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Will self aligning roller rockers work on 86-earlier style heads?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by BayouBlazer88, May 19, 2003.

  1. BayouBlazer88

    BayouBlazer88 1/2 ton status

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    The reason I'm asking is that I've already got a brand new set of self aligning roller rockers which I bought on ebay so I can't return them. At the time I was just planning on doing the Vortec conversion with the Vortec kit that Scoggin Dickey sells, but after reading a few posts bashing Vortec heads, I've changed my mind to getting World S/R Torquers instead since I won't have to buy a new intake and for other reasons. And while we're on the subject of Vortec heads, is there anyone out there that has done the switch? How do you like it? Do you wish you had gone with something like the S/R Torquer heads instead?
     
  2. sled_dog

    sled_dog 1 ton status

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    I was considering vortecs but I think I am going the factory 2.02 route or World Products Sportsman II heads. If I go aftermarket I think it will almost definetally be those. Cheap iron heads that seem well designed still. Heard nothing but good things so far.
     
  3. dyeager535

    dyeager535 1 ton status Premium Member

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    Apparently most of the time you *can* use the guided ones on non-guided heads, the problem is that you run the chance (and probably fairly good one at that) of pushing the retainer down with the "rails", which will let the locks fall out, and boom, you've got a serious failure.

    I know I've posted a few times in response to your questions, but yet another I feel compelled to give my opinion on.

    The Vortec/other head debate is really almost too complex for most people to objectively say is better than the other. Both have benefits and downsides, but it really depends on what you need. Like you said, the intake for one is an issue. If you had an older engine, your choice would have been even easier, right?

    I'm going TPI/Vortecs on mine, and had I known/had they been available at the time, I probably would have gone with the E-Tecs. Then again, that opens up another can of worms, but in my case, the only intake I can run with Vortecs is $400. That basically kills ALL of the cost savings of the Vortecs right there. But thats my personal issue, everyone will have different. Heck, World heads probably would have worked for me ok too...EGR in the heads, 64CC, older intake pattern, etc. You just can't win, kind of like building a computer, too many paths to take. /forums/images/graemlins/smile.gif
     
  4. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

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    Yes they will work so long as you drill out the guided holes in the heads so that the rocker arms don't bind the pushrods. If you have the guided hole in the head as well as the rail rockers you have a chance of the pushrods binding up and bending on you.
     
  5. dyeager535

    dyeager535 1 ton status Premium Member

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    [ QUOTE ]
    Yes they will work so long as you drill out the guided holes in the heads so that the rocker arms don't bind the pushrods.

    [/ QUOTE ]

    Compare valves. The groove cut in the Vortecs (for instance) for the locks are different. The rail rocker valves are set up with extra length at the top above the retainer, so the rail won't come in contact with the retainer. GM didn't have to worry about extra rocker to retainer clearance when they weren't using rail rockers. This is why it's dangerous to try.
     
  6. BayouBlazer88

    BayouBlazer88 1/2 ton status

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    The heads I'm actually getting are the 87-up style (part# 042770-1) but I don't think that makes a big difference, I think they are still setup for early style rockers. Anyway, so you're saying I'd need to get the non-self aligning type roller rockers instead, otherwise I run the risk of damaging the pushrods and other stuff? Man, this rebuild keeps getting pricier by the day. Oh well, looks like its time to spend some more money. Thanks for the help.
     
  7. jms

    jms 1/2 ton status Author

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    I've done the switch a little more than a year ago. '85 K5 w/ about 37k miles on a rebuilt 350. Vortec heads, spreadbore EGR intake, Edelbrock TES headers w/AIR, used the O2 sensor port on the driver's side header to plumb the EGR tube that connects back up to the intake. Rockers are stamped/self-aligning, maybe I should have done rollers but the $$ were adding up at the time, so I stuck with the regular ones. Cam is (still) stock, but the top end makeover really woke up the motor.

    Driveability is greatly improved - even my harshest critic (my wife) agrees. The motor used to wheeze at about 3200rpm; now you can rev it over 4000 without any problems. It also pulls nicely at low rpm, which is why I haven't touched the cam. With the increased compression, the motor runs a bit hotter than before. I've switched to electric fans, and may have to tinker with the whole cooling system a bit more; I'm suspecting that my radiator isn't helping as much as it should.

    I'm happy with the way it runs; still have carb issues every once in a while. I found that jetting the Q-Jet down by two jet sizes helped a lot, and I haven't had an issue w/ detonation - presumably due to the Vortec heads.

    Now, I didn't try to squeeze every last bit of performance out of this motor, just looking for improved everyday driveability as in throttle response, acceleration on freeway on-ramps, holding speed uphill, and good pulling power from low rpm; for that, redoing the top of the motor with vortec heads worked really well.
     
  8. marv_springer

    marv_springer 1/2 ton status

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    [ QUOTE ]
    And while we're on the subject of Vortec heads, is there anyone out there that has done the switch? How do you like it? Do you wish you had gone with something like the S/R Torquer heads instead?

    [/ QUOTE ]

    My present motor:

    355, 9:1 CR, Vortec heads, Edelbrock intake, Q-jet, 204/214-112 cam


    The motor before was:

    355, 9:1 CR, S/R Torquer heads (2.02), Weiand "Action +" intake, Q-jet, 214/228-112 cam

    The Vortec motor runs better in every situation except over 4500 rpm. Since I didn't really need a high rpm screamer in my Blazer, I very much prefer the Vortec motor...

    /forums/images/graemlins/tongue.gif Just my .02

    Marv
     
  9. BayouBlazer88

    BayouBlazer88 1/2 ton status

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    thanks for the info guys. the only difference between you and me is that I'll be using TBI instead of a carb. but its good to hear that you're happy with the switch. I'll probably end up going with Vortecs now, it'll be a much easier swap. By the way, what octane gas do you use in your motors now that they have Vortec heads? thanks.
     
  10. dyeager535

    dyeager535 1 ton status Premium Member

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    Running up to about 9.5:1 on the Vortecs should be no problem on 87. My setup is 9.2:1, and I built it fully intending to run 87 octane. /forums/images/graemlins/smile.gif

    IIRC, the Vortec motors are 9:1+, and require 87, so at least there is a definite baseline.
     
  11. jms

    jms 1/2 ton status Author

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    I'm running 89 most of the time, but that's mostly because it's the cheapest around here - Nebraska, with growing all that corn, is subsidizing the gas that contains 15% Ethanol (which is made from corn, of course). I haven't noticed a difference to the 87 regular.

    I should add one more thing, although I don't know whether that applies to a TBI motor: I've managed to hook up all the emmissions equipment as before, same vacuum line routing etc. Only exception was the heat riser valve. Ain't going to work as the vortecs have no exhaust crossover; I tried to hook it up anyway, and a blown heat riser gasket tought me otherwise, so I connected that vacuum line after I plugged it shut. But since I've vowed to no longer drive the truck in the winter, the slightly longer warm-up period won't matter anymore.

    Actually, another piece of info: the oxygen sensor port thread is 18mm; I managed to get a fitting (1/2 inch pipe flare / 90 degree angle / 18mm thread / soft aluminum as gasket) to connect the EGR tube from a hydraulics store; the tube was short so I used about 5 inches of 1/2 inch flared pipe to connect to the header. Just FYI.
     
  12. BayouBlazer88

    BayouBlazer88 1/2 ton status

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    Well as far as the EGR system goes, Scoggin' Dickey sells an EGR adapter that connects to the header, being that I need the Oxygen sensor port for TBI. I've never seen the adpater so I'm not sure how or where it connects to the header, but at least it's there.

    And correct me if I'm wrong, but I don't think TBI motors have heat risers so I don't think I'll have to worry about that. Well, thanks for all the help guys. I'll probably order the heads and intake in a couple of days.
     

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