Longevity & Power Of Your Rig!
#81
I know I'll be the odd guy out here, but other than bypassing the AC compressor after it seized last year, I really haven't made any other modifications to my '02 Durango. I run it everyday, mostly highway miles (65-75mph), and though it does burn a bit of oil (running 20w50 year round seems to help a bit) I'm still getting a little over 17mpg highway and just passed 400000 miles with pretty much just basic maintenance on the engine and drivetrain.
#82
#83
Old thread but
I posted this how I would build a motor for longevity and fuel mpg's as well as keeping the octane requirements down so that less money is spent at the pump but more power to the wheels. This is only my opinion.
All I'm saying on the subject of cam's is exactly that. If you have too much fuel & air combo going in detonation can happen requiring higher octane requirments which is not saving at the pump but rather building a performance machine. By boreing the cylinders and head this will get ya up to about 10:1 from the 9:1 and maybe upwards slightly.
1.7:1 rockers can be installed later if wanted or needed but I BET you will ping.
Lastly, boreing the motor close to OEM and adding P&P heads should run 87 octane. Pontiac run OEM more compression. I don't understand how putting in a bigger cam can fix detonation because it adds fuel/air and more compression thus creating MORE ping.
Where is the motor suppost to bleed from in a sealed combustion chamber?
All I'm saying on the subject of cam's is exactly that. If you have too much fuel & air combo going in detonation can happen requiring higher octane requirments which is not saving at the pump but rather building a performance machine. By boreing the cylinders and head this will get ya up to about 10:1 from the 9:1 and maybe upwards slightly.
1.7:1 rockers can be installed later if wanted or needed but I BET you will ping.
Lastly, boreing the motor close to OEM and adding P&P heads should run 87 octane. Pontiac run OEM more compression. I don't understand how putting in a bigger cam can fix detonation because it adds fuel/air and more compression thus creating MORE ping.
Where is the motor suppost to bleed from in a sealed combustion chamber?
#84
One step often overlooked is found while people are doing head work. If the casts are good and you send them to a machine shop to tell you so, then at least have the valves and seats ground or replaced and have the heads polished. Polising is very productive as it allows more air into the cylider this creating more horse power. This can be added to your bill as a small amount and some people will at least smooth the high edges down and clean up all the casing errors. Sometimes dropping a $20 down on the hand of the shop employee will get things rolling.....Ha Ha
If one does not have the motor broke down then larger rockers might be your choise. OEM rockers are at 1.6:1 ratio and an upgrade to a 1.7:1 Basiclly this is just like camshafting your motor. This provides longer opening of the valves for a longer duration. This is about a 30-50 hp bolt on and takes about 1 1/2 hours. 1.6:1 is only about 8 hp. Cost between $350 to $750 depending on the maker. The part numbers are as follows for the 5.9L/5.2L
Mopar
P5007404 1.7 ratio roller rocker
P5249800 1.6 ratio roller rocker
The valve OEM covers can be reused if you take out the baffles on the stock covers or adjust them out of the way. If you want the look then you can buy MP valve covers because the look better and are a bolt on.
If you buy the Crower rockers, they are stainless, not aluminum like MOPAR, much better longevity. Stainless doesn't "harden" and fail down the road. To properly (and easily) adjust your new rockers do it this way. Use the exhaust opening/intake closing method. This is the EOIC method. Turn the motor until the exhaust valve is just opening. Adjust intake rocker 3/4 turn, tighten. Turn motor until the intake valve is 1/2 to 3/4 closed, adjust exhaust rocker 3/4 turn, tighten. Do all rockers this way, adjust baffle, assemble motor, enjoy. Roller lifters need .045 to .060 preload. You get the proper preload with 3/4 turn, not the 1/2 everyone tells you to use. Remember to set each one in bolt sequence just like torque order.
If one does not have the motor broke down then larger rockers might be your choise. OEM rockers are at 1.6:1 ratio and an upgrade to a 1.7:1 Basiclly this is just like camshafting your motor. This provides longer opening of the valves for a longer duration. This is about a 30-50 hp bolt on and takes about 1 1/2 hours. 1.6:1 is only about 8 hp. Cost between $350 to $750 depending on the maker. The part numbers are as follows for the 5.9L/5.2L
Mopar
P5007404 1.7 ratio roller rocker
P5249800 1.6 ratio roller rocker
The valve OEM covers can be reused if you take out the baffles on the stock covers or adjust them out of the way. If you want the look then you can buy MP valve covers because the look better and are a bolt on.
If you buy the Crower rockers, they are stainless, not aluminum like MOPAR, much better longevity. Stainless doesn't "harden" and fail down the road. To properly (and easily) adjust your new rockers do it this way. Use the exhaust opening/intake closing method. This is the EOIC method. Turn the motor until the exhaust valve is just opening. Adjust intake rocker 3/4 turn, tighten. Turn motor until the intake valve is 1/2 to 3/4 closed, adjust exhaust rocker 3/4 turn, tighten. Do all rockers this way, adjust baffle, assemble motor, enjoy. Roller lifters need .045 to .060 preload. You get the proper preload with 3/4 turn, not the 1/2 everyone tells you to use. Remember to set each one in bolt sequence just like torque order.
Any option like this for the 4.7? I don't have the HO cam or Intake Manifold I'd like yet but curious what all I can do before I add the Supercharger for some gains. I am going to SVT tune it soon I just passed smog this last week 👍
Off road bumper design plans or parts so I can do some more wheeling mods?
Thanks!
The following users liked this post:
James Vining (08-02-2021)
#85
Much respect and appreciation for the knowledge shared and how its helped me along the way.
Any option like this for the 4.7? I don't have the HO cam or Intake Manifold I'd like yet but curious what all I can do before I add the Supercharger for some gains. I am going to SVT tune it soon I just passed smog this last week 👍
Off road bumper design plans or parts so I can do some more wheeling mods?
Thanks!
Any option like this for the 4.7? I don't have the HO cam or Intake Manifold I'd like yet but curious what all I can do before I add the Supercharger for some gains. I am going to SVT tune it soon I just passed smog this last week 👍
Off road bumper design plans or parts so I can do some more wheeling mods?
Thanks!
Forced induction will certainly wake it up though.
The following users liked this post:
DR4NG20 (01-10-2021)
#86
There just isn't much in the way of performance parts for the 4.7. No idea why the aftermarket never really did anything for it. Even finding the HO cams these days is a tough nut to crack. Given the Overhead Cam design, there are no options for higher ratio rockers. (that would have been just too easy. )
Forced induction will certainly wake it up though.
Forced induction will certainly wake it up though.
I appreciate the confirmation of lack of options though!
I should be done with the rest and start on that in a couple months though.
Any leads on a HO Intake or cams lmk!!!