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Discussion Starter · #1 ·
Has anyone ever installed roller rockers on a 3.9l V6 amd if so what was tour experience with them? Ive been thinking about installing some in my 03 Dakota. Was just curious if they are worth the investment.

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Nate, they do offer roller rockers in std ratio as well as extended ratio I decide to go back with OEM std ratio rockers which are also offered in extended ratio. Due to the rpm range of my small engines I can only use the very best offered and some of them fail. I have used extended ratio and found some cams don't seem to respond well to the added lift. Another thing I'd consider is valve stem wear. How many miles are on the engine? I'd have to do the math which is not my favorite subject to figure out how much lift the rocker would add. My new cam only adds around .050 lift and that exceeds what the std valve springs allow. If going with std ratio rollers I'd think you would be disappointed with the results vs cost. Steve
 

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Discussion Starter · #3 · (Edited)
Nate, they do offer roller rockers in std ratio as well as extended ratio I decide to go back with OEM std ratio rockers which are also offered in extended ratio. Due to the rpm range of my small engines I can only use the very best offered and some of them fail. I have used extended ratio and found some cams don't seem to respond well to the added lift. Another thing I'd consider is valve stem wear. How many miles are on the engine? I'd have to do the math which is not my favorite subject to figure out how much lift the rocker would add. My new cam only adds around .050 lift and that exceeds what the std valve springs allow. If going with std ratio rollers I'd think you would be disappointed with the results vs cost. Steve
210,000 miles on the truck, I bought it in 2004 when it was a year old and had 6,000 on the odometer, it was a loaner for the dealership, but ive never had any real issues with it, just your typical parts that wear out. But ive never had to go into the engine to do any repairs. But i have always had a desire to get a little more from it, and ive been following your build very closely and living vicariously through that. But these rollers for some reason have always kinda stuck with me as a potential upgrade. Since finding aftermarket heads, cams, and the like is nigh on impossible unless you getting custom made parts.
 

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Having owned the truck so long is a real advantage. You have a good idea of how it has been treated and cared for. I have learned more about mine as I pulled the engine. I'm thinking about starting another thread to follow the engine change out. In spite of having 175,000 miles when mine ran well it ran really well. I'm still waiting for parts to complete the new engine. Once they show up, expected delivery parts today and everyday till thanksgiving I'll add to the build thread. With the information I have collected I plan to price up a cheaper rebuild for the old engine from my truck. Of course that will depend on the out come of the new engine. Keep in mind all I'm looking for is the best 3.9 engine I can put together for a everyday family truck. I started my project with no MOPAR back ground. Being a FORD person I was accustom to parts being hard to find and expensive. Building race engines based on a 1959 design that made 32 horsepower currently knocking at the 150 horsepower door, block and head casting is all we use. Those engines with a race tranny again using only the case run in the $25,000 and above range. The engine build you have been following from complete cooling system, engine and clutch has run up a slightly over $6,000 bill with a couple hundred in fuel injectors to buy. My original estimate was much closer to $4,000, cracked heads and the aftermarket parts I did find ran it up a bit. Would I do it again? I'll let you know after my next round trip to almost Fla. Ga. One thousand miles in one day with one of those 1 hour pauses on 95 for a wreck on one of the bridges. Steve
 

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Discussion Starter · #5 ·
Having owned the truck so long is a real advantage. You have a good idea of how it has been treated and cared for. I have learned more about mine as I pulled the engine. I'm thinking about starting another thread to follow the engine change out. In spite of having 175,000 miles when mine ran well it ran really well. I'm still waiting for parts to complete the new engine. Once they show up, expected delivery parts today and everyday till thanksgiving I'll add to the build thread. With the information I have collected I plan to price up a cheaper rebuild for the old engine from my truck. Of course that will depend on the out come of the new engine. Keep in mind all I'm looking for is the best 3.9 engine I can put together for a everyday family truck. I started my project with no MOPAR back ground. Being a FORD person I was accustom to parts being hard to find and expensive. Building race engines based on a 1959 design that made 32 horsepower currently knocking at the 150 horsepower door, block and head casting is all we use. Those engines with a race tranny again using only the case run in the $25,000 and above range. The engine build you have been following from complete cooling system, engine and clutch has run up a slightly over $6,000 bill with a couple hundred in fuel injectors to buy. My original estimate was much closer to $4,000, cracked heads and the aftermarket parts I did find ran it up a bit. Would I do it again? I'll let you know after my next round trip to almost Fla. Ga. One thousand miles in one day with one of those 1 hour pauses on 95 for a wreck on one of the bridges. Steve
You have an impressive build for sure. I feel like you will blow well past the additional 20 horsepower you were after. Id love to do one similar, but in the meantime, its living and learning and doing incremental upgrades when and where i can
 

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You have an impressive build for sure. I feel like you will blow well past the additional 20 horsepower you were after. Id love to do one similar, but in the meantime, its living and learning and doing incremental upgrades when and where i can
Unless you increase rocker ratio, rollers won't do much for you. The thing is the stamped steel Mopar ones coming on your truck are notorious for being so out of whack ratio wise, as to give a totally anemic valve response. Some have measure less than 1 to 5. They are easy enough to put in. A set of rollers in the 1/6 range will show you at least a bit of gain.
As far as "lift" numbers, if indeed your stamped ones are say 1.5 and your cam lift is .412, then 1.6 will increase the cam lift by about 35 points to around .439. The math is .412 divided by 1.5 times 1.6.
You won't have to change springs as that lift is still manageable.
 

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Discussion Starter · #7 ·
Unless you increase rocker ratio, rollers won't do much for you. The thing is the stamped steel Mopar ones coming on your truck are notorious for being so out of whack ratio wise, as to give a totally anemic valve response. Some have measure less than 1 to 5. They are easy enough to put in. A set of rollers in the 1/6 range will show you at least a bit of gain.
As far as "lift" numbers, if indeed your stamped ones are say 1.5 and your cam lift is .412, then 1.6 will increase the cam lift by about 35 points to around .439. The math is .412 divided by 1.5 times 1.6.
You won't have to change springs as that lift is still manageable.
The ones I was looking at are 1.7s so it should help a little, the cam is still stock in the engine. Havent been able to find a replacement and dont have the money for a custom grind. But then again, im not going for huge power numbers, just something a bit more snappy and responsive with minimal friction and restriction.
 

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The ones I was looking at are 1.7s so it should help a little, the cam is still stock in the engine. Havent been able to find a replacement and dont have the money for a custom grind. But then again, im not going for huge power numbers, just something a bit more snappy and responsive with minimal friction and restriction.
Put on a set of headers, your rollers, Dynomax straight thru muffler, better y pipe from JBA and a set of 3.91's for the rears. You'll have a different truck with all the "snap" you could ask for.
 

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Discussion Starter · #9 ·
Put on a set of headers, your rollers, Dynomax straight thru muffler, better y pipe from JBA and a set of 3.91's for the rears. You'll have a different truck with all the "snap" you could ask for.
Actually had been looking into the JBA headers for a while now, and will be ordering a set in the next week or so. I had the truck dualled out years ago but at the time i knew nothing about making horsepower, so its probably not the most efficient setup. But when i install the headers i can redo it then if needed
 

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Actually had been looking into the JBA headers for a while now, and will be ordering a set in the next week or so. I had the truck dualled out years ago but at the time i knew nothing about making horsepower, so its probably not the most efficient setup. But when i install the headers i can redo it then if needed
Headers on these wake up the entire range.
 

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My core engine came with a set of headers SS look real nice but I questioned the welds. Had my exhaust guy take a look and he was able add material where needed make a shallow cut one side to relieve stress and surface. They line up with a 2 inch opening meeting the 2 inch Y pipe going to my 3 inch back system. Looking forward to hearing the new engine. Steve
 

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Discussion Starter · #12 ·
My core engine came with a set of headers SS look real nice but I questioned the welds. Had my exhaust guy take a look and he was able add material where needed make a shallow cut one side to relieve stress and surface. They line up with a 2 inch opening meeting the 2 inch Y pipe going to my 3 inch back system. Looking forward to hearing the new engine. Steve
Well i bit the bullet and bought a set of the JBA headers today for my truck. Been wanting to add them for the whole 18 years ive owned the truck, just never did until now. But with the black friday deals i was able to get them a bit more reasonable. So as soon as i get them ill get them installed and plumbed into my existing exhaust if i can. I had already installed the 360 throttle body on the truck about a year ago, so this should help with the exhaling a little bit. Still looking at the roller rockers, but that may get pushed back a bit now until i get some more expendable income.
 

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Well i bit the bullet and bought a set of the JBA headers today for my truck. Been wanting to add them for the whole 18 years ive owned the truck, just never did until now. But with the black friday deals i was able to get them a bit more reasonable. So as soon as i get them ill get them installed and plumbed into my existing exhaust if i can. I had already installed the 360 throttle body on the truck about a year ago, so this should help with the exhaling a little bit. Still looking at the roller rockers, but that may get pushed back a bit now until i get some more expendable income.
Can the gaskets that come with the JBA's and get a set of Remflex. No leaks first time out.
 

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Hey Nate, I went on line to buy these gaskets but could not find a way to pay for them. I made the phone call and they said it happens. I ordered them and have a tracking #. Once they arrive I'll get a picture of the three different exhaust gaskets I'll have. Steve
 

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Discussion Starter · #15 ·
Hey Nate, I went on line to buy these gaskets but could not find a way to pay for them. I made the phone call and they said it happens. I ordered them and have a tracking #. Once they arrive I'll get a picture of the three different exhaust gaskets I'll have. Steve
Thank you. I appreciate it
 
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