Roller Rocker arm sets and a cam
#11
RE: Roller Rocker arm sets
What gears do you have? Do you have the factory converter? The 20-746-9 is listed as 114* lobe seperation. IMO less duration with a little tighter seperation will pull harder. Assuming it's a mostly stock dd, I bet you would be happy with either the Comp20-602-9 or 20-604-9. Or if you can live with a bit of arough idle the KRC 206x or 210x.Also you may want to go with adjustable rockers just to make sure you get the preloadright. The rockers are cheaper, but you will have to buy studs, plates, and hardenedpushrods. It may be a good idea to buy the stock length pushrods, a set .050" above stock, and a set .050" below and return the ones you don't use. Might save you some down time.
#12
RE: Roller Rocker arm sets
thanks for the input,i have stock gears and i want to change them out...but all projects are on hold till my wife pops out our first child which was suppose to be may 27 but she is still prego...after the baby is born hopefully all the stuff i am trying to order locally will be in and available for pickup...right now i get "sir there are a few people before that ordered the same thing and we can only get 3 at a time"....so you will have to wait, yeah thats BS but i cant do much..i just save money to pay for it all in cash...thanks again for the advice from all the project is still a go...sorry i got off track a little
#13
i have a 2001 ram 1500 5.2. if i buy non adjustable 1.7 harland sharp roller rockers will i just be able to bolt them right on or does it require more work with different parts that go along with the rockers? and also i heard 1.7's will float valves therefore if i upgrade i also need to upgrade to stiffer valve springs. should i just get 1.6's?
#15
#16
I'm of the mindset that you can't over TB this engine. The point of greatest constriction is the intake ports and valves in the heads not the TB.
Think about how large the Plenum area is. Is it bigger than the TB butterfly openings? Does that area in the plenum have air in it? What keeps the excess air in there from going down the runner after it passes the TB? After you answer those questions you'll understand why a bigger TB won't affect top end performance by being too big.
The perceived loss of low end with a bigger TB is due to the factory Tune expecting to see the MAP sensor pressure drop at the factory curve. When you increase the size of the TB, the pressure off tip in drops faster and probably causes the map sensor to put a little too much fuel in the mix and hurts performance. A good tune written for a larger TB should see no loss in low end performance.
Think about how large the Plenum area is. Is it bigger than the TB butterfly openings? Does that area in the plenum have air in it? What keeps the excess air in there from going down the runner after it passes the TB? After you answer those questions you'll understand why a bigger TB won't affect top end performance by being too big.
The perceived loss of low end with a bigger TB is due to the factory Tune expecting to see the MAP sensor pressure drop at the factory curve. When you increase the size of the TB, the pressure off tip in drops faster and probably causes the map sensor to put a little too much fuel in the mix and hurts performance. A good tune written for a larger TB should see no loss in low end performance.
#17
1.7rr dont sit dead center of the valve stem when closed, when open they are even closer to the edge. Higher the lift closer the roller is to slipping off.
I only had .487 lift (rt+10cam) when I was running 1.7rr & shifting at 5400rpms
My rev limiter was set for 5600rpms & I only missed a shift once at the track & spanked the limiter (auto/hit neutral).
Later when tearing down for the 408 could see a few of the valve stems had nicks on them from slipping off the edge.
If you go with .512 lift, I wouldnt push it past 5200rpms
#18
Depending on the cam I wouldnt go over 5200-5400rpms w/1.7rr
1.7rr dont sit dead center of the valve stem when closed, when open they are even closer to the edge. Higher the lift closer the roller is to slipping off.
I only had .487 lift (rt+10cam) when I was running 1.7rr & shifting at 5400rpms
My rev limiter was set for 5600rpms & I only missed a shift once at the track & spanked the limiter (auto/hit neutral).
Later when tearing down for the 408 could see a few of the valve stems had nicks on them from slipping off the edge.
If you go with .512 lift, I wouldnt push it past 5200rpms
1.7rr dont sit dead center of the valve stem when closed, when open they are even closer to the edge. Higher the lift closer the roller is to slipping off.
I only had .487 lift (rt+10cam) when I was running 1.7rr & shifting at 5400rpms
My rev limiter was set for 5600rpms & I only missed a shift once at the track & spanked the limiter (auto/hit neutral).
Later when tearing down for the 408 could see a few of the valve stems had nicks on them from slipping off the edge.
If you go with .512 lift, I wouldnt push it past 5200rpms
#19
Actually more like 5500ish, at least that's where my stock valve springs crap out. But you aren't going to be reving that high with the stock rev limiter or kegger anyways.
#20