New to me 73 duster 340
- Thread starter t2ae
- Start date
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t2ae
Active Member
t2ae
Active Member
t2ae
Active Member
Kendog 170
Let the boy go !
Rotor position looks correct.
middleagecrisis
Well-Known Member
It’s always possible the harmonic balancer has slipped, because I just can’t see how you’re motor could run with 30 degrees initial timing. Is it hard to start when the motor has set for 10-15 minutes after being at operating temperature?
t2ae
Active Member
I verified today tdc and the harmonic balance is perfect. Also found out my timing light isn’t correct unless you have the clip over the wire at a specific angle. So the motor is at 20 initially
middleagecrisis
Well-Known Member
Those plugs look like they could stand to be replaced. Go back and read Post 21 by demonracer, that’s some good advice. Did you ever try the new Holley 600 that you had to see if it ran better?
t2ae
Active Member
Those plugs are new. Yes I put the summit 600 carb on and didn’t really help
middleagecrisis
Well-Known Member
I can’t tell from the picture if that’s oil or fuel residue on the plugs. They definitely don’t look like fresh plugs should look. Does it smoke (blue or black) any at idle?
t2ae
Active Member
Nope no smoking ever. I thought they looked lean
Kendog 170
Let the boy go !
t2ae
Active Member
lol yes.
t2ae
Active Member
Lomg time no post but have been busy with life …nothing has changed besides my concern of oil pressure. What oil pressure do you guys see fully warm and at idle / cruise. When mine is warmed up idle being at 750 literally the gauge will read about 3psi. Cruising say at 2500 rpm will be about 22psi
middleagecrisis
Well-Known Member
Understand about life, it constantly jacks with my available "Duster time"! That's very low oil pressure. I assume that's a mechanical aftermarket gauge and not a factory gauge (without going through 4 pages to verify) reading, correct? The old standard is 10 psi for every 1000 rpm, which still seems too low for me. That would indicate worn out bearings and excessive clearance. I don't know what oil weight is in it (again, without going through 4 pages to verify). If you don't already have 20W-50 oil in it, add some of that and see if it pops up the oil pressure. You could even throw straight 50W in if you can find it. Only recommending this thicker oil to verify loose clearances. Before you change any oil, run Sea Foam in the oil to clean out any carbon build up in the motor. Doubt it will help with the oil pressure, but it definitely won't hurt and might free up carbon build up in the piston rings and lifters. Get the motor up to operating temp and vary the rpm. I don't drive the car when doing this cleaning. Do this a few times and you'll be surprised at all of the crap that comes out when you drain the oil. Let us know if this helps with the oil pressure. If not, it might be time to pull the motor and check oil clearances, using plasti-gauge, on your rod and main bearings.
Howard1784
Well-Known Member
Consideration: not knowing the year the motor came from. Model year stock 1973 340s were nothing to write home about and dont expect "high performance" per say. 70 to 72 340s are a close second. Moreover, 73 Dusters are considerably heavier than 70 to 72 models
t2ae
Active Member
I’ve changed the oil to straight 40 weight and really no difference. The motor was rebuilt years ago but I don’t if the oil pressure has been like this the whole time or not. I’m reading about the oil galley plugs and if they are left out it being a low oil pressure as well. I’m not against pulling the motor but it was bored .60 over so no real room left
t2ae
Active Member
It’s a numbers matching motor so 73
middleagecrisis
Well-Known Member
I was thinking more about pulling it out to check the bearing clearances, more so for inspection purposes. If you pull the #3 main cap, #3 and #5 rod bearings you can check for excessive wear and use plasti-gauge to see what your bearing oil clearances look like. You could also see what the cylinder walls look like (good cross hatch) with the oil pan off and make sure nothing funky is going on with the oil pump/pickup. You've got to figure out the oil pressure problem and most likely can't figure out why with the engine in the car, unless you've got a bad sending unit and have more oil pressure than you think. I'll ask again, before you pull the engine, is this a mechanical aftermarket gauge with an oil pressure tube/line or factory/aftermarket gauge with an electric sending unit? 3 lbs. of oil pressure at idle should bleed down the lifters and make all kinds of clattering.
middleagecrisis
Well-Known Member
OK, Hold the door! Post #77 shows an electric sending unit (to the left of the distributor) for your oil pressure gauge. Go buy a cheap mechanical gauge from one of the auto parts houses, take out that electric sending unit and slave in the mechanical gauge. I'll bet the current sending unit is way off! Do this before you do anything else on this motor and let us know what the idle psi reads with real mechanical gauge.
t2ae
Active Member
Good eye!! I actually replaced that unit to be sure it wasn’t faulty. I do not know off the top of my head if it has an actual tube running to the engine or just electrical. The gauge itself it mechanical “looking” I will check this out tomorrow!
t2ae
Active Member
It is a mechanical gauge. On cold start will be around 60psi. Been idling for about ten minutes and is at about 13psi at idle 1k rpm in park. If I go to drive the idle goes to about 600 rpm and the pressure is at about 3psi
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