If you're gonna break it, break it good...

Holy CRAP!

-Drgonzo

That happened to my friends '92 also. Same exact thing almost, just not quite as bad. We took the motor out and everything was still together, we then took it all apart and the motor was barely held together by the rear main and front. I know if we try we can break it in half very easily. He actually built another 302 with all of his stock internals since nothing was wrong with them. But lucky him got a good deal on my old 331 so he is building the 331 up with his top end. Erik D. '94 white lightning

-------------------------

Ok, so what's the deal? Are these blocks specifically prone to cracking like this, or could someone suggest a specific reason why this sort of catastrophe occurred? Might the mods or machining work done to the engine prior helped to cause the crack? Or...??? I'd like to know exactly what might cause this to occur. Throwing rods or cracking mains is more common and such problems make more sense. I've heard of blocks cracking near the motor mount area, that makes sense too. But splitting a block down the middle??? ...and already two reports of the same type of failure... seems like something that should be looked into if it hasn't been already. These blocks may have a serious inherent weakness, or a certain popular machining mod may be weakening things on an otherwise good block.. ? Have no idea, but would be interesting to know.

OUCH!

The stock 5.0L blocks have two major weak points. One is the main caps and the other is the lifter valley. When the power levels get above

450-500 rwhp the odds of block failure go up substantially. This guy was running a supercharger which further adds to the risk of detonation. The blocks are very reliable for N/A applications turning less the 6,500 rpm. Throw > >

I was wondering the same thing myself. I've never heard of anything like that happening on an old 289 block, which is almost identical to an old 302 block (I own both a '67 289 and a '68 302). I've never seen a modern roller cam 5.0 block though, and don't know much about them and what the differences are compared to an old 289/302 block.

I'd venture a guess that the old 289/302 blocks were stronger though, as after seeing this today I've heard of a couple similar failures, but have found nothing remotely similar with regards to the old blocks. Hell, I even heard of a guy that built a 289 which revved to 12,000 RPM and shifted at 10 grand every run. Not sure how true that is, but there it is for waht it's worth.

When I first got my '67 at 16 years old my friends were encouraging me to really rev the crap out of it while in neutral since we couldn't drive the car yet. I was hesitant but I stood on it a few times and let it rev as high as it would go. Man did that thing scream! Especially with all the exhaust leaks. :) I knew next to nothing about cars back then... I sure was lucky nothing decided to let go! I'm sure I was spinning it _way_ past the 4,400 RPM it's rated at for max HP from the factory. If I had to venture a guess I'd imagine it was almost twice that, as I've heard other peoples 289s revving to 6,000 and mine sounded like it was spinning a lot faster than that! Not bad for a stock bottom end with hi-po closed chamber heads that runs on 87 octane and has 100,000+ miles!

Anyway, if these new 5.0 blocks have trouble handling 7000-8000 yet old

289/302 blocks could apparently take it that makes me wonder about a few things. The only failures I've ever heard of from 289s that wind up to 8-10 grand are mostly dropping a valve or losing a valve head. Sometimes a cracked main, bent or even thrown rod, spun bearings or other oil starvation related problems. That sort of thing, but never have I heard of anything so drastic as a *split* block. I mean hell, that's pretty damned crazy!

I was actually considering getting one of these fancy modern 5.0 blocks, stroking it and putting my closed chamber hi-po 289 heads on it to put in my '68 Galaxie. The rings hold virtually no pressure in two cylinders and the heads are shot so it needs a rebuild anyway... Figured I'd upgrade to the newer block and get some of those benefits like the roller cam and such, and probably an AOD too while I'm at it. Now I'm wondering if I would be better off sticking with my '68 block. I mean I don't plan on building anything crazy, but I want it to be durable and last me 150,000+ miles. Not planning on taking it to the track, just a fun daily driver for the summer months. I suppose I'll work that all out next year if I've got the time and money for it.

Cory

Does Carquest make the blocks though? I was under the impression they were just a rebuilder and it was a standard 5.0 Ford block.

Cory

The older blocks weren't stronger it's just that they didn't see the same horsepower levels that are possible today. We Mustang owners have a wealth of parts available that can make incredible power. Nowdays if you want to be run with the big dogs you had better be sporting 600 rwhp or you'll get your butt handed to you. Go back to the 60's and tell a

289 owner to get 600 rwhp from his engine and he would look at you like you were insane.

You are not going to break your block, Cory. If you look at the direction and location of the crack, you can see it was caused by excessive pressure exerted from the crank toward the heads. IOW, seriously high compression, supercharging, and a V-shaped block. Ever wonder how Porsche got 1200 hp out of the similar-sized 917 engine without breaking the blocks? How BMW got around 1400 hp out of a 1.4 liter (*stock* cast iron) inline four? Think about it.

-- C.R. Krieger Automotive Iconoclast

I do hope you're not saying that you can't make massive HP with a V engine...

Just needs a little duct tape. No problem really.

John

No, that's a job for JB weld :)

That is why Ford decided to use the NASCAR 427 to win LeMans. Even the HiPo

289's that had thicker mains and a higher nickel block cracked their main webs after 24 hours of racing. The 427's were actually rather low powered in reality ( approx 485 hp) but in a light GT40 they could run literally all day and not break due to there crossbolted, deep skirted bottom end and the fact that they were relatively understressed in the GT (usually they were pulling Galaxie 500's and Marauders around!) StuK

Ahh, the handy man's secret weapon! It's kind of like the force. It's got a dark side, a light side and it holds the universe together...

289's that had

of racing.

a light GT40

I agree, as big of a 5.0 fan as I am, I must say that the bottom end of a 4.6 is one of the strongest looking blocks I have ever laid eyes on. Erik D. '94 white lightning

Yep, I've seen 'em. I had a 4.6 in my F150 and a friend has a 5.4 DOHC Navigator motor waiting for a donour vehicle. The bottom skirting is very reminiscent of the 427 with the cross bolting and the DOHC heads make it look like a BOSS 429 ( and as big!) StuK

had

racing.

GT40

they