How to deal with block casting flash and voids?

[Gaugster]

I've been documenting a MCC 105 block as I remove the last items like core plugs. I will take it to a local shop for cleaning and inspection. If no cracks are found and the sonic goes well how would most proceed with items such as flash and voids? Horsepower goal is somewhere between 650hp+ so cross bolts on at least two of the mains it probably the plan. Is anything pictures here cause to dump this block and find another? It appears the factory covered up an external void with some type of block fill material.

 

[Gregwill16]

With that hp goal I would save money and go aftermarket.

[fekbmax]

Casting flash is common.  Good (careful) use of a die grinder and mostly a sanding drum will clean it right up. Be careful to not leave sharp edges and make sure to clean block super well afterwards.  Just takes a little time and patience .

[Gaugster]

With that hp goal I would save money and go aftermarket.

I hear ya. Kind of depends on what the cross ram etc.. intake system can achieve with enough street manners to run vacuum accessories.

[Gaugster]

Casting flash is common.  Good (careful) use of a die grinder and mostly a sanding drum will clean it right up. Be careful to not leave sharp edges and make sure to clean block super well afterwards.  Just takes a little time and patience .

Thanks. That's what I figured. Any thoughts on the voids? Just ignore and move on?

[67xr7cat]

You can fill the voids in with JB Weld and fill flat.

[Nightmist66]

+1 what Keith said.

My block had a lot of porosity in the pan rail. I figured it wouldn't hurt much, so I just made sure to fill the cavities with silicone. How many cubes are you planning? I think 650hp is do-able if the block checks out alright. I am only turning 7500rpm, although I am sure the block would take 8,000+ as well as the rotating assembly and valvetrain. I had some custom main caps made for mine. You may also check with Cody(bluef100fe) he was making some caps that sit closer to the pan rail for the cross bolts, so you don't remove as much material from the webbing. I did the same on my caps. It seems the ProGram caps sit lower and take a little chunk out of the webbing. Another thing to consider is the screw-in core plugs. They add a little rigidity and will leave the worry of popping a plug out behind. I got mine from DSC and they are .650" thick. If you want, you can check out my build here, it sounds like you are planning a similar approach with the block: http://fepower.net/simplemachinesforum/index.php?topic=7851.0

Good luck!

[Gaugster]

Thanks Jared and all for the replies. I was in on one of Brent's group buys and picked up a SCAT 4.375 stroker crank. So the build would be 460 cid if the block ends up at 0.040" overbore. Pistons that came out are 0.030". So I'll clean up the flash and make sure the crank fits while I'm at it. A shift point of 6,250 would have the piston speed at 4557 average fpm. I guess that's a good but perhaps conservative piston speed. A 7,500 shift point would put the piston speed up at close to 5500 fpm. With Jay's heads flowing so good running it up to 6,250 should give me plenty of HP. Overall I guess it will be a max horsepower/ great vacuum street build with the block as the limiting factor. I'll need to price out (in today's dollars) and review the pros/cons of going for an aftermarket iron block.

Currently my transmission swap is going well. So I will have a 390 with the 6R80 Auto behind it for this season. Next winter I will update the rear end to a gear set and also get serious about chassis upgrades for strength and traction.

[blykins]

An aftermarket block would be very prudent.  I wouldn’t trust a factory block at all at that horsepower level, with a 4.375 stroke turning over 6000 rpm.  That’s a lot of weight to be slinging around and a lot of stress on an old block. 

[Gaugster]

An aftermarket block would be very prudent.  I wouldn't trust a factory block at all at that horsepower level, with a 4.375 stroke turning over 6000 rpm.  That's a lot of weight to be slinging around and a lot of stress on an old block.

Thanks Brent. Being able to shut the factory hood on my Cougar is the only engine characteristic that I have decided so far. Once there is some data about the cross-ram setup I can set an actual horsepower target. Heck - 650HP @ 5,000 RPM sounds fun as heck. Just need to find 680 FTLBS of torque without sending it to the moon. Knocking on 1.5FTLBS per CID...easy as pie right?