[Z06] LS7 Rebuild
11-04-2017, 09:48 PM
#101
Melting Slicks
11-06-2017, 01:53 PM
#103
Instructor
On the older engines, aka SBC and BBC, the rule of thumb on gasket thickness really is like Michael D said on quench liking around .040 or so for safety and compression. These engines in smaller sizes especially need tight quench to get the compression up and of course if you run the piston too close it can start hitting the head which is a no no.
The tremendously better design of these later model LSx aluminum heads though doesn't seem to care too much about quench as long as you can still make what compression you want without hitting the head by running quench too close. The factory engines when hot are running at around .051 to .060 quench which is almost the worst you can do according to old SAE papers on detonation resistance as Michael D alluded to.
Chrysler ran .070 to .080 quench on millions of engines for 50+ years as they still do or more on many of the hemis etc. The SAE also said that over .070 or so the quench is not on the bad zone anymore at least on most engines if I am remembering correctly. A ton of the modern stuff even runs over .080 on many power adder engines like say the Ford GT 5.4 blower engine or GT500 etc.
You also have another trend on power adders using extra fuel with METH or stand alone NOS systems with their own fuel or even engines using straight METH or E85 or running no quench at all by dequenching the cylinder heads and or running a full dished piston or by running the piston way in the hole. Most real power adder stuff is like this for many reasons but they never want to see tight quench.
Many times you end up with excess fuel in the chambers and with tight quench you will essentially hydrolock and break 2nd ring lands plenty often. It's even common to see domed pistons but yet way in the hole on many big NOS setups. Most of these guys don't talk about it as it takes a lot of broken parts to learn this lessons. Anyway to make a long story longer if this engine will see big NOS I'd generally rather not see any really tight quench to control head lifting and rind land problems.
Also one more tip is the the head gasket bore needs to be bigger than the chamber and the cylinder bore. Many chambers are much bigger than the cylinder bore in the block and you will still risk having a red hot glowing head gasket in the chamber there and then you very well will see some bad pre-ignition and detonation too!
The tremendously better design of these later model LSx aluminum heads though doesn't seem to care too much about quench as long as you can still make what compression you want without hitting the head by running quench too close. The factory engines when hot are running at around .051 to .060 quench which is almost the worst you can do according to old SAE papers on detonation resistance as Michael D alluded to.
Chrysler ran .070 to .080 quench on millions of engines for 50+ years as they still do or more on many of the hemis etc. The SAE also said that over .070 or so the quench is not on the bad zone anymore at least on most engines if I am remembering correctly. A ton of the modern stuff even runs over .080 on many power adder engines like say the Ford GT 5.4 blower engine or GT500 etc.
You also have another trend on power adders using extra fuel with METH or stand alone NOS systems with their own fuel or even engines using straight METH or E85 or running no quench at all by dequenching the cylinder heads and or running a full dished piston or by running the piston way in the hole. Most real power adder stuff is like this for many reasons but they never want to see tight quench.
Many times you end up with excess fuel in the chambers and with tight quench you will essentially hydrolock and break 2nd ring lands plenty often. It's even common to see domed pistons but yet way in the hole on many big NOS setups. Most of these guys don't talk about it as it takes a lot of broken parts to learn this lessons. Anyway to make a long story longer if this engine will see big NOS I'd generally rather not see any really tight quench to control head lifting and rind land problems.
Also one more tip is the the head gasket bore needs to be bigger than the chamber and the cylinder bore. Many chambers are much bigger than the cylinder bore in the block and you will still risk having a red hot glowing head gasket in the chamber there and then you very well will see some bad pre-ignition and detonation too!
The following 3 users liked this post by RACER7088:
11-07-2017, 06:22 PM
#104
Le Mans Master
On the older engines, aka SBC and BBC, the rule of thumb on gasket thickness really is like Michael D said on quench liking around .040 or so for safety and compression. These engines in smaller sizes especially need tight quench to get the compression up and of course if you run the piston too close it can start hitting the head which is a no no.
The tremendously better design of these later model LSx aluminum heads though doesn't seem to care too much about quench as long as you can still make what compression you want without hitting the head by running quench too close. The factory engines when hot are running at around .051 to .060 quench which is almost the worst you can do according to old SAE papers on detonation resistance as Michael D alluded to.
Chrysler ran .070 to .080 quench on millions of engines for 50+ years as they still do or more on many of the hemis etc. The SAE also said that over .070 or so the quench is not on the bad zone anymore at least on most engines if I am remembering correctly. A ton of the modern stuff even runs over .080 on many power adder engines like say the Ford GT 5.4 blower engine or GT500 etc.
You also have another trend on power adders using extra fuel with METH or stand alone NOS systems with their own fuel or even engines using straight METH or E85 or running no quench at all by dequenching the cylinder heads and or running a full dished piston or by running the piston way in the hole. Most real power adder stuff is like this for many reasons but they never want to see tight quench.
Many times you end up with excess fuel in the chambers and with tight quench you will essentially hydrolock and break 2nd ring lands plenty often. It's even common to see domed pistons but yet way in the hole on many big NOS setups. Most of these guys don't talk about it as it takes a lot of broken parts to learn this lessons. Anyway to make a long story longer if this engine will see big NOS I'd generally rather not see any really tight quench to control head lifting and rind land problems.
Also one more tip is the the head gasket bore needs to be bigger than the chamber and the cylinder bore. Many chambers are much bigger than the cylinder bore in the block and you will still risk having a red hot glowing head gasket in the chamber there and then you very well will see some bad pre-ignition and detonation too!
The tremendously better design of these later model LSx aluminum heads though doesn't seem to care too much about quench as long as you can still make what compression you want without hitting the head by running quench too close. The factory engines when hot are running at around .051 to .060 quench which is almost the worst you can do according to old SAE papers on detonation resistance as Michael D alluded to.
Chrysler ran .070 to .080 quench on millions of engines for 50+ years as they still do or more on many of the hemis etc. The SAE also said that over .070 or so the quench is not on the bad zone anymore at least on most engines if I am remembering correctly. A ton of the modern stuff even runs over .080 on many power adder engines like say the Ford GT 5.4 blower engine or GT500 etc.
You also have another trend on power adders using extra fuel with METH or stand alone NOS systems with their own fuel or even engines using straight METH or E85 or running no quench at all by dequenching the cylinder heads and or running a full dished piston or by running the piston way in the hole. Most real power adder stuff is like this for many reasons but they never want to see tight quench.
Many times you end up with excess fuel in the chambers and with tight quench you will essentially hydrolock and break 2nd ring lands plenty often. It's even common to see domed pistons but yet way in the hole on many big NOS setups. Most of these guys don't talk about it as it takes a lot of broken parts to learn this lessons. Anyway to make a long story longer if this engine will see big NOS I'd generally rather not see any really tight quench to control head lifting and rind land problems.
Also one more tip is the the head gasket bore needs to be bigger than the chamber and the cylinder bore. Many chambers are much bigger than the cylinder bore in the block and you will still risk having a red hot glowing head gasket in the chamber there and then you very well will see some bad pre-ignition and detonation too!
The following users liked this post:
HP RESEARCH (11-08-2017)
11-09-2017, 06:42 PM
#106
Race Director
Going to change to billet engine mounts?
11-09-2017, 06:50 PM
#108
Team Owner
11-09-2017, 06:54 PM
#109
Burning Brakes
Thread Starter
11-09-2017, 07:05 PM
#110
Team Owner
Hinson makes a shorter (by ~3/8") mount which I believe was originally developed for those who were having FAST intake/cowl clearance problems (maybe on C5's) before FAST revised the intake. I've seen guys on here saying the 3/8" drop created other clearance issues, but a simple ~1/8 - 3/16" washer/spacer remedied all issues.
11-09-2017, 09:56 PM
#111
Race Director
My OEM mounts were leaking when I had my HCI work done at CPR, which was sort of expected on my part. They installed Fabberge billet motor mounts and I do not have any issues with the MSD intake rubbing. I don't have the part number. Just make sure the billet mounts you get are no higher than the OEM mounts.
I do get some modest vibration that I occasionally notice, but it is not objectionable at all.
I do get some modest vibration that I occasionally notice, but it is not objectionable at all.
11-09-2017, 11:27 PM
#112
Burning Brakes
Hinson standard mounts usually don't work with mad it seems and I would not want to lower my engine that much (some have had other issues) which is why I just got new OEM mounts when mine went bad. So far so good. I'd probably get new OEM ones even if yours don't look bad cause they aren't expensive and who knows how much life u have left.
11-10-2017, 11:25 AM
#113
Just plan to clearance the firewall to fit the MSD. You may regret it later if you don't. The shorter Hinson mounts will cause pan to leaf spring contact when the spring is unloaded. A shim will fix that, but don't assume you will find one the correct dimension. I had to make mine. The Hinson mounts are a good compromise between OEM and solid. They offer rigidity, with mild vibration damping. I can feel mild drive train noise more than with OEM mounts, but it is much less than fealt with billit style mounts.
11-12-2017, 04:54 PM
#114
Melting Slicks
I had a bit of an issue with the shorter mounts where I had my oil pan heavily resting on the oil pan when weight was lifted from the front end. I added a spacer to make them work. The "stock height" mounts are taller than stock. I would have run these either way. I did get the engine lower than factory either way to clear my hood with the direct port lines.
https://www.corvetteforum.com/forums...ts-issues.html
https://www.corvetteforum.com/forums...ts-issues.html
11-16-2017, 09:23 PM
#115
Burning Brakes
Thread Starter
She's alive. My installer and tuner got my new engine fired up today and heat cycled it a couple of times and all is good.
I have had the Monster Triple disc clutch on my car for the past 4,000 miles and have more than a dozen 1/2 mile passes and probably more than 20 1/4 mile passes and a lot of hard street driven miles. He said that my clutch basically looks new and he was somewhat surprised that it showed no wear.
I ended up reusing my OEM engine mounts. I have less than 9,000 miles on my car so they should go for at least a few more years.
I also decided to go with the OEM head gasket, which will put my SCR at 12:1 and DCR at 8.65:1.
I am ready to get my car back.
I have had the Monster Triple disc clutch on my car for the past 4,000 miles and have more than a dozen 1/2 mile passes and probably more than 20 1/4 mile passes and a lot of hard street driven miles. He said that my clutch basically looks new and he was somewhat surprised that it showed no wear.
I ended up reusing my OEM engine mounts. I have less than 9,000 miles on my car so they should go for at least a few more years.
I also decided to go with the OEM head gasket, which will put my SCR at 12:1 and DCR at 8.65:1.
I am ready to get my car back.
11-17-2017, 12:33 AM
#116
Race Director
Great progress!
11-17-2017, 01:00 AM
#117
Instructor
11-17-2017, 09:24 AM
#118
Burning Brakes
Thread Starter
Honestly, it drives like stock. You can slip the clutch like the stock clutch and it will hold 1000whp. The only negative is that it is heavy and I am sure that I give up a few whp because of that but it drives great.
11-17-2017, 09:50 AM
#119
Instructor
At that small diameter, I wouldn't expect too much hp loss.
http://www.tickperformance.com/monst...capacity-1000/
Last edited by Nexxussian; 11-17-2017 at 09:52 AM. Reason: Forgot the link.
11-19-2017, 08:24 AM
#120
Le Mans Master
Thanks, I appreciate it.
At that small diameter, I wouldn't expect too much hp loss.
http://www.tickperformance.com/monst...capacity-1000/
At that small diameter, I wouldn't expect too much hp loss.
http://www.tickperformance.com/monst...capacity-1000/