Whipple Stage 2 Engine failure (2017)

[mike3105]

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[HKusp]

I don't think they are correct, but they want to alleviate as much blame/suspicion as they can from themselves, and honestly, it's not their fault. It's Ford's top ring gap. I suspect, you were running the car for an extended period of time on a road course and put enough heat in the pistons to close the ring gap until it broke the ring land off of #1 and #6 pistons. I and a few others have done similar. The stock top ring gap is too tight on these engines at .009 for boost with any extended pulls. It starts to close and when it closes, the ring land fails.

If you are rebuilding the engine, I would have the builder gap the top 2 rings at least .025. You won't lose compression, and it will be much more friendly when you do it again.

Edit: added the photos of my #6 piston to demonstrate the issue.

 

[HKusp]

If you were WOT for a good portion of it, it could cause detonation and these engines in stock form are not too good once you are getting detonation. I would HIGHLY recommend that you consider gapping the rings. Either that, or going with an Ethanol fuel and custom tuning, but I don't know the situation for ethanol availability in the UK.

 

[J17GT]

Whipple has a warning in the manual about modifications or changes to the front fascia can cause "running issues" with fueling. Below is a pic of that page in the manual. Not sure why it says 2018+ when this is the manual for my 2017 car. But I doubt this was the main cause of your engine failure.

What fuel was in the car? The whipple tune requires 91+ octane. Even with 93 octane I always add some boostane for extra insurance when racing the car (I do some drag racing).

Bummed for you that it didn't last long. I do not think your experience is very typical, but it does happen. Always a risk when going with boost. Especially when running pump gas.

 

[frestylmotox01]

@HKusp, does that apply to both Gen 2 and Gen 3 Motors?

 

[J17GT]

Ethanol not a viable option in the UK, at least around where I live unfortunately.

I did enquire with the garage about Mahle pistons etc., and whilst the parts were cheap the quote to send the engine off to a proper engine builder to do the work was more than the cost of the block! I will double check that just gapping the rings isn't a small part of that and more reasonable.

Another option would be just to put a Ford aluminator shortblock in the car and be on your way. That's the route I'll go if I ever end up in your situation. The aluminator will be fine unless you're really pushing big power.

 

[mike3105]

Whipple has a warning in the manual about modifications or changes to the front fascia can cause "running issues" with fueling. Below is a pic of that page in the manual. Not sure why it says 2018+ when this is the manual for my 2017 car. But I doubt this was the main cause of your engine failure.

What fuel was in the car? The whipple tune requires 91+ octane. Even with 93 octane I always add some boostane for extra insurance when racing the car (I do some drag racing).

Bummed for you that it didn't last long. I do not think your experience is very typical, but it does happen. Always a risk when going with boost. Especially when running pump gas.

I was running the best 99RON (I think the same as a decent 93 in the US?) and have always done with the car. Thanks for the response. It doesn't sound like the more I read that maybe a Whipple isn't the right thing for a car that does occasional track-days without more work to support it.

 

[HKusp]

You CAN do it yourself, it just takes a few specialty tools that shouldn't cost a lot. I am not sure how handy you may or may not be, but it's pretty straight forward. That being said, it shouldn't cost too much just to file the rings. They have to pull the pistons to do it, but it's not a total tear down.

 

[J17GT]

I was running the best 99RON (I think the same as a decent 93 in the US?) and have always done with the car. Thanks for the response. It doesn't sound like the more I read that maybe a Whipple isn't the right thing for a car that does occasional track-days without more work to support it.

Google says that's as good as our pump 93 if not better. Either you had a bad tank of fuel or possibly your rings were just setup a bit tight right from the factory and just didn't like the boost. How big was the track? Were you WOT for a long extended period? I've put a bunch of track passes on my car, but that's only 10-11 secs at WOT at a time.

 

[HKusp]

How many laps in were you? I was in stop and go traffic for about 30 mins at about 95*+ F (35*C) ambient temps, then got out on the highway with 2 GT500's and we were doing repeated pulls from 60-120mph for 7 mins when mine popped.

 

[J17GT]

It's Goodwood which is quite a straight track. I would say the longest straight is 15-20 seconds, but it does have three bits that are >8s at full throttle. The failure happened at the end of the Lavant straight.

That track looks like a good time! Sounds like some decent extended periods of WOT back to back. As efficient as these blowers are, that will still generate a lot of heat.

Best of luck getting things back together!

 

[HKusp]

@HKusp, does that apply to both Gen 2 and Gen 3 Motors?

Yessir. I know CoryS has done it to two Gen 2 engines, both #6 piston, like me.

@Cory S

 

[HKusp]

Well, I respectfully disagree with them, but they know more than I do. Are they saying there was a casting issue with the pistons that caused the failure, or do they suspect detonation was the culprit?

So you had a decent heat cycle in the car on the way there, how long were you sitting at the track before going out and lapping the car?

 

[HKusp]

I may not be making my point clear, so allow me to clarify. I'm not saying the car overheated, from an oiling and cooling system standpoint. I am saying that 93 octane on boost burns VERY hot relative to the top of the cylinder head and piston. When you are in sustained boost, that heat is absorbed by the piston and rings and is concentrated right at the top of the piston and the the top ring. That heat causes expansion of that very small ring gap, which starts at .009 inches, then when it gets warm it becomes .008, then warmer .007...until it's basically .000 and there is no more room for expansion. Then POP. The stress has to go somewhere and the ring land area is the weakest point in that chain. All of this is with the assumption that the top ring was properly gapped at .009. There are tolerances with production runs, and maybe yours started at .007, or .006, etc. Who knows?

 

[ShadesOfBloo]

(circuit not drag strip)

Good

mid-August and on the second lap (around 400 miles after the install) I suddenly lost the engine

Bad

Is it reasonable to expect a Whipple and pre-facelift to be able to handle a 15min track session on a fairly simple circuit in UK weather (21 Celsius)?

I would think so but if you're just using Whipple's canned tune, I can see where perhaps that's not optimal for circuit use, your local fuel, or some other condition they can't account for.

If you can find a tuner to tweak your Whipple-ized car on a dyno, I vote to do that.

I have seen a Mustang GT-PP2 with a Whipple do lap after lap, for 20 minute sessions, and at least 3 sessions. He hadn't had any dyno testing, so if I understand correctly he was using the canned tune.
It's also possible he wasn't pushing it at all, seeing as I was driving my 160hp Nissan and he had to give me a point-by for every lap session.

EDIT: Does your local petrol have ethanol in it?
Here in the USA we're subject to a false economy in which the industry has reduced our price per gallon by selling us gasoline that's about 10% ethanol. Ethanol is bad for mile/gallon figures but good for running cool and avoiding detonation.

If you are using "E5" fuel and Whipple's default tune is made for "E10", that's all the more reason to have a local tuner tweak your software on a dyno.

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