Dissapointment on the Dyno
Melting Slicks
Joined: Jun 1999
Posts: 2,872
Likes: 3
From: Wilmington NC
thats what the piston stop is going to help him do, he will need to get number 6 on TDC using the piston stop, then set a pointer on zero of the ATI balancer.. then the motor is timed with the pointer and if the cam is out it will show with the timing light and the shown idle timing setting.. ie.. if datalogging shows timing in the ecm to be 29*s, but the balancer is showing 5-10 degrees off.. he will know his cam is off a tooth. the other thing I had asked was about the timing set, some adjustable timing sets will allow a few deghree variance on a variety of keyways, if the crank sprocket is not on zero and is advanced or retarded, this would also show the timing being off and would need to be corrected the same way as previously mentioned by going into the front of the motor.
Chris
Chris
Thread Starter
Instructor
Joined: Dec 2004
Posts: 175
Likes: 0
From: Athens Alabama
Chris,
The timing set is non adjustable, there are keyways machined for advance/retard, I used the keyway for no advance/retard.
Don't know where to find a piston stop, I will probably need to dig around and order one from somewhere. As soon as I can get one I will perform the procedure to see if the ECM and timing ight are giving the same readings.
Thanks,
prattman
The timing set is non adjustable, there are keyways machined for advance/retard, I used the keyway for no advance/retard.
Don't know where to find a piston stop, I will probably need to dig around and order one from somewhere. As soon as I can get one I will perform the procedure to see if the ECM and timing ight are giving the same readings.
Thanks,
prattman
Melting Slicks
Joined: Jun 1999
Posts: 2,872
Likes: 3
From: Wilmington NC
order one from summitracing.. they are only a couple bucks! should be in the catalog..
if not give them a ring and ask for one I ordered mine from them.. works like a charm.. make sur eyou get the spark plug hole style and not the one for the block deck.. may have some trouble getting that one to work..lol
CHRIS
if not give them a ring and ask for one I ordered mine from them.. works like a charm.. make sur eyou get the spark plug hole style and not the one for the block deck.. may have some trouble getting that one to work..lolCHRIS
Drifting
Joined: May 2003
Posts: 1,730
Likes: 1
From: Charlotte NC
St. Jude Donor '05
Hi,
Haven't been following too closely.
Are we 100% sure it was a hotcam installed? I had a guy swear to me that he had a hotcam lately and it turned out just to be a LT4 stock cam.
Anything is possible. The AFR is lean, but thats not whats causing hte power to be that low. In fact most cars will make the most power around 13.5 or so.
Haven't been following too closely.
Are we 100% sure it was a hotcam installed? I had a guy swear to me that he had a hotcam lately and it turned out just to be a LT4 stock cam.
Anything is possible. The AFR is lean, but thats not whats causing hte power to be that low. In fact most cars will make the most power around 13.5 or so.
Racer
Joined: Apr 2004
Posts: 487
Likes: 0
From: Huntsville AL
Hey Prattman, was hoping to see your chart on trackmaster's site, but don't see it posted yet. Hope you get it figured out soon. My a/f is around 12.5 across now, the little bit richer helped tq and I wanted to be extra safe. My chart on their site is outdated btw. Do you have or need a LT-4 knock module?
Thread Starter
Instructor
Joined: Dec 2004
Posts: 175
Likes: 0
From: Athens Alabama
Originally Posted by lcvette
order one from summitracing.. they are only a couple bucks! should be in the catalog.. if not give them a ring and ask for one I ordered mine from them.. works like a charm.. make sur eyou get the spark plug hole style and not the one for the block deck.. may have some trouble getting that one to work..lol
CHRIS
if not give them a ring and ask for one I ordered mine from them.. works like a charm.. make sur eyou get the spark plug hole style and not the one for the block deck.. may have some trouble getting that one to work..lolCHRIS
Thanks for the info Chris.
I got one on order yesterday, should be here tomorrow.
prattman
Thread Starter
Instructor
Joined: Dec 2004
Posts: 175
Likes: 0
From: Athens Alabama
Originally Posted by Alvin
Hi,
Haven't been following too closely.
Are we 100% sure it was a hotcam installed? I had a guy swear to me that he had a hotcam lately and it turned out just to be a LT4 stock cam.
Anything is possible. The AFR is lean, but thats not whats causing hte power to be that low. In fact most cars will make the most power around 13.5 or so.
Haven't been following too closely.
Are we 100% sure it was a hotcam installed? I had a guy swear to me that he had a hotcam lately and it turned out just to be a LT4 stock cam.
Anything is possible. The AFR is lean, but thats not whats causing hte power to be that low. In fact most cars will make the most power around 13.5 or so.
GM part # 24502586.
I am going to pursue the 1 tooth off suggestion, it will take me a while.
prattman
Thread Starter
Instructor
Joined: Dec 2004
Posts: 175
Likes: 0
From: Athens Alabama
Originally Posted by Wildcat1
Hey Prattman, was hoping to see your chart on trackmaster's site, but don't see it posted yet. Hope you get it figured out soon. My a/f is around 12.5 across now, the little bit richer helped tq and I wanted to be extra safe. My chart on their site is outdated btw. Do you have or need a LT-4 knock module?
On this thread go to page 3, about halfway through it was posted for me by MarkuzLS1. You can see the dyno graph there.
Went to the drag strip and made tow terrible passes before getting rained out last Friday evening. Best time was 9.7
It was more me than the car, so I will be out there as much as I can working on it.
Oh, I already installed the LT4 KM. Thanks.
prattman
Last edited by prattman; Jul 18, 2006 at 06:16 PM.
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Racer
Joined: Apr 2004
Posts: 487
Likes: 0
From: Huntsville AL
Yeah, I saw the chart he posted for you, I was hoping for a "better" chart with tq & rpm to be posted on their site though. I saw another thread a minute ago where an LT-4 with catback got around 305rwhp and 305rwtq, I was expecting 340rwhp at least out of your combo, a lot more actually. You see bigger numbers posted all the time on this site with your combo. I wouldn't run it anymore until you get this resolved. Hope to meet ya at the track next time, I was outta town when you guys got rained out. I was suppose to race the viper when I got back sat night.
Le Mans Master
Joined: Jul 2000
Posts: 7,639
Likes: 326
From: Greenville SC
I was reading Hot Rod today and saw a small "tech bit" that said not to polish the intake port, the rough walls will create a boundary layer, this air does not move, but acts as a smooth surface for the air to move along, and make the port "act smaller".
Also on the web regarding head porting:
"Do not polish intake ports, the roughness helps to keep gasoline vapor in suspension by creating turbulence"
Also on the web regarding head porting:
"Do not polish intake ports, the roughness helps to keep gasoline vapor in suspension by creating turbulence"
Melting Slicks
Joined: Dec 2004
Posts: 2,137
Likes: 5
From: Howard PA
Originally Posted by 95wht6spd
I was reading Hot Rod today and saw a small "tech bit" that said not to polish the intake port, the rough walls will create a boundary layer, this air does not move, but acts as a smooth surface for the air to move along, and make the port "act smaller".
Also on the web regarding head porting:
"Do not polish intake ports, the roughness helps to keep gasoline vapor in suspension by creating turbulence"
Also on the web regarding head porting:
"Do not polish intake ports, the roughness helps to keep gasoline vapor in suspension by creating turbulence"
You know what I mean...
Team Owner
Joined: Apr 2001
Posts: 22,267
Likes: 3
From: Dallas TX
Originally Posted by 93 ragtop
If your scans turn out ok, please consider what I said about the cam being off 1 tooth. There is another forum member and I believe he went by Glock LT4, but anyways I believe it was he who had the same problem. He installed the hotcam a tooth off and didnt realize it. Finally figured it out when trying to dyno tune and was adding rediclous amounts of timing and just couldnt make any power. But trying to recall from memory, his did not run bad, it was just down on power. Good luck and let us know how it goes.
Team Owner
Joined: Apr 2001
Posts: 22,267
Likes: 3
From: Dallas TX
Originally Posted by ALLT4
You sure that's the only way? Would a small degree wheel fit while the motor is in? Might have to space it out and it would be a giant pain. Almost as much as tearing the cover off and everything that goes with that. But if you could get one centered up, you could attach a dial indicator looking at a spring retainer. You'd have to covert your base lift to whatever ratio rockers you have and use a very light checking spring. Might be more trouble that it's worth though.
This is why you degree your cam before you button up the timing cover. Now everything is a mystery.
This is why you degree your cam before you button up the timing cover. Now everything is a mystery.
Last edited by GlockLT4; Jul 23, 2006 at 09:07 PM.
Team Owner
Joined: Apr 2001
Posts: 22,267
Likes: 3
From: Dallas TX
Originally Posted by Wildcat1
Yeah, I saw the chart he posted for you, I was hoping for a "better" chart with tq & rpm to be posted on their site though. I saw another thread a minute ago where an LT-4 with catback got around 305rwhp and 305rwtq, I was expecting 340rwhp at least out of your combo, a lot more actually. You see bigger numbers posted all the time on this site with your combo. I wouldn't run it anymore until you get this resolved. Hope to meet ya at the track next time, I was outta town when you guys got rained out. I was suppose to race the viper when I got back sat night.
I'm running 354rwhp. Only changes are HOT cam, 3" catback, and Longtubes.
Thread Starter
Instructor
Joined: Dec 2004
Posts: 175
Likes: 0
From: Athens Alabama
Update:
Pulled the cover on the timing chain and the cam is installed correctly.
Once I figure out which Fuel injectors to use, I will replace the old injectors and check the fuel pressure.
Will update the results when done.
prattman
Pulled the cover on the timing chain and the cam is installed correctly.
Once I figure out which Fuel injectors to use, I will replace the old injectors and check the fuel pressure.
Will update the results when done.
prattman
