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1.6 rocker arms?

Discussion in 'The Garage' started by Chevy305, Dec 13, 2006.

  1. Chevy305

    Chevy305 6 Lug 14bsf Status Premium Member GMOTM Winner

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    I was thinking that if the stock rocker arm ratio of my 83 305 is 1.5:1, why shouldn't I put in 1.6 rocker arms? Essenctially i would be increasing the lift on the cam and hence getting more power right?

    Well being that my 305 has all stock internals, would there be any side effects in the valve train?

    My 305 is from a 83 Firebird L69 if that matters...
     
  2. sandawgk5

    sandawgk5 3/4 ton status

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    It can be done but I would recommend checking valve to piston clearance before doing it. It you have too much lift you can put a valve through the piston. I think .001-.003 is recommended but do not quote me on that.

    Ira
     
  3. Chevy305

    Chevy305 6 Lug 14bsf Status Premium Member GMOTM Winner

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    Well, how do I check it?

    I'm pretty sure the L69s had flat top pistons if that helps.
     
  4. 1979jimmy350

    1979jimmy350 1/2 ton status

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    the best way to check it is take the head off and use clay to be able to measure the clearence
     
  5. 76zimmer

    76zimmer Flyin Rat Premium Member GMOTM Winner

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    You need .080 to .100 clearance on the valves. I don't think you'll even come close with stock valvetrain.
     
  6. sandawgk5

    sandawgk5 3/4 ton status

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    I thought mine was a little too close:doah:.

    Ira
     
  7. blazinzuk

    blazinzuk Buzzbox voodoo Premium Member GMOTM Winner

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    Yah stock blocks aren't exactly zero decked, in otherwards TDC isn't dead even with the top of the block. I really really doubt you will have any problems with valve to piston clearance. I say go for it
     
  8. garlicbreath

    garlicbreath 1/2 ton status

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    Most people run into issues with the pushrod slot not being long enough on stock heads.
     
  9. MaxPF

    MaxPF 1/2 ton status

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    That and the stock springs aren't designed for a lot of lift. If you put em on be sure to check for coil bind. Most cam manufacturers specify .060" clearance. That is an aggregate measurement, meaning that is how much more the spring should be able to compress when the valve is fully open.
     
  10. Chevy305

    Chevy305 6 Lug 14bsf Status Premium Member GMOTM Winner

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    Well, I guess there is only one way to find out...

    I think I'll buy some over xmas break. If I break something, it will be over the break and I will have time to fix it. Also it'll be a perfect excuse to get a valve job ;)

    So what kind would be the best for me to get? Full roller aluminum, roller tipped steel, or just stamped steal?
     
  11. RustBuket

    RustBuket 1/2 ton status

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    For 305 with stock internals I think stamped steel would be just fine...
     
  12. pauly383

    pauly383 Daddy383 Staff Member Moderator

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    Full roller is of course the best , less friction , and smoother , closer to its stated ratio than stamped steel . Why don't you get 1.5 ratio full rollers , and of course see an improvement .

    That said , my 83 305 with the 9.2:1 compression , runs great without any thing except TLC .
     
  13. Chevy305

    Chevy305 6 Lug 14bsf Status Premium Member GMOTM Winner

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    Well, my 305 runs really strong, I'd just like a little more power out of it to roast the tires on comand, and not have to find the right surface to just squeak out a 15ft peal out. I did get a brake stand going once, but I ended up breaking an axel :rolleyes:. Well actually my 305 does have plenty of power, but without really tearring into the engine I'd like more power, I mean who doesn't?
     
  14. pauly383

    pauly383 Daddy383 Staff Member Moderator

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    I tell you what , I will send supersize75 out to be your buddy :p:
     
  15. Chevy305

    Chevy305 6 Lug 14bsf Status Premium Member GMOTM Winner

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    Ya **** happens... :rolleyes:


    My 10bolt has never complained until I tried that brake stand. :eek1:
    I plan on getting a 14b soon though so I can actually complete one ;)
     
  16. pauly383

    pauly383 Daddy383 Staff Member Moderator

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    If you want to spend money on a 305 , try a 400 crank . You can make a 334 with .030 over .

    I am just swapping when mine expires :thumb:
     
  17. Chevy305

    Chevy305 6 Lug 14bsf Status Premium Member GMOTM Winner

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    Well I'm not going that far...

    If were going to sink that much into an engine to put a 400 crank in it, why not get another 50 cubes, or better yet just start off with a 400.
     
  18. MudFlap

    MudFlap 1/2 ton status

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    You should be fine with just stamped steel 1.6 rockers, if you have the money buy a good set of roller rockers, you can always swap them to another motor if you build one. The springs should be fine, they should not bind, but you can also get springs for cheap now would be time to do it since you'll already have your rockers off. you won't have any piston to valve interference problems.
     
  19. diesel4me

    diesel4me 1 ton status Premium Member

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    stamped steel...

    If I remember correctly, the 400 SB uses 1.6 ratio rockers factory..so if you bought stock replacement ones, they should bolt right on,and still be reliable..

    I've seen aluminum roller rockers wear out on the street pretty quickly..I think they are meant more for drag racing engines that get rebuilt after one or two seasons,more than a daily driver sort of motor..:crazy:
     
  20. Chevy305

    Chevy305 6 Lug 14bsf Status Premium Member GMOTM Winner

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    how a about roller tip stamped steel rockers?
     

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