Lap Speeds

[ChrisMX105]

Re: Lap Speeds

Ask Kerch(=
I have witnessed the damage on a 3350 and have been told by one of the masters that it was the case with Tiger.

[Gibbs]

Re: Lap Speeds

From what I understand, technical causale for Strega's burned piston could be this:

ADI on, throttle is at max MAP the whole race (two hands on the stick), but the dives resulted in too much RPMs and killed the motor - exactly?

Gibbs

[Mluvara]

Re: Lap Speeds

Ask Kerch(=
I have witnessed the damage on a 3350 and have been told by one of the masters that it was the case with Tiger.

I have asked Kerch on numerous occasions and he has said he has had people run motors with the ADI on at low power and it doesn't hurt them.

If you ask me, I think the motor got cooked because of being too hot. He ran it hard and temps likely got out of limits.

Michael

[RichH]

Re: Lap Speeds

If you ask me, I think the motor got cooked because of being too hot. He ran it hard and temps likely got out of limits.

Michael

+1000

[AAFO_WSagar]

Questioning Tiger's Flying?

I have not had time or reliable internet to keep up here until yesterday/today.. Still have yet to read 456 messages on the board.

I've noticed a few posts where we're Monday morning quarterbacking Tiger..

Really?

Tiger is an old member here, rarely, if ever, has posted... I encouraged him to visit talking with him at Reno at the banquet... Geez, I wonder what he'd think if he read some of this stuff..

Remember who you're talking about and what he has accomplished in his racing career.

If anyone who wrote a critical post wants it removed, I'll have to do it for you.. Again, I've not read everything and probably will not have time for a while to go back and digest it all..

Do you really want to critique that man's performance?

[rchevyman]

Re: Lap Speeds

I saw Tiger race sat and boy was that about the most exciting thing I have ever seen! The sides of my face hurt from smiling so long! I wont criticize him one bit. The way I see it is who cares if didnt get the trophy. He beat Stevo in an awesome race. Its nice to see some real guts out there. We need to see more of that these days. Unfortunately there seems to be a lack of it these days.

[RichH]

Re: Lap Speeds

Also, Consider my Rear Bare crow eaten.

"Rear Bare"? Bare Rear?? LOL!

[grampi]

Re: Lap Speeds

still sticking with Dago being the fastest of all time.

I agree, and I think it would've broken RBs 3km record by a healthy margin too...

[toldjaso]

Re: Lap Speeds

I respectfully disagree. ADI is typically between 1 to 2 gallons per minute. I fail to see how 4 ounces of fluid per second going through a blower and essentially being vaporized is going to crack the head of a 1400 lb mass of metal that dissipates the heat. It's not pouring water on one part of an engine. There have been racers who have left ADI on without damage. A motor just doesn't like to run on water.

Running an engine too hot will definitely distort and crack components...

Michael

It looked to me like Strega was trailing a little white or gray smoke for a while before that last lap pass, I thought it was eating itself up before the pass. I don't think the ADI being left on is what did the engine in at all, in this case.

Tiger will always have won that one, in my book. Don't care what the rulebook pansies say about it. How cool was that?! Best move I ever did see.

Although I hate to keep digging up these old bones, I do not share exactly the same opinion as you on what "a little too much" ADI can do when it is introduced to the valve seats in the head of an air-cooled cylinder, for example. Let's use the cylinder of the Curtis-Wright R-3350 as an example. On this engine, a rather largish exhaust valve is situated at an angle to the piston, due to the hemispherical shape of the combustion chamber. This means that about 85% of the outside surface of the Stellite valve seat is surrounded by a nice generous amount of FORGED aluminum, (Good for 530 degrees F) and is nowhere near the steel cylinder barrel.
But then, there is that 15% of the valve seat that is right over in the corner of the cylinder head, so to speak, next to where the aluminum cylinder head (which has internal threads) is screwed onto the external threads of the steel cylinder barrel.
Now, due to the valve head being as close as they could get it to the outside edge of the cylinder head, next to the inner bore of the cylinder, and the aluminum that is lost due to the threads being cut into the head, there is a spot that has VERY LITTLE aluminum left to imbed the valve seat in. This means less heat transfer possible in this part of the valve seat, right? So, if a slug of cool ADI hits this seat, at a low power setting, where everything is not running at full tilt, that shock-cools the seat, and since the seat has copper around the base of the seat, the copper can be forced to "migrate" to the hotter part of the head, which leaves you with a "low spot" on the face of the valve seat, because the seat has shifted ever so slightly in the head now, and the valve will no longer seal all the way around when it is supposed to hold the compression in the cylinder on the firing stroke. (Leaky valves). This causes a rough running engine, bad mag drop checks, high cylinder head temps, low power, all of those undesirable things that take you from being a Gold contender to being a big disappointment. Also, with the 3350, once you get 3500 lbs. of metal hot, it is not going to cool down immediately when you back off the power, it will keep getting hotter, and then the temps will slowly start to come back down.
I don't really know any of this, of course, but it sounds kinda cool to the untrained ear.
What say you?

[Dialtapper]

Re: Lap Speeds

It looked to me like Strega was trailing a little white or gray smoke for a while before that last lap pass, I thought it was eating itself up before the pass. I don't think the ADI being left on is what did the engine in at all, in this case.

Tiger will always have won that one, in my book. Don't care what the rulebook pansies say about it. How cool was that?! Best move I ever did see.

Although I hate to keep digging up these old bones, I do not share exactly the same opinion as you on what "a little too much" ADI can do when it is introduced to the valve seats in the head of an air-cooled cylinder, for example. Let's use the cylinder of the Curtis-Wright R-3350 as an example. On this engine, a rather largish exhaust valve is situated at an angle to the piston, due to the hemispherical shape of the combustion chamber. This means that about 85% of the outside surface of the Stellite valve seat is surrounded by a nice generous amount of FORGED aluminum, (Good for 530 degrees F)and is nowhere near the steel cylinder barrel.
But then, there is that 15% of the cylinder head that is right over in the corner, so to speak, next to where the aluminum cylinder head (which has internal threads) is screwed onto the external threads of the steel cylinder barrel.
Now, due to the valve head being as close as they could get it to the outside edge of the cylinder head, next to the inner bore of the cylinder, and the aluminum that is lost due to the threads being cut into the head, there is a spot that has VERY LITTLE aluminum left to imbed the valve seat in. This means less heat transfer possible in this part of the valve seat, right? So, if a slug of cool ADI hits this seat, at a low power setting, where everything is not running at full tilt, that shock-cools the seat, and since the seat has copper around the base of the seat, the copper can be forced to "migrate" to the hotter part of the head, which leaves you with a "low spot" on the face of the valve seat, because the seat has shifted ever so slightly in the head now, and the valve will no longer seal all the way around when it is supposed to hold the compression in the cylinder on the firing stroke. (Leaky valves). This causes a rough running engine, bad mag drop checks, high cylinder head temps, low power, all of those undesirable things that take you from being a Gold contender to being a big disappointment. Also, with the 3350, once you get 3500 lbs. of metal hot, it is not going to cool down immediately when you back off the power, it will keep getting hotter, and then the temps will slowly start to come back down.
I don't really know any of this, of course, but it sounds kinda cool to the untrained ear.
What say you?

" I don't really know any of this, of course, but it sounds kinda cool to the untrained ear"

Yeah, right.

It's like a Dennis Miller rant about something very true and relevant, at the end he says "That's just my opinion, I could be wrong."

You Sir are the Dennis Miller of Air Racing.

[jarrodeu]

Re: Lap Speeds

It looked to me like Strega was trailing a little white or gray smoke for a while before that last lap pass, I thought it was eating itself up before the pass. I don't think the ADI being left on is what did the engine in at all, in this case.

He was running quite a bit more water than Voodoo. Maybe that is what you saw.
Jarrod

[RAD2LTR]

Re: Lap Speeds

He was running quite a bit more water than Voodoo. Maybe that is what you saw.
Jarrod

Quite a bit more to the point that I couldn't see anything coming off Voodoo, and Strega looked like a jet at 40K feet streaming contrails. I shot these from the hillside.




Will

[boomtown]

Re: Lap Speeds

Great shots!! I was wondereing about the right wing venting. I have never seen the vapor off the wing on Strega ala Miss A. or Dago. Can someone with some knowlege please explain that? Boil off for oil perhaps?

[RAD2LTR]

Re: Lap Speeds

I was wondering about the wing venting as well. I don't remember seeing it in past years. I can't say I've seen this much vapor or water from any of the other P51s. Heck, Dreadnought was running a lot of spray bar, but not that much.

Voodoo, a little spray but much.

Dreadnought.


Sawbones had a little as well


I have to wonder if Strega had issues early in the race since I shot the pics above on laps 3 and 4 I think.

Will

[GRNDP51]

Re: Lap Speeds

Quite a bit more to the point that I couldn't see anything coming off Voodoo, and Strega looked like a jet at 40K feet streaming contrails. I shot these from the hillside.




Will

These pictures are SO cool, thanks for posting, she does look like a 747 lol