Nice job checking, we used to get a cutter kit slight larger than the valve diameter., bolt the head down mark the shaft for depth and cut your reliefs , time consuming but old school get her done and cheap
thank you.. I want to show my steps to get some information out. its frustrating when you have questions and cant find detailed posts. I am making a follow up video on the engine. and I think the plan is exactly what you use to do. fly cut the pistons with the head bolted down.
The ly6 is a dish piston with valve relief necause they had vvt. The ls3 is a flat top piston with no valve relief. It had a larger cam than the ly6. My cam is 230 235 at .05 lsa 114+4. my pistons are out of the hole .006 with a 051 gasket.. no valve to piston problems.
Idk about the LS but with old gen ones with different brands of rockers the ratios were all over the place and often not what was stated. So i like to set it up and use checker springs because its never set in stone and you can avoid some math. I think some of the chinesium ls3 heads have smaller valves, i know ive seen a few with 2.08. Im building a similar setup with an ly6 block, molnar rods mahle pistons w/stock ls3 821 castings. The mahle's have valve reliefs but after watching this it makes me wonder what my clearance will be on an ls1 im assembling atm. I bet im screwed with cam im using. Smaller valve 243's and the cam im using was designed for stock ls1 setups but im second guessing that now.
I initially made this vid as a response to someone in a chat forum. I was going to delete the vid and redo it because my comments were kinda condescending and I came across as a d-bag. when I seen that it had 1k views in 3 days I figured I would leave it and hope for the best. when I had the idea of using the LS3 heads on the LQ9 I did research and asked questions. the answers I got and the information I found was not the best. I decided to check it for myself and post my results. there will be follow up vids......... I am going to be confirming my PTV clearance when I get my rocker arms. I will use the clay on the piston trick and include it into the next vid on this. the intake valve is a Manley race series stainless valve that is 2.165.
Curious as to why you dismissed using thicker gaskets when talking about a budget build and yet decide to fly cut the pistons? What's the compression ratio with these heads and standard gasket?
the minimum PTV clearance is 0.080" on the intake and 0.0100" on the exhaust. I have 0.051 thick head gaskets and my PTV clearance is 0.019". that means that I am 0.061" to tight. I would have to use a head gasket 0.112" thick. a gasket that thick is a custom order and would be prone to blow outs. I will be making a homemade fly cutting tool and cutting the pistons myself. the compression ratio is the next question I have to figure out. I have to measure the fly cut notches and I am going to check the combustion chamber also. the specs on the heads is 69cc but I will check and confirm. if the compression ratio is to high then I will use thicker head gaskets to dial it in the best I can. I can use thicker gaskets to lower compression but I cant use them to gain the TV clearance I need. .. fly cutting the pistons will also effect the balance, but hopefully not enough to hurt anything. ... .. the reason I am doing all of this to stock pistons, is because I have questions and I have read lots of posts of other guys that have questions. nobody seems to post what they are doing or how they are doing it... this vid and the follow up videos on this engine is because I want to know if it can be done and what it takes to do it. . ..
I wanted to put LS3 heads on my lq9 I was thinking a sloppy mechanic stage 2 but the lift is 585 intake 585 you think I'll still have that same issue with a smaller cam
there is allot to think about on this.... keep in mind that even though we are talking about LS engines that are common, and even though thousands of people have built various versions of the LS engine. take a step back and look at through your own eyes. the LY6 is a 6L rec port headed engine with flat top pistons, the pistons have valve reliefs from factory. gm knew about PTV problems with the larger valve LS3 style head. the LQ9 with the LS3 heads is basically a LY6, only the LQ9 doesn't have valve reliefs. .. the minimum piston to valve clearance is 0.080" on the intake valves and 0.100" on the exhaust. . I have 0.019" clearance on the intake with a 0.051 head gasket. I am 0.061" to close.. I would need a head gasket 0.112" thick.. that would make my compression ratio around 8.53 :1. that is way to low, even on big boost. .... don't worry. im getting to your question...... so to gain the PTV clearance I have 3 options, 1 flycut, 2 put in LY6 pistons and 3 buy aftermarket pistons.. Im going down the fly cut road because I want to actually see what it takes, and to post a vid of the actual results. ... ok... now onto your question... I did more checking and the heads I have are exact copies of the LS3 head with bigger ports, so my results should be actuate to your setup... I looked up your cam and see the the intake centerline is at 108 degrees, and the lobe separation angle is 112 degrees. you're cam lobe peaks 2 degrees sooner and is 3 degrees closer to the exhaust lobe max lift. . your lift is also only 0.020" smaller on the intake and 0.028" smaller on the exhaust. . .. ok so what does this mean.. I think that even though your cam is smaller I dont think that there is enough clearance... the installed centerline of the cam does make a difference on valve timing, BUT.... even gm added valve reliefs to the flat tops with an even smaller cam.. I might be wrong and don't have that cam to check in my engine.... I can only give you my opinion.. I know that you will get ALLOT of different answers the more you research.. I am making follow up vids where I will answer questions further... but I don't know the answers yet, and I wont know the answers until I try it out myself and post a detailed vid of what I did and how I got there... I might check PTV clearance with the stock 317 cat port heads with my cam, just for curiosity also.. don't stop the build and don't let people get into your head. don't forget the most important part of playing with cars. and that is that its you're car, you're build and you are suppose to be having fun doing it...
I believe that the LY6 already has flat top pistons with valve reliefs. Im not sure if they are the same height as the LQ9 I have been doing some checking into things and a little confused on the piston volume and compression ratio's between a LQ9 and a LY6. they have close to the same combustion chamber size, but very different compression ratios......I haven't been able to find what the piston to valve clearance of a stock LY6 is. but would highly suspect that cutting the heads 0.030" would result in bent intake valves, especially if you are using a bigger than stock cam... I am assuming that you ment 0.030" and not 0.300, because at 0.300 the heads would be unusable anyway...
@@davidreed6070 you might be ok then... I would still put playdough on a piston and bolt the head on with the gasket and confirm you have enough clearance. you should be good to go, buy you should also confirm your measurements. this stuff is fun and its awesome that others are messing around with different combinations. .
@@rnmgarage9655 yeah I have a set of forged flat top pistons. I was going to turbocharge it. Im old and the car does a 1.40 sixty now and I will be content with a little more top end.
Nice job checking, we used to get a cutter kit slight larger than the valve diameter., bolt the head down mark the shaft for depth and cut your reliefs , time consuming but old school get her done and cheap
thank you.. I want to show my steps to get some information out. its frustrating when you have questions and cant find detailed posts. I am making a follow up video on the engine. and I think the plan is exactly what you use to do. fly cut the pistons with the head bolted down.
I’m planning to do a lq4 build with ls3 heads with ls3 stage 2 cam! I’m wondering would I make nice power
The ly6 is a dish piston with valve relief necause they had vvt. The ls3 is a flat top piston with no valve relief. It had a larger cam than the ly6. My cam is 230 235 at .05 lsa 114+4. my pistons are out of the hole .006 with a 051 gasket.. no valve to piston problems.
Idk about the LS but with old gen ones with different brands of rockers the ratios were all over the place and often not what was stated. So i like to set it up and use checker springs because its never set in stone and you can avoid some math. I think some of the chinesium ls3 heads have smaller valves, i know ive seen a few with 2.08. Im building a similar setup with an ly6 block, molnar rods mahle pistons w/stock ls3 821 castings. The mahle's have valve reliefs but after watching this it makes me wonder what my clearance will be on an ls1 im assembling atm. I bet im screwed with cam im using. Smaller valve 243's and the cam im using was designed for stock ls1 setups but im second guessing that now.
I initially made this vid as a response to someone in a chat forum. I was going to delete the vid and redo it because my comments were kinda condescending and I came across as a d-bag. when I seen that it had 1k views in 3 days I figured I would leave it and hope for the best. when I had the idea of using the LS3 heads on the LQ9 I did research and asked questions. the answers I got and the information I found was not the best. I decided to check it for myself and post my results. there will be follow up vids......... I am going to be confirming my PTV clearance when I get my rocker arms. I will use the clay on the piston trick and include it into the next vid on this. the intake valve is a Manley race series stainless valve that is 2.165.
Mopar degree wheel is not compatible with an LS! 😉 No valve reliefs in pistons can easily be changed.
Never use plastic sugar, it is not compatible!!
Did I miss it, are you checking with a stock cam?
Yea you missed it..
Curious as to why you dismissed using thicker gaskets when talking about a budget build and yet decide to fly cut the pistons?
What's the compression ratio with these heads and standard gasket?
the minimum PTV clearance is 0.080" on the intake and 0.0100" on the exhaust. I have 0.051 thick head gaskets and my PTV clearance is 0.019". that means that I am 0.061" to tight. I would have to use a head gasket 0.112" thick. a gasket that thick is a custom order and would be prone to blow outs. I will be making a homemade fly cutting tool and cutting the pistons myself. the compression ratio is the next question I have to figure out. I have to measure the fly cut notches and I am going to check the combustion chamber also. the specs on the heads is 69cc but I will check and confirm. if the compression ratio is to high then I will use thicker head gaskets to dial it in the best I can. I can use thicker gaskets to lower compression but I cant use them to gain the TV clearance I need. .. fly cutting the pistons will also effect the balance, but hopefully not enough to hurt anything. ... .. the reason I am doing all of this to stock pistons, is because I have questions and I have read lots of posts of other guys that have questions. nobody seems to post what they are doing or how they are doing it... this vid and the follow up videos on this engine is because I want to know if it can be done and what it takes to do it. . ..
@@rnmgarage9655 Impressive answers...thanks
Have you compared the results using a solid lifter and some plasticine in the bore ?
not yet. Im waiting for my rocker arms to arrive. my next step is to put clay on the pistons and recheck clearance
I wanted to put LS3 heads on my lq9 I was thinking a sloppy mechanic stage 2 but the lift is 585 intake 585 you think I'll still have that same issue with a smaller cam
there is allot to think about on this.... keep in mind that even though we are talking about LS engines that are common, and even though thousands of people have built various versions of the LS engine. take a step back and look at through your own eyes. the LY6 is a 6L rec port headed engine with flat top pistons, the pistons have valve reliefs from factory. gm knew about PTV problems with the larger valve LS3 style head. the LQ9 with the LS3 heads is basically a LY6, only the LQ9 doesn't have valve reliefs. .. the minimum piston to valve clearance is 0.080" on the intake valves and 0.100" on the exhaust. . I have 0.019" clearance on the intake with a 0.051 head gasket. I am 0.061" to close.. I would need a head gasket 0.112" thick.. that would make my compression ratio around 8.53 :1. that is way to low, even on big boost. .... don't worry. im getting to your question...... so to gain the PTV clearance I have 3 options, 1 flycut, 2 put in LY6 pistons and 3 buy aftermarket pistons.. Im going down the fly cut road because I want to actually see what it takes, and to post a vid of the actual results. ... ok... now onto your question... I did more checking and the heads I have are exact copies of the LS3 head with bigger ports, so my results should be actuate to your setup... I looked up your cam and see the the intake centerline is at 108 degrees, and the lobe separation angle is 112 degrees. you're cam lobe peaks 2 degrees sooner and is 3 degrees closer to the exhaust lobe max lift. . your lift is also only 0.020" smaller on the intake and 0.028" smaller on the exhaust. . .. ok so what does this mean.. I think that even though your cam is smaller I dont think that there is enough clearance... the installed centerline of the cam does make a difference on valve timing, BUT.... even gm added valve reliefs to the flat tops with an even smaller cam.. I might be wrong and don't have that cam to check in my engine.... I can only give you my opinion.. I know that you will get ALLOT of different answers the more you research.. I am making follow up vids where I will answer questions further... but I don't know the answers yet, and I wont know the answers until I try it out myself and post a detailed vid of what I did and how I got there... I might check PTV clearance with the stock 317 cat port heads with my cam, just for curiosity also.. don't stop the build and don't let people get into your head. don't forget the most important part of playing with cars. and that is that its you're car, you're build and you are suppose to be having fun doing it...
Im using an ly6 with the stock pistons. I wonder how much more power it will make with flattop pistons and the heads cut about 0.30.
I believe that the LY6 already has flat top pistons with valve reliefs. Im not sure if they are the same height as the LQ9 I have been doing some checking into things and a little confused on the piston volume and compression ratio's between a LQ9 and a LY6. they have close to the same combustion chamber size, but very different compression ratios......I haven't been able to find what the piston to valve clearance of a stock LY6 is. but would highly suspect that cutting the heads 0.030" would result in bent intake valves, especially if you are using a bigger than stock cam... I am assuming that you ment 0.030" and not 0.300, because at 0.300 the heads would be unusable anyway...
@@rnmgarage9655 it has a dish piston but it does have valve reliefs because it had vvt.9.64 to 1 compression
Yes I meant . 030.
@@davidreed6070 you might be ok then... I would still put playdough on a piston and bolt the head on with the gasket and confirm you have enough clearance. you should be good to go, buy you should also confirm your measurements. this stuff is fun and its awesome that others are messing around with different combinations. .
@@rnmgarage9655 yeah I have a set of forged flat top pistons. I was going to turbocharge it. Im old and the car does a 1.40 sixty now and I will be content with a little more top end.