All OEM hardware will work with the BMP aluminum Chevy Big Block

A piece of art is what most people would say.  A real go-fast part is what most performance enthusiasts will see.  Perfection is what Bill Mitchell Jr. is looking for.


One of the most recognized names in the performance aftermarket industry is Bill Mitchell.  Known the world over for producing parts for hardcore racers, street enthusiasts and engine builders that wanted to start with a solid foundation, Mr. Mitchell created the market for aftermarket cylinder heads and blocks based on improved versions of OEM products.   Names like World Products, Merlin and Motown bring to mind quality products for those who wanted to go fast.  The short story is that Bill Sr. saw a need for affordable parts that were better than the mass-produced pieces GM was spitting out, made them for thousands of customers then saw production problems eat away at what he had created.  So he retired!


Now the torch has been handed down to Bill Mitchell Jr.  Bill Sr. is off enjoying life in warmer weather, while Bill Jr. is essentially reinventing the company his dad had spent so many years perfecting, and he’s doing it under the trusted BMP moniker.


As Bill Jr. told us, “After taking over BMP 100% as my own deal, and trying to pick up the pieces of the mess that a few foundries and machining centers left World Products in, it’s definitely been a challenge.”  To listen to the younger Mitchell tell it, it’s a challenge he’s definitely ready to tackle head-on.

Close tolerances, precision machining process equal a near perfect product.

Close tolerances, precision machining process equal a near perfect aluminum big block Chevy.

“Lack of inventory means lack of sales,” Bill explained.  “And with a lack of sales there’s a lack money, which of course brings it all full circle, meaning no inventory,”


While most people associate the old World Products with blocks and heads, Mitchell has chosen to release his new line of parts under only the BMP name.  “BMP is a new brand to some and certainly to those thinking of blocks, heads and manifolds,” he said.


When Mitchell took over from his father, the first thing he did was pull all the foundry tools out of the foundries and sent them to the pattern shop for changes that he felt would make the parts better, stronger and more user friendly.  Despite increasing costs, he also changed foundries to those he felt would pay better attention to the level of quality he was shooting for, to which he said, “So I make a little less, so be it.  But I will have the best damn pieces available — bar none!”


To finish his transformation, Mitchell moved the operation into new machining centers.  Not just any run of the mill machine operation with big machines, but two facilities where the owner/operators not only had race cars (or involved in the business of racing) but that they also had a solid understanding of what the parts were supposed to do.  The two facilities he chose mirrored his perspective on what he was trying to accomplish.  “Their level of perfection was what I liked most, and I felt that it was a perfect fit as I’m a perfectionist myself.”

Thicker material means

Expanded water jackets means better cooling.  O-rings sealing the cylinder sleeves keeps oil in place.


While it will take some time to get to the point where Bill is satisfied, he has taken the first step with his brand new aluminum Big Block Chevy block.  Known from here on out as the BMP BBC, this state of the art engine case, made from 357T6 aluminum, has a plethora of features including:


–1020 Billet Steel Splayed Main Caps utilizing ring dowels around two center studs to lock the cap in place, in addition to stock OE registers


–9.800 and 10.200″ deck heights along with 4.250 and 4.500 bores available


–ARP Main cap hardware


–Centrifugally cast ductile iron replaceable sleeves seated at the top of the bore


–O-rings sealing the outside diameter of the sleeve to the block itself, keeping the oil from getting behind the sleeve


–Expanded water jackets for better cooling along with outer ribs for the cool factor, which also adds to the block’s stability, which Mitchell believes is what transitioned an aluminum block from losing power to being on par with a cast iron block


–Priority main oiling


–All stock OE accessories are compatible


–Stock fuel pump boss


–Standard cam location


–Stock BBC cam bearings, no need for a special set


Iron four-bolt man caps with splayed out bolts ties the block together, making for one strong case.

Billet steel four-bolt man caps with splayed outer ARP bolts ties the block together, making for one strong case. 

As for the finish machining processes, Bill let us in on a few items, but maintains that there are secrets to coming up with the perfect part.  He explained that the machine operations his new blocks go through are far better than before.  Previous models and other manufacturers leave the block under or over spec for the engine builder to finish machine.  Mitchell professes that isn’t going to happen with the new BMP parts.  “I want these blocks to be as close to perfect as possible,” he explained.  “Deck height targets for us are .0005” in any direction, bank to bank.  This spec caries all the way through the block.  I have engine builders calling and telling me how impressed they are with the new versions compared with the old ones.  The best they have seen in 20 years, they say!  We say, the best is yet to come and we’re certain that Bill Jr., despite having huge shoes to fill, will be up to the challenge.

All OEM hardware will work with the BMP aluminum Chevy Big Block

All OEM hardware will work with the BMP aluminum Chevy Big Block


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