V8-Ranger.com

Oh my, That's by far the worst SBF I've ever seen. What's the story behind the explosion?

WOW!!!! Ya, what made it do that???

Don't know, but I'm fairly sure there was either boost or NOS involved.

These were pics posted by someone else on the EECTuning.org forum. He found them somewhere on the NET and thought he'd share. They are from someone's photobucket site. So you might get more info going to their photobucket album and looking around. You might find the vehicle it was pulled from and see what was on it.

glad to see im not the only one that has ever split a factory 5.0 block like that ....

i split mine EXACTLY like that when i built my 347... then i said to hell with it and bought the SVO 4 bolt main block .... i was told that either one of two things caused it.....
1. over 500 hp and the stock block cant hold more than that because of it not being beefy enuff to hold the HP levels due to it being a 2 bolt block ....
2. main cap walk or chatter due to the caps not being but a 2 bolt configuration or the timing not being right and have MASSIVE amounts of detonation and that will cause the main caps to walk and put MASSIVE amounts of pressure into the block which will cause it to split

they prob could have avoided that with a main stud girdle or like i was told to do and didnt do ...... pin the main caps witch consists of drilling a small hole in the surface of the mating surfaces of the caps and the block and putting in a HARDENED roll pin to stop the main caps from walking under high PRM's or under detonation ... i didnt listen and it cost me exactly like that .. luckily i could reuse everything in mine... except the cam and rod and main bearings ... and the gaskets of course

According to some, the biggest stress on the engine is not the torque produced, but rather the RPMs. Keep the RPMs under 6000 with a strong enough crank, and the block should handle up to around 700HP. Beyond that, you start hitting the limits. Most people adjust boost to target not to exceed 650hp, even if the combo would do more. Anything above 700hp, you need to either be in an aftermarket block or in a 351w block. That's all repeated info, not info I know from 1st hand knowledge.

I have had several built earlier 302's that would crack the center main cap in two pieces. They would be running fine with great oil pressure and I tore them down just to make sure everything was good and I was shocked to see what I saw, but nothing like that!

After looking at those pics again. That motor doesn't look like it was together for very long. Look at the cylinder walls. They look freshly honed. Then it looks like there is some notching for a stroker kit. After you say that cgrey8, I think your right. To much boots or NOS. I would lean more at the to much NOS.... I think some people build a low budget engine, cut corners and then throw a large amount of NOS at it and think they have a race car...... Look at all the smurff chit they used on the oil pan gasket....

keep it under 6000 rpm ????? hhhhhhhhhmmmmmmmmmmm...................... mine split at around 4800 RPM ... glad i had all forged eagle stuff (crank and "I" beam rods) ..... oh and i was only in like 3rd gear too.... in town so there was no way i was anywhere around the redline or speed that it would have taken to split it ... but also it was a blown 306 before i built it into a 347 so that might have had a negative effect on it too .... when i built it it didnt have a blower .. was naturally aspirated with a 1050 Dominator on it after i split it i went and got all the RIGHT stuff to put it together .... if ya want to see what i had in it.... go here.... and MOST of this list will be going into my Ranger .. SOON now!!!!

http://www.mustanggt.org/photo/90dorris.htm

I've heard from some locals at the track 500 hp is the magic mark to stop on stock blocks. Go over that and you end up with pics like posted above.

Malcolm ..... i agree.... lol... i did it

mine made 508 at 6500 on motor. he said that was pushing the block at that power

I could believe that if it was supercharged. I should've specified those HP numbers I was quoting was from turbo, not super. Super requires ~25% of the engine's power to do what it does. So 500hp with a supercharger is actually producing closer to 625hp. And if detonation was in the mix, that'll drop the breaking point for sure.

But yeah the more I hear from people, 700hp is barely attainable on stock 351w blocks and 500-550 is the breaking point on most 302 stock blocks that are supercharged.

before I did mine the motor shop checked to make sure it was a good block, no cracks. I know some people say that main cap supports just hold the block together after they break. I think it stops parts from moving. I also think if you have a weak crank not 4340 weak rods things move which would cause it to break. if it keeps running mid to low 11s ill be happy.