727 noisy wining wont drive

[Petri.]

Hi again , now it has a rebuilt tranny in it and manual valve body but when sitting for a day it drains the converter back to the pan, what causes this.

Also i bought a coan converter thas has been sitting in a mild 440 and stalled 2800rpm, i have problems when i want to drive slowly, its twitching and jumping before i get som rpm and the engine can also stopp before i get rpm , i did not have these problems before but it has always been a little annoying when cruising but i know it gets to much fuel at iddle so that i have to fix,ignition is at 36 degrees and 10 at idle, this is the setup from previous owner.


Block Hi-Nickel Content (not original block)
Bore .030 over
Mopar steel rods
Keith Black 9.0 to 1 comp pistons
Moly rings
Clevite 77 main & rod bearings
Forged steel crank shaft
Complete balanced assembly
Cylinder heads (906) large valves with hard seats
Valve job with comp springs
Comp hyd cam 272 degree x 480" of lift
Cloyes dbl roller chain & gears
Melling high volume oil pump
Intake manifold is a HP 383 with Carter afb 625
Pertronics electronic ignition with MSD coil (no points)
Exhaust is a 383-440 magnum HP manifolds

/Petri

 

[AMX364]

Converter drain back is helped by starting in neutral, so I have read. Most changes to the valve body seem to effect the drain back issue.

 

[oldbee]

I'm about rdy to start a new thread on "drain-back" issues. Mine has 20+ yrs but only 5-8000 miles on a rebuilt trans. Just started to do same things as everyone complains about, this is with a completely stock trans that never had this problem until the last 500 miles.

 

[AR67GTX]

We need to start a support group. After rebuilding mine with new converter, seals, bushings, pump innards, rings, valve body mods, etc - works great but still drains completely down in probably 7 or 8 hours.

Can't help much on the converter - I put a 2500 Hughes stall converter in mine and it's a little looser than I was expecting. I will render an opinion that 10 degrees initial timing is probably insufficient for you motor. I had to weld up the advance plate on mine but I have it now with 16 degrees initial, 20 degrees mechanical, for 36 total and it pulls real strong from idle. I also run vacuum advance hooked to a full time vacuum source on the carb.

It sort of sounds like your motor is "trailer hitching" at low speed which could be due to the timing. If the distributor has the small, weak springs on it, your advance may also be kicking in at idle and fluctuating as your motor begins to hunt and buck, just accentuating the issue. Sometimes a medium weight spring with a little slower advance curve works better on the street. Just an opinion.

 

[Petri.]

I also think it is iginition problems , propably will buy msd8386 or firecore.