Hey all!

I just picked up my 96 GT today after two months of parts not being shipped and other little hiccups. Here is the deal. The car pings like mad. It has some 87 octane gas mixed in with new 91 and a bottle of octane booster, but it still pings way hard. Now to give you a run down.

The motor is a total PI Head and Intake swap out, motor has forged flat top pistons (recommended by the builder), Forged Crank, Mach 1 8 bolt Flywheel for an automatic (which is what it is), it has Steeda underdrive pulleys, a steeda timing adjuster (which was set to 8 degree's due to pinging), Autolite Iridium Plugs and UPR Cold Air Intake and FRPP 70mm Throttle body.

Now I am thinking the timing should go back to the stock setting of 10 degrees. Taking that out of the equation like it isn't even there and the motor pinging without it like it would be stock, can anyone tell me what steps or places I should look to correct this? I am at a loss and don't want to lose a $6000 investment. I have an appointment on November 10th to have a professional tune done on it to get the best performance out of it, but this is my daily driver and can't have it pinging when you press the gas everytime I drive.

Seriously, if any of you truly know what I should do as my course of action, I would greatly appreciate it. I am going to check the wires and make sure they are on all of the plugs correctly and fill up the tank the rest of the way with 91 octane gas (which is our highest here in Utah).

I appreciate any and all help and advice I can get. Thanks!!!

John

 

Take it to a tuner and get that thing checked out professionally. It could be as simple as changing the timing or fixing the air/fuel ratio. A guy locally is still trying to get the kinks out of his new motor so he's towing it up to Modular Power House real soon to have the guys check it out get it on a dyno and let them do their magic.

 

Thanks! I plan on doing that and have an appointment, however there has to be something I could do to minimize my pinging a bit for the next 30 days. Again I appreciate your reply. Thanks.

 

If you can get the Air/fuel a little richer give it a try but if that doesnt work i'd find another ride till you can get it looked at. You dont want to cause any damage to your project. Because by the time you get it looked at you may have made things worse

 

given that you have flat top slugs in a PI swapped block, I'm assuming your compression is right around 11:1 which is pretty high on 91 octane. You'll need to adjust not just the global timing but tip-in as well and the fuel curve needs lots of work.

I'd drain the tank and fuel lines, fill it with 91, try it out and if it's still pinging, then toss in a bottle of 104+. I'd also hook up a PCV oil air separator to keep ingested oil from dropping your effective octane rating until you get that thing tuned.

Whatever you do, try not to drive it until it's been properly dyno tuned.

 

Thank you for the help. I have a kirban fuel regulator I can adjust to try the fuel pressure increase. Any suggestions what to set it at to begin with? Otherwise, it will stay parked and trailered to the tuners next month. Thankfully I have little need for a vehicle this month except for a handfull of work days. Again, thanks for all the help.

 

park the car till you can get it on the dyno. no sense in tearing it up before you get a chance to step in it. I'd imagine the base timing and the fuel curve need tinkering with to keep the pinging at bay.

 

By the way, I topped it off with more 91 octane gas and another bottle of octane booster. I again thank you for your comments and I will heed the warnings as I don't want $6000 grand going south with the destruction on my motor.

 

w00t!. Good call on both counts.

Just for clarity could you fill in some details? Does it ping at idle, off idle WOT, all the damn time? What injectors are you running? Stock tune? Are your heads ported? Are the swirl damns cut out of the chambers?

BTW... from my calculations, you have about 12.6:1 compression. Put some 100 octane in it (drain the tank and lines first) and see if that stops the pinging. Just as an aside, the Ferrari F430 has 11.3:1 compression which is considered sky high for a pump gas motor. You may be able to get a cam with lots of overlap like a VT stage 2 (108deg LSA) and that may just reduce the dynamic compression by bleeding out some of the intake charge to the exhaust which might allow you to use unadulterated pump gas.

 

Really that high of compression? I will have to see what my builder knows about that. Ok the other details: It pings at idle a bit at the stock 10 degree timing. backed out to 8 degrees, it would ping under a load. At 10 it pings a bit under load as well.

The heads are stock, unported, stock cam installed PI Heads from FRPP. The Intake is the stock PI intake with the aluminum crossover tube swapped out. The crank is forged, rods forged, flat topped pistons, motor bored .030 over, new water pump and oil pump installed. The injectors are standard 19lb hr injectors which is fed by stock fuel pump in the tank and a kirban fuel regulator. It has about 90 miles on the motor and I am not ready to add anymore without knowing what to do and as I said before, I will trailer it to the tuner and get it done.

I hope this helps with what you are figuring out for me. Thanks. I appreciate it.

 

Oh by the way, seems to go away from what I can tell at WOT. Not certain, but it seems it does and feels responsive as more fuel is pressed into it. I did have a chip, but pulled it, so yes it is running on the stock computer program.

 

Yeah... the compression is up really high. It should probably be at 12.6-12.8:1 at this point. Ported heads with the swirl dam cut off will drop it to closer to 12:1. No matter what you're probably going to be adding some octane booster to each tank of gas.

With compression that high you'll make sick power but I'd recommend a SVT Focus fuel pump, and 24lb injectors to feed the motor. The 19's are taxed pretty well at 260bhp and I'm betting you'll see closer to 325bhp (~280rwhp). Add cams and the number goes up. So 24lb squirters will definitely be a good idea.

With the timing that far back the continuance of pinging is almost certainly a compression related issue.

 

Thanks for the help. I am going to print this out for my builder and I thought I might have to possibly buy new injectors at some point. Just not so soon. Oh well. Will the tuners be able to tell me while one the dyno exactly what the compression is or accurateky estimate it you think? I appreciate your comments and assisting me on this. Thanks again. By the way, what do you think fuel pressure should or do you know what it should be on a car with a set-up like this? I think my Automatic is set at like 31psi and I believe that was based off the stock regulator pressure and I believe it was maybe getting tired. I have heard it should be up to about 35psi.

Have a great weekend and again thanks.

 

Oh yeah! By the way, The motor is also using FRPP shortie headers on it. I doubt that changes anything, but I forgot to add it.

 

Those are just educated guesses based on common numbers. If your tuner needs to know, the CR I estimated is based on a 3.582 bore, 3.550 stroke, .036 gasket, .008 deck height, 42cc chamber, 0cc piston dish. They'll probably have a good idea if they're mustang guys but they won't be able to tell for sure since it's based on physical dimensions. Your engine builder should know for sure what it is. The tuners will need to know from you what the CR is so they can put a good baseline tune on it before they start running it for power.

I couldn't even begin to tell what the fuel pressure should be. I've seen them as high as 47psi for various applications.. not my area of specialty.

 

Thanks!!!! I greatly needed some ideas. I will try to find out from the builder the exact dimensions and then I will try to get them back to you to see what you think if ok. I will make sure I get the information from my builder for the tuners though. I appreciate it.

 

no worries. see if you can get the exact part numbers for the pistons he used and the rods. Also find out if he had the heads decked at all.

 

uh...

check your plugs... and let us know if they are normal... if they arent then post a pic...

plugs can tell alot about how your car is running...

 

The new motor only has about 90 miles on it. Do you think the plugs will still tell me anything? I will pull them and look at them. I will grab the camera and take some pics to upload on here. Thanks!

 

plugs will only tell you if it's really rich or really lean. They're not going to help in all likelihood for stngmn96. Might as well check but I doubt it'll make any difference. post up pics of your #1 and #8 plugs.

 

Well everyone, some sad news I think in my new motor. I found the new oil on almost all the new plugs, causing the anti-seize on the plugs to be very runny. Then further evidence shows I have oil from the crossover tube running from the drivers side valve cover inside the cold air intake. I am not real knowledgeable about building motors, but I believe what I have is "blowby" and as I recall, this will cause pinging and the problems I am having as well. I did bring the fuel pressure up to 35 psi from the 31 it was at. I am not going to try and drive it and find out anything still just yet. I do have a pick of the plug which looks the same as the rest of the plugs. I will post that here in a bit. From what my book showed, it was a normal plug.

 

take it back to the mechanic on a trailer. he didn't build it right. oil on plugs is hugely bad. oil in the cai is a sign of serious blow by...like missing a set of rings massive blow by or a popped head gasket.

You have my condolences. I hope it gets running soon. That's too nice a thing to have to not have working right. When he pulls the motor apart have him have the pistons fly cut for valve relief. that'll drop your compression far enough to run pump gas without worry.

 

I appreciate it. I am pretty upset about it. I will ask him to do what you said. I have never found oil in my CAI with my old 165,000 mile motor. To see this just dumbfounded me. I left it on there for him to see when I take it back. I am pissed about this too no end. 90 miles on it and it is ****ed....Thanks again for the help.

 

Where do you live? Who built the motor and where are you planning on getting it tuned?

 

I live outside Ogden, UT. I had Chet's Engines in Ogden build it. I am hoping to have Modular Mustangs West in Salt Lake City (about 35 miles from me) do the tuning on it.

 

see... i told ya you'd finf the problem w/ the plugs...

he should take care of it at no cost... he ****ed something up...

good luck

 

If he doesn't cover them, I will sue his *** something fierce.

 

well...

you paid for a working motor... not a non working one...

so unless he's a total crook he should fix it...

 

I worry about it just the same. The thing is he knows I am a police officer and won't let him slide by. I have more than $5400 paid to him thus far. I am not a happy guy about this ****. I just hope it gets fixed right. Thanks for the help.

 

your welcome for the help...

hopefully ya'll stick around after its all fixed and post some pics of that bad boy... and a video too...