History repeats itself. The turbo car is broken again and will be for a while..

Discussion in 'Small Block Tech' started by jay3000, Apr 24, 2011.

  1. jay3000

    jay3000 RIP 1-16-21

    Believe it or not.. I called and the knowledge here is far superior..
     
  2. DaWildcat

    DaWildcat Platinum Level Contributor

    Good grief! Kudos to V8Buick, too bad for Fastenal!

    Devon
     
  3. jay3000

    jay3000 RIP 1-16-21

    I would love to be able to use something like that, but that fastener would be too big to fit. The plate is only 3/8 thick with only an additional 1/8 inch under the rockers. So it can only sit a max of 1/8 above the plate unless I found some different shaped rockers.. Plus the fact that the plates already have a v shaped countersink.. Too late to change that..
     
  4. Big Matt

    Big Matt Well-Known Member

    Just a suggestion here, maybe try going to the nearest college/university and getting somebody in their engineering department to weigh in on the selection? I bet they could also do some failure and/or fatigue testing on several fasteners and then you could pick the strongest one. I'm sure there's a grad student (or even undergrad) that would be willing to do it for free.
     
  5. jay3000

    jay3000 RIP 1-16-21

    Once he found out I was not looking to buy thousands of them, only 8, he was ready to go.. Guess I can see that..
     
  6. jay3000

    jay3000 RIP 1-16-21

  7. bammax

    bammax Well-Known Member

    If you're running a conical countersink than you could cut it to a squared countersink easily. What you already have will work to ensure proper alignment also. Just bring the diameter at the top of the hole down about halfway (3/16"). That will allow you to use a full headed cap screw like the one GSJohnny pictured. I figure 3/16" deep will leave you with half the thickness of the plate untouched to ensure not too much weakening occurs at the hole.
     
  8. jay3000

    jay3000 RIP 1-16-21

    Alright.. I think here's what I've decided to do. Use the full headed capscrew in the link. Cut a squared countersink the diameter of the head down 3/16".. That will leave 3/16" of the head above the plate which is too much, but I can massage that a little with the grinder and make that work fine.. This one has a 180,000 PSI tensile strength.. it's 3/8-24..

    http://www.mcmaster.com/#socket-head-cap-screws/=c8d93i

    I can't find a shouldered fastener that will work with the dimensions I have.. Geee.. I've learned so much..
     
  9. gsjohnny1

    gsjohnny1 Well-Known Member

    forget stainless. its not made to handle this situation. shcs is ok, but the shoulder screw is made for vertical use and its offers location and vertical strength. but nothing beyond this will solve the end rocker from coming up. you have to build linear strength on the plate which you currently cant do unless you have a new thicker plate. your old plate is bent. molecules are scattered. it has lost its originality for a lack of a better description. you need a new thicker plate or use shaft mounted chevy rockers.
    :Smarty:
     
  10. jay3000

    jay3000 RIP 1-16-21

    The link doesn't work right..
     
  11. jay3000

    jay3000 RIP 1-16-21

    Here are the specs on what I referenced. It's way beefier than what is in there now..

    <TABLE id=ItemAttributesTable cellSpacing=0 cellPadding=0><TBODY><TR class=featValRow><TD class=featureNameCell>Head Style


    </TD><TD class=featureValueCell>Standard


    </TD></TR><TR class=featValRow><TD class=featureNameCell>Standard Head Style


    </TD><TD class=featureValueCell>Standard


    </TD></TR><TR class=featValRow><TD class=featureNameCell>Material Type


    </TD><TD class=featureValueCell>Steel


    </TD></TR><TR class=featValRow><TD class=featureNameCell>Finish


    </TD><TD class=featureValueCell>Black-Oxide


    </TD></TR><TR class=featValRow><TD class=featureNameCell>Class


    </TD><TD class=featureValueCell>Not Rated


    </TD></TR><TR class=featValRow><TD class=featureNameCell>Drive Style


    </TD><TD class=featureValueCell>Hex Socket


    </TD></TR><TR class=featValRow><TD class=featureNameCell>Inch Thread Size


    </TD><TD class=featureValueCell>3/8"-24


    </TD></TR><TR class=featValRow><TD class=featureNameCell>Length


    </TD><TD class=featureValueCell>5/8"


    </TD></TR><TR class=featValRow><TD class=featureNameCell>Thread Length


    </TD><TD class=featureValueCell>Fully Threaded


    </TD></TR><TR class=featValRow><TD class=featureNameCell>Thread Direction


    </TD><TD class=featureValueCell>Right Handed


    </TD></TR><TR class=featValRow><TD class=featureNameCell>Tip Type


    </TD><TD class=featureValueCell>Plain


    </TD></TR><TR class=featValRow><TD class=featureNameCell>Self-Locking Method


    </TD><TD class=featureValueCell>None


    </TD></TR><TR class=featValRow><TD class=featureNameCell>Screw Quantity


    </TD><TD class=featureValueCell>Individual Screw


    </TD></TR><TR class=featValRow><TD class=featureNameCell>Hex Size


    </TD><TD class=featureValueCell>5/16"


    </TD></TR><TR class=featValRowHL><TD class=featureNameCell>Head Diameter


    </TD><TD class=featureValueCell>9/16"


    </TD></TR><TR class=featValRow><TD class=featureNameCell>Head Height


    </TD><TD class=featureValueCell>3/8"


    </TD></TR><TR class=featValRow><TD class=featureNameCell>Rockwell Hardness


    </TD><TD class=featureValueCell>Minimum C39


    </TD></TR><TR class=featValRow><TD class=featureNameCell>Minimum Tensile Strength


    </TD><TD class=featureValueCell>180,000 psi


    </TD></TR><TR class=featValRow><TD class=featureNameCell>Thread Fit


    </TD><TD class=featureValueCell>Class 3A


    </TD></TR><TR class=featValRow><TD class=featureNameCell>Specifications Met


    </TD><TD class=featureValueCell>American Society for Testing and Materials (ASTM)


    </TD></TR><TR class=featValRow><TD class=featureNameCell>ASTM Specification


    </TD><TD class=featureValueCell>ASTM A574


    </TD></TR></TBODY></TABLE>
     

    Attached Files:

  12. jay3000

    jay3000 RIP 1-16-21

  13. online170

    online170 Well-Known Member

    sounds like a plan!

    Jay, stupid question, since im not very familiar with the conversion, but why are you limited to a 3/8 diameter screw?
     
  14. gsjohnny1

    gsjohnny1 Well-Known Member

    won't work. chevy vs buick valve are not in the same position. shoulder screw is better.
     
  15. jay3000

    jay3000 RIP 1-16-21

    Ah.. Yes the spacing is different.. Still stiicking with my last idea to use a 3/8-24 socket head cap screw. Can't find a shoulder screw that will work. A thicker plate would mean milling more off the heads to get the geometry right and running out of thread depth..
     
  16. jay3000

    jay3000 RIP 1-16-21

    Scared to weaken that area any more.. Go back and look at the pictures of the area where the fastener broke. What's there is a 5/16"..
     
  17. bammax

    bammax Well-Known Member

    I know this is not really a good idea at the moment, but maybe something to consider for the future.

    How about making a 1 piece aluminum support that mounts on the perimeter of the head, basically like a valve cover spacer, and has bridges that run across the head to hold down the roller shafts. That way the load is spread out over a larger area and there's less chance of flexing.

    Like a block girdle but on the head instead.
     
  18. Big Matt

    Big Matt Well-Known Member

    I like that idea.

    This might be too late also but what about making the stud plate shaped like an "L" rather than a flat plate? I bet Mark could do it; the long part of the "L" holds the studs like before while the short part acts like a beam to resist the bending of the plate, exactly like a structural element. The short side could stick up towards the intake inside the valvecover. I don't know if there's enough room for it to point down, but maybe depending on how much of the pedestal mounts are milled off?
     
  19. Jim Blackwood

    Jim Blackwood Well-Known Member

    Best idea I've heard for awhile, it'd be stronger if you could use a "U" shape, and if you know anyone with a hydraulic press brake they could probably bend that out of 3/8" plate for you. Alternatively you could use rectangular bar stock and run a ball end mill down the center of it to get lifter clearance.

    JB
     
  20. jay3000

    jay3000 RIP 1-16-21

    The pushrod guides cut into it are on the intake side, so that won't work, but it could be made so that the short side of the L is beside the springs.
     

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