Discussion of Hemi crate engines.
6 posts • Page 1 of 1
I have tried a 750 avenger and 750 double pumper and everytime I start the car 5 minutes or overnight the black smoke bellows out the pipes and some at idle all the time. I have modded my 750 dp to a smaller power valve, drilled holes in the front butterflys to allow me to idle it down enough to adjust the 4 corner idle. Float level is fine and it is not percolating. What works for you guys? Mine is a 4 spd with the 292 duration cam. Choppy idle. Mash it to the floor and except for the initial cloud of a rich exhaust smoke, it screams. It was a crate engine but rebuilt correctly the second time. Thanks
Moss, without knowing the compression ratio, etc. it is hard to tell. But, from years of building engines of all types, I would start with your timing. The engine will tell you what it needs with a simple vacume gauge. Plug the gauge into a MANIFOLD source. Advance timing until gauge tops out and begins to drop, come back to max reading. Check initial timing at that point. It is not uncommon for it to read 20 degrees! You want a maximum of 35 degrees so you may have to limit the mechanical timing in the distributor to make the maximum come in at 35. I had to weld the advance slots closed (start by closing 1/2 way) and open with a file until I had 35 degrees. Also, don't assume TDC is correct on the balancer, use a piston stop in #1 to confirm TDC. I have found several balancers to be off 10 degrees. With the timing that the engine asks for, you won't believe the difference!