ITS Ford Mustang(s) Build - Stripper Stang Part II

[Ron Earp]

Work has been progressing on my new engine and now that the heads are here we'll quickly progress on that front.



This engine is the same as Jeff's new motor and has the same improvements over his original motor. My original motor is still going strong, knock on wood, but it has always been my intention to have a spare motor at all times so once this one is finish it'll replace the unit in the car and the old one will be rebuilt to the new specs.

Progress has occurred on other fronts as well, Jeff finished up the bench top Ford EEC-V programmer and it has been successfully used at the track a couple of times. This allows us to program an ECU without the car being present, which is useful for setting up multiple ECUs to be swapped in in dire situations.



But the big news is that Jeff's new motor, with less than ten hours of racing on the clock, decided to shit the bed. Yep, it's done and we're now in the middle of a rebuild on it.

Jeff's car did fine at CMP, raced all the entered races and seemed to be doing what it was supposed to do. Loaded on the trailer, loaded off the trailer, nary a sign of trouble. We parked the car at my house while we finished up the cam swap on the Torino, which by the way took way longer than expected. Anyhow, ten days later we go to put Jeff's stang on the scales and there is a puddle of oil under it just where the bellhousing and engine block are mated together. No big deal we figure, we'll put it up in the air, drop the tranny, and fix that rear main seal.

Nope. When we got the tranny out and drove a new rear seal in we noticed this:



And then a few hours and beers of work later we saw this:



Bummer. So we had to have a beer of sorrow. Then a smoke of sorrow. Then another beer of sorrow. After that we said enough and got our asses to work and tore the motor down completely.

[Ron Earp]

And another:





The engine has since been completely torn down, with a lot of swearing and cussing, and I dropped the block and crank off with the machine shop this morning. We hope to get the newly line bored block back tomorrow and reassemble the engine Thursday night.

What happened?

We don't know. I called the Ford V6 specialists, Jeff called Ford and Dave Brown, and we talked with the shop. Nobody has ever seen a rear main cap failure on a Ford 3.8L V6. It happens on Ford 302s pretty frequently but only if they are making a lot of power and turned up to a lot of RPM, neither of which apply here. The data doesn't show any over revs, oil pressure issues, or anything that would be indicative of this type of failure.

The engine is relatively un-stressed, doesn't turn a lot of RPM, and all the parts removed from the engine look great. The bearings look like normal bearings with a bit of wear, I'd have no problem using them again. The engine even ran and behaved normally, mostly, although now we know that something was up with it I suspect one could detect an issue. Rods good, the crank is straight (checked this morning), pistons all good, we're a bit perplexed but as we develop theories and test them out we'll sort through it.

Anyhow, our goal is to have the engine back in the car and running this weekend for the RRR race. The removal and installation of this V6 into the Mustang sort of sucks. The old Datsun inline six was so much easier. Unfortunately we're stuck at around 2-3 hours for a removal just because so much has to be unhooked and access is limited around a vee engine in a small engine compartment. Hopefully we'll make.

[joeg]

YIKES!!!

From the Internet:

"A cap broken/cracked in a block --it can be any number of things. A lot of times it can be tracked back to how the cap was installed in the first place in torqueing the caps down. Was that cap checked for cracks before installation? If so,...was it also checked inside the bolt hole?"

[Ron Earp]

The block and caps are being checked now. It was installed and torqued correctly. We've some other theories too but at this point they are just that.

[joeg]

Then have the crank crack checked too...

[Ron Earp]

Already did, in original post. They checked it before I left the shop.

[Ron Earp]

Woo hoo, machine shop finished and engine headed back to the Stangwerks. We plan to build it up tonight and drop it in on Thursday. Damn sure is a lot of work butit is good to have it turned around quickly.

Also got news our new wheels are shipping Monday so we're going to ditch about 9.5 lbs of rotating weight once we get them on the cars. 9.5 lbs down, let's see, about 300 more to go.......

Crank in, pistons in, rods and mains torqued: