Big Al

iTrader: (1)

Anybody here have a Dart Big M set up? How much did it cost?

Al 4.5 bore 4.25 stoke Big M

CNC BLOCKS N/E

I have machined alot of the Dart Big-M blocks and those blocks require alot of work but are a nice foundatiion.

Here is what I do for machine work on the Big-M blocks

I deck all of them to a finished number depending on gasket & desired piston height
Block needs to be honed with a plate or bored & honed depending on bore
Bottoms of bores need to be chamfered
Most need the lifter bores honed, at the least checked
Most need line honing
All pipe threads need to be retapped
Oil return from fuel pump cavity needs to be done
Core plug holes need deburiing and rrear cam plug hole
CHECK THAT THE DISTRIBUTOR GEAR DOES NOT CONTACT THE BLOCK BY THE CAM. There is a big cast blob down there you may want to relieve.
You can machine the gear to clear if you forget but it is nicer to fix the block if necessary
Check all the timing bolt holes with air, some may go into water.