replacing the junk LS7
11-14-2018, 05:38 PM
#61
There are affordable options out there for replacing the entire rotating assembly with aftermarket and not picking up too much extra weight to cost you any power. Dave Foote just replaced the entire rotating assembly with aftermarket stuff in his LS7 and dynoed within 3 rwhp of his original motor ...reusing everything but the crank, rods and pistons. That's within the realm of statisitcal and dyno deviation, as well as a tight motor that is not broken in yet.The OEM rods are plenty strong, but like you've identified, they have a coating on them that will eventually wear off. You just need to decide if you want to go boost or N/A.
I'm the one who posted about a recent rod failure, and the discussion on options for recoating the rods by going to Calico....got take a read.
An easy solution would be to call up Anthony Fourney at HorsePower Research, and discuss with them your concerns, wants, and needs. They have affordable solutions, including outright purchase of sleeved blocks based on OEM LS blocks if you have concerns about cracking a cylinder.
For my personal LS7, which recently experienced a rod failure which damaged my crank as well, I went with a complete replacement of the rotating assembly AND sleeved my perfectly good block to increase the cylinder liner strength and to accept an over-bore for my new setup. The cost, and lack of long term data regarding the reconditioning of the rods, combined with the fact I was looking at a replacement crank and pistons anyways, it was an easy decision to make.
I'm the one who posted about a recent rod failure, and the discussion on options for recoating the rods by going to Calico....got take a read.
An easy solution would be to call up Anthony Fourney at HorsePower Research, and discuss with them your concerns, wants, and needs. They have affordable solutions, including outright purchase of sleeved blocks based on OEM LS blocks if you have concerns about cracking a cylinder.
For my personal LS7, which recently experienced a rod failure which damaged my crank as well, I went with a complete replacement of the rotating assembly AND sleeved my perfectly good block to increase the cylinder liner strength and to accept an over-bore for my new setup. The cost, and lack of long term data regarding the reconditioning of the rods, combined with the fact I was looking at a replacement crank and pistons anyways, it was an easy decision to make.
Sorry to hear about a failure even after a refresh. I was looking at your thread which caused me to consider steering clear of re-using my stock rods. Anthony mentioned he has put out a few re-coated sets with no failures HOWEVER he said they had not seen a lot of miles (we agreed 40-50k would be a considered higher miles between us). Have you gotten any solid figures on cost of a block and re-sleeve? I was looking into selling my block and purchasing a GEN IV unit to be bored and sleeved with DARTON sleeves. However I go through cars like water and not sure if I want to commit to what seems like a 4-6k dollar block alone to be sleeved/labor from RED in CA or by HPR if they do it. Are you using the ductile iron Darton sleeves in the stock LS7 block? I was reading it is around 2,000 in labor to do punch the old sleeves out and insert new ones in.
I was using it to support my point that a stock ZR1 has been as fast as most HCI C6Z when the C6Z guys starting detracting from the LS9/ZR1. We all know that most ZR1's run 10.8-11.2 @ 128-130 anyways just need to bring some guys back down to reality as well as need 100rwhp to edge out a C6Z on a roll because of the gearing/weight/power delivery. My own friend ran 10.7@132 in his stock ZR1 on a set of DR's during the summer here around 2,000' DA and 80* which is even on the quicker end of stock cars
Last edited by zaquhree; 11-14-2018 at 05:41 PM.
11-14-2018, 06:09 PM
#63
11-14-2018, 06:09 PM
#64
Reduced rotating weight will show up marginally on a 4th gear dyno pull to 160mph. You can't say rotating weight doesn't matter just because one dyno sheet showed a set of steel rods made the same power at near steady state.
Rotating inertia has the greatest impact when the rotating mass is accelerating rapidly.
Same as F = Mass times Acceleration, Torque = I (mass moment of inertia) times rotational acceleration. The rate of change of revs is very slow on a 4th gear pull. Power difference due to rotational weight would show up even less on an engine dyno where you hold each RPM steady.
Stabbing the gas in first gear or free reving the engine will show a dramatic change in response and torque output. Same with a super light clutch, light wheels, carbon driveshaft etc. The faster you go the less impactful these things become.
Rotating inertia has the greatest impact when the rotating mass is accelerating rapidly.
Same as F = Mass times Acceleration, Torque = I (mass moment of inertia) times rotational acceleration. The rate of change of revs is very slow on a 4th gear pull. Power difference due to rotational weight would show up even less on an engine dyno where you hold each RPM steady.
Stabbing the gas in first gear or free reving the engine will show a dramatic change in response and torque output. Same with a super light clutch, light wheels, carbon driveshaft etc. The faster you go the less impactful these things become.
11-14-2018, 06:13 PM
#65
That is what I like to hear. I agree the statistical variation of 3rwhp is not even worth debating. I was thinking I would lose power under the curve because of piston acceleration as well as a little peak power. Anthony has been a guiding light as well as a few other forum members. We have been chatting back and forth about me sending my block, rods, crank, piston out to him or him sending me a balanced rotating assembly (my block has no issues and the sleeves still have factory crosshatching visible). He has been very, very, very helpful and I would suggest anyone looking at this thread with a hurt or who wants to build a motor to talk to HPR. The wait time is 60-90 days right now for work to get started however it is seemingly well worth it with nothing but success stories out of that camp.
Sorry to hear about a failure even after a refresh. I was looking at your thread which caused me to consider steering clear of re-using my stock rods. Anthony mentioned he has put out a few re-coated sets with no failures HOWEVER he said they had not seen a lot of miles (we agreed 40-50k would be a considered higher miles between us). Have you gotten any solid figures on cost of a block and re-sleeve? I was looking into selling my block and purchasing a GEN IV unit to be bored and sleeved with DARTON sleeves. However I go through cars like water and not sure if I want to commit to what seems like a 4-6k dollar block alone to be sleeved/labor from RED in CA or by HPR if they do it. Are you using the ductile iron Darton sleeves in the stock LS7 block? I was reading it is around 2,000 in labor to do punch the old sleeves out and insert new ones in.
I was using it to support my point that a stock ZR1 has been as fast as most HCI C6Z when the C6Z guys starting detracting from the LS9/ZR1. We all know that most ZR1's run 10.8-11.2 @ 128-130 anyways just need to bring some guys back down to reality as well as need 100rwhp to edge out a C6Z on a roll because of the gearing/weight/power delivery. My own friend ran 10.7@132 in his stock ZR1 on a set of DR's during the summer here around 2,000' DA and 80* which is even on the quicker end of stock cars
Sorry to hear about a failure even after a refresh. I was looking at your thread which caused me to consider steering clear of re-using my stock rods. Anthony mentioned he has put out a few re-coated sets with no failures HOWEVER he said they had not seen a lot of miles (we agreed 40-50k would be a considered higher miles between us). Have you gotten any solid figures on cost of a block and re-sleeve? I was looking into selling my block and purchasing a GEN IV unit to be bored and sleeved with DARTON sleeves. However I go through cars like water and not sure if I want to commit to what seems like a 4-6k dollar block alone to be sleeved/labor from RED in CA or by HPR if they do it. Are you using the ductile iron Darton sleeves in the stock LS7 block? I was reading it is around 2,000 in labor to do punch the old sleeves out and insert new ones in.
I was using it to support my point that a stock ZR1 has been as fast as most HCI C6Z when the C6Z guys starting detracting from the LS9/ZR1. We all know that most ZR1's run 10.8-11.2 @ 128-130 anyways just need to bring some guys back down to reality as well as need 100rwhp to edge out a C6Z on a roll because of the gearing/weight/power delivery. My own friend ran 10.7@132 in his stock ZR1 on a set of DR's during the summer here around 2,000' DA and 80* which is even on the quicker end of stock cars
The following users liked this post:
angeldog (10-22-2019)
11-15-2018, 09:44 AM
#66
HPR just got my original block back with new Darton sleeves...... around 2K . They will give you a trade in value for your LS7 block if you want a sleeved block based on the LS2 block, if you're wanting to save some money, but you'll lose a few key items that may cost you some power....talk to Anthony about the specifics. He'll give you an honest breakdown on cost so you can make an informed decision. I chose to use my LS7 block.
11-15-2018, 01:53 PM
#68
I'm increasing bore and stroke on mine.
02-14-2019, 10:28 PM
#69
update:
Bought a 630/540 40k mile Z06 8/25/16, changed oil since lifter failed next day and found glitter so here I am. Ended up deciding to keep the junk LS7 block, bought the updated Ti rods from Louis, and kept the stock crank. My goal is 150-155mph rowing the gears with this bottom end
so I did a set of Darton sleeves, Diamond dished pistons to lower my CR to 11:1 (I have AI heads at 64cc so I was around 12:1), spec'd a mild blower cam, re-coated the rods by Calico and had the stock crank freshened up since it was in such good shape. Just waiting on the slugs to show up.
Bought a 630/540 40k mile Z06 8/25/16, changed oil since lifter failed next day and found glitter so here I am. Ended up deciding to keep the junk LS7 block, bought the updated Ti rods from Louis, and kept the stock crank. My goal is 150-155mph rowing the gears with this bottom end
so I did a set of Darton sleeves, Diamond dished pistons to lower my CR to 11:1 (I have AI heads at 64cc so I was around 12:1), spec'd a mild blower cam, re-coated the rods by Calico and had the stock crank freshened up since it was in such good shape. Just waiting on the slugs to show up.
Last edited by zaquhree; 02-14-2019 at 10:30 PM.
02-15-2019, 01:13 PM
#70
Pro
Damn Zach - I am really sorry to hear about the ordeal with your new car. That totally sucks. Sounds like the rebuild will be an absolute monster. Make sure to post some vids when she's done and ready to rip.
02-15-2019, 07:11 PM
#71
This makes me realize I should never have sold the Silver one you put together. Ran into a situation to where I had an offer I couldn't refuse on the car and I missed the car a lot. This one supposedly made 630/540 at the wheels and the other car felt faster to me. Makes me appreciate how well you treated the car. How's the C7Z? Treating you well I hope
02-16-2019, 12:10 AM
#72
Team Owner
A Darton sleeved LS7 block is now far from junk...weak link has been addressed IMO.
02-16-2019, 09:14 AM
#74
Pro
This makes me realize I should never have sold the Silver one you put together. Ran into a situation to where I had an offer I couldn't refuse on the car and I missed the car a lot. This one supposedly made 630/540 at the wheels and the other car felt faster to me. Makes me appreciate how well you treated the car. How's the C7Z? Treating you well I hope
The C7 has been good. I got the A8 with base stage 1 aero the thing is wicked fast off the line. It’s still stock as I’m not ready to ditch the warranty quite yet. It’s a totally different car. The silver one was much more fun to drive fast. The C7 is better for everyday. Eventually I am going to get the bigger blower 2300 which puts the car in a totally different level.
Keep me me updated on the new build it looks like it will be a monster. I always enjoyed the videos you put together of the silver car.
Take care.
Last edited by Chonger; 02-16-2019 at 09:20 AM. Reason: Add sentence
