Ford Mustang Forums banner

93 351w weak?

2K views 24 replies 11 participants last post by  HELMUT RONER 
#1 ·
i have a 93 lightning 5.8 with a kenne bell 9psi .24lb injectors 75mm throttle body/headers.ran top shape.slight pinging.all of a sudden piston gave out!is it normal? 351w weak? NEED HELP!
 
#3 ·
GTPhreak said:
if it pinged its possible. the motors have hyperuetectic pistons in them
The Hyper pistons are the weak link in the L motors. They won't stand for much ping under boost. The rods crank and block are all very well made and should stand for up to 500hp with no problem. There is some guys running more HP than that with the stock long block.

It must have been running consistently lean. You will need an EEC Tuner or a Tweecer to recalibrate the fuel curve for the 24's and boost. Does it have a chip or tuner presently?

David
 
#4 ·
ASAP said:
The Hyper pistons are the weak link in the L motors. They won't stand for much ping under boost. The rods crank and block are all very well made and should stand for up to 500hp with no problem. There is some guys running more HP than that with the stock long block.

It must have been running consistently lean. You will need an EEC Tuner or a Tweecer to recalibrate the fuel curve for the 24's and boost. Does it have a chip or tuner presently?

David
i was told by kb not to run a after market chip.blowzilla kit comes with timing retard /boost apump.if any thing looks like its running rich?tried 30lb injectors.way to rich.looked like a diesel!
 
#5 ·
ASAP said:
The Hyper pistons are the weak link in the L motors. They won't stand for much ping under boost. The rods crank and block are all very well made and should stand for up to 500hp with no problem. There is some guys running more HP than that with the stock long block.

It must have been running consistently lean. You will need an EEC Tuner or a Tweecer to recalibrate the fuel curve for the 24's and boost. Does it have a chip or tuner presently?

David
I agree the hyper pistons are junk
 
#6 ·
dirtydanz93lightning said:
i was told by kb not to run a after market chip.blowzilla kit comes with timing retard /boost apump.if any thing looks like its running rich?tried 30lb injectors.way to rich.looked like a diesel!
Ya, I understand what you're saying, but if there is nothing to tell the computer you are running 24's(like a mass air flow meter does), then until you reprogram it, it uses the 19's fuel curve. This could lead to lean and rich spots throughout the rpm band. :crying:
I would be looking for the reason it was detonating as it could cause future problems as well.

David
 
#7 ·
not really junk you just gotta have a good tune. I know lots of people running boosed setups with hyperuetectic pistons and do just fine. I was gonna run a turbo on my 94 gt with hyperuetectic pistons when i had it (stock bottom end)
 
#9 ·
My car has a 351W in it with the hyper pistons etc. I made 425 rwhp and 464 rwtq with a safe and conservative tune. I'm pushing 12 psi.
 
#11 ·
redlightningssf said:
Check the compresson it maybe just the head gasket.Did you leave the FMU hooked up when you tried the 30's?. You can run a chip with KB, any pinging is bad at high or low RPMs.You may have blown more than one hole. I blew three with my KB.
i checked compresson.all was good.even the number 5 piston that was damaged.i did have fmu with 30lb injectors.it ran way to rich! i put 24lb it ran way better.thats why im trying to figure out if its just the pistons?i just ordered a stock short block and aluminum heads!
 
#16 ·
Yes, there are other chip guys out there. Johnson Motorsports comes to mind (www.jmschip.com). As mentioned above, your stock fuel curve is probably way off for a supercharged motor and not richening up enough at the top of the tach. You also might want to check out the Nat'l Lighting club and see what those guys are doing to tune their blown 1st gens (www.nloc.com).

blackcobra46, impressive numbers. What's your combo that you're running low 10's? Are you supercharged, nitrous, turbo or natural?
 
#17 ·
Racer LX said:
Yes, there are other chip guys out there. Johnson Motorsports comes to mind (www.jmschip.com). As mentioned above, your stock fuel curve is probably way off for a supercharged motor and not richening up enough at the top of the tach. You also might want to check out the Nat'l Lighting club and see what those guys are doing to tune their blown 1st gens (www.nloc.com).

blackcobra46, impressive numbers. What's your combo that you're running low 10's? Are you supercharged, nitrous, turbo or natural?
thanks yes got 200 shot right now im haven hooking up probelms..last week was first time out ,,run 2 motor passes 11.44 /119 ..that mph 134 i should be in the 9s ...i need to get anti roll bar for rear ..and bigger carb..any thing else you want to know just feel free to p m me..
 
#19 ·
ASAP said:
Ya, I understand what you're saying, but if there is nothing to tell the computer you are running 24's(like a mass air flow meter does), then until you reprogram it, it uses the 19's fuel curve. This could lead to lean and rich spots throughout the rpm band. :crying:
I would be looking for the reason it was detonating as it could cause future problems as well.

David
All gen 1 Lightnings came with 24 lbs injectors stock. Unless you are not using the stock processor, it will not use fuel curves for 19 lb injectors.
 
#21 ·
tohard2hook said:
All gen 1 Lightnings came with 24 lbs injectors stock. Unless you are not using the stock processor, it will not use fuel curves for 19 lb injectors.
Sorry man... You're misinformed on that one. All Gen 1 L's came with 19's. It's rediculous, I know but the SD doesn't require as big of injectors as Mass Air. :)
 
#22 ·
I worked on the program at Ford, so I am pretty I am correct. BTW, injector size has nothing to do with mass air and everything to do with HP. They ran 24's in a 93 Corbra with almost the same hardware as the gen1 lightning (except more displacement in the Lightnings). Show me a picture of a stock gen 1 lightning with orange top injectors and I will eat my words. I am sure you'll will find that they all have blue tops.

Thanks, Fred

ASAP said:
Sorry man... You're misinformed on that one. All Gen 1 L's came with 19's. It's rediculous, I know but the SD doesn't require as big of injectors as Mass Air. :)
 
#23 ·
tohard2hook said:
I worked on the program at Ford, so I am pretty I am correct. BTW, injector size has nothing to do with mass air and everything to do with HP. They ran 24's in a 93 Corbra with almost the same hardware as the gen1 lightning (except more displacement in the Lightnings). Show me a picture of a stock gen 1 lightning with orange top injectors and I will eat my words. I am sure you'll will find that they all have blue tops.

Thanks, Fred
I checked on some of the Lightning forums and I see some people say they have orange top injectors. Like I said I would eat my words. I eating right now!
Sorry about the misinformation. Fred
 
#24 ·
tohard2hook said:
I checked on some of the Lightning forums and I see some people say they have orange top injectors. Like I said I would eat my words. I eating right now!
Sorry about the misinformation. Fred
lol...I wish they did...I know what you're saying though. My bro had a 1995 Cobra with the stock 24LB injectors. I always heard the reason for not using bigger injectors on the SD is its Batch fire set up compared to the MA's sequential injection. Its a PITA to change them out too, because you have to have a tweecer, chip or eec tuner to recalibrate instead of a mass air meter. This is why I've yet to change mine...lol

Take Care,
David :)
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top