Spec me a cam for a high compression 347
Spec me a cam for a high compression 347 The car is not making much power at all, and I think we have narrowed it down to the cam being wrong for the motor.
Specs:
12:1 347ci shortblock, Wiseco pistsons, Manley rods, polished and balanced stock crank
Livernois Stage II LS6 heads milled to 62cc
Fast 92/PTM 92mm TB
Kooks 1-3/4" headers
42# Injectors
Racetronix fuel pump kit with the hotwire
Right now it has a 236/240 .601/.608 111+2lsa cam. It seems to run decent, but only put down 399.7rwhp and like 386rwtq. Weak!!
I was thinking about the HPE Big E cam, 244/248 .612/.615 112lsa.
Thoughts?
Specs:
12:1 347ci shortblock, Wiseco pistsons, Manley rods, polished and balanced stock crank
Livernois Stage II LS6 heads milled to 62cc
Fast 92/PTM 92mm TB
Kooks 1-3/4" headers
42# Injectors
Racetronix fuel pump kit with the hotwire
Right now it has a 236/240 .601/.608 111+2lsa cam. It seems to run decent, but only put down 399.7rwhp and like 386rwtq. Weak!!
I was thinking about the HPE Big E cam, 244/248 .612/.615 112lsa.
Thoughts?
Is this an auto or 6 speed car? Did you have the cam degreed when it was installed? Who tuned it? i wouldn't jump to just swaping cams. You might swap the cam and only gain 3-5 hp. There are some cam only auto cars on here with smaller cams than the one you have makeing 420 rwhp. There probly something not right in the tune or valve train / cam timing. Maybe your clutch was slipping?
Last edited by bigfatls6; Dec 1, 2008 at 08:03 AM.
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From: BFE
You have domed pistons?
How are you getting 12:1 with 62cc heads, with .01 piston out of hole and .040 gasket, 2cc reliefs, I'm only getting 11.2
Is this a Mustang dyno?
How are you getting 12:1 with 62cc heads, with .01 piston out of hole and .040 gasket, 2cc reliefs, I'm only getting 11.2
Is this a Mustang dyno?
Last edited by PREDATOR-Z; Dec 1, 2008 at 08:13 AM.
2 different Dynojets, Chuck (formerly of HPE) did the tuning. He has tuned my car 3 times before with no issues. It does run a little rich, but this setup should be making upper 400s, so I doubt tuning is going to get me 80+hp. The first pull untuned was 325hp...
It is a 6 speed also. The clutch grabs a little late but doesn't slip. Also I don't see that making 80hp as well. At first I thought something was off with the dyno so I took it to another shop and the 2 dynos were within 10hp of each other.
The cam wasn't degreed with a wheel, just lined up to 0 degrees with the dot on the other gear. It is a double roller chain.
The quickest 346ci heads/cam car in the country runs an MS4 
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What if I put a mix of race fuel in it?
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From: BFE
For sure you'll need a colder plug than TR55, instead of running around in circles you should live scan and record at various rpms to see what is happening.
You said it is running rich, that had to be for a reason (clue)
You said it is running rich, that had to be for a reason (clue)
+6cc dome.
2 different Dynojets, Chuck (formerly of HPE) did the tuning. He has tuned my car 3 times before with no issues. It does run a little rich, but this setup should be making upper 400s, so I doubt tuning is going to get me 80+hp. The first pull untuned was 325hp...
It is a 6 speed also. The clutch grabs a little late but doesn't slip. Also I don't see that making 80hp as well. At first I thought something was off with the dyno so I took it to another shop and the 2 dynos were within 10hp of each other.
The cam wasn't degreed with a wheel, just lined up to 0 degrees with the dot on the other gear. It is a double roller chain.
2 different Dynojets, Chuck (formerly of HPE) did the tuning. He has tuned my car 3 times before with no issues. It does run a little rich, but this setup should be making upper 400s, so I doubt tuning is going to get me 80+hp. The first pull untuned was 325hp...
It is a 6 speed also. The clutch grabs a little late but doesn't slip. Also I don't see that making 80hp as well. At first I thought something was off with the dyno so I took it to another shop and the 2 dynos were within 10hp of each other.
The cam wasn't degreed with a wheel, just lined up to 0 degrees with the dot on the other gear. It is a double roller chain.
With that compression, you'll want to run some race gas mix in the tank to avoid pinging/detonation. Also a cooler plug like Predator said would be to your advantage!
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You said it runs a little rich. Do you know this because it read rich on the wideband or because it smells like fuel??
With that compression, you'll want to run some race gas mix in the tank to avoid pinging/detonation. Also a cooler plug like Predator said would be to your advantage!
With that compression, you'll want to run some race gas mix in the tank to avoid pinging/detonation. Also a cooler plug like Predator said would be to your advantage!
Unfortunately the wideband was not working when he tuned it... so it was a guess. I am talking to another tuner around here to retune it because I am not happy with the way Chuck did it.
So I am basing it on smelling like fuel, it is horrible standing behind the car, even driving it with the windows down or up you can barely breathe.
Ya need to log the dyno runs and see if there's any knock pulling the timing out. You definately have something going on, I made 403 cam only in 2003 before any of the new technology came out.
Granted, the motor is probably built with heavier then stock components that aren't going to help make power, but you should be seeing in the 450+ range with a stick in the car.
The cam you're running isn't so small that it shouldn't me making a good bit more then it is.
I agree that you probably need some 100 octane gas, probably don't need leaded fuel, but something better then pump is probably needed.
I'd put a set of TR7 plugs in the car, that would be a good starting point as well.
Granted, the motor is probably built with heavier then stock components that aren't going to help make power, but you should be seeing in the 450+ range with a stick in the car.
The cam you're running isn't so small that it shouldn't me making a good bit more then it is.
I agree that you probably need some 100 octane gas, probably don't need leaded fuel, but something better then pump is probably needed.
I'd put a set of TR7 plugs in the car, that would be a good starting point as well.
I know the numbers are horrible, I made 436rwhp cam only before I built this motor, with a Fast 90 and 244/242 cam on the stock heads and stock bottom end.
I'll order a set of TR7s and try some race fuel along with a retune and see where it gets me.
I'll order a set of TR7s and try some race fuel along with a retune and see where it gets me.
Can't hurt, I don't know what you have available for race fuel, if you have an unleaded 105 or something like that I'd start there, if not a 5 gallons of C10 and4 to 5 gallons of 93 should be fine as well. I assume there's no cats in the car to get screwed up, and if you tune it open loop the o2's aren't gonna be a problem with leaded fuel.
But if you are running the o2's the leaded fuel is gonna be a problem, cats, even with unleaded fuel won't be happy either.
But if you are running the o2's the leaded fuel is gonna be a problem, cats, even with unleaded fuel won't be happy either.
....Ask for your money back because you surely didn't get a proper tune without the wide band. 
cam should not be an issue
TR6 should be a good starting point for plugs
good luck getting it sorted out