Apollo77 Posted January 29, 2017 Report Share Posted January 29, 2017 So mostly sure I blew the head gasket. Did the tear down and rebuild, got rid of some of the emissions stuff, new thermostat, radiator, and headlights. Once together I tried starting it and began to build pressure in the radiator and still have white smoke in the exhaust. Gonna tear down again tomorrow and get the head milled down. Anything I'm missing here? Quote Link to comment
Doctor510 Posted January 29, 2017 Report Share Posted January 29, 2017 Be sure to remove the cam and rockers before you take it to the machine shop Quote Link to comment
datzenmike Posted January 29, 2017 Report Share Posted January 29, 2017 Straight edge across head in an X pattern. Anything over a 0.004" feeler gauge gets under, it should be milled down flat. Suspect the middle two cylinders because the 2 and 3 combustion chambers are cleaner. 1 Quote Link to comment
Stoffregen Motorsports Posted January 29, 2017 Report Share Posted January 29, 2017 Overheating often causes a head to crack too. If you don't have a straight edge (no, I'm not talking about a yard stick from Home Depot), you will need to bring it to a machine shop and have them check it for straight and pressure test it too. Cracks can go undetected at room temp, so be prepared for that. 1 Quote Link to comment
banzai510(hainz) Posted January 30, 2017 Report Share Posted January 30, 2017 was this over heated recently. Or frozen outside and ran maybe not enough antifrreze? White smoke all of seddin is rare unless no water. Quote Link to comment
kelowg Posted January 31, 2017 Report Share Posted January 31, 2017 Make sure intake/exh manifold bolts/nuts r tight. U can not reuse manifold gasket. could b Leaking coolant into intake causing white smoke Quote Link to comment
banzai510(hainz) Posted January 31, 2017 Report Share Posted January 31, 2017 Kelowg Hes not using a water passage type manifold as it looks like no holes in the manifold unless the head has holes. I cant tell. But I see the. to me its a mated heat riser type manifold Quote Link to comment
datzenmike Posted January 31, 2017 Report Share Posted January 31, 2017 Only the '75-'77 L20Bs had the co-joined intake/exhausts. I don't see the water outlet pipe just under the front of the carb either. The stock original gasket does not have the holes in it but all after market us a 'one size fits all' gasket. This one is likely that. The holes serve no purpose on a U67 head... there are no holes on the intake either. The gasket just left an imprint. Quote Link to comment
Apollo77 Posted January 31, 2017 Author Report Share Posted January 31, 2017 Head is warped 0.019" and need to find a shim kit to get me by until I find another one. The truck has always ran hotter than I thought it should but nothing I could do would fix it. Quote Link to comment
banzai510(hainz) Posted January 31, 2017 Report Share Posted January 31, 2017 Im not a machinst but I got a feeling that is not alot of warpage. Anybody? 2thousanth is not alot unless you wrote that down wrong Quote Link to comment
Apollo77 Posted January 31, 2017 Author Report Share Posted January 31, 2017 Too many 0's Quote Link to comment
datzenmike Posted February 1, 2017 Report Share Posted February 1, 2017 0.019" is 19 thou. almost half a mm. That's 4X the limit in the FSMs Quote Link to comment
scooter Posted February 1, 2017 Report Share Posted February 1, 2017 Mill it... Put some shims in, let er buck Quote Link to comment
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