Hurt my '94 Vert on the Dyno :(

[R100RT]

I went to the local dynojet yesterday to try to get a baseline for my mild 331 daily driver. I had a premonition that the day wouldn't end well. First run went 288HP/342T. A/F was 11-12. I took out 10% fuel, and went 297/345 but A/F was unexpectedly 13.5-14. We didn't hear any pinging. We rolled back in 5% fuel and went 284/335. Then we noticed engine temp climbing and it wouldn't cool down. Radiator was low and failed the pressure check. Then I found the milky death on the dip stick.

So, I'm tearing down today. I hope I just find a head gasket problem. The car has been using water but never had any get into the oil pan before the pulls. I hope the bearing aren't toast.

Somebody call the waaaambulance.

Eric

 

[Venom351R]

Not cool, that sucks

 

[ProKiller]

that does suck. good luck with fixing it.

 

[Stanger007]

Sorry to hear that man, do you have a datalog of it and a copy of your tune I could check out?

Wes

 

[Bullitt95]

Then we noticed engine temp climbing and it wouldn't cool down. Radiator was low and failed the pressure check. Then I found the milky death on the dip stick.

So, I'm tearing down today. I hope I just find a head gasket problem. The car has been using water but never had any get into the oil pan before the pulls. I hope the bearing aren't toast.

It sounds like you might have had a leaking head gasket for some time and the dyno pulls just finished it off. The only way you'll find out if the bearings are toast is to pull the engine out of the car and remove the oil pan.

 

[R100RT]

OK, I'm having trouble deciding my next step. Here is what I see...

Compression check showed 160-170 PSI. Plug check showed all uniform, good color. I was thinking I would get off easy with intake gasket problem. I pulled the intake and didn't see anything unusual with the intake gaskets. These are the .070 think ones recommended by Ford for the 303Y heads. I checked the intake base to block clearance and the RTV shows about .020 thick in all areas, (the heads have been milled).

I drained about 10 qts. of oil mocha out of the pan. I don't have an idea when the water got into the pan so there is a good possibility I did a dyno run with oil/water emulsion. I would like to get your input into the potential for bearing damage.

At this point, I was going to slap the intake back on and do an air pressure test. That's about all I can think to do.

Eric

 

[Stanger007]

Sounds like a head gasket dawg. My last set would only leak under high boost but were fine otherwise. I've got a buddy with similar problem and his compression check showed out fine.

Were you running it with the wastegates open at the dyno?

Wes

 

[Bullitt95]

Yeah, I also still think it's a head gasket. The leak could just be between the water jacket and an oil gallery so I reckon the heads will have to come off anyway.

 

[R100RT]

Problem found!

#@&!%@# Ford A302 gasket! I'm going to take this up with FMS. This may have cost me my motor. FYI heads were prepared by top notch local shop and the block was done by M&R Racing. The deck and heads are straight.

 

[Stanger007]

Most likely detonated judging by the picture.

If the gasket didn't go, something more expensive would have.

Wes

 

[Bullitt95]

It's hard to tell from the photo that the engine was detonating but you can't rule it out either. What was the timing set at?
The engine damage may not be as bad as feared. Surprisingly (and this is a good thing), the aluminium AFR heads didn't warp. Just check the bearings and if they're still OK, it should be safe enough to reassemble the engine with fresh oil and oil filter. Change the oil and filter after about 100 miles to remove any remaining contaminants.

 

[Stanger007]

That darker color on the compression ring looks to me like the flame front went over it and shot some pressure in the cooling system which pushed out a hole into the lifter valley.

Which # cylinder and side was it on? Driver's side?

Wes

 

[R100RT]

This shot is cylinder #7. #6 showed the same but not completely through to the lifter valley.

Dyno pull #2 was lean, about 13.5-15 A/F.

Guys, my sig is my TT '65. This car is my NA '94 Vert.

Eric

 

[Stanger007]

Yup, that is textbook what happens when the car goes lean and detonates, it will show up driver's side in the middle of the rail.

Wes

 

[R100RT]

Warp Up

Well,

Here is what I think I learned:


The ARP bolts were down to less than 50 Ft-Lbs. Maybe the 1011-2 gasket needs to be checked more than I did. I put 8548PT2s back in, 80 ft-lbs on the long bolts, 70 on the short bolts.
I used anti-seize on the intake bolts probably lifting the middle of the heads. The intake gaskets were really squished!
I should have immediately checked for oil in the pan as soon as the radiator went low and no water was leaking anywhere.
If the block drain plugs strip, you can drain by putting a ¼” plastic tube in the lower bolt holes. I love this M&R racing short block but they used very soft drain plugs. FYI, I went 15,000 miles on ¾ quart of oil.


The car is back on the road, no problems have showed up, despite doing a pull with water in the oil. I drained 10 qts of mocha!


Eric B

 

[Bullitt95]

Good to hear your Stang is back on the road. Just change the oil and oil filter again after about 100 miles to make sure that any remaining mocha is gone forvever.