Forced Induction and lifting heads.
1) Precision head surface
2) Precision block surface
Seen a couple blocks "push coolant" they all have leaked/pushed coolant where the mating surfaces were not perfect.
My LSx showed signs of pushing coolant when we pulled the heads off, after we put it in the CNC and decked it, it was apparent that it was due to a very very slight low spot.
2) Precision block surface
Seen a couple blocks "push coolant" they all have leaked/pushed coolant where the mating surfaces were not perfect.
My LSx showed signs of pushing coolant when we pulled the heads off, after we put it in the CNC and decked it, it was apparent that it was due to a very very slight low spot.
8 Second Club
Joined: May 2004
Posts: 371
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From: Savannah, TN
1) Precision head surface
2) Precision block surface
Seen a couple blocks "push coolant" they all have leaked/pushed coolant where the mating surfaces were not perfect.
My LSx showed signs of pushing coolant when we pulled the heads off, after we put it in the CNC and decked it, it was apparent that it was due to a very very slight low spot.
2) Precision block surface
Seen a couple blocks "push coolant" they all have leaked/pushed coolant where the mating surfaces were not perfect.
My LSx showed signs of pushing coolant when we pulled the heads off, after we put it in the CNC and decked it, it was apparent that it was due to a very very slight low spot.
Thread Starter
Launching!
Joined: Apr 2006
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From: Maple Grove, MN
I like where this thread is going. So with a properly decked block and heads and high quality studs and gaskets, would making 800-1000whp be challenging at keeping the heads down/pushing coolant? (provided a stout 4-bolt LS engine was built)
TECH Apprentice
Joined: Nov 2006
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From: Copenhagen
the problem with internet engineers is that many of them havent done what they are talking about.... there is a thread here thats about 2 weeks old https://ls1tech.com/forums/forced-in...6-0-lit-2.html
where the guy makes 1360 Hp on an engine dyno on a used 6.0L block/head engine with pyramid rings...
where the guy makes 1360 Hp on an engine dyno on a used 6.0L block/head engine with pyramid rings...
TECH Addict
Joined: Aug 2004
Posts: 2,866
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the problem with internet engineers is that many of them havent done what they are talking about.... there is a thread here thats about 2 weeks old https://ls1tech.com/forums/forced-in...6-0-lit-2.html
where the guy makes 1360 Hp on an engine dyno on a used 6.0L block/head engine with pyramid rings...
where the guy makes 1360 Hp on an engine dyno on a used 6.0L block/head engine with pyramid rings...
Here is that guys other thread..https://ls1tech.com/forums/forced-in...lbs-today.html
Chris.
Joined: Nov 2001
Posts: 8,484
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From: Cecil County Raceway!!!
1) Precision head surface
2) Precision block surface
Seen a couple blocks "push coolant" they all have leaked/pushed coolant where the mating surfaces were not perfect.
My LSx showed signs of pushing coolant when we pulled the heads off, after we put it in the CNC and decked it, it was apparent that it was due to a very very slight low spot.
2) Precision block surface
Seen a couple blocks "push coolant" they all have leaked/pushed coolant where the mating surfaces were not perfect.
My LSx showed signs of pushing coolant when we pulled the heads off, after we put it in the CNC and decked it, it was apparent that it was due to a very very slight low spot.
Like Phil, my block showed that the block deck was a smidge low right where it had leakage.
I've even seen guys clean a deck surface during a head swap with a scotch brite pad...sometimes in their hand, sometimes on a wheel. You can VERY VERY quickly wind up with a deck that isn't flat when you do that...removing a little bit of iron or aluminum, even by hand, is not hard to do.
PaulC, I think if you're very careful with who you have machining your block as well as your head decks, and you run a high quality gasket and high quality fasteners for the heads, you shouldn't have an issue. Talk to the gasket manufacturer about the Ra requirements for the block and heads when running their gasket, make sure they understand what you're building, find a means to measure it after it's cut to ensure it's done properly...after that, I think your power goals are within reach with the parts you want to use...the fact that you cared enough to ask and read all the responses means (to me) that you're going to pay enough attention to detail to get it right.
You will also want to make sure the mating surfaces are deburred properly (by the CNC) after they're decked...a very very very minor burr can cause a serious sealing issue as well.
This sounds like a dig at me...some of us "internet engineers" are in fact real engineers who DO have the experience to back up what we post.
PaulC, I think if you're very careful with who you have machining your block as well as your head decks, and you run a high quality gasket and high quality fasteners for the heads, you shouldn't have an issue. Talk to the gasket manufacturer about the Ra requirements for the block and heads when running their gasket, make sure they understand what you're building, find a means to measure it after it's cut to ensure it's done properly...after that, I think your power goals are within reach with the parts you want to use...the fact that you cared enough to ask and read all the responses means (to me) that you're going to pay enough attention to detail to get it right.
You will also want to make sure the mating surfaces are deburred properly (by the CNC) after they're decked...a very very very minor burr can cause a serious sealing issue as well.
This sounds like a dig at me...some of us "internet engineers" are in fact real engineers who DO have the experience to back up what we post.
Last edited by Mike454SS; Mar 3, 2009 at 10:07 AM.
I'll second that...My LS2 had a little bit of carbon tracking on cylinders 3&4 on the thrust side of the block. No cylinder-to cylinder cross-talk whatsoever. Had the heads "lifted" there would've been more evidence other than one spot on each gasket IMHO.
Like Phil, my block showed that the block deck was a smidge low right where it had leakage.
Like Phil, my block showed that the block deck was a smidge low right where it had leakage.
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Verdad Gallardo Joined: Nov 2001
Posts: 8,484
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From: Cecil County Raceway!!!
All I know is he noted irregularities in the surface as he decked it. depth would be based on how much he had to take off to remove the irregularity...
wasn't alot IIRC
Thread Starter
Launching!
Joined: Apr 2006
Posts: 216
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From: Maple Grove, MN
the problem with internet engineers is that many of them havent done what they are talking about.... there is a thread here thats about 2 weeks old https://ls1tech.com/forums/forced-in...6-0-lit-2.html
where the guy makes 1360 Hp on an engine dyno on a used 6.0L block/head engine with pyramid rings...
where the guy makes 1360 Hp on an engine dyno on a used 6.0L block/head engine with pyramid rings...
I agree with you, but what really matters is holding the gasket properly right? That said, I think those pyramid rings are probably a great benefit...but I also like to think of a head gasket as a fuse...granted when you're looking for huge power numbers, you need a big fuse that doesn't want to blow easily.
If your gaskets can hold without something like that, then I prefer to stay away from it...if it's just flat out too much pressure no matter what and you need something like that too, thats a different story. I prefer to pay attention to every detail along the way (flatness, surface finish, squareness...) rather than not be as careful with those things and go for some new hot trick instead...if my way doesn't blow a head gasket, and the pyramid ring setup doesn't either...they both achieved the same goal.
If your gaskets can hold without something like that, then I prefer to stay away from it...if it's just flat out too much pressure no matter what and you need something like that too, thats a different story. I prefer to pay attention to every detail along the way (flatness, surface finish, squareness...) rather than not be as careful with those things and go for some new hot trick instead...if my way doesn't blow a head gasket, and the pyramid ring setup doesn't either...they both achieved the same goal.
TECH Apprentice
Joined: Nov 2006
Posts: 369
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From: Copenhagen
If the heads move around too much(they allways do to some extent) they put a shear(bending) stress on the head bolts&studs and when they do that the fasteners go over there yield point and loose clamping force and stretch.The dowel pins must fit as tight as possible to locate them properly in the first place
I think of it in this way:
Why have a gasket to take all the pressure and heat of a FI when you can have the sleeves up above the deck of the block to go into the cyllender heads deck that have been cut with a recever groove and make a barrier for the heat and pressure with the sleeve
Gaskets shouldent be a problem,cometic,copper or carbon fiber
I think of it in this way:
Why have a gasket to take all the pressure and heat of a FI when you can have the sleeves up above the deck of the block to go into the cyllender heads deck that have been cut with a recever groove and make a barrier for the heat and pressure with the sleeve
Gaskets shouldent be a problem,cometic,copper or carbon fiber
I have read your build but what gasket are you using? Off subject // I think your build was won to show people that if you want it bad you can do it yourself and be one of the bad boys on the block . I have great respect for guys that build there own car from the ground up. I build cars and know how long it takes to get it right.
My setup showed signs of leaking into the water passages in 2 maybe 3 spots, when the block was decked on the CNC it showed very slight low spots ONLY in the areas it was leaking. The leaking was very minimal.
We're running 4 1/2" && 2 3/8" studs per cylinder, .800 deck head, CNC'd deck on block and head, o-rings on each cylinder, and hopefully 40# of boost.
Thread Starter
Launching!
Joined: Apr 2006
Posts: 216
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From: Maple Grove, MN
Oh boy, 6-bolt heads and an o-ringed block and you're still pushing water, what is there left to do? Weld the heads down? (joke) Of course you're running incredibly high pressures and making more power than most of us need.
I wouldn't say pushing water but we noticed some slight leakage. Our previous Deck was not perfect and o-ring had inconsistent heights. It will be machined right this time.
From the people that have seen it, when they see it leave they all say its a 9 second car. Once it gets 200' out its starts getting exciting. I'm hoping the suspension changes will get our 60' down into the 1.19-1.22 range.
8 Second Club
Joined: May 2004
Posts: 371
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From: Savannah, TN
Turbos are funny my car runs low 8s and high 170s and i have heard people in the videos say somthing must be wrong it didnt leave and then the same guys say holy **** how did it do that. I get a kick out of it.
Joined: Nov 2001
Posts: 8,484
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From: Cecil County Raceway!!!
