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engine ???s

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by jms, Aug 26, 2001.

  1. jms

    jms 1/2 ton status Author

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    Well, since the SoCal guys of course HAD to pick the wrong [​IMG] weekend, it looks like I won't be needing my Jimmy for a while... So I'm thinking it's time to slowly start my engine makeover [​IMG].

    I have a stock-rebuilt 350/Q-jet with about 37k miles, no smoke, some deposits on plugs (Delco R43, no carbon deposits when I use hotter Bosch Super, but electrodes are a bit white). Coil is Summit 48kV, new wires recently. Game plan is vortec heads, and eventually TBI.

    Checked compression today w/ Haynes manual in hand, recorded values after four strokes. Readings were between 150 and 170. Probably o.k., maybe a bit high acc. to Haynes; highest was #8 w/ 170; that's were I always had the most carbon buildup before I started using the Bosch plugs. Not sure how quickly it should build compression; first stroke readings for all cylinders were between 75 and 100.

    I'm trying to figure out whether my engine is worth the attention. Anything else I should check before I tear into it/start to order parts? Oil pressure acc. to the gauge in the dash is 40--50. Thanks for your input,


    michael

    <a target="_blank" href=http://desertrider.net>http://desertrider.net</a>
     
  2. DesertDueler

    DesertDueler 1/2 ton status

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    If the motor was cold when you did it, that is why the numbers were so low at first. The more you crank it, the oil comes up and helps seat the rings. Between 150 and 170 are perfect. would leave the pistons alone. When you do a compression test, you are supose to do it after the motor is at normal running temp. Like between 180-210 degrees.

    86 Jimmy 4"lift 35"MTRs locked front.Other cars 69 Firebird w/525 hp,and 70 GTO <a target="_blank" href=http://www.geocities.com/modifierperformance>MY vehicles</a>
     
  3. jms

    jms 1/2 ton status Author

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    I had the engine idle for about 15 min, temp gauge showed about normal operating temp, but then it cooled down as I got around to take the plugs out. Exhaust manifolds were hot but not too bad.

    <a target="_blank" href=http://desertrider.net>http://desertrider.net</a>
     
  4. DesertDueler

    DesertDueler 1/2 ton status

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    Thats why they read so low at first then went up to normal. Dont worry there fine.

    86 Jimmy 4"lift 35"MTRs locked front.Other cars 69 Firebird w/525 hp,and 70 GTO <a target="_blank" href=http://www.geocities.com/modifierperformance>MY vehicles</a>
     

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