Bear Block Motors price and machining

[tboneheller]

Anybody used one of these BBM iron or aluminum blocks, yet?

[blykins]

I’ve used all kinds of their cast iron blocks. Aluminums are not available yet.

[Hoodabest]

Originally Posted by blykins

I’ve used all kinds of their cast iron blocks. Aluminums are not available yet.

So, are they really in need of JUST a finish hone? Or is there more to it?

[blykins]

I know guys that will pull an engine block out of a salvage yard, run a dingle berry hone through it, assemble, and run it. It will run but it won’t be right.

There are ZERO aftermarket blocks out there that don't need the full machine work treatment: bore and hone cylinders (hone only if they come rough within .005" or so of finished bore size), align hone mains, square the decks.

The BBM blocks come with a 4.245" rough bore size, so they just need the cylinders honed to finished size, but they need everything else.

Don't let anyone tell you that they are usable out of the box.

In addition, you need to grind on the china wall to make the distributor fit, and if you use Durabond FP-01 cam bearings, each bearing has to be installed carefully to make sure it doesn't block the adjoining lifter bore. If you use the front bearing out of the FP-01 set, then you have to clearance it to make the distributor fit.

The blocks also need pressure tested and all of the oil passages need to be eyeballed for drill throughs as well.

Not dogging BBM, but this is par for the course for any FE aftermarket block.

[eschaider]

Originally Posted by blykins

I know guys that will pull an engine block out of a salvage yard, run a dingle berry hone through it, assemble, and run it. It will run but it won’t be right.

There are ZERO aftermarket blocks out there that don't need the full machine work treatment: bore and hone cylinders (hone only if they come rough within .005" or so of finished bore size), align hone mains, square the decks.

The BBM blocks come with a 4.245" rough bore size, so they just need the cylinders honed to finished size, but they need everything else.

Don't let anyone tell you that they are usable out of the box.

In addition, you need to grind on the china wall to make the distributor fit, and if you use Durabond FP-01 cam bearings, each bearing has to be installed carefully to make sure it doesn't block the adjoining lifter bore. If you use the front bearing out of the FP-01 set, then you have to clearance it to make the distributor fit.

The blocks also need pressure tested and all of the oil passages need to be eyeballed for drill throughs as well.

Not dogging BBM, but this is par for the course for any FE aftermarket block.

Brent is absolutely right and while I didn't mean to imply the BBM pieces were ready for assembly right out of the box, I did mean to say that the quality of the casting and the machine work done on the casting you receive will be very good. To my knowledge and experience BBM will not provide you with poorly machined surfaces, for example, decks that were not flat and parallel to the crank bore.

While I don't know with certainty, I believe this level of finish machining is attributable to the type of shop used to machine the castings as received from the foundry. The BBM guys tend to fall into the Korean OEM production automotive machining facilities rather than aftermarket and the parts reflect a job that was CNC managed with a complete block program from the first cut.

That said, all builds whether new pieces like a BBM piece or refurbished OEM components need to have every component checked verified and massaged where necessary before final assembly.


Ed

[blykins]

The decks are not perfectly flat or parallel to the crank.

That type of accuracy can not be held by large volume rough machining processes. We do it with a BHJ fixture and it takes a considerable amount of time to set it up.