I'm obviously not 100% on the problem since I haven't had my hands on it. World Products had an issue around 10 or so years ago. I know of quite a few builders that ran into it. There was apparantly some core shift when casting the block and one of the oil passages got really close to the water jacket.Over time, it would crack through to the water jacket. After the coolers were changed, that left the assumption that this is the issue. Like I said, I'm not 100%, but it's where I would put my money.
Eddie

Riverrat, I guess you deleted your post, but I see it was quoted. I assume that your comment was directed to me. Not only did I not charge him, but I drove 7 hours to look at it and give Randy my thoughts on it. I try my hardest to help anyone that I can anytime that I can....and I've certainly never charged for it. Not sure what possessed you to make that comment considering that you know nothing about me, but it's WAY off base.
Eddie

eddie,thanks for posting this info,the op must have not had the time to do it.and as far as riverrat,s derogative post,i dont know what happened,but all of his posts are gone,so i dont think he will respond to this.

I have seen people banned, I have seen deleted posts.....I have never seen entire posts just disappear, all his stuff is gone.

This has to be the "oso death penalty" Seems to me in his last few days he was just making it his job to try to upset everyone.

4bus,maybe the powers that be just decided enough is enough,but it does not look like he got banned,maybe he got a time out,i cant imagine what would happen if he comes back,it seems like i was a personal target for him,and i have no clue as to why.

Mike , some people just are not happy unless they have someone to hate . Isn't that what we call douchebaggery .

No problem Mike. Like I said, my money is on a crack in the oil passage. I've seen it happen to quite a few builders. They all got stuck with the cost of fixing it. World replaced the blocks, but they didn't cover the machine work, gaskets, etc. nor did they cover the labor to swap all of the parts. It was a bad deal. I think there was somewhere around 100 blocks that got out. Luckily, they got it fixed. I don't remember exactly when it was but it was at least 10 yrs ago.
As for riverrat, I don't know what that was about. I did notice that he had a hard on for you for whatever reason. He's just an angry little fellow I guess.
Eddie

eddie,what blockdo you like to use on a new build,i have had good luck with the dart big m.

Personally, I prefer the Merlin block. I have used a bunch of Dart blocks. I don't have anything against them. Mainly, I prefer the Merlin's billet main caps, especially on something making over 1000 hp. When the Dart block first came out, I actually preferred them on stuff less than 1000 hp. They had a really clean casting, all the holes were already bottom tapped,etc. Those items saved me a ton of work by not having to bottom tap every hole (all of the blocks are very hard with all the nickel they have, so they are all hard to tap) It also saved us a bunch of time not having to remove a bunch of casting flash. Then, after not even a year, they stopped bottom tapping them, the castings weren't as clean, etc. I always used the Merlin b/c of the billet mains on the larger engines, so I figured that I would just use it on everything. Dart didn't have a billet main cap version. They had nodular iron caps and a steel cap version, but they didn't compare to the billet caps. I think that Dart may have a billet cap now, but I haven't used one in quite a while. I certianly don't have anything against them. I just prefer to use the Merlin.
Eddie