Thread: General Hemi Info Part 5

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The prep:

Building a Hemi is no more difficult than building any other American V8 engine (a good deal more expensive than doing a SBC, but no more difficult). That being the case, I will not necessarily go into all the different aspects of engine building that would be common to any engine rebuild, but rather try to concentrate on those areas that specifically relate to building an early Hemi.

Like any other engine the first step is the tear down and inspection. Due to the weight of the heads, I prefer to remove (and re-install) the heads on the floor dollies I have built to move these engines around on. Once the heads are removed the short block is put on an engine stand and the disassembly completed. Don’t be shocked once you get the heads off, as impressive as the engine looks when assembled once the heads are off you’re got a basic MOPAR small block poly motor!!!!!!

During the inspection/tear down you’ll be looking for the same things you would in any other rebuild. This will include condition of cylinders, pistons, rods, crank etc.

Two things that you will want to remove prior to sending the engine off to the machine shop are:

The intermediate shaft bushing (the bronze bushing the intermediate shaft goes through. You can see this bushing in the picture that shows removal of the galley plug).

The oil by-pass valve located under the rear main cap. This is removed by pushing it out by using a 1/8 rod through the oil pressure sending unit hole.

Once the engine is stripped, it’s time to send it off the machine shop for all the standard procedures that take place during any engine rebuild.

For a “normal” street motor this should include vatting, polishing/grinding the crank, re-sizing the rods if necessary, boring, valve job (including guides and seats if necessary) decking the heads/block and any of the other things you normally would have done.

Unless you have already removed them, one thing to stress to your machine shop is to remove the galley plugs in the back of the block prior to it going into the vat (or however your machine shop cleans them. While the two larger outside plugs are not necessarily real critical to remove (they go into the water jacket), the smaller 2 plugs and the “hidden” one go into the oil galley and their removal is crucial to proper cleaning of the lifter oil galleys. The smaller of the 2 plugs the goes directly into the right side (passenger side) oil galley. The larger left hand (driver’s side) plug goes into the lifter valley, but needs to be removed to access and remove/install the oil galley plug in front of the intermediate shaft bushing.

The machine work can as simple as a “standard” rebuild or as extensive as prepping a full blown race motor. That will depend on what your plans for the engine are and your budget will allow.

If your building a normally aspirated street engine that will be operated at a reasonable RPM range, you really don’t need a lot high buck race prep as your starting out with a pretty stout motor to begin with.


Just because it’s a Hemi, the actual machine work should cost no more than having it done on any other engine, nor are there any other “special hemi steps” necessary required (based on the performance level your building for).