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Discussion Starter · #1 ·
Wsup FBN need some advice, so sooner or later I planning on camming my 3800 bird out. My question is what is a good roller rocker set to add to the cam? I already completed the bolt ons phase and I already have most of the cam parts sitting in My room for the heads. All I need now is the cam which im gonna run, the intense s1x cam. I wanna know is there any roller rockers out there fits oem specs, but better. Any advice helps, thanks.
 

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Pretty sure stock is 1.6X

Rocker arm ratio has to be coordinated with cam lift and piston-to-valve clearance. Is may also affect pushrod length. Gross lift has to take into consideration the head flow. No sense opening the valve to 0.600" of the heads stall at 0.500" and flow starts to drop off as lift increases. I don't think the stock 3.8L heads stall and drop off, but there is probably only a little gain over 0.500". Then there's the advantage of getting the most area under the curve by using the higher rocker ratio. Point is, the cam selection, including the rocker ratio, should reflect the flow characteristics of the heads.

Do you want full rollers or roller tip?

Consider the Comp Cams Utlra Pro-Magnum full rollers.
 

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Good call Fred. A lot of builders just stick a massive bumpstick in a motor and think more lift is better(heavier springs???). I need to find a place here locally that can flow bench my heads so I can get them all pretty close and pick a cam lift.
 

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Pretty sure stock is 1.6X

Rocker arm ratio has to be coordinated with cam lift and piston-to-valve clearance. Is may also affect pushrod length. Gross lift has to take into consideration the head flow. No sense opening the valve to 0.600" of the heads stall at 0.500" and flow starts to drop off as lift increases. I don't think the stock 3.8L heads stall and drop off, but there is probably only a little gain over 0.500". Then there's the advantage of getting the most area under the curve by using the higher rocker ratio. Point is, the cam selection, including the rocker ratio, should reflect the flow characteristics of the heads.

Do you want full rollers or roller tip?

Consider the Comp Cams Utlra Pro-Magnum full rollers.
Which well be better? Full roller or tips. I was thinking full, but if I don't really need all that I'll just get tips. How about the ratio? I was thinking a 1.7 might be a good fit. Are those comp cam rockers compatible for the 3.8 engine?
Good call Fred. A lot of builders just stick a massive bumpstick in a motor and think more lift is better(heavier springs???). I need to find a place here locally that can flow bench my heads so I can get them all pretty close and pick a cam lift.
what you thinks Will fit my setup? The cam im getting is a mild one, should I upgrade the roller rockers even thought the cam is mild?
Good call Fred. A lot of builders just stick a massive bumpstick in a motor and think more lift is better(heavier springs???). I need to find a place here locally that can flow bench my heads so I can get them all pretty close and pick a cam lift.
what you thinks Will fit my setup? The cam im getting is a mild one, should I upgrade the roller rockers even thought the cam is mild?
 

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']['exXxas']['itan
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What I think Fred was saying is there is no sense in exceeding your total max flow lift of the heads. Thats what needs to be key here. Some heads dont flow well over .500 lift, some pick up after .550 lift. It all depends on the port design ect of the head. There is no sense in running a total lift (cam lobe lift x rocker ratio= total lift) beyond the heads capacity. E.g. your heads flow say 200cfm @ .480" lift, but really dont pick up much CFM after .500" lift, why run a total lift of .580"? All it does is drive up the spring rate requirement, and puts more stress on the valve train all together. Need to do some research for flow numbers @ given lift conditions on your heads. Should be plenty of info available via google. Once you have that, then lift is the easy part. LSA and duration ect come into play next determining your power band, idle conditions, dynamic compression, ect..

Personally I prefer stock ratio rockers but to each their own. Seems less stressful on the stud bosses, less stud flex, and rocker arms when greater distance from the pushrod to the rocker pivot point exists. just my .02c

Valve lift is valve lift, regardless of how you achieve it.
 

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I don't know a lot about the 3.8L V6. Seems like there are a few V6 addicts on the site who have done their research, tracked down the best parts, and have built, or are building what appear to be some impressive engines. What I was going after was to make sure you understood that cam, and valve train selection is a very complex issue. Derrick explained it very well, and raised additional points like rocker stud considerations.

My first goal was to find a good set of heads. Stock LT1/LT4 heads can be ported to flow extremely well. Back in 1999 when I was in the market, I found a supplier and had them shipped to my engine builder. First thing they did was flow them on their bench, and compare them to other LTx heads they had used. For that point in time, they were just about as good as they had seen (technology has continued to advanced where ported stock LT4's can exceed 300 CFM). The shop also listened to the head porter, who claimed that his matching ported LT4 intake manifold would actually improve flow. They tested that, and verified that flow increased 3% with the manifold installed. Other setups they had tested usually lost flow when the manifold replaced the standard inlet fixture. They were close to 300 CFM at 0.700" lift. A few CFM less between 0.650 and 0.700. The exhaust on the other hand did not impress them.

Now the strategy got complex. We wanted a street cam with decent manners, that would pass NJ rolling emissions. Then it had to be able to support a 300 HP shot of nitrous. Nitrous needs big exhaust and minimum overlap. We came up with the idea for a solid roller cam, with 0.590 intake / 0.590 exhaust, 230 I / 242 E 114 LSA. Being concerned about low exhaust flow numbers, they achieved the 0.590" gross lift with a 1.6X rocker on the intake, and a 1.55X rocker on the exhaust, allowing them to step up to 1.6X on the exhaust, in case they needed more lift if there was evidence of problems on the dyno. They saw little benefit in going anywhere near the 0.700" max flow lift, because the added stress on the valve train wasn't worth it.

Without the nitrous, 496 HP, shifting at 6,400 RPM. With the nitrous, 800 HP shifting at 7,000 RPM. Over 700 lb-ft between 5,000 - 7,000 RPM. Engine redline 7,200 RPM.

Now to hold the valve train together. Crower Cutaway solid roller lifters, 3/8" chrome moly pushrods, Comp Pro Magnum non-self aligning full roller rockers, PSI springs that apply almost 600 # at max lift, titanium locks, 7/16" rocker studs. We were borderline on the rocker studs. Stock is 7/16" threads into the heads, 3/8" stud for the rocker. 7/16" stud for the rocker was mandatory, T&D shaft rockers were given consideration, but we went with the 7/16".

A lot of info, probably boring, but just an idea of the level of thought that went into the valve train. And the expertise all came from the engine shop. I was just glad they involved me in the process so I could learn.

And YES you want full roller rockers. Roller trunion bearing and roller tip. Frees up HP and reduces oil temp gain by eliminating friction. Consider whether the 3.8 uses self-aligning or non-self aligning rockers. Consider whether the 3.8 head has pressed or screwed rocker studs, consider the diameter options for the studs. Consider whether the 3.8 can use a standard width rocker or a narrow body rocker. If you are changing the pistons or milling the heads, consider a fit up with clay to verify P-T-V clearance. Use a pushrod measuring tool to find the pushrod length that puts the roller tip range of contact on the correct place on the valve tip.

As I mentioned, I don't know the answer to any of those issues for the 3.8. You need to do the research, or find a reliable source of the info. If you are basically working with stock components and just changing the cam, all this gets simpler, because you can probably find someone who was used that cam and knows the answers.
 

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"http://www.3800performance.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=MS-RA&Category_Code=CVT&Product_Count=0"]http://www.3800performance.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=MS-RA&Category_Code=CVT&Product_Count=0
I don't know a lot about the 3.8L V6. Seems like there are a few V6 addicts on the site who have done their research, tracked down the best parts, and have built, or are building what appear to be some impressive engines. What I was going after was to make sure you understood that cam, and valve train selection is a very complex issue. Derrick explained it very well, and raised additional points like rocker stud considerations.

My first goal was to find a good set of heads. Stock LT1/LT4 heads can be ported to flow extremely well. Back in 1999 when I was in the market, I found a supplier and had them shipped to my engine builder. First thing they did was flow them on their bench, and compare them to other LTx heads they had used. For that point in time, they were just about as good as they had seen (technology has continued to advanced where ported stock LT4's can exceed 300 CFM). The shop also listened to the head porter, who claimed that his matching ported LT4 intake manifold would actually improve flow. They tested that, and verified that flow increased 3% with the manifold installed. Other setups they had tested usually lost flow when the manifold replaced the standard inlet fixture. They were close to 300 CFM at 0.700" lift. A few CFM less between 0.650 and 0.700. The exhaust on the other hand did not impress them.

Now the strategy got complex. We wanted a street cam with decent manners, that would pass NJ rolling emissions. Then it had to be able to support a 300 HP shot of nitrous. Nitrous needs big exhaust and minimum overlap. We came up with the idea for a solid roller cam, with 0.590 intake / 0.590 exhaust, 230 I / 242 E 114 LSA. Being concerned about low exhaust flow numbers, they achieved the 0.590" gross lift with a 1.6X rocker on the intake, and a 1.55X rocker on the exhaust, allowing them to step up to 1.6X on the exhaust, in case they needed more lift if there was evidence of problems on the dyno. They saw little benefit in going anywhere near the 0.700" max flow lift, because the added stress on the valve train wasn't worth it.

Without the nitrous, 496 HP, shifting at 6,400 RPM. With the nitrous, 800 HP shifting at 7,000 RPM. Over 700 lb-ft between 5,000 - 7,000 RPM. Engine redline 7,200 RPM.

Now to hold the valve train together. Crower Cutaway solid roller lifters, 3/8" chrome moly pushrods, Comp Pro Magnum non-self aligning full roller rockers, PSI springs that apply almost 600 # at max lift, titanium locks, 7/16" rocker studs. We were borderline on the rocker studs. Stock is 7/16" threads into the heads, 3/8" stud for the rocker. 7/16" stud for the rocker was mandatory, T&D shaft rockers were given consideration, but we went with the 7/16".

A lot of info, probably boring, but just an idea of the level of thought that went into the valve train. And the expertise all came from the engine shop. I was just glad they involved me in the process so I could learn.

And YES you want full roller rockers. Roller trunion bearing and roller tip. Frees up HP and reduces oil temp gain by eliminating friction. Consider whether the 3.8 uses self-aligning or non-self aligning rockers. Consider whether the 3.8 head has pressed or screwed rocker studs, consider the diameter options for the studs. Consider whether the 3.8 can use a standard width rocker or a narrow body rocker. If you are changing the pistons or milling the heads, consider a fit up with clay to verify P-T-V clearance. Use a pushrod measuring tool to find the pushrod length that puts the roller tip range of contact on the correct place on the valve tip.

As I mentioned, I don't know the answer to any of those issues for the 3.8. You need to do the research, or find a reliable source of the info. If you are basically working with stock components and just changing the cam, all this gets simpler, because you can probably find someone who was used that cam and knows the answers.
Yikes that's a lot lol. At least you achieved what you was aiming for Fred, this is not boring, this is valuable information. Question like these need to be ask so we learn on what we getting ourselves into.. I'm going to have to do some more digging, cause internals are bit more complicated. But what you think about this set of rockershttp://www.3800performance.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=MS-RA&Category_Code=CVT&Product_Count=0
 

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Those are only roller pivot, not full roller. Also they take stock rockers and modify them? No way ho-zzay...just my .02c but if your going to invest money in a good set of rockers, I'd steer clear of modified stock GM stuff.
 

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Crane cam p/n: CRANE-144750-12 1.75 ratio

Comp cam p/n: COMP-1375-12 1.75 ratio

Comp cam p/n: COMP-1370-12 1.8 ratio

Crane cam p/n: CRANE-144759-12 1.8 ratio

www.ftpp.net/v6/internal engine/V6 Rocker Arms.htm

Chatted with Summit, they dont have them and say they cant get them...I call BS but whatever.
 

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Discussion Starter · #15 ·
Those are only roller pivot, not full roller. Also they take stock rockers and modify them? No way ho-zzay...just my .02c but if your going to invest money in a good set of rockers, I'd steer clear of modified stock GM stuff.
Yeah You Right, sounds sketchy.. I might just try the intense racing roller rockers like Fred mention.
 

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Discussion Starter · #16 ·
Since you have the Intense cam, why not ask Intense for input. They sell the Yella Terra full roller rockers in various ratios (1.6, 1.7, 1.8, 1.9). Not cheap, but includes pushrods, guide/pedestal and bolts. The CC Ultra Pro-Magnum are less expensive, but I can't find an application specifically for the V6.

http://intense-racing.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=IR&Product_Code=3800-YTRR-yyy&Category_Code=3800_HCV
I have been leaning towards intense racing YT rockers set for the longest. I already have lightweight pushrods from them, maybe I can just get the rocker set without the pushrods that comes with it.. What ratio should I get? I was thinking 1.7 ratio.
Crane cam p/n: CRANE-144750-12 1.75 ratio
Comp cam p/n: COMP-1375-12 1.75 ratio

Comp cam p/n: COMP-1370-12 1.8 ratio
Crane cam p/n: CRANE-144759-12 1.8 ratio

www.ftpp.net/v6/internal engine/V6 Rocker Arms.htm

Chatted with Summit, they dont have them and say they cant get them...I call BS but whatever.
That's suck.. My only option is intense racing YT roller rocker set. I Actually been eyeing them for a good while now since I am getting the intense s1x cam from them too. It make sense.
 

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I would ask Intense what they recommend for your specific heads.
 

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You haven't explained your build yet, what you will be using it for, boosted, nitrous, N/A, ported heads, intake, TB?
 

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You haven't explained your build yet, what you will be using it for, boosted, nitrous, N/A, ported heads, intake, TB?
This build is mainly to accommodate for all the bolt ons that I put on my car, its a N/A engine so it needs all the support for futures builts. Also I think YT roller rockers set will very well help the breathing.. I should have good results from this, especially since all the old oem parts has been replaced.. In the future im thinking of putting a SC in.
 

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I don't think the YT rockers will fit under the stock valve covers. Double-check with Warshrike though, he was running them at some point.
 
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