Need help with engine combo

Discussion in 'Engine Topic' started by TheSkippy, Oct 18, 2012.

  1. TheSkippy

    TheSkippy New Member

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    I advanced the timing 3 degrees. 15 initial, 36 mechanical, 51 vacuum advance. The car felt like it ran fine. Started fine. Shut off fine. I also checked the throttle cable. The bracket seemed to have shifted a little. Full throttle was not quite full on the carb. Maybe 1/16-1/8 inch short. I also ordered a new timing chain/gear set. It has 3 keyways on the crank. 4 advanced, straight up, 4 retarded. I am planning on installing it 4 advanced. Any thoughts? I will also move the fuel pressure gauge where I can see it and see whats going on there. I have not made any changes to the carb from stock other than the idle screws. I'll have to order a jet/spring kit for it to try different settings. My converter is stock stall. Don't want to buy a stall converter for the TH400 since I am planning on installing the 700R4 soon. It will have a 2400-2600 stall converter. Hoping to get the timing chain installed and to the track (Cecil County) in a week or two to see if things have improved any so far. Cats are magnaflow. They seem ok. Don't think they are melted yet. No smell or anything.
     
  2. Damon

    Damon Veteran Member

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    That cam already has 4* of advance ground into it. 106* ICL against a 110* LSA = 4* advance. I would use the straight-up keyway.

    BEFORE YOU TAKE THE OLD CHAIN OFF ROLL THE ENGINE AROUND IN THE DIRECTION OF NORMAL ROTATION UNTIL IT'S DOT-TO-DOT AGAIN. Then LOOK at the position of the cam dowel. This is what I call a "quick visual cam degreeing method." Not perfect, but good enough to catch something that might be way off. I'm practiced enough I can catch a difference as small as 4* (crankshaft degrees).... maybe even a little less if I'm super careful (and wearing my good reading glasses!). That's a difference as small as changing from the 0* to the + or - 4* keyways.

    Where the cam dowel SHOULD be is just a smidge past the 3:00 position. Like 3:15. That would be consistent with a typical good quality aftermarket chain installed in the "straight up" position. Some factory chains are known to be manufactured a little retarded- putting the dowel around the 3:00 position or even a little less. A stretched out chain can compound the effect.

    WHY DO THIS? It will give you a point of visual comparison vs. the new chain. If the dowel is in exactly the same position as the old chain you are taking off you know you haven't changed a damned thing. But if it IS different..... then you KNOW something was "off" with the old chain set.

    What I'm saying is DON'T JUST CHANGE PARTS AND PRAY SOMETHING MAGICAL HAPPENS. Whenever possible, devise a scheme to try to compare what you're taking off against what you're putting on. You may not be able to measure the difference precisely in every situation, but if you can see a difference with your eyeballs, believe me, your engine will DEFINITELY notice a difference. Knowing is always better than hoping.
     
  3. TheSkippy

    TheSkippy New Member

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    Great advice. I will do that before I change the timing set. I will go ahead and put it straight up. I should have the parts tomorrow, but I just decided to straighten some things out on the interior over the weekend and one thing led to another. Now new carpet and seat upholstery are on the way and the interior is gutted. Won't get back to the track until probably 10/31.
     

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