[george kujanski]

This comment on the Caddy HT-4100 "but the worst came from Cadillac's choice to use cast-iron head bolts. but the worst came from Cadillac's choice to use cast-iron head bolts. "

Seriously, cast iron head bolts? I doubt if that's true... I had the 4.5L version in a '93 Eldo. It had cast iron heads on an aluminum block, maybe that's what the ignoramus writer had in mind.

george

[Sirrotica]

The 6.5 Detroit Diesel designed engine had faulty harmonic balancers, which caused the cranks to break soon after the balancers failed. The balancers became a maintenance item after the failures were determined to have caused the cranks to break.

I have 2 trucks with 6.5 engines, both over 250,000 miles, not buying that they can't run reliably if the balancers problems are addressed. JMO.

[hurryinhoosier62]

Originally Posted by Sirrotica

The 6.5 Detroit Diesel designed engine had faulty harmonic balancers, which caused the cranks to break soon after the balancers failed. The balancers became a maintenance item after the failures were determined to have caused the cranks to break.

I have 2 trucks with 6.5 engines, both over 250,000 miles, not buying that they can't run reliably if the balancers problems are addressed. JMO.

Brad, the cracking in 6.2/6.5 cranks was primarily in early 6.2 nodular cranks. We magnafluxed hundreds a month; never found a late 6.2 (one piece rear seal) or a 6.5 crank that was cracked. Since WHEN do millennial automotive writers know ANYTHING about anything?

[hurryinhoosier62]

Originally Posted by george kujanski

This comment on the Caddy HT-4100 "but the worst came from Cadillac's choice to use cast-iron head bolts. but the worst came from Cadillac's choice to use cast-iron head bolts. "

Seriously, cast iron head bolts? I doubt if that's true... I had the 4.5L version in a '93 Eldo. It had cast iron heads on an aluminum block, maybe that's what the ignoramus writer had in mind.

george

Odd, but ALL the nearly two thousand HT4100 engines I machined had steel head bolts and main cap bolts. It was one of the many weaknesses of this engine: galvanic corrosion in the main saddle and head bolt bosses. George, all of the HT4100 had cast iron heads( which were amazingly durable) on aluminum blocks. If you ever get the chance, lift a 4.1 block, then lift a late 4.9 block. The 4.9 block is nearly fifty percent heavier.