The first, second and third thing you do before starting measuring and assembling your short block is to clean it, clean it and clean it again. you can not get the block too clean - it just spent a considerable amount of time being machined. Several pounds of aluminum shavings were produced along with quite a bit of very hard steel sleeve machining left overs.

You can see that the oil galley plugs have been remover - there are three of them and they should all be removed to clean the block and then replaced.

For those that want a very clean block we can bead blast the block before starting machine work - if the block has been bead blasted you may have to clean and flush the block several more times to ensure that there no abrasives left.

When you think you are done - clean it one more time, then spray down the cylinders with WD40 and cover with a big trash bag. Never leave the block exposed when not working on it. Dirt and dust are evil and have no place inside an engine.

The next step is to clean the assembly area. I will wash the floors before each engine project starts. I am planning to dedicate a corner of the shop for a clean room for engine assembly only.


The first step in to check all engine dimensions - here we are checking piston to cylinder clearance - its a lot different on a sleeved motor compared to a stock alusil block.

Don’t assume anything is correct (unless you trust your machinist!) - even then it is a good idea to check measurements.


Select your connecting rods - here are the 3 basic choices - 1) Pauter 2) Carrillo 3) stock forged. All are capable of supporting some serious power output. the Pauter and Carrillo are a reasonable amount lighter than the stock - this is a very good feature if you are planing to run the engine at higher rpm. The less reciprocating mass the better.

The Carrillo and Pauter rods also offer the ability to run a 3.0 crank in a 2.5 block - as you can see there is a lot more clearance by the rod bolts.

As always - check the dimensions - even brand new rods can be out of round.


In case you were wondering -

Stock = 837 grams

Carrillo = 720 grams

Pauter = 671 grams


Proper balancing of the rods requires a special rig to match the little ends and the big ends. The rods are the one engine part that both rotates and reciprocates. Proper balancing of all the components makes for a smoother engine - and a better wearing engine.


Pistons need some attention also - even custom JE pistons may need a little balancing work. Some shops are OK with matching to a couple of grams - but since my Digital scale goes to .1 grams - why not match them that close?

The Piston on the scale is a 3.1l 16v turbo piston with anti friction skirt coating and a heat barrier coating on the crown.


Ring gapping - kind of a tedious part of any engine build - there are so dam many of them!

Getting the wrong gap can trash your new motor in one heat cycle. To much gap is better than too little. the gap setting depends on the ring selection and the application.


This is the way to gap rings! The hand crank units can do the job but you tend to get a little tired of it Dan accept ‘close enough’ thinking. However - it is tough to justify the cost of one of these powered babies for one engine build.


Now we finally get to start building something - here the main bearings are being installed. these are coated bearing - not much of an extra expense - call it insurance. Will it save you from a number 2 rod bearing might give you the split second of protection you need.


So - the first step in building requires you to assemble the crank girdle measure it and then take it apart. Well, that’s the way it goes - you can’t just slam these things together. here we are checking the main bearing clearances. Some folks use plasticgage, it can work but I find that really measuring the clearances is the way to go. you will need a good snap gauge and some good micrometers. Note how nice and clean things are.


Now we are finally assembling something! I am happy with the main bearing clearances so I am starting to torque down the crank girdle. note the nice digital torque meter - its the way to go for this type work. “Clicker” type torque wrenches need to be calibrates frequently to be really accurate - and that $20 JC Whitney one isn’t a real torque wrench either!

When torqued down with the right clearance you should be able to spin the crank with one finger (OK, you might need a strong finger)!

pistons dish 02
piston marked up
sleeved block w pistons rods

Now we get to some fun stuff - assembling the pistons to the connecting rods and checking the clearances. Sorry, you still don’t get to just bolt stuff together - you still have some checking to do. The installed height of the rod & piston combo has to be checked - it is better to do this before putting the rings on the pistons.

The installed piston in this picture sticks out of the sleeve quite a bit - between .016 and .019 thousandths of an inch - if nothing was done about this is would hit the head at higher rpms - that would ruin your day. This can be cause by a block that has been decked more than once, out of sepc rods or pistons. You can sure this a couple of ways - either machine the tops of the pistons, go with a custom head gasket or resize the large end or the rod (worst fix!). This is why measuring the parts every step of the way is a must. Even brand new parts can be manufactured incorrectly.


Now you finally get to finish up the bottom end of the project - torquing up the rod bolts. In this case these are Pauter rods in a 2.5 block with a 3.0 crank. You can really see why the aftermarket rods are needed for this combination of parts.

Even with the rods torqued in place and the pistons and rings installed the crank should turn over with out significant force. The ring friction will be noticeable but easily over come with a ratchet on the crank bolt.

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