam I took them to my engine builder, to go through the heads/check the cam.
Upon inspecting the heads they found that the valves weren't seated correctly (up to 30% difference), they never lapped the valves in correctly and when completing the hand porting work they hit the bottom of a few valve guides, and they removed the vein out.
I am told there is a ledge or something in the intake pocket from the runner that is called a vein, that when the fuel comes in, it hits that, and atomizes, and when they removed that from the porting/polishing, it made the fuel "puddle" and you could see where it ran down inside.
My engine builder is very up on the new engines, but they mainly deal with older engines, so I am lookin for other opinions.
Did the guy who ported the heads messup by removing the vein?
Also can you give me a little more detail as to what it actually does/looks like?
These are the heads/cam purchased from Ryan Seagraves, who got the heads from Precision Motorsports.
"Stage 3 port/polish LS1 Heads ceramic coated, larger ferroa valves"
http://pm-fl.com/catalog/
Last edited by QuickdomesticRacer; Jan 2, 2007 at 09:45 AM.
mixing at the expense of airflow. A "Stage 3" job means
all out for airflow and this is a likely victim in the process.
Not abnormal for the claimed type of port job, but not a
great idea for a street car that wants to not be a pig
around town either.
Why you would put coating on / in heads I dunno either.
I guess to cut that last little bit of heat from the air but
I sure would be paranoid about flaked coating going
through the motor if it's in the runners, and if it isn't in
the runners then it's useless other than show.
why the heads were coated? b/c bob who owns precision motorsports first started out as precision coatings. that was his first business. nothing wrong with coating the heads.
as for taking the swirl vein out, many many head porters do this. it was designed for emissions standards, which we have none in FL. it has nothing to do with fuel puddling. that is a product of the stock tune and the Ltrims fighting the big cam. it happens to every single cammed car on this site. it will not hurt low end velocity. your head porter should know this. the heads made over 400 ft lbs of tq at the rear wheels on an honest dyno on pump gas.
why haven't you put the heads on the car yet? better question, why didnt you just call the head porter with these questions since you have his contact info?
Last edited by gator's 99TA; Jan 1, 2007 at 11:05 AM.
I recently purchased heads/cam from a local area guy who got the heads from a company called Precision Motorsports.
After I purchased heads/cam I took them to my engine builder, to go through the heads/check the cam.
Upon inspecting the heads they found that the valves weren't seated correctly (up to 30% difference), they never lapped the valves in correctly and when completing the hand porting work they hit the bottom of a few valve guides, and they removed the vein out.
I am told there is a ledge or something in the intake pocket from the runner that is called a vein, that when the fuel comes in, it hits that, and atomizes, and when they removed that from the porting/polishing, it made the fuel "puddle" and you could see where it ran down inside.
My engine builder is very up on the new engines, but they mainly deal with older engines, so I am lookin for other opinions.
Did the guy who ported the heads messup by removing the vein?
Also can you give me a little more detail as to what it actually does/looks like?
These are the heads/cam purchased from Ryan Seagraves, who got the heads from Precision Motorsports.
"Stage 3 port/polish LS1 Heads ceramic coated, larger ferroa valves"
http://pm-fl.com/catalog/
I guess to cut that last little bit of heat from the air but
I sure would be paranoid about flaked coating going
through the motor if it's in the runners, and if it isn't in
the runners then it's useless other than show.
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With my job I can save maybe 100-120 a week. I need
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and 375 +dyno time tune by Jeremy.
Again, I am not complaining. My dad thought it would be a good idea to run them by our engine builder just to make sure, because we aren't rich this is my only way of transportation, we don't have a spare vehicle, and I can't have a valve dropping or anything.
I was just gonna have them check the springs and remove the valves, clean up the pockets and reseat the valves.
Than they came to me with all this stuff. I am trying to gather more info, rather than taking one person's word.
and Ryan, I got your PM and my dad called but they were out of the shop all last week, and I emailed him about it, and got his cell phone number yesterday. My dad called him today about them.
As far as I thought, you ordered them and had them installed, I wouldn't of thought you yourself or RevXtreme thoroughly examined them, just put them on, So there may have been some imperfections in the porting, even though they performed that well. Maybe there could of been even more power made.
Last edited by QuickdomesticRacer; Jan 1, 2007 at 11:55 PM.
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what does your budget have anything to do with bob's head porting? learn what to look for, save up and go have fun. like the rest of us. imo you shot without thinking and are taking the words of everyone you can find without forming your own educated opinion. if your engine builder thinks there are problems and you believe him, go ask him why and fix it. simple right? you have asked everyone's opinion under the sun looking for problems. if you dont feel comfortable with a part, dont install it.
again the most rediculous thing about this is you have not once (according to this thread) talked to the very person who ported them. bob is easy to get ahold of. i have not seen bob's work but on a few cars. none made the power of these heads. those heads worked. if you cant make power with them, its your combo that is the problem. you cant argue with 400 ft lbs of tq.
Last edited by gator's 99TA; Jan 1, 2007 at 08:29 PM.
I am not even accusing anyone of anything, I am asking to be more well informed, I didnt even mention anyones name.
Last edited by QuickdomesticRacer; Jan 1, 2007 at 08:36 PM.
How ever.. do your self a favor.. and ask the guy who ported them about a certain few things you have questions about.. if your still uneasy.. take pictures.. and post them up in the internal engine section.. you'll have knowledgable people and sponsors there to help you out.. the FLorida forum is more of a communication forum..
what it comes down to is you need to be 100% confident in what you bought.. if they made power great they made power.. but i agree there could be more there.. who knows.. every car is different..
I personally see no problem with asking questions.. your here to learn.. and if your anything like me you'll learn to trust no one and do most things yourself.. ask your questions just try the right forum and before you know it you'll be out there making the horsa powa
Mike
(he is)
, good to know the person who put them in and knows the motor is able to actually give an educated answer. 




