So both the 6.2 and 6.5 is “Knocking”, I would try and figure out what the knocking noise is before you go crazy on spending huge amounts of money. Could be something simple, like a bad injector, lifter or ip timing could be off.
Steel crank is not needed. Waste of money. Crank failure is cause by failed harmonic balancer and or in the case of a 6.5 failed crank pulley as it is dampened as well.
HP rocker arms are a waste of money.IMO
6.2 and 6.5 heads are interchangeable. Many people make hybrid 6.2/6.5 motors that work well.
Porting does help as already mentioned. But if you are going to do that, why not put in some 18:1 pistons?
Also porting helps non turbo motors much more then motors that are turboed.
Studding the heads is not needed unless you plan on boosting 15+ psi. Anything more then 15psi then I recommend 18:1 pistons.
1. What really helps the most for durability is tapering every bolt hole to prevent cracks and grind or file all sharp edges. This is preferred for the older model 6.5 and 6.2 blocks.
2. IMO I believe all older 6.5 and 6.2 diesels should get the lock n stitch inserts installed in the heads between the valves. For only $20, one could save or restore a pair of heads that are cracked by simply buying some brass tubing instead of buying the Lock n stitch kit
Doing 1 and 2 on an older block will make it as strong if not stronger then an optimizer or P400.
The HX35w is a great cheap turbo upgrade.
The HX40 is an even better turbo upgrade that will help a 6.2 or 6.5 reach its full potential.
Whatever turbo you choose, it is highly highly recommended to have an inner cooler when going above 7psi.
My personal temperature testing shows that with a opened 180 degree thermostat, the rear of the heads usually show about 15-20 degrees hotter. So at 180 you are really at 200 in the rear. The sweet spot is 180 in the rear, so I recommend a high flow 6.5 or 6.2 water pump with a high flow 160 degree thermostat to hit that 180 rear degree temp. A lot of guys that do a lot of towing, don’t even have a thermostat.
Between the 6.2 and 6.5 motors, I would have preferred to have build a turbo charged 6.2. However… there are much more options for the 6.5 as far as upgrades goes and I am seeing them more in the junk yards now that they are rolling over 230k, (I work in a recycling yard and average the life expectancy of 6.5 diesels to 220k-250k) so basically parts availability and cost is why I dropped a 6.5 in my ride.
I could talk all day about this stuff in person. But right now, I think you should start slow and figure out the current problems with whatever knocking motor you choose to build.
After it is all said and done, you will take a step back and realize all the time and money you just blew on an old block… You could have bought a P400 or Optimizer block and transferred your existing accessories over, saving you thousands and even thousands more in the future from potential maintenance.
Hope this helps! Cheers!
