[Z06] LS7 Rebuild
10-07-2017, 02:57 PM
#62
Burning Brakes
Thread Starter
Calico coatings is about 30 minutes from where I live, so they did it. $300 for the tops and skirts and I don't think that the ring groves were coated. The pistons are an "off the shelf" CP piston with a 4.135 bore specifically for the LS7 TI rods. Chrome moly pins with a 180 wall and rings are also included with the pistons for $670, so I have about $1,000 all-in for the pistons.
10-07-2017, 07:17 PM
#63
Le Mans Master
Honestly, go with a BTR Stage 4 ground on an 8620 core. Since you have a better tuner now, he should be able to get that cam to drive just as good as what you have now. It’ll make more power NA and on spray.
10-07-2017, 08:19 PM
#64
Race Director
Those specs are also close to my Katech K501 cam. It has some modest surging (my first cam'd street car) and it makes good power and torque with MSD, NW102 and ARH 2" w/ catted x-pipe
10-12-2017, 08:41 PM
#65
Burning Brakes
Thread Starter
I decided to go with an new cam from Cam Motion. Here are the specs:
Intake Duration @ .050: 238, Intake Valve Lift: .650, Rocker Ratio Intake: 1.8, Exhaust Duration @ .050: 252, Exhaust Valve Lift: .652, Rocker Ratio Exhaust: 1.8, Lobe Separation: 114, Camshaft Advance: +3, Roller Lifter Wheel Diameter: .70, Options: Hydraulic, Induction Type: Naturally Aspirated, Camshaft Core Types: 3-Bolt, 8620 Steel Alloy Camshaft
Here are some weights:
Stock LS7 block with stock hardware and the caps on it is 107lbs dead even.
Darton Sleeved 5.3 Gen IV block at 4.135 bore with ARP hardware comes in at 105.9 lbs.
Stock LS7 piston weights
Piston - 483 grams
Pin - 132 grams
ring set - 28 grams
total (no locks) 643 grams
Size
top ring 0.47
second ring 0.47
oil ring 2mm
CP pistons BLS1202-010
Pistons - 450 grams with Top and Side Coating
Pin - 122 grams
ring set - 37 grams
total (no locks) 609 grams
Size
top ring 0.58
second ring 0.58
oil ring 3mm
Intake Duration @ .050: 238, Intake Valve Lift: .650, Rocker Ratio Intake: 1.8, Exhaust Duration @ .050: 252, Exhaust Valve Lift: .652, Rocker Ratio Exhaust: 1.8, Lobe Separation: 114, Camshaft Advance: +3, Roller Lifter Wheel Diameter: .70, Options: Hydraulic, Induction Type: Naturally Aspirated, Camshaft Core Types: 3-Bolt, 8620 Steel Alloy Camshaft
Here are some weights:
Stock LS7 block with stock hardware and the caps on it is 107lbs dead even.
Darton Sleeved 5.3 Gen IV block at 4.135 bore with ARP hardware comes in at 105.9 lbs.
Stock LS7 piston weights
Piston - 483 grams
Pin - 132 grams
ring set - 28 grams
total (no locks) 643 grams
Size
top ring 0.47
second ring 0.47
oil ring 2mm
CP pistons BLS1202-010
Pistons - 450 grams with Top and Side Coating
Pin - 122 grams
ring set - 37 grams
total (no locks) 609 grams
Size
top ring 0.58
second ring 0.58
oil ring 3mm
Last edited by lamboworld; 10-12-2017 at 08:49 PM.
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HP RESEARCH (10-13-2017)
10-12-2017, 09:36 PM
#66
Race Director
Your cam specs are very close to my Katech K501.
Katech K501 Camshaft
235 / 251 @ .050, . 657/ .660 lift, 113 LSA
((235+251)/2)-(113*2)
243 - 226 = 17
Katech K501 Camshaft
235 / 251 @ .050, . 657/ .660 lift, 113 LSA
((235+251)/2)-(113*2)
243 - 226 = 17
Last edited by AzDave47; 10-12-2017 at 09:38 PM.
10-13-2017, 10:25 PM
#67
Burning Brakes
Whats with all this recent talk about weaknesses involving the stock rods? I have been on the forums for years and have never once seen or heard of anyone experience a rod bushing/bearing or bolt failure. Is this one of those uneeded "upgrades" that people latch onto like the stupid trunion upgrade? Also what's katech charge for the bushings and bolts if you send them your rods?
10-13-2017, 11:07 PM
#68
Burning Brakes
Thread Starter
Whats with all this recent talk about weaknesses involving the stock rods? I have been on the forums for years and have never once seen or heard of anyone experience a rod bushing/bearing or bolt failure. Is this one of those uneeded "upgrades" that people latch onto like the stupid trunion upgrade? Also what's katech charge for the bushings and bolts if you send them your rods?
I did not replace the rod bushings. Katech charges $100 a rod which is crazy expensive. My engine builder said that they have never seen a bushing failure and I took their advice and just had the bushing resized to fit my PINs.
10-13-2017, 11:44 PM
#69
Burning Brakes
You probably missed the update on my rebuild. I am actually reusing the TI Rods and LS7 Crank. I replaced the LS7 block with a Darton Sleeved LS block and I am using CP Forged Pistons. I came to the same conclusion that the weak points are the sleeves, pistons and rod bolts.
I did not replace the rod bushings. Katech charges $100 a rod which is crazy expensive. My engine builder said that they have never seen a bushing failure and I took their advice and just had the bushing resized to fit my PINs.
I did not replace the rod bushings. Katech charges $100 a rod which is crazy expensive. My engine builder said that they have never seen a bushing failure and I took their advice and just had the bushing resized to fit my PINs.
No I followed your build just fine. Still thought I'd ask this question since I'm in a similar boat.
Did you figure out the pros and cons of the different block to sleeve? Seems like a lot of people use ls2 blocks for some reasom, but I've seen people use pretty much all of them for a 427+ sleeved short block. I'm guessing a 5.3 block is one of the less expensive options, but are there benefits of the other LS options?
10-19-2017, 06:13 PM
#70
Former Vendor
No I followed your build just fine. Still thought I'd ask this question since I'm in a similar boat.
Did you figure out the pros and cons of the different block to sleeve? Seems like a lot of people use ls2 blocks for some reasom, but I've seen people use pretty much all of them for a 427+ sleeved short block. I'm guessing a 5.3 block is one of the less expensive options, but are there benefits of the other LS options?
Did you figure out the pros and cons of the different block to sleeve? Seems like a lot of people use ls2 blocks for some reasom, but I've seen people use pretty much all of them for a 427+ sleeved short block. I'm guessing a 5.3 block is one of the less expensive options, but are there benefits of the other LS options?
There are changes in the blocks, the LSA and LS9's are a different material, caps change, piston oilers.....amoung other things. The LS7 has a longer skirt (not that it matters if you sleeve it), steel caps like the LSA/LS9 and a few other small details.
Now the LS6/2/3/7/A/9 engines do have some better internal breathing due to some cuts in the main webbing. This does aid in making more HP on a wet sump engine, dry sump engines it should have little impact on however. That is probably the biggest difference in the actual bare block itself.
10-19-2017, 11:13 PM
#71
Burning Brakes
Probably the biggest reason the 5.3 is used, is that you can find tons of them and the price is lower than a LS3/ LSA / LS9 block...
There are changes in the blocks, the LSA and LS9's are a different material, caps change, piston oilers.....amoung other things. The LS7 has a longer skirt (not that it matters if you sleeve it), steel caps like the LSA/LS9 and a few other small details.
Now the LS6/2/3/7/A/9 engines do have some better internal breathing due to some cuts in the main webbing. This does aid in making more HP on a wet sump engine, dry sump engines it should have little impact on however. That is probably the biggest difference in the actual bare block itself.
There are changes in the blocks, the LSA and LS9's are a different material, caps change, piston oilers.....amoung other things. The LS7 has a longer skirt (not that it matters if you sleeve it), steel caps like the LSA/LS9 and a few other small details.
Now the LS6/2/3/7/A/9 engines do have some better internal breathing due to some cuts in the main webbing. This does aid in making more HP on a wet sump engine, dry sump engines it should have little impact on however. That is probably the biggest difference in the actual bare block itself.
10-20-2017, 04:34 PM
#72
Former Vendor
Left to right: LS7, LS3, 5.3L
5.3L front
LS3 front
LS7 front
5.3L Mains
LS3 Mains
LS7 Mains
LS7 sleeve length, windage cuts on main webbing. Notice they use a very small dowl to locate the caps and from the witness marks notice they have zero register to the block itself.
OEM LS3 sleeve length. Notice the same cuts in the main webbing for windage. Notice no dowls on the caps but register marks now for location (which is generally stronger).
Darton sleeves in a 5.3L block. No cutting to the main webbing in the block and you now have a longer than normal sleeve with the same cap location register as the LS3.
10-20-2017, 10:22 PM
#73
Le Mans Master
Great thread.
10-20-2017, 10:48 PM
#74
Burning Brakes
Thread Starter
After doing a little research.
The LS7 block is cast out of 319-T5 and the 5.3 LH6 block is cast out of A356-T6.
https://sfsa.org/tutorials/eng_block/GMBlock.pdf
The LS7 block is cast out of 319-T5 and the 5.3 LH6 block is cast out of A356-T6.
https://sfsa.org/tutorials/eng_block/GMBlock.pdf
10-21-2017, 08:39 AM
#75
Former Vendor
After doing a little research.
The LS7 block is cast out of 319-T5 and the 5.3 LH6 block is cast out of A356-T6.
https://sfsa.org/tutorials/eng_block/GMBlock.pdf
The LS7 block is cast out of 319-T5 and the 5.3 LH6 block is cast out of A356-T6.
https://sfsa.org/tutorials/eng_block/GMBlock.pdf
The LSA and LS9 blocks are LSA are cast from 319-T7 aluminum. The C5R block is a “hipped” and X-rayed 356-T6M aluminum casting. The Chevy site confirms the 319-T5 material for the LS7 block as well.
http://www.chevrolet.com/performance...ylinder-blocks
http://gmauthority.com/blog/gm/gm-engines/lsa/
The LSA/9/7 blocks are also (I believe) the only ones to be torque plate honed from the factory.
10-21-2017, 04:14 PM
#78
This is a pretty good summary that doesn't get too far into the metallurgy world. http://www.alcotec.com/us/en/educati...f-aluminum.cfm
Last edited by Michael_D; 10-21-2017 at 04:15 PM. Reason: stinking spell check.....
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Buddy A (10-21-2017)
10-25-2017, 01:19 AM
#79
Burning Brakes
Thread Starter
HPR has finished my short block and I am trying to decide what head gasket to use. I am debating between .060, .066 or .075. I am leaning toward the .075 gasket, which will put my CR at 11.34:1. Is there any issue using a .075 gasket and running a 300 shot of Nitrous.