wellLittle bit of a late start this morning …. hey relax we’re on…. So I went back over to the machinist yesterday …. wanted to show first a couple of things on the motor they are setting up for me then we’ll get into the classic cracked intake story you must hear and see….. matter of fact I think I’ll do a Patreon video on this later… today it’s scheduled for me to talk a littler about paint so watch for that later.
Right now I wanted to show a little more on the headwork Mike found on this motor Here you see the large intake valve and the smaller exhaust. The exhaust did have a proper small seat like we do but is had raised edges, wasn’t fitted will and the lap job was weak The black on the intake valve is lapping material… but you can see the small exhaust valve seat and how mike ground the inside edge smooth to the head and the nice even lapped surface on the seat. You must put seats in the exhaust valves… the original temper is gone after so many heat cycles so new seats and valves help all that.
NOW, working on the “Pickles” motor Andy drove from Atlanta to Orlando 1 hours run at a time. Cold, the motor ran fine but as it got deep heat (@ 1 hours driving) the motor would loose power and shut down. Pulling over it would fire back up and idle but would shut down when put in gear. Andy could wait a couple of hours and drive at night and get another hour or so of driving and it would start all over! Yes, that makes for a LONG drive south!
The scenario is classic of a cracked intake manifold. The motor was built stock or a production style if you will… flat tappet valve train, no blockoffa and a “turkey tray” or valley pan was used to seal the intake in. The hot gasses passing through our concave intake (BTW, the only concave intake GM ever made and not done 1 sense..) When Andy called me I told him we need to looksee because many engine builders would just put it together stock.
OK, so we pulled his intake and in the first pic still in the coach you could see his intake crack big time Well, this is a bad pit but first Andy was told he has a rebuilt carb…. that carb gasket first is the wrong one but it’s petrified! It is NOT only 2 weeks old. Never install a carb with an old gasket. Look into the left side of the intake….it’s soaking wet even after what 4-5 days sitting…… It’s pewking…. rebuilt? Makes ya wanna say Hmmmm….
Here is a better pic of the crack that bout every intake has from the heat of the concave crossover port That crack will reach the inside floor of the intake and contaminate your vacuum. The crack opens up when the metal swells getting hot and there it is. We’ll clean up the intake, have it magnafluxed and if there are no other cracks use 2 stainless steel plates to block off that heat you can see was blowing out all over the intake Hey and looking inwith the “turkey tray” out reveals some cam wear 20,000 miles will show wear but I want to be safe so we’ll be recommending an oil with 15 parts per million of ZDDP Late news flash>>>>>>>> just got a call from the machinist… the 403 motor we’re building has the dreaded crack on the bottom of the intake. I give you a pic of that tomorrow. We’ll have to harvest a new intake for the motor. Nick, we have an intake so no downtime….. Meanwhile they did your rails yesterday so we’re moovin… OK, that’s all for today… gonna talk about paint next on Patreon… check it out later… .If ya like the video, support me and send me a dollar….See ya later…