LQ9 head question.
Thread Starter
Racer
Joined: Sep 2005
Posts: 341
Likes: 2
LQ9 head question.
I have a turboed LS6. I was thinking about installing a set of LQ9 heads to drop the CR.
What else do I need? Are these heads complete (valves/springs)? Are the springs good? Are the valve stems hollow like the LS6 valves? Should/can the springs be swapped?
You get the point! I need info!
Thanks guys!
Tommy
What else do I need? Are these heads complete (valves/springs)? Are the springs good? Are the valve stems hollow like the LS6 valves? Should/can the springs be swapped?
You get the point! I need info!
Thanks guys!
Tommy
Premium Supporting Vendor
Joined: Mar 2001
Posts: 5,241
Likes: 21
From: Knoxville Tennessee
Originally Posted by TaTommy888
I have a turboed LS6. I was thinking about installing a set of LQ9 heads to drop the CR.
What else do I need? Are these heads complete (valves/springs)? Are the springs good? Are the valve stems hollow like the LS6 valves? Should/can the springs be swapped?
You get the point! I need info!
Thanks guys!
Tommy
What else do I need? Are these heads complete (valves/springs)? Are the springs good? Are the valve stems hollow like the LS6 valves? Should/can the springs be swapped?
You get the point! I need info!
Thanks guys!
Tommy
I just got and installed a set of 225 dart heads. They come complete and are a direct bolt on. Slight modification of the rocker stand is required and will only take you 10 minutes with a grinder. These heads were less than $1300 shipped to my door. The pockets are CNC cut, 225 intake with 2.05, 1.60 stainless valves.. they are VERY nice. Price is nice also. They are not going to help your compression situation though, they are 62cc. You can use a thicker head gasket to lower your compression, but I would recommend you just wait until you build your motor.
If you are just going to try to lower your compression the easy way, then those heads will work for you and they are pretty cheap.
Thread Starter
Racer
Joined: Sep 2005
Posts: 341
Likes: 2
Originally Posted by BLOWNZO6
If you are just going to try to lower your compression the easy way, then those heads will work for you and they are pretty cheap.
The Dart heads you mentioned sound great for the price, but they will not help my situation (as you mentioned!)
So the valves are not interchangable for LS6 to LQ9? The ideal situation for me if to buy a set of bare LQ9s and use the valves and springs from my LS6, but it doesn't seem like that is the case.
I don't want to experience any valve float of resonation problems. The LS6 heads don't seem to have these issues. I'm just getting a little worried about the CR, and my never-satified attitude!
Thanks for the info.
Tommy
Premium Supporting Vendor
Joined: Mar 2001
Posts: 5,241
Likes: 21
From: Knoxville Tennessee
You would have to check with one of the head guys on here on the valve specs. I would ASSume they are the same length and size.. but that would be way to much. From a valve perspective you would be fine. I am pretty sure the springs can just be swapped.
You can get a set very resonably. I just sold a brand new pair for $550.
You can get a set very resonably. I just sold a brand new pair for $550.
Thread Starter
Racer
Joined: Sep 2005
Posts: 341
Likes: 2
Originally Posted by BLOWNZO6
You would have to check with one of the head guys on here on the valve specs. I would ASSume they are the same length and size.. but that would be way to much. From a valve perspective you would be fine. I am pretty sure the springs can just be swapped.
You can get a set very resonably. I just sold a brand new pair for $550.
You can get a set very resonably. I just sold a brand new pair for $550.
Did you have the 12572035 castings?
I checked a bunch of GM parts sites and that part number is no where to be found. I was trying to get a price on stock heads...
Thanks again for the info.
Tommy
Supporting Tuner
Joined: Sep 2004
Posts: 51,896
Likes: 39
From: ================== Houston, Texas www.englandgreen.com ================== Necessary Evil™ __________
CI 6-7-8-9-10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14
Originally Posted by BLOWNZO6
The ones I had were the "317" heads.
I did not have the full casting number written down.
I can find the number for you probably though if you need it.
I did not have the full casting number written down.
I can find the number for you probably though if you need it.
EG
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
PM me if your interested.
Drifting
Joined: Oct 2003
Posts: 1,923
Likes: 5
From: San Antonio TX
if you are ditching the ls6 heads and going to the darts with 62 ish cc chambers you will be lowering the CR to about where the ls1 is, 64 ish on the ls1, I do not know how much boost you are running but I would stay away from the lq9's unless you are going to run past 12psi.
you will lose power due to the lower CR and I'm not sure how much reliability you will be getting. also the dart heads with the 3/4" deck will be better for you down the road if you forge the botom end and get dished pistons.
JMO
More Than Zero
you will lose power due to the lower CR and I'm not sure how much reliability you will be getting. also the dart heads with the 3/4" deck will be better for you down the road if you forge the botom end and get dished pistons.
JMO
More Than Zero
Melting Slicks
Joined: Feb 2002
Posts: 2,285
Likes: 2
From: Crooks SD
i believe you'll only lose about 3% of your HP for every full point drop in CR (that's from memory and could be completely wrong).
If my memory suits me correctly, that's a small price to pay for additional boost up top.
If my memory suits me correctly, that's a small price to pay for additional boost up top.
Drifting
Joined: Oct 2003
Posts: 1,923
Likes: 5
From: San Antonio TX
Originally Posted by Jesse_Boyer
i believe you'll only lose about 3% of your HP for every full point drop in CR (that's from memory and could be completely wrong).
If my memory suits me correctly, that's a small price to pay for additional boost up top.
If my memory suits me correctly, that's a small price to pay for additional boost up top.
I do not think that he has give any info on what boost he is running or how much he is going to shoot for, so with out that info I do not think that we can answer any of this.
JMO
More Than Zero
Thread Starter
Racer
Joined: Sep 2005
Posts: 341
Likes: 2
Originally Posted by M_T_0
I do not think that he has give any info on what boost he is running or how much he is going to shoot for, so with out that info I do not think that we can answer any of this.
JMO
More Than Zero
JMO
More Than Zero
My only reservation with going with the LQ9 heads is if I have to replace the valve springs. Then it can become expensive. The only reason for adding LQ9 heads is to lower my compression a bit which adds a margin of safety without spending a lot of money (but not doing it "cheap") if that makes any sense!
When I have more time I will look into this further. Thanks guys.
Tommy
Drifting
Joined: Oct 2003
Posts: 1,923
Likes: 5
From: San Antonio TX
Originally Posted by TaTommy888
I did not plan on running more than 7 lbs of boost.
My only reservation with going with the LQ9 heads is if I have to replace the valve springs. Then it can become expensive. The only reason for adding LQ9 heads is to lower my compression a bit which adds a margin of safety without spending a lot of money (but not doing it "cheap") if that makes any sense!
When I have more time I will look into this further. Thanks guys.
Tommy
My only reservation with going with the LQ9 heads is if I have to replace the valve springs. Then it can become expensive. The only reason for adding LQ9 heads is to lower my compression a bit which adds a margin of safety without spending a lot of money (but not doing it "cheap") if that makes any sense!
When I have more time I will look into this further. Thanks guys.
Tommy
More Than Zero
Team Owner
Joined: Apr 2001
Posts: 26,794
Likes: 614
From: Elmhurst, IL (West Suburb of Chicago) & Home of MEGA Horsepower
St. Jude Donor '06
Originally Posted by TaTommy888
I did not plan on running more than 7 lbs of boost.
My only reservation with going with the LQ9 heads is if I have to replace the valve springs. Then it can become expensive. The only reason for adding LQ9 heads is to lower my compression a bit which adds a margin of safety without spending a lot of money (but not doing it "cheap") if that makes any sense!
When I have more time I will look into this further. Thanks guys.
Tommy
My only reservation with going with the LQ9 heads is if I have to replace the valve springs. Then it can become expensive. The only reason for adding LQ9 heads is to lower my compression a bit which adds a margin of safety without spending a lot of money (but not doing it "cheap") if that makes any sense!
When I have more time I will look into this further. Thanks guys.
Tommy
The patriot gold springs perform great and fit without any machining to the heads and are about $275.00. That's pretty affordable and is the way you want to go if you do the LQ9 heads to drop your compression. I am thinking about doing the same thing!
Melting Slicks
Joined: Feb 2002
Posts: 2,285
Likes: 2
From: Crooks SD
my only reservation with switching to the LQ9's is the "where will it end" factor.
Once I pull the heads/intake, I might as well replace with my LS6 intake, LQ9 heads, and Patriot Golds. Then, what about the cam, pushrods, timing set, oil pump... etc...
it'll never end... So, I'm thinking i'll just tune it with the stock Longblock.
Once I pull the heads/intake, I might as well replace with my LS6 intake, LQ9 heads, and Patriot Golds. Then, what about the cam, pushrods, timing set, oil pump... etc...
it'll never end... So, I'm thinking i'll just tune it with the stock Longblock.
Le Mans Master
Joined: Oct 2003
Posts: 8,863
Likes: 86
From: PA
St. Jude Donor '08
[QUOTE=Jesse_Boyer]my only reservation with switching to the LQ9's is the "where will it end" factor.
Once I pull the heads/intake, I might as well replace with my LS6
so funny but sooooooooooooo true!
Once I pull the heads/intake, I might as well replace with my LS6
so funny but sooooooooooooo true!
