LQ4 + 862 heads + TSP CHOPacabra cam
#11
Most likely, but I am going to punt. I'm going to swap the converter next. It was doing weird stuff on the dyno when i locked it. On the street I notice it shuddering a little bit when it locks up sometimes. If no improvement, I'll change the cam and heads. I have a really nice set of 799s touched up by AI just sitting in my spare bedroom.
#13
The more I look at flow numbers of factory cylinder heads in stock form... I think I F'd up using those 862s. Too much hype on the Internet saying they are they the best thing since sliced bread. My experience with them has been lackluster. I am not a fan and would not do it again.
On the cams, if my math is right:
TSP CHOPacabra = +2 overlap
my old EPS = -7 overlap
The Sloppy best = +1 overlap
Going from -7 to +2 overlsp, despite the roughly 1 point in static compression increase explains some of the TQ loss. I mentioned the "best cam" because I have one and am most likely going to pair it with those AI 799s. My only other cam option is a Summit 218/227 .600"/.600", which is -1.5 overlap.
I am still going to change the tq converter and go back to the dyno to see if that was part of the issue. Kind of a give it one last chance. But, I'm pretty much dead set on swapping the heads and cam for something different.
On the cams, if my math is right:
TSP CHOPacabra = +2 overlap
my old EPS = -7 overlap
The Sloppy best = +1 overlap
Going from -7 to +2 overlsp, despite the roughly 1 point in static compression increase explains some of the TQ loss. I mentioned the "best cam" because I have one and am most likely going to pair it with those AI 799s. My only other cam option is a Summit 218/227 .600"/.600", which is -1.5 overlap.
I am still going to change the tq converter and go back to the dyno to see if that was part of the issue. Kind of a give it one last chance. But, I'm pretty much dead set on swapping the heads and cam for something different.
Last edited by Bluecollar Hotrods; 12-28-2022 at 09:09 PM.
#14
Custm2500's Rude Friend
iTrader: (17)
The more I look at flow numbers of factory cylinder heads in stock form... I think I F'd up using those 862s. Too much hype on the Internet saying they are they the best thing since sliced bread. My experience with them has been lackluster. I am not a fan and would not do it again.
The following 2 users liked this post by 1FastBrick:
Bluecollar Hotrods (12-28-2022),
strutaeng (12-28-2022)
#16
I have a contact at Cam Motion when i order cam for a setup. I tell them all the specs and they grind a cam and ship it. They have all the cool stuff to know the details. Havent been dissapointed yet.
#17
makes children cry
iTrader: (5)
The more I look at flow numbers of factory cylinder heads in stock form... I think I F'd up using those 862s. Too much hype on the Internet saying they are they the best thing since sliced bread. My experience with them has been lackluster. I am not a fan and would not do it again.
On the cams, if my math is right:
TSP CHOPacabra = +2 overlap
my old EPS = -7 overlap
The Sloppy best = -1 overlap
Going from -7 to +2 overlsp, despite the roughly 1 point in static compression increase explains some of the TQ loss. I mentioned the "best cam" because I have one and am most likely going to pair it with those AI 799s. My only other cam option is a Summit 218/227 .600"/.600", which is -1.5 overlap.
I am still going to change the tq converter and go back to the dyno to see if that was part of the issue. Kind of a give it one last chance. But, I'm pretty much dead set on swapping the heads and cam for something different.
On the cams, if my math is right:
TSP CHOPacabra = +2 overlap
my old EPS = -7 overlap
The Sloppy best = -1 overlap
Going from -7 to +2 overlsp, despite the roughly 1 point in static compression increase explains some of the TQ loss. I mentioned the "best cam" because I have one and am most likely going to pair it with those AI 799s. My only other cam option is a Summit 218/227 .600"/.600", which is -1.5 overlap.
I am still going to change the tq converter and go back to the dyno to see if that was part of the issue. Kind of a give it one last chance. But, I'm pretty much dead set on swapping the heads and cam for something different.
if you've already got some worked 799s, then i'd say mill a few thousandths off, get new pushrods, and let it eat.
#18
Goals? Make decent power, maintain some drivability. My truck is 4600lbs and some change w/o driver, 4.10s, will have a converter and supporting mods. 336rwhp just isn't going to cut it, I'd like to be around 375-380
#19
Custm2500's Rude Friend
iTrader: (17)
Just so every one is on the same page...
Summit Racing 8720R1 Camshaft,
Stage 2, LS Truck Swap Cam, High lift version, 218/227 .600/.600 , 112+2
So this is a Stock LQ4 with the 8 cc dish piston.
Depending on your out of the hole piston measurement and what gasket you use, You will be around 10.25:1 compression ratio with 63 CC
Curious if they removed the casting flash where the seats enter the bowel in the head?
Should be a STOUT combo and I believe you will net what your looking for within 10 HP at the wheels.
Summit Racing 8720R1 Camshaft,
Stage 2, LS Truck Swap Cam, High lift version, 218/227 .600/.600 , 112+2
So this is a Stock LQ4 with the 8 cc dish piston.
Depending on your out of the hole piston measurement and what gasket you use, You will be around 10.25:1 compression ratio with 63 CC
Curious if they removed the casting flash where the seats enter the bowel in the head?
Should be a STOUT combo and I believe you will net what your looking for within 10 HP at the wheels.
The following users liked this post:
68Formula (01-20-2023)
#20
As promised, changed the converter last weekend - went back to the dyno today. And... absolutely ZERO gain. Kind of what I expected. We made a few changes trying to squeeze more out, but it has no more to give.
So my thoughts, I would never do stock 706/862 heads on a 6.0L again. I don't care what the engine dyno on the Internet says, real world experience... hard pass.
Now, just need to figure out when I can do the heads and cam swap + retune next month. I'd also like to make a few passes with this set up first. I'm going to guess mid 13s, maybe it will surprise me.
Blue lines are current, red is previous with the factory converter.
So my thoughts, I would never do stock 706/862 heads on a 6.0L again. I don't care what the engine dyno on the Internet says, real world experience... hard pass.
Now, just need to figure out when I can do the heads and cam swap + retune next month. I'd also like to make a few passes with this set up first. I'm going to guess mid 13s, maybe it will surprise me.
Blue lines are current, red is previous with the factory converter.
Last edited by Bluecollar Hotrods; 06-25-2023 at 11:24 AM.