cyl. head ????
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Teching In
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cyl. head ???? hello all... I bought a set of ported 5.3 heads that have 2.05, 1.60 valves .650 lift springs and titanium ret... the heads were suppose to be flowing in the 320 cfm range.. well I took them to my local machine shop to have them checked out before i install them on my lq4 build. he cc'd em and checked to see what kind of numbers they were flowing and he informs me that they are only flowing around 230 sumthin...he said that whoever did the port job took to much out of the head. so now im kinda in a pickle bc i spent a good bit of money on these heads... i have the 317 heads that came stock on my lq4. i was thinking of taking the bigger valves and springs and retainers out of the other heads and put in the 317, but i know it will not give me the comp. that the 5.3 heads will have. any input on what i should do would be appreciated... oh yea, im doin a na lq4 stock bottom end build going into a 240sx...thanks,
hello all... I bought a set of ported 5.3 heads that have 2.05, 1.60 valves .650 lift springs and titanium ret... the heads were suppose to be flowing in the 320 cfm range.. well I took them to my local machine shop to have them checked out before i install them on my lq4 build. he cc'd em and checked to see what kind of numbers they were flowing and he informs me that they are only flowing around 230 sumthin...he said that whoever did the port job took to much out of the head. so now im kinda in a pickle bc i spent a good bit of money on these heads... i have the 317 heads that came stock on my lq4. i was thinking of taking the bigger valves and springs and retainers out of the other heads and put in the 317, but i know it will not give me the comp. that the 5.3 heads will have. any input on what i should do would be appreciated... oh yea, im doin a na lq4 stock bottom end build going into a 240sx...thanks,
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Joined: Jan 2010
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From: Houston Tx
Weld "repairs"can be made, but weld overlay in a set of heads is crazy. you would put way too much heat input into the heads causing them to warp all directions. You are better off porting and milling the 317's with a bigger set of valves. Sorry about the loss and good luck.
It's really hard to believe a set of ported heads with 2.05" intake valves only flows 230cfm. Usually when you "take too much out" of the ports, they flow more (not that that is always a good thing).
Are you sure he didn't flow the exhaust instead of the intake?
Are you sure he didn't flow the exhaust instead of the intake?
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From: Houston Tx
The combo works good for me. I think the converter has alot to do with it. It runs good throughout the RPM range. It makes a good street car. My next build I think I would go with a little bit bigger cam something like the MS4.
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Teching In
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idk that he did the flow test right or not... i thought it sounded crazy for the numbers to be so low.... but i have been using him for a long time and he has always done good work for me.. but i have never had him flow any heads. im thinking aabout letting him flow the stock 317 i have since i already know what those flow... im thinkin now about the l92 heads if these 5.3 heads are crap. whats yalls opinion on them? i have about 2 grand to spend on heads and cam and i want the best i can get for the money...
Are these brand new cnc ported heads from TSP? Or did you buy them used? Who ported them? A known shop, or unknown. What lift did he see that flow number from? Clay or other type of flow chamber. what flow bench? Too many questions and very little detail.
Last edited by 95ONE; Oct 23, 2011 at 09:16 PM.
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Joined: Aug 2010
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From: houston, texas
when you take too much material out of the floor of the intake ports it causes the air to stall...that sucks man. not sure where you're located but i got a set of 5.3's my buddy was gonna put on his truck. they were hand ported by a company here in houston, had stock ls1 valves installed, competition valve job and milled to give 11.2/1 compression with stock ls1 pistons. pm me if youre interested. you can have them for what he's got in them since you got screwed on the others. i'll have to get the flow sheet from them but i think they were in the high 290's.
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no these are not tsp heads.. these were done for a "friend" of mine by a machine shop that i dont know much about. i have talked with the guy i got them from and he says that they told him they flowed in the 320 cfm range and my machinist has flowed them twice and recalibrated his flow bench between test... he says too much material has been removed.
no these are not tsp heads.. these were done for a "friend" of mine by a machine shop that i dont know much about. i have talked with the guy i got them from and he says that they told him they flowed in the 320 cfm range and my machinist has flowed them twice and recalibrated his flow bench between test... he says too much material has been removed.
