Two stepping

Discussion in 'Manton Push Rods Top Alcohol Tech Questions' started by Bob sherry, Nov 20, 2017.

  1. Bob sherry

    Bob sherry New Member

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    does stepping on and off the pedal cause extra load on a blown alcohol engine and push gaskets out along with other damage
     
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  2. aj481x

    aj481x Member

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    Probably not, a lot of blown alcohol motors have been "pedaled" without obvious damage. Of course this assumes that the motor was setup and tuned right in the first place.
     
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  3. Bob sherry

    Bob sherry New Member

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    Will Hanna Do you have anything to add to that , this is an arias blown hydro with a 60 over whipple . The new prop surprised the pilot so he gave it a big peddle at 1/8 mile 153 mph and it pushed the head gasket out of no 3,5 and 7 cylinders . It did the same thing once before when he fitted too big a prop and loaded the hell out of it on the hit , just curious if this rings a bell thanks.
     
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  4. Mike Canter

    Mike Canter Top Dragster

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    So if you are pedaling and blowing head gaskets then do you have a WOT switch that actives timing or fuel control? If so then that is most likely the cause. Something that may help us to know what is going on is if any of the rod bearings are smashed, or the rings are pinched or the spark plugs are damaged in any of the cylinders?
     
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  5. Bob sherry

    Bob sherry New Member

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    No mate there are no switches or damaged bearings and rings just a simple 18 gallon waterman pump and high speed . 8 nozzles in hat and 8 in ports , ex temps are 950 1000 at end of run normally . Full 1/4 mile over here in Australia
     
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  6. Mike Canter

    Mike Canter Top Dragster

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    Another question then. Do you torque your head bolts in the conventional way starting in the middle and working out or do you torque them starting all the way out and working in.
     
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  7. Bob sherry

    Bob sherry New Member

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    We do it the normal way inside to out , I have herd of people doing it the other way but can’t for the life of me see that working. If you could educate me about that it would be appreciated. Thanks
     
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  8. Mike Canter

    Mike Canter Top Dragster

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    It is recommended by BAE and everybody I know does it from the outside going in and the reason we do it this way is to stop blowing head gaskets. It works very well because I haven’t seen a blown head gasket since racers here switched.
     
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  9. Bob sherry

    Bob sherry New Member

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    Oh well we have nothing to loose we will give it a go , thanks for the info I still would like to know the reason that would work but if it does so be it , thanks once again mate.
     
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  10. Mike Canter

    Mike Canter Top Dragster

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    I understand that if you torque from the middle and out the ends of the heads lift up a small amount and will not go back down with full pressure when torque is completed. That’s the only thing that I have ever heard. Probably there are several stories on why it works but the big thing is that it does work.
     
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  11. Bob sherry

    Bob sherry New Member

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    That sounds reasonable Mike we will definitely give it a go , thanks once again . It's 2 o'clock in the morning here in Adelaide south Australia and bloody hot too .
     
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  12. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    I will say the outside in method is preferred, I have customers that run fast that still do it inside out. The torquing method may make it less prone but if theres enough of a problem, it will still push a gasket.

    If it's pushing the gasket out on multiple cylinders, sounds like detonation is dancing the head. Or could be if the head studs are old they could be stretched so much they aren't providing the proper clamping force.

    From what I have been around boat racing is how hard the water can load an engine. Lugging the hell out of a motor can certainly lead to detonation problems. Especially if you pedal it. It looses pump speed and goes lean. That's why most of the front running TAD and TAFC almost have to pedal out of shake - they are close enough to the edge if they short shift and lug the motor without pump speed, it will burn pistons or tulip valves.

    Look at the parts - inspect the wire, make sure it's at the proper depth.

    Mixing and matching head gaskets can lead to similar problems, especially on older heads that may not be 100% stock spec on every hole, and the gasket really needs to be matched to the head/block.
     
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  13. Bob sherry

    Bob sherry New Member

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    Thank you very much Will Hanna , the arias 10 litre motor is on of the first they made hence the age of the head studs . I have been working on boats for 40 odd years and after 20 I realised they lug far more than most Drag cars by the amount of Lenco's they break. You said the magic words Will ( the pump speed slows down) now that makes a lot of sense especially in a blown hydro . Bloody boats are enough to drive a man crazy Thanks very much Will. I have been awake most of the night thinking about another normally aspirated boat problem LOL
     
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  14. Mike Canter

    Mike Canter Top Dragster

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    It would seem to me that if it was caused by detonation then there would be evidence of it in the bearings and maybe pinched rings but you said all looked good.
     
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  15. Bob sherry

    Bob sherry New Member

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    Sorry Mike I didn't see your reply till now , yes everything is ok so I will go with the torque method and see if I can buy new studs , and make sure he doesn't 2 step it , thanks mate
     
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