11:1 Compression 347 Quesitons

Mdean2437

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Mar 14, 2014
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I am looking at purchasing a fox box with 11:1 compression
  • the bleow are some of the internals
  • BOSS BLOCK
  • CALLIES CRANKSHAFT
  • MAHLES PISTONS
  • VIC JR ALUMINUM HEADS
  • TRICKFLOW INTAKE

Would this even run on 93 Octane? What are some problmes with 11:1 compression?
 
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I guess a lot would depend on actual compression vs advertised compression. The camshaft used could be a big factor in this as well. It also depends on if this is EFI or carbureted, and if EFI, is it the stock EFI or are you using a stand-alone engine management system. There are a lot of variables that could determine if it would live on 93 octane fuel.
 
It is efi. This all I really know about it. It has nice paint.

BBK FUEL RAIL
Aluminum drive shaft
5 LUG DISC BRAKE CONVERSION
MOSER AXLES
BRAND NEW BBK SHORT TUBE HEADERS
BBK 70MM THROTTLE BODY
PDX 95M MASS AIR SENSOR
BBK INJECTORS
ARP head studs
ARP main studs
FRP High Volume Oil Pump
Ported and Polished PI cylinder heads
Comp Cams high lift beehive Valve Springs
BRAND NEW AC COMPRESSOR
WILWOOD BRAKE DIST
MSD 6AL DIGITAL IGNITION
CUSTOM GRIND CAM
BILLET CRANK & UNDER DRIVE PULLEYS
BUILT REAR END WITH STEEDA BILLET UPPER AND LOWER ARMS

STEEDA SWAY, AND ANTI ROLL BARS AS WELL
STEEDA COIL OVER 4 LINK SUSPENSION KIT. HAS ADJUSTABLE COIL OVERS AS WELL AS BLISTEIN GAS SHOCKS. THERE IS 8 SHOCKS IN ALL. 2 COIL OVERS ON THE FRONT, 2 COIL OVERS ON THE REAR AND 2 FRONT AND 2 REAR GAS SHOCKS.
 
It can be done, after all the Z06 Corvette is 11.0:1 compression, as well as the 5.0 Coyote engine, but they also have modern electronics that allow for adjustments to be made to prevent detonation, ect.
 
It can be done, after all the Z06 Corvette is 11.0:1 compression, as well as the 5.0 Coyote engine, but they also have modern electronics that allow for adjustments to be made to prevent detonation, ect.
....and knock sensors. That's a big reason either of those cars are able to run on the lower octane stuff, with so much compression. The old 302w on the other hand.... Does not. :(
 
@Gearbanger 101 ,While technically you are correct, the knock sensor is just a safety valve in the whole system. The main reasons the Z06 and Coyote engines can run 11.0:1 compression is combustion efficiency's. These modern cylinder heads/combustion chamber/piston shapes have so much more efficiency built into them that detonation of pump gas is not likely. And in the case of the Coyote engine, the variable cam timing plays a huge role in preventing detonation. Let alone injector timing and spark timing maps that are light years ahead of the obd1 system. Heck, just the processing speed of the ECU is a major reason for being able to run such high compression. The knock sensor is just the fail-safe in case the rest of it goes fubar, or crap fuel is introduced.
 
I would throw some octane boost or a gallon of race gas in and for street driving back the timing down to be safe. The quality of gas- especially with ethanol that lowers the octane by about 10% IMO- makes 11:1 on pump gas iffy.

Drive it for a day or two, if you hear any detonation then lay off. I would pull a plug or two regardless. I didn't see it mentioned, but if it's a solid cam, you are going to be adjusting them more often than you like on a street driven car. I would also make sure they are set up on the looser side of tolerances for the street.
 
Does the current owner drive it on 93? If it has a custom cam, ask what it was designed for. I don't think 11:1 is too crazy for 93 if the cam is right and you don't go crazy with timing. I run 10.15:1 with old iron GT40's, N41 cam, and 14 degrees of timing. Everyone says 10:1 is the limit for irons and pump gas, but I have no problems.

Joe
 
I think you're all crazy. Running 11:1 compression on a Windsor has been done a countless number of times.... On 91 octane no less.

These days with a good meth injection system, you can push way beyond that number and run even more timing.
 
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It is efi. This all I really know about it. It has nice paint.

BBK FUEL RAIL
Aluminum drive shaft
5 LUG DISC BRAKE CONVERSION
MOSER AXLES
BRAND NEW BBK SHORT TUBE HEADERS
BBK 70MM THROTTLE BODY
PDX 95M MASS AIR SENSOR
BBK INJECTORS
ARP head studs
ARP main studs
FRP High Volume Oil Pump
Ported and Polished PI cylinder heads
Comp Cams high lift beehive Valve Springs
BRAND NEW AC COMPRESSOR
WILWOOD BRAKE DIST
MSD 6AL DIGITAL IGNITION
CUSTOM GRIND CAM
BILLET CRANK & UNDER DRIVE PULLEYS
BUILT REAR END WITH STEEDA BILLET UPPER AND LOWER ARMS

STEEDA SWAY, AND ANTI ROLL BARS AS WELL
STEEDA COIL OVER 4 LINK SUSPENSION KIT. HAS ADJUSTABLE COIL OVERS AS WELL AS BLISTEIN GAS SHOCKS. THERE IS 8 SHOCKS IN ALL. 2 COIL OVERS ON THE FRONT, 2 COIL OVERS ON THE REAR AND 2 FRONT AND 2 REAR GAS SHOCKS.
Also in the first post you said it has Vic Jr heads and later claim it has PI heads?! uhh PI heads are for the 4.6 liter engines not 5.0 pushrod engines. Not to be a douche but do you or the seller even know whats going on with this engine? And 8 shocks? wth? There are 4 springs and 4 shocks.
 
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Also in the first post you said it has Vic Jr heads and later claim it has PI heads?! uhh PI heads are for the 4.6 liter engines not 5.0 pushrod engines. Not to be a douche but do you or the seller even know whats going on with this engine? And 8 shocks? wth? There are 4 springs and 4 shocks.


I pasted straight form his ad here. I dont know much about cars, so know offense taken. I provided link any advice would be appreciated.

http://www.ebay.com/itm/38086263362...862633621.N23.S2.M103.R2.TR5&autorefresh=true
 
WTF? Cmon now. Coilovers AND struts/shocks?

"STEEDA COIL OVER 4 LINK SUSPENSION KIT. HAS ADJUSTABLE COIL OVERS AS WELL AS BLISTEIN GAS SHOCKS. THERE IS 8 SHOCKS IN ALL. 2 COIL OVERS ON THE FRONT, 2 COIL OVERS ON THE REAR AND 2 FRONT AND 2 REAR GAS SHOCKS. "

Bro, you need to get the following before you bid

1. build sheet for the motor
2. dyno sheet for the claimed hp
3. receipts for the parts claimed to be on the car
 
WTF? Cmon now. Coilovers AND struts/shocks?

"STEEDA COIL OVER 4 LINK SUSPENSION KIT. HAS ADJUSTABLE COIL OVERS AS WELL AS BLISTEIN GAS SHOCKS. THERE IS 8 SHOCKS IN ALL. 2 COIL OVERS ON THE FRONT, 2 COIL OVERS ON THE REAR AND 2 FRONT AND 2 REAR GAS SHOCKS. "

Bro, you need to get the following before you bid

1. build sheet for the motor
2. dyno sheet for the claimed hp
3. receipts for the parts claimed to be on the car


He doesn't have the dyno or receipts . He claimed he could give part list and some build info. The transmission is little worrisome too. I have never heard that.
 
He reaffirmed the shocks/coil on the phone on it but the coils too. 8 total. He said the guy he bought put every random part out of a magazine on it.

wait. this guy didn't even build the car? Who's the guy that did? How did this guy end up with the car. Ported PI heads? That's for a mod motor not a pushrod motor. WTF is WILWOOD BRAKE DIST?

And the fact he is calling it a Mustang "Cobra" is all I need to know. It's not a Cobra. That is waht scammers use to try and suck in newbs.Oh and he's asking $10599 for it on another site :rlaugh: http://autos.vinaudit.com/car-detai...A-90-MUSTANG-GT-COBRA-CLONE_221386714971.html

and $6000 for it on this site?

http://www.search-vehicles.com/detail/mustang/Ford-Mustang-GT-StreetStrip-car_161178027600.html



No receipts, build or dyno sheet? Sorry, too many red flags for me.
 
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