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Discussion Starter #1
Hello guys,
There is a potential group buy on Roller Rockers for the 3.8 going on at V6 power. Both 1.73 and 1.8's may be available if anyone is interested. here is the price info.

These ARE the same rockers Morana sells. They come with pedestals in sets of 16. Buy three sets and get a fourth for free. So four guys split the cost of three sets and pay about $195 plus shipping. That is cheaper than the FMS 173's and adds .020 lift.

In a group buy, if more than 20 sets are bought, they knock off another $25 per set I believe. So if you guys bought 21 sets, you would have enough rockers for 28 people and would bring your costs down to $168.75 plus shipping.
 

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Flex said:
In a group buy, if more than 20 sets are bought, they knock off another $25 per set I believe. So if you guys bought 21 sets, you would have enough rockers for 28 people and would bring your costs down to $168.75 plus shipping.
I saw that. I'd be interested if we could get them for that price, not sure where the cash will come from after Christmas though! :uppoint:

Joe
 

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How would increased valve lift work on a split-port engine? As far as I know, the split-port heads mostly need more exhaust flow. Also, over-camming the 4.2 has proven counter-productive, hasn't it? Reason I am asking is because I am beginning to think ahead for my engine upgrades, and I feel that I should build-up a bit before supercharging... But would I benefit that much from new rockers? I don't know much about these, but will I need stiffer valve-springs? I would like to boost my red-line a bit, but I don't really know what's safe yet.

PJ
 

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Discussion Starter #4
PJ,
They increased lift only works out to .02 over stock with the 1.8's and they may also have the stock 1.73 ration in the buy for those that do not wish the higher ratio.

A mild cam for a split port motor is .505/.495 and that is way more than the added lift would bring you to at .463/.465.

The increase stroke of the 4.2 will just bring your power band sooner and will limit the ability of the engine to rev higher. That is most likely why too large a cam would not do you any good. When my bro converted his 429 to a 460, it stopped reving to 7000 rpm but made way more power. So now there is no point in putting a cam in it that will make power to 7500 rpm cause the engine will never get there. I don't know that it would be detrimental to power but you would never realize the potential of the piece.

The stock lift of the 460 was about .450 and there is a .530 lift cam & spring combo in it now. The power is unreal throughout the curve.

The rockers have numerous benefits over just the lift. They are precisely machined to be identical. Go ahead and find 12 stamped rockers that are the same. On a 5.0 hear in town, my machinist found a range of .02 lift across the set. So some rockers were good, while most were off with the biggest offender providing .015 less lift than it should.
Roller trunion eliminates friction which robs horsepower and can drop temp at the fulcrum by 400 *F. Lets your oil maintain viscosity longer.
The body is more rigid than a stamped rocker and doesn't flex at higher rpm. This allows the engine to run smoother at higher rpms as well and may extend your rpm curve a few hundred rpm.
The rockers also quiet down the valve train. A common complaint on the 3.8/4.2 motor.
 

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Discussion Starter #5
Dude,
Hear is an article I posted at 3.8 Mustang. Keep in mind that the results are not going to be the same as a hopped up V8 but the principles will be the same. That is that the 6 will see the same increases just not the same amounts.

Justang,
I found that rocker article. It is a January 2001 Car Craft. They tested stocked stamped rockers versus various ratio rollers.

Base HP is 389.9 and TQ is 407. Going to 1.5 rollers, HP is 401.1 and TQ is 412.9. That's 11.2 HP and 5.9 TQ. Going to a 1.6 ratio rocker the HP is 413.6 and TQ is 422.8. Finally, 1.65 ration HP is 414 and TQ is 424.3.

As you can see, going to a 1 full ratio roller netted 23.7 HP and 15.8 TQ. This is a V8 but the results speak volumes.

From the same article.

" Second, a higher rocker arm ratio effectively increases the camshaft's lift and duration by holding the valves open farther and longer, allowing more air to flow through the head ports without changing the cam.
 

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Flex, mighty informative. This thread should be sticky. Would I need stiffer valve springs?

PJ
 

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someone better hurry up and get this group buy going...i'm ordering the 1.8's in about a week and a half...
 

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for 300+ dollars Roller rockers just are not worth it, but for 167$ I would get a set for sure. The higher your engine revs the More HP rollerrockers can save. For an engine that only sees 4000rpm its not worth it, but for running 6000+ rpm they are.
 

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hmmm....

Determining how much each specific engine application require is complex and dependent on the intake/exhaust flow characteristics during the overlap triangle in relation to the cubic inch displacement of the cylinder. A V8's cylinder cubic inch displacement is different than a V6's cylinder cubic displacement. I would be wary of assuming the same results netted from a V8 test would net similar results for a V6, however I could be wrong, this is all just my 2 cents. Take it or leave it, or better yet help me learn more about this topic.

The amount of overlap an engine requires to meet the application's needs primarily depends on the rpm involved plus the displacement of the engine in relation to the flow characteristics of the valves at LOW LIFT. Remember low lift is where the valves are during the overlap period. Obviously the more rpm the engine is expected to turn the more overlap required, but only up to a point. If the cubic inches get bigger, more overlap is required for a given rpm band. On the other side of the coin, the greater the low lift flow of the valves, or the faster the valve opening acceration, especially the inlet, the less the overlap required for optimum results. A valid reason for contradicting those who tell you low lift flow does not matter, because it does.

A person should keep in mind the intake-to-exhaust duration needed for each engine. The optimum exhaust-to-intake ratio is influenced by the compression ratio and the rpm. The higher the intended compression ratio is, the less exhaust flow is needed in relation to the intake.

When a cam is selected for a motor, it HAS TO MATCH THE CYLINDER HEAD FLOW CHARACTERISTICS whether they're optimum or not. In other words I would be careful about leaving a stock cam, which is designed to run optimumally with the current heads, in an engine whose heads' flow characteristics are going to be changed. I really do not know if it would be that much of a benefit for a 3.8/4.2 with stock cam to switch to a set of heads with flow characteristics not designed to work with the current stock cam? Maybe someone else here can enlighten me? I am always hoping to learn something new, which is why this site is cool.

I can see how changing the stock head roller rockers to the previously mentioned aftermarket ones, along with A NEW CUSTOM CAM to suit the new flow characteristics of the heads could net great gains. But I am not sure about just putting on some new roller rockers, with a stock cam and hoping to see worth while results? Hmmmm? Just do not know...:) Maybe this is something to think on...
 

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Discussion Starter #10
PJ,
Your engine is too new to see a need for increased spring with only .02 added to the lift. My brother's 3.8 has 220 000 km on it and the rockers did not affect the springs in any way. If anything, it revs up further than before. The motor is glass smooth right up until it shifts and runs absolutely quiet.
Those interested should go to the V6 power link.

http://www.v6power.net/ubb/ultimatebb.php?ubb=get_topic&f=1&t=003468

and add yourself to the gowing list. of people that are interested. So far there are 12 for sures and potentially 7 more including yourselves. There are 4 or 5 other boards involved so 28 is not really out of reach.
 

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Discussion Starter #11 (Edited)
Espicer,
I said that the results were not going to be the same but the priciples of gain will. It doesn't matter what engine you are working on, increased lift will enhance flow and reduced friction will be benefical. Of course it will not be as much as with ported induction but many rodders stick mild cams into stock motors and net gains.
The 3.8 is a big V6 with 38.6 cubic inches per cylinder. A 5.0 only has 37.75 so in essence the cylinder displacement to flow dynamics should be quite similiar if all else is identical.
You are over analizing this. The added .02 lift does not warrant considerations of displacement or cam overlap or flow etc. They are simply a bolt on piece that will compliment any other component that is added. Port the induction and you will improve flow. Add a larger cam and the increased profile of the rockers will not affect spring rate.
 

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i sure hope we could get 28 in a week or so!
 

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Discussion Starter #13
Don't tell me Jim, get your butt over to V6 power and throw your name in the purchase so that they know you are interested. Be sure to say what ratio you are after too.
 

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i said i was down for the 1.8s over there
 

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Discussion Starter #15
I didn't see your name over there unless its jimmyT. There are so far about 20.
 

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jimmyt....thats me!
 

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Discussion Starter #18
I just spoke with Randy Becker of CSP so here it is from himself.

Price per set is $260. So if 4 guys buy 3 sets and split them, cost is $195 plus shipping.

He will knock %20 of 20 or more sets, so the price for 21 sets would be $156 per set not $168.

He will charge an additional $20 per set to machine for an adjustable pushrod cup which the customer would have to buy. It is sold by Crans, Comp etc. Both 1.73 and 1.8 ratios are available.
 

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yeah i'm jim tumminelli...i thought you new that was me...156 is an awesome price! how much do you figure for 12 adjustable pushrod cups?
 

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Discussion Starter #20
Sorry bro,
I figured jimmyt was you but here you have just jim. How did the setup work out with RGR? Did you do the install?

I don't think they would be more than $50. We would have to get a part number and get a price from someone like Summit racing.
 
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