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Self Aligning 1.6 ratio Roller Rockers

Discussion in 'The Garage' started by sled_dog, May 15, 2003.

  1. sled_dog

    sled_dog 1 ton status

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    Anyone know where to get some Self Aligning 1.6 ratio Roller Rockers? Considering a project and think its gonna have some vortec heads atop it. I know Summit has some but they are $300, just wondering if anyone knows where I could get some just a little cheaper.
     
  2. TX Mudder

    TX Mudder 1/2 ton status

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    PowerHouse makes them, I believe.
    -- Mike
     
  3. sled_dog

    sled_dog 1 ton status

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    just found that at Jegs they have ProForm ones that are only $200.
     
  4. heavy4x4

    heavy4x4 1/2 ton status

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    You need to be really careful with the cam that you pick. For example; a cam that will get you .44" lift at the valves with 1.5 ratio rockers will give you .47" with 1.6 ratio rockers. That's on the very edge of what stock vortec heads can handle.
     
  5. sled_dog

    sled_dog 1 ton status

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    I will upgrade valve springs, and the cam I am thinking pushes the limits itself. I am planning on mimicing a buildup I found online for a 350 bored .060 over with 1.6 rockers vortec heads and 440hp. Should do just fine sitting in a S10.
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

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    Add the machining cost of the Vortec heads for the higher lift to whatever cost you are figuring. Anything over .450 is REALLY pushing the retainer seal clearance, as was mentioned. .050" is the smallest amount of clearance you will find recommended (.060" is more commonly recommended), and you'll hit .050" with a .450" lift cam on Vortec heads.

    And .060" over on a (street?) 350?? Don't think I'd be trying to mimic that. See enough people on here that can't keep their rigs cool, boring a 350 that big and sticking it in a vehicle with even less cooling capability is asking for trouble, especially without having the block tested first.

    Precautions against boring to max diameter are not something to ignore. I've got a motor (non-Chev) that is bored to what is considered "max", and it will NOT stay cool like it should...it's no fun having to keep your eyes on the temp gauge all the time.
     
  7. rodzzilla

    rodzzilla 1/2 ton status

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    Check out Tommy Johnson's. He used to be in IA, now he is in NC. His son races for Don Prudome. Not sure what his Web site is. He used to have them for around $150 for the Proform's.
     
  8. HarryH3

    HarryH3 1 ton status Author

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    Investigate the cost of all the machine work before you commit to the Vortec heads. When you get into that much lift, then in addition to the machine work that Dorian mentioned, you should also have screw-in studs installed. That gets your total out of pocket expense pretty close to the price of a set of aftermarket heads that will flow even better than the Vortecs and will be a direct bolt on. /forums/images/graemlins/cool.gif
     
  9. sled_dog

    sled_dog 1 ton status

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    trying to stay fairly low buck. Gonna check out what a few friends say as far as machinists and builders then talk to them. What are some good factory bolt on heads? $1000 for heads pretty well destroys my budget so yeah. My one friend always says he can get me "fuelie" heads cheap and easy, I have no idea what they are though. Anyone help me out with taht?
     
  10. dyeager535

    dyeager535 1 ton status Premium Member

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    [ QUOTE ]
    My one friend always says he can get me "fuelie" heads cheap and easy

    [/ QUOTE ]

    Generic term referring to the "camel hump" heads that GM produced in the 60's and 70's. "Fuelie" referring to the fact that they were used with the Corvette mechanical fuel injection system, then later used on just about everything.

    Ok head, probably stronger casting than the Vortec, but those heads have pretty much been rejected by everyone except the folks that are forced to run them based on class restrictions in racing. Good porting potential, but the combustion chambers leave something to be desired compared to modern options, besides all the other work thats gone into head design in the last 25 or so years.
     
  11. Diesel Dan

    Diesel Dan 1/2 ton status

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    [ QUOTE ]
    Investigate the cost of all the machine work before you commit to the Vortec heads.

    [/ QUOTE ]

    Machine shop only charged me $50 to cut down the towers and open up the spring pockets on a new set of vortecs. Guy has been running the GM "hot cam" for 2 years now, no issues with the stock studs moving, yet. Cam is .525" at the valve, 1.6 rockers and roller lifters. Rockers still fit under the stock valve covers.
     
  12. HarryH3

    HarryH3 1 ton status Author

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    Sounds like you've been lucky with that setup, or you're running pretty weak valve springs. If you aren't going to wind the engine up to very high revs, then you can get away with that, for a while. But to make the 400 plus HP that sled_dog wants, he's going to have to rev it pretty hard. It takes strong springs to keep the valve train from bouncing when you get into high lifts and high rpms. If it were my engine on the line, I'd want screw-in studs. /forums/images/graemlins/cool.gif
     
  13. Topdown

    Topdown 1/2 ton status

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    Summit has a set of aluminum 1.6's for around $160.00 I believe they are the "summit" brand which means Summit bought a butt-load from proform and are selling them under thier name. /forums/images/graemlins/thumb.gif
    They are full roller rockers, needle bearing fulcrum and roller tips.
     
  14. slimlynn1

    slimlynn1 1/2 ton status

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    If you are running self-aligning rockers I would keep the RPMs under 6K. They do not like to be reved very high. Also Crane does not recomend them with high spring pressures. Self-aligning rockers + high RPMs + High spring pressures= TROUBLE!! As far as I know Crane is the only MFG that makes the narrowed self-aligning rockers that are needed for the center bolt valve covers. They are $300 from Summit.
     
  15. sled_dog

    sled_dog 1 ton status

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    I am going to talk to an engine builder and a few friends. I really don't want to spend $1300 on heads and still ahve to put like roller rockers on them.
     
  16. dyeager535

    dyeager535 1 ton status Premium Member

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    It's true about the high RPM/self aligning "rail" rockers. With the kind of power you are talking, don' tknow as I'd want to do that. The Vortec valve stem sticks up further than earlier styles because of the way they are "guided". Although I've heard it before that you don't want to run rail rockers at very high RPM's, wonder what GM is doing with the 'vette motors and what not. I thought all of them were roller now. Not making 400HP (I don't think) but still, I'm sure those motors are intended to rev.

    I've got a set of Comps pro-magnum steel roller rockers, and the body on them is *wide*. They STILL fit in the stock ceneterbolt valve covers, although you have to modify the valve cover just a hair. About 15 minutes with a grinder, and no mods that you can see, won't hurt sealing or strength, and they will fit no problem. Look at how roller rockers are designed, and you'll notice that they are wide at the trunnion, the piece that doesn't move. Even if you end up with slight interference when you install them, it doesn't matter, the moving parts of the rocker won't hit anything.
     
  17. HarryH3

    HarryH3 1 ton status Author

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    Here are some 2003 'vette specs, from www.chevrolet.com :

    [ QUOTE ]
    The LS1 engine is concealed under the sleek hood of Corvette coupe and convertible models. Technical highlights of this award-winning V8 include lightweight aluminum construction, Sequential Fuel Injection and Electronic Throttle Control. Horsepower is 350 at 5200 rpm. Choose between the available high performance six-speed manual and the standard electronically controlled four-speed automatic transmission.

    The LS6 engine is at the heart of Z06. Producing 405 horsepower at 6000 rpm and mated to a high performance six-speed manual transmission, Z06 is the quickest, most powerful production Corvette ever.

    [/ QUOTE ]

    But these engines have pretty high compression ratios and all the latest electronic engine management tricks. /forums/images/graemlins/thumb.gif
     
  18. HarryH3

    HarryH3 1 ton status Author

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    Aha. Here's some of the stuff that helps the Z06 make so much power:

    " Z06 Exclusive Cylinder-Head Design

    At the heart and soul of the LS6: unique cylinder heads for better engine breathing. Larger ports than those in the LS1 engine also improve airflow by 10 percent. Compression ratio is a healthy 10.5:1. "

    "Z06-Specific Higher Lift Camshaft

    As the intake air comes through the manifolds in greater volume, it is important for the air to enter the combustion chamber as quickly as possible to produce power. The LS6 engine has a camshaft that has higher lift lobes than the LS1, resulting in a 5 percent increase in airflow through the cylinder chamber."

    "Z06-Specific Exhaust Manifold Design

    Compared with the stamped-steel exhaust manifolds used on the LS1, the LS6 cast-iron exhaust manifolds provide improved flow of exhaust gases, increasing both engine performance and durability. A freer-flowing exhaust system increases the exhaust flow out of the engine, further increasing engine power."

    "Z06-Specific LS6 Engine Block

    The all-aluminum LS6 engine block has been refined to enable higher piston speed and higher overall rpm than the Corvette LS1 block on which it is based. Hollow-stem intake valves and liquid alloy exhaust valves are lightweight and designed to maintain solid contact with the rocker arms during high-speed operation. Displacement: 5.7 liters."
     
  19. sled_dog

    sled_dog 1 ton status

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  20. Diesel Dan

    Diesel Dan 1/2 ton status

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    [ QUOTE ]
    Sounds like you've been lucky with that setup, or you're running pretty weak valve springs

    [/ QUOTE ]

    Maybe lucky. The springs and retainers came in the "hot cam" kit from GM. Not sure on HP but had to be close to the 400 mark. 9.6CR, vortec heads, Performer RPM intake, 750 CFM carb and the .525" cam/ full roller.

    The LS6 in the corvette doesn't apply here, different design. The 1996 LT4 however does. They ran that motor fairly high with factory self-aligning roller rockers. I had a set, problem was the were for a metric stud.
     

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