The post I saw about your issues was a SCCA post, just about the transmission.

All in all not a fun way to spend your Labor Day weekend, but sounds like you already knew the block was a temp.

It was smoking really bad on the second run and I decided to start calling the car "Smokey," but wasn't going to say anything to you until after day 2...just in case.


Jumping back to the transmission, this is what the output shaft looked like. In case you don't know, they're #1) not supposed to be snapped like that, #2), have helical cracks like that, #3) have bendy splines like that

https://lh3.googleusercontent.com/06...VKGEYdA0Q=w800

https://lh3.googleusercontent.com/TO...NsZXNBZlw=w800

The next morning, JV dumped the just-picked-up replacement transmission in paddock, went to work his shift and sent one of us a text: "Please cut 20mm off the input shaft before I get back." We looked at it, we looked at the old one, we looked at them both again and discussed. "The old one is missing way less than 20mm. Not gonna cut it. Let him do that. We only have an Imperial tape measure anyway, but we do have painter tape. We can mark it like the other one. What did he use to cut the old one? A rusty hacksaw? Jesus."

https://lh3.googleusercontent.com/yi...nyvVztCJc=w800


JV got back and scolded us, "Well, I said to use the old one as a guide" and got to cutting.

https://lh3.googleusercontent.com/P-...GNZtf1cN8=w800

The trans then went in. The clutch was bled.

https://lh3.googleusercontent.com/8C...izOd1Syq8=w800

And the car went to grid.

https://lh3.googleusercontent.com/6u...hidvhAVD4=w800

90 minutes from beginning to cut to grid.

To be fair... my text said "I *think* it's *about* 20mm to remove" from the input shaft. And I cut it with an angle grinder the first time! Sigh.

:lol:

Those of you that have been to my house know that this was challenging. :lol: Only two inches on each side of the trailer fenders going to the upper garage. But it was better than pushing the car up that hill

https://lh3.googleusercontent.com/9S...=w1036-h777-no

Starting the teardown.

https://lh3.googleusercontent.com/OM...=w1036-h777-no

Ring lands aren't supposed to look like that.

https://lh3.googleusercontent.com/Ag...=w1036-h777-no

Whoops.

https://lh3.googleusercontent.com/-a...=w1036-h777-no

So what happened?

Here is my theory. The engine had low compression before Nationals, and the turbo spool was extremely slow. That led me to believe it had cracked rings. Why did the rings crack? A few theories. First, I overheated the engine early on. It had cooling system problems... too small of a radiator, an insufficient fan, and a coolant temp sensor with the wrong calibration (thanks, Haltech). It didn't overheat badly enough to compromise the head gasket, but it probably fatigued the ring pack. Second, it overboosted quite badly when I was setting up the closed-loop boost control. It overscaled my MAP sensor, but my guess based on the turbo efficiency is roughly 30psi. The engine didn't have enough fuel to run up there, but it probably created some pretty crazy cylinder pressures. Third, with all the fuel system problems that took me forever to sort out, the thing had a lot of events of very lean mixtures. E85 is pretty knock tolerant, but even so that's violent.

But why the spun bearings? Well when the compression got worse and worse, eventually the ring land material (Aluminum) got into the oil pan and clogged the pick up screen and the oil filter. Also when you pressurize the crank case, the oil has to go somewhere and it typically stays in the cylinder head. That makes sense, the car had good oil pressure until my very last run on course where it gradually went down to zero.

Tomorrow I'm stopping by my local salvage yard. They have fifteen 2.5L Duratec motors, and five of them are under 20,000 miles, so they should be good candidates for rebuilding. I'm doing the most basic of engine builds.

1) New forged pistons (stock are cast) with a point more compression: 10.7:1 versus 9.7:1. Should help with turbo spool.
2) New forged H-beam rods. The stock rods are very strong, but I want to turn this motor to 8,000 RPM and the stock ones are marginal at the 7,400 I was spinning it to this year
3) ARP head studs. The stock bolts are very strong, but studs will improve clamping and ensure I should never have any issues lifting the head off the block.

Other upgrades for the winter are also coming but that'll have to wait for another post.

fingers crossed this new one holds up. :)

Good luck JV! We're looking forward to v2.

Musta been fun. Wondering if i took longer backing it up there or pulling teh block once the car was in the garage. :dunno:

How many you bringing home?

Holy crap

Time to build a 45 liter inline 60. Need fourteen more turbos. Might have to work on an articulating crank, though, so it can turn.