[QUOTE=sstonebreaker;1604291488]Dang, if those are marks from the valve, it must have been wobbling all over the place. Valve guide time!

Seeing how something let go and shot a hole in the other side of the block, I'm almost surprised it isn't worse than that. But then again I'm sure it locked up pretty quickly after it let go

 

You could definitely see the dished piston imprint on the other head as well. Is is this what they call catastrophic failure? And I believe from the picture of the cylinders you can tell which cylinder it is that let go. If you look carefully you can see a bearing cap laying on the tray inside the oil Pan

 

Wow, never realized a block is that thin. Carnage!

 

It's been a little while since I have responded to the thread, things that work has been insane. However I have had a little bit of time to do a little work on the car. Also during this time I've been reading and watching videos and reading some more about the l98 and what other people have done with them. I guess when I got the car and decided what its fate was going to be, which is as soon as it's ready to go it's going to be given to my seventy-year-old father to play around in. Initially when I got the Corvette my first thought was 400 / 400. It's a Corvette should be easy. Now knowing what I've gotten myself into and what's the end results going to be my decision is since this motor is a known quantity, as far as what you were going to get out of it using stock heads and intake, that I'm going to do a conservative full blend, port and polish the hell out of what I can, try and find a cam, roller rockers, heavier Springs, and a set of lifters cheap as I can. But I think I'm going to try the hot cam or an lt4. Originally I wanted to make as much horsepower is I could because if my dad is messing around on a weekend and some kid comes up in a 5 L Mustang and walks away from him, even at 70 years old my father will put that car in the garage tear the motor out and drop a cast iron 396 with a Holley double Pumper on it and make it breathe fire. And nobody wants that, the only wiring left in the car would be for the starter, water temperature, oil pressure, and fuel gauge.
okay so this is where I asked the million-dollar question... What would everyone recommend for a cam his suit what I just outlined? The car already has two and a half inch MagnaFlow exhaust all the way back and I did pick up the set of long tube headers as well. The one thing to keep in mind is my budget is pretty much gone it's about $2,000 ago. Do I need to do the rest of it as inexpensive as possible.

 

Actually, the block is a little thicker than the picture would make you believe. It's a good .25" I'm guessing. At 2nd glance I noticed not only #5 piston was twisted, but #6 as well. Wonder if the crank broke? Hope to have a cherry picker here tomorrow or Thurs and get that thing out of there and see.

 

So I thought I would post an update in case someone may be interested. Getting a good start on a mild bowl blend on my way to having everything from the tb to the exhaust ports polished and ported. Still have really no idea what I am going to do for a cam...thought about putting the stock back in with 1.6rr's to save $ but I think I would regret that down the road. Was considering a zz9 or maybe lt4...****, I've read so many threads on L98 cams that I've gone permanently cross eyed...but never find anything that makes me certain of what route to go. Praying someone on here will chine in with something to make my epiphany happen

 

Ohh booy...be careful about DIY yt porting 99 percent dont have a frigging clue whats going on.
No need to polish your ports it will run the same either way.

 

I'm trying to be as careful as possible, just removing some of the "bulk" around the guide and blending a little...from what I've read there is only so much you can expect from these heads so no real reason to get to aggressive with the grinder! Still waiting on the good advice on cam choice though....hint, hint

 

...

 

So you're saying I should save my polishing for useless things like this?

 

Highly polished ports can actually decrease performance. It was thought a good idea in the 50's and 60's but it was found that over polished ports encouraged the fuel to fall out of suspension causing inconsistent fuel/air delivery.

A nice machined surface encourages some turbulence giving better fuel atomisation.

 

Better AIR flow, too.

There is a test out there where someone flows an CNC machined AFR 225(?) head, then smooths the CNC lines and flows it again....it did 4CFM worse.

 

Good info. Thank you

 

Thanks again for the good info, I had every intention to polish. Glad I saved the time.

 

211/219 cam was popular for the L98 engines
PM me about a set of springs