High compression 347 with Texas Giant?
I bounce back and forth A LOT. Tuned for phoenix, but come down here for months at a time. Its a pain really. I do need some slight tuning for my tb settings and what not though. But I do like the way my car drives once I am cruising and its fully warmed up. No issues...just can't drive the car like when it was stock.
Major tune issues, get a new tuner. I've tuned a few cars now and my buddies 04 Trex m6 drives just fine and does not surge much at all even around 1400 rpm. Always starts and finds idle. I was actually very surprised that his Trex car tuned easier than my little cam car. My car also drives amazing but it took a long time to get the tune there. Sounds like the airflow tables, fuel and spark tables all need adjusted.
Classic case of over camming an engine. Classic case of flow numbers do not always equal dyno power. This should be stickied under "what NOT to do."
The overlap triangle on that cam in a 346 will want peak power way over the normal 6400 where the intake wants to peak, and the heads may be running out of air or stalling bad before it ever gets there. That's why it falls off so bad. Engines don't run at 28" of water depression.
This is a mismatched pile of junk. Look at the numbers the poster above me made with a 224 cam and 243's with a valve job. I don't care if god is tuning his car, it's not going to sniff 475 with what he has. He'll be lucky with 450.
The overlap triangle on that cam in a 346 will want peak power way over the normal 6400 where the intake wants to peak, and the heads may be running out of air or stalling bad before it ever gets there. That's why it falls off so bad. Engines don't run at 28" of water depression.
This is a mismatched pile of junk. Look at the numbers the poster above me made with a 224 cam and 243's with a valve job. I don't care if god is tuning his car, it's not going to sniff 475 with what he has. He'll be lucky with 450.
If those LS1 castings really do flow 340 cfm, sounds more like a happy bench, I do port LS heads too, someone was chasing numbers on a flow bench. They have to be huge runners, thin in a number of spots, and valves so big they are probably shrouded by the cylinder wall.
If those LS1 castings really do flow 340 cfm, sounds more like a happy bench, I do port LS heads too, someone was chasing numbers on a flow bench. They have to be huge runners, thin in a number of spots, and valves so big they are probably shrouded by the cylinder wall.
I have a hard time believing that the heads flow 340 but if they do they have to be hogged out bad. I had a set of Rapid heads that were great for stock castings and they only flowed 305 with 245cc runners. I think the heads are the main problem and the low end torque of the big cam isn't helping any. I think the parts are mis-matched baddly at this point but I wanted to get everybodys opinion. Thanks
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Not that I was a fan of this idea when he called originally and started asking questions about this build, but I do remember him saying it was going to be right at a 100% race and no street application. Again, this was not our idea, and I tried to talk him out of it...but I wanted to let you guys know that Jared was not concerned with the bottom end power or street manners when he ordered, so discussing that is sort of a mute point anyway.
I think about 10º less duration on both sides would have been a better idea, but maybe he'll get the kinks in the combo worked out and run an ET.
I think about 10º less duration on both sides would have been a better idea, but maybe he'll get the kinks in the combo worked out and run an ET.
__________________
Largest Stocking Distributor of LS-x Engines / CHECK OUT OUR NEW WEBSITE!
COMP - FAST - PACESETTER - DIAMOND RACING - EAGLE SPECIALTY PRODUCTS - CALLIES - COMETIC GASKETS
RAM CLUTCHES - MOSER ENGINEERING - KOOK'S HEADERS - ARP - GM BOLTS AND GASKETS - MSD - NGK
POWERBOND - ASP - AND MORE!
Largest Stocking Distributor of LS-x Engines / CHECK OUT OUR NEW WEBSITE!
COMP - FAST - PACESETTER - DIAMOND RACING - EAGLE SPECIALTY PRODUCTS - CALLIES - COMETIC GASKETS
RAM CLUTCHES - MOSER ENGINEERING - KOOK'S HEADERS - ARP - GM BOLTS AND GASKETS - MSD - NGK
POWERBOND - ASP - AND MORE!
Not that I was a fan of this idea when he called originally and started asking questions about this build, but I do remember him saying it was going to be right at a 100% race and no street application. Again, this was not our idea, and I tried to talk him out of it...but I wanted to let you guys know that Jared was not concerned with the bottom end power or street manners when he ordered, so discussing that is sort of a mute point anyway.
I think about 10º less duration on both sides would have been a better idea, but maybe he'll get the kinks in the combo worked out and run an ET.
I think about 10º less duration on both sides would have been a better idea, but maybe he'll get the kinks in the combo worked out and run an ET.
Yea, he was pretty adamant about running that thing, and IIRC he had a Magic Stick before at some point and now wanted bigger.
__________________
Largest Stocking Distributor of LS-x Engines / CHECK OUT OUR NEW WEBSITE!
COMP - FAST - PACESETTER - DIAMOND RACING - EAGLE SPECIALTY PRODUCTS - CALLIES - COMETIC GASKETS
RAM CLUTCHES - MOSER ENGINEERING - KOOK'S HEADERS - ARP - GM BOLTS AND GASKETS - MSD - NGK
POWERBOND - ASP - AND MORE!
Largest Stocking Distributor of LS-x Engines / CHECK OUT OUR NEW WEBSITE!
COMP - FAST - PACESETTER - DIAMOND RACING - EAGLE SPECIALTY PRODUCTS - CALLIES - COMETIC GASKETS
RAM CLUTCHES - MOSER ENGINEERING - KOOK'S HEADERS - ARP - GM BOLTS AND GASKETS - MSD - NGK
POWERBOND - ASP - AND MORE!
I think he got caught up on how well the texas giant works in my 402 and wouldn't listen when we said that it wasn't right for his setup. Typical bigger is always better threory which we know doesn't really work in the real world.
There is a "perfect" cam for each combo. If you are going to miss it, it is better to miss on the small side than to be too big. At least being too small isn't killing the pressure wave, it's just not taking complete advantage of it. Too big and the air in the runner is going to stall, not reflect off the back of the valve to return a pressure wave when the valve is reopened, and could very well push some of the air column back out of the cylinder before the intake valve closes. Especially if the heads have good low lift flow (another reason why low lift flow should be as little as possible).
There is a "perfect" cam for each combo. If you are going to miss it, it is better to miss on the small side than to be too big. At least being too small isn't killing the pressure wave, it's just not taking complete advantage of it. Too big and the air in the runner is going to stall, not reflect off the back of the valve to return a pressure wave when the valve is reopened, and could very well push some of the air column back out of the cylinder before the intake valve closes. Especially if the heads have good low lift flow (another reason why low lift flow should be as little as possible).
Or maybe a cam ground with this in mind. Eliminating more of the overlap at lower lifts. There is nothing really wrong with big fast ramping agressive lobes, but how you set there valve events, well, that's another topic.
Yep, and way too advanced to talk about here.. or even at all. It would **** off a number of people to have some of those theories made public knowledge.
I have a new cam ground that I'll be trying once this summer school semester is over. A pinch bigger than a Trex, but I think I am going to pick up power everywhere. Small total duration, but agressive lobes, and specific valve timing.