Safe to weld exhaust pipe on 8v71 crossover??

[Larry B]

I have not had any questions to ask until now so I have not done any posting, just reading the comments of other. I finally got my engine back together after having the valve seat inserts changed on one head. What a difference in the sound and smoothness of the running. I bought a compression tester off e-bay, not sure I would recommend that to others. (made in China) no return. Kept breaking down and very uncertain readings. So went and bought a second one with a warranty.  I got readings of 350psi on seven cylinders and 355 on the last. Not as high as the book says it should be,( for my alt. 400psi) but nice and even. I had all the air box covers off, I don't believe I have any broken rings. I have decided to run engine and not look for last 50 pounds. Put my Jake's back on engine and checked everything as I went. (bridges, valve clearances, injector timing, Jake clearance)I had never set up a jake/ buffer/high idle assembly before, but with help from a previous post it went well. I used a  test light for a few tries before trying the jakes. I checked each jake solenoid separately and then as a group (all four). The engine did not stall out with all four activated. At operating temp and idle speed 570 rpm I have 18psi oil pressure and at 1200 rpm I have 60psi. I have no oil, water, or fuel leaks yet. They may develop but will fix as they happen. I do have one leak that I really don't want. The 3 1/2" crossover pipe from the left exhaust manifold to tee type fitting at the right side exhaust manifold leaks where they join in the middle at the muffler clamp. This black unburnt diesel fuel started to show up when setting maximum no load speed and when testing jakes. I would guess at 4 to 5 teaspoons have dripped on front of engine while testing.Please tell me that this much unburnt fuel in the exhaust would be a normal thing considering I have been revving the cr** out of the engine. As a fix I was going to seal weld with mig the two pieces of pipe at the join in the middle where muffler clamp is located. These two pieces of pipe are surely not designed to slide back and forth inside each other with heat expansion or something silly like that. I do not want to correct a minor problem (fuel leak) and create  a larger one (expansion between exhaust manifolds). I would make sure I have a good fit at all joint before welding and not do any welding on engine. Once welded there would be no adjusting fit at joints. As always thanks for all advise and guidance.  Larry B 

[bevans6]

Mine always leaked fuel there.  The slip joint allows for some expansion and contraction with heat (why is that silly?), it you weld it you may find that the cast iron Y-joint cracks.  The fuel is more from idling than running, so should lessen when you start to use the engine more.  All else sounds very good!

Brian

[Stormcloud]

 "I have no oil.. leaks yet."

Are you sure you're working on a Detroit??   

Glad its all coming together for you!

Mark

[gus]

You don't want to spend too much time at idle or anywhere near 600 rpm, 900-1000 is much better.

[Gerry4104]

why would 600 rpm be an issue....please elaborate as i dont know tons about 2 stroker tricks...TIA