World cast iron 4.490 rough bore block problem !

I bought a cast iron 4.490 rough bore cast iron wedge World block from my local Dodge dealer several years back when they where still available, I had that block machined last year and I built it for a customer last year, we had a issue with the current model B1 valve covers not clearing a MSD billet distributor properly last year that was discovered while attempting to dyno it. I bought some original B1 valve covers from a member on here and went back to the dyno on Monday to test and tune it, the motor had started and ran fine for short while warming up the oil and water before twisting the oil pump drive rod off while running due to the oil pump gear hitting the cover I had no problems priming it on the engine stand either time, no problem with any of the Milidon oiling system parts, it took a while to figure out the root cause which was the block wasn't machined completely flat and properly on the oil pump mounting pad mating surface It had a very small thin ridge that was around .012 to .018 raised above the oil pump mounting surface which ended up pushing on the bottom of the pump pinching, raising, the oil pump gear up against the pump cover eliminating the end clearances
My message is if you have one of those blocks look very closely at that surface, especially if your going to use the Milidon 21815 oil pump using the two O rings and no gasket
What a pain in the rear which ended up causing us to use up most of one day on the dyno identifying the cause and resolution
IHTHs some one else to avoid this same issue

Thanks for the heads up Cab,, How do you like those pump's, that is the pump I had in mind for my new build.

This is the second and third of those pumps I've used. I will continue to use them We tried replacing the gears in the first pump with a new set I keep in stock and then tried replacing the entire pump to identify the problem with another new one, the pumps or gears wasn't the problem I looked at trying to use the built in passage in the World Block for the second oil line but decided to not use that option due to the small hole and sharp bend in the oil passage in the block

It would seem that the o-ring would have absorbed the offset of the raised ridge of .012-.018 and not put the pump in a bind.

That pump has two O rings on it to seal up the suction side of the pump to the block oil pickup, one goes in between the block and the pump and the other one is in between the pump and the pump cover. The smaller narrower O ring that fits on the pump snout completes the sealing on the suction side between the pump and block, they sealed it up when cold and worked until the oil temps and water temps. exceeded around 150 F on both. Once they, the block and oil pump, warmed up above those temps. the pump gear was forced into contact with the pump cover which ended up seizing the gear twisting off the shaft Theory is one thing, reality is the real results That short narrow ridge of metal left on that block left witness marks on the pump snout which led us to the solution, we where chasing our tails trying to I.D. what was really causing that problem, that is why we're offering the help to others on here who may run into the same problem later

I have a World Products block also, Hemi aluminum that I have had a few years also. Haven't started assembly yet but will make sure to look at the pump mounting surface. Thanks for the heads up.

I had called Milodon several times on Monday trying to get some input from them why thier pump bound up twisting the drive off, they pointed us towards the O ring on the pump being the wrong one. They gave us the specs. and part number for the O ring on the snout saying that they had seen people put the wrong one in the wrong place causing similar problems, once we went and bought several of those O rings and compared them to the ones on the pump we realized that wasn't our problem
I callled them today to explain what had caused our problem so they would be aware of what we found and they said that wouldn't have been a problem on a KB aluminum block because KB tapers the snout entrance hole for the O ring to slide in so it does tear up that O ring. Look at yours to make sure tha taper is in place All the stock OEM cast iron blocks I have used had that stock Murphy loves messing with us drag racers
I have another new World cast iron 4,490 rough bore Hemi block that I will look at that surface the first time it is up on a engine stand to start with

I have the same 4.490 rough bore block, a couple years old, fresh machined getting ready to assemble. You can bet I'll be double checking that surface! I'll check the new one too and compare, THANK YOU for sharing and preventing potential disaster!