Dropping Valves

Discussion in 'Manton Push Rods Top Alcohol Tech Questions' started by ProMod83, Apr 12, 2009.

  1. Mike Canter

    Mike Canter Top Dragster

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    Will, my 10 year old grandson says that if you need help with the 8973 then just ask him. LOL:D;)
     
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  2. ProMod83

    ProMod83 Member

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    OK guys that for the response. Sonnys did assemble the heads and obviously doesnt know much about how this all should work, considering he sold me the camshaft,pushrods,assembled heads, crank etc etc.

    So i dropped the valve the first time which he though was due to the fact he didnt use hardened tipped valves nor did he leave room for a lash cap with the length of the pushrod so he thought the valve was mushrooming and thats why it pulled thorugh the retainer. So we put it back together with lash caps all new pushrods and did it all over again.

    I decided let me measure some things on my own, the valve was installed at 2.365 and my max lift is .900 so we have .465 or so to coil bind. I have talked to a few guys and everyone agrees we need to be .080 to .100 to coil bind. We also believe that the spring pressure needs to be about 100 or so lbs more than we currently have.

    I bought the heads assembled as we assumed just as some of you assumed that a name like sonny would know the basics but apparently he over looked them with our parts.
     
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  3. Mike Canter

    Mike Canter Top Dragster

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    I would recommend getting different retainers. Like I said to start with the Ti retainers sold by Brad Anderson seems to work very well for most people. I use them on the BBF also.
     
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  4. ProMod83

    ProMod83 Member

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    Mike,

    Are they tripple retainers? 10 deg? Of course we need new ones now that it is broken again.
     
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  5. Mike Canter

    Mike Canter Top Dragster

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  6. ProMod83

    ProMod83 Member

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    that looks idenical to my 10 deg manley. I bet you anything those are manley retainers.
     
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  7. Mike Canter

    Mike Canter Top Dragster

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    Nope, according to BAE they are especially made for them. All retainers look pretty close to the same.
     
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  8. Alkydrag

    Alkydrag Sr. Dragster

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    I don't know if it holds true now, but, a few years ago I tried to order some ti retainers from Manley. They had a manley part number. I called Manley and they asked where I got the number from because it is made for BAE and I would have to order from them. You've got something amiss in your valvetrain. Start with the basics.
    Without ample spring pressure, the lifters won't track the cam correctly, they bounce. When they bounce, the rocker arm loses control of the valve. Valve clearance increases and the valves slam shut instead of closing. When they slam shut, they bounce on the seat. Then it's just a matter of time. To me you have clear signs of weak valve springs. Will is right.
     
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  9. ProMod83

    ProMod83 Member

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    I also agree the spring is our problem. What are most of you guys running for a valve spring? I see Manley on a lot of car, PAC for sure is used a lot. Anyone using the Renton Ti springs? Are they worth the money?

    I only have 2 bent valves out of the deal this time but I am affraid to just put 2 valves in and new springs because I feel maybe these valves are fatigued.

    Thanks,
    Billy
     
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  10. T.Howell

    T.Howell Member

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    Bottlefed, check your math.;)

    Billy, in my opinion the Ti vlave springs are no longer worth the price. Sometime back the Rentons had issues. They might have rectified that by now. We have had good luck with the PAC springs at far less the cost to this point.
    If you have calculated your distance to coil bind correctly, that might be part of your problem. That, along with the fact you effectively had under 200 lbs. of seat pressure left you with a noddle trying to control your valve train. You will need to run much closer to coil bind to control spring surge.
    Check to see the lash caps are not pressing on the keepers instead of the valve tip.

    2.55 valve with 32 lbs of boost:

    2.55 x 2.55 = 6.502
    6.502 x .7854 = 5.107
    5.107 x 32 = 163 lbs backside of valve. Just ignore the stem as it only reduces it by around 4-5 lbs.
    --------------------------------
    2.45 valve with 45 lbs of boost:

    2.45 x 2.45 = 6.002
    6.002 x .7854 = 4.714
    4.714 x 45 = 212 lbs.

    Tom
     
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  11. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    retainers

    Billy,

    I don't think your retainers are the problem. Victory and Manton make great retainers if you want to switch brands.

    Luckily for our bank accounts, steel spring technology has surpassed the Ti Springs as the springs to have on a high revving alky motor. Don't get me wrong, a Ti spring works great, but their reliability over the past few years leaves a lot to be desired. Not to mention they are twice the cost for a set.

    Talk to Noel or Kenny, they'll get you set up with a good spring combo.
     
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  12. Bottlefed

    Bottlefed New to Blowers

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    Bottlefed, check your math. T.Howell you are correct :confused:

    Thanks for the correction, unfortunatly it was not my math, I could not find my calculator and used an online area of a circle calculator on the web, how it got so screwed up I will never know the site works fine now...Errh I guess that would probably mean it was operator error anyway wouln't it :eek:.

    But at least the theory was good, coil bind and not enough seat pressure to control the vavle under boost :rolleyes:



    Richard (back to the 4th grade) Gavle
     
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  13. eli

    eli Banned

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    just a tought, what kind of pressure dose the cam see opening the ex valve, and doesn't the boost help open the intake valve, should the ex valve have more or less seat pressure acording to your calculations, just food for tought. and or a monkey wrench. Gene Terenzio Sr.
     
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  14. GregM784

    GregM784 Member

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    I believe rocker arms on high boost applications are the ones prone to failure, because they are opening against pressure.
     
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  15. Mike Canter

    Mike Canter Top Dragster

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    You mean the exhaust rocker arms?
     
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  16. Dale H.

    Dale H. Member

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    I don't think that the boost on the backside of the intake valve has much effect on valve float. It don't take much spring pressure to hold the valve closed,but it does take alot of spring pressure to reverse the movement of the valve,retainer, rocker arm,push rod and lifter at 8 to 10,000 rpms. Besides the pressure acting on the backside of the valve is most when the valve is closed, once the the valve cracks open,the effect is negligible.My rule of thumb on valve springs is:too much is better than not enough.

    -Dale
     
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  17. shawn davis

    shawn davis Member

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    Sonnys head, like a 2005 or big chief style?
    i hope those are titanium valves to start with, if not get some
     
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  18. GregM784

    GregM784 Member

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    Yes. Thanks Mike. (head up ass syndrome)
     
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  19. Bottlefed

    Bottlefed New to Blowers

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    Hey since I contributed to this whole boost pressure on the intake vavle deal, I assume most of you guys read this board on a regular basis, Noel Manton has been kind enough to come on here and explain that he feels that the boost pressure needs to be considered as a contributing factor for intake valve spring pressure. I was just offering up the information as well since having seen Noel post it I am sure it is valid, the same goes for coil bind, I am sure that if you don't have sufficient room between coils it can cause a myriad of problems in the valve train.

    When I am not sure of something I usually say "this is my 2 cents" since that may be all its worth, however in this case you can take this stuff to the bank.

    As far as any monkey wrench goes I rarely use one but I do have one in my tool box if you need to borrow it ;)


    Richard Gavle
     
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  20. ProMod83

    ProMod83 Member

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    How does everyone feel about keepers? I hear the all the fuel guys use super 7's as they are much better than the 10 deg. Any input?
     
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