Hemi Crate Problems

This information

gathered

from personal experience with NEW

Mopar Hemi

crate

engines

block

and head castings.

These are problems

that

I have

observed,

not opinions or rumors.

See pictures below...

Even though they could use a little improvement, I give Mopar lots of credit for

still making Hemi parts

Consider new hemi blocks and heads "cores" that

should be carefully inspected and re-machined.

This list has been limited to the top 23 issues that we feel are the most

concerning.

1. Threading in blocks rough / rounded. All block threads MUST be retapped.

2. Fuel pump bolt threads may be tapped off center, pump may hit block / block

or pump need to be

clearance

or threads may need to be retapped / helicoiled

to align fuel pump rod/ arm.

3. Rough machine work / casting flashing sharp edges on main machining

causing main bearing misalignment

4. Deck surfaces too rough for head gasket type- deck may need to be re-

machined for flatness.

5. Water jackets full of metal chips.

6. Sharp edges / excessive flashing/ restriction in oil passages

7. Rear main walls are not flat on sides (ripple where side seals slide in) creates

rear main leaks (Seal walls perpendicular to upper mail seal half).

8.Cylinder bores not finish bored with honing plates- bores tapered / out of

round. Creates oil consumption/ blow by / low power.

9. Stock style connecting rods are extremely heavy (1000+ grams) and weak

causing MANY windowed Hemi blocks over the years. They should not be

used.

The rod bolts in the crate engines are throwaways! Cap screws are a

must!

10. 528 Hemi crate engines use aftermarket style rods and 4.150 stroke...the rod

contacts the 1/2 inch oil pickup. Mopar solution... the pickups are smashed to

avoid contact. They are restricted to less than 3/8 to clear the #1 rod

11. Excessive connecting rod side clearance .035 - .042 thousandths found.

Creates oiling problems / excessive cylinder wall oiling / splashing, lack of ring

seal / high blow by / oil leaks.

12. Cheap aluminum core / freeze plugs carelessly installed crooked creating

coolant seepage.

13. Large metal chips from block machining / dirt / lint found in oil pans from

improper cleaning / casting preparation.

14. Excessive lifter to lifter bore clearance

15. Block valley walls lack clearance for pushrods even for low lift cam- must

be properly clearanced to avoid pushrod contact and tossed push rods,

possible catastrophic failure.

16. Rotating assemblies "target balanced" found to be 7+ grams out of balance.

17. TDC improperly indexed to timing pointer / balancer marking

18. Fasteners improperly torqued / incorrect thread depth

19. Head bolt threads in block vary greatly in depth / bolt engagement

20. Poor machine work on heads. Improper clearance valve to guide / dropped

valves / valve seat leakage / damage

21. Power levels inconsistent / low

22. Oil consumption – 2+qts in 1000 miles

23. Blow-by creates oil control problems / leakage past breathers / oil blows on

engine / engine bay / or fills / fouls breather if routed to air cleaner.