I need schooling - old vs. new engines

Interesting thread and good input from all. Opinions can become heated, with the passage of time, the rose we remember the thorns we often forget. As someone who has run street/strip LAs and Gen II Hemis and is looking to possibly update to supercharged Gen III Hemi power, as always it depends what you want ot use the vehicle for and what you can afford and are prepared to put up with.

LA:

I love LA engines and have gone fast with NA, stock stroke pump, gas combos over 25 yrs ago on the street. Were they great drivers? Not really. Its now expensive to build a decent one, blocks not much good long term above 600HP, would need decent 4500-5500K stall, non lock up converters, stiffer CR, bigger cams, stiffer rear gearing, the usual maladies apply. The LA platform, although improved, is not as well embraced by the aftermarket compared to the Gen III - there is a reason for this. Especially blocks.

Gen II Hemi:

I run a pump gas 572 Hemi in my street/strip car. It's a blast. Makes great, reliable HP/TQ on pump gas. Are there cheaper ways to make the power? Yes. Perhaps more efficient ways? Definately yes. One issue is the Gen II Hemi also has less aftermarket support and what is there is expensive, esp blocks and valvetrains; low demand = low volume = $$$.

Looking back, the Hemi was DESIGNED as a race engine from the outset and OEM focus was on developing it a such. The Max Wedge is the exception of course. Even Chrysler realised that they needed to develop the Hemis breathing advantage. The Hemi was compromised to be put in street cars b/w 66-71; common at the time was adding a set of headers and a cam and it made them very fast on the street back then. The Hemi's race record speaks for itself and still does. Racers like Landy, Sox & Martin, Leal & Co were'nt stupid. The knew the platform that the Hemi was and made it even better. So did TF. I love wedges esp the 6 packs, however the Hemi had the reputation of being fast at the time - because it WAS. Street based wedges with 6 packs were fast, but well sorted/dialled Hemi with solid cams and headers were way over 500HP on the street. Production wedges (even 6 paks) were out of gas when the Hemi was just winding up.

Did it have its issues? Absolutely. EVERY engine design has compromises. Since that time, the aftermarket has changed a lot and yes Wedges have come a LONG way today and make serious HP/TQ now.. Advanced cyl head design, esp in the chambers and ports have changed the game significantly, not to mention big cubic inches. Both designs have inherent design advantages and disadvantages, lets remember WHEN they were designed and how. Choose your poison and spend your dineros.

Having said all this - if I had my way over in my current ride, Id have a.....

Gen III Hemi:

Specifically, a 1000+HP to the tire, supercharged Gen III Hemi. Not cheap either, but WHY ???

  • aftermarket parts availability
  • more modern, efficient design capitalizing on computers and decades of engine design experience
  • capitalizing on aftermarket tuners intellectual property, knowledge and experience.
  • less mass over the front end (a big one)
  • double OD ZF 8 speed, less ratio drop b/w gears, lockup converter ( a huge one)
  • less rear gear needed (another big one)
  • o ringed seals
  • hyd roller cams and stable valvetrains
  • COP/dual plug
  • very good production based cyl heads, BGE blocks and cranks
  • cyl to cyl tunable EFI
  • cheaply and widely available
  • serious, RELIABLE power over the long haul.
The Gen III also has some issues regardless of what the platform has to offer.

Once again, it depends on what you want to do with the car, what you can afford and your preferences. For me this platform would enable me to better USE the car, have my cake and eat it so to speak. No stiff gearing or looser converters. Pump gas. Killer HP/TQ. Modern trans. Driveability. I'm not getting any younger and have been at it for decades - sometimes one has to embrace things that the modern age has given us.

Kinda long winded....but my 2c

Good stuff. Just a note to add and not sure if they're readily available in Australia but the 5.2/5.9L Magnum engines have helped extend the practical usage of SBM engines. Primarily in the short block there are many improvements to the LA platform; blocks, crankshafts, connecting rods and pistons are stronger with better materials, more precise machining, tighter tolerances, lighter weight (mainly pistons) and interchangeability with LA-based parts aside from oil supply to stock-type shaft-mounted rocker arms. They're also factory equipped with roller lifters that typically don't require replacement which saves a lot of expense.

Here in the U.S., Magnum engines are dirt cheap at junkyards and the factory short blocks show little to no wear even with over 150,000 miles on them thanks to the factory EFI and tighter machining tolerances. The factory pistons also have less of a dish than LA versions and sit higher in the bores at TDC allowing for higher compression ratios with typical aftermarket heads (around 9.5:1 is pretty realistic).