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Oiling system modification necessary on a 383

Jim Liddle

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I am building a street/strip 383 and just guessing that it would not turn more than6500 rpm.
I have read about several mods for the oiling system on big blocks. Going to a 1/2" NTP oil pick up tube seems to be very popular one but, on my block the hole looks to be too close the edge to enlarge it with out cutting through the side. So my question is, are there enough benefits gained by doing this to go through the trouble of setting up on a mill (which I do have) to move the hole so that side of the hole does not move any closer the edge? Also are any of the other hole enlarging mods necessary? There are several different opinions on this that I have read about and I am not sure if I should do any of it or not. I don't want to spend hours machining and grinding if it is fine the way it is now.
Thanks Jim
IMG_2137.JPG
 
Are you using an aftermarket pump? If so, place the pump base over the mounting location and ensure the pick-up hole in the block matches the diameter of the hole in the pump base. Simple insurance.
 
Using a Melling M-63-HV I will check it out to be sure.
This engine was built sometime in the 80's to drag race. It had big dome TRW forged pistons in it.
I bought it disassembled and some parts missing. The cylinders look great just going to hone
and have some KB400 pistons for it. It also had ported 906 heads on it. I am going to get them milled
.030 to bump up the compression a little more right now they are about 88cc's . I am wanting just under 10:1. I am at about 9.3:1 with a .020 head gasket before getting them milled.
 
Watch bearing clearences. I like to stay witin .003.
High volume pump and 60 psi at idle. Windage tray with 6 qt pan. Have had excellent results at 7000 rpm with quality filters.
Have thougt about the 1/2" tube but really don't see the need. Key is keep the pickup under oil.
Also clean the block of anything that catches oil.
 
I always to a few things: enlarge the feeds to the mains from the lifter galley, deburr the valley and add extra drainback holes, and smooth the intersection of the pickup boss hole and passage to the oil pump. The 1/2" pickup is an overkill thing IMO. If you run loose clearances and need the volume, you'll switch to the external pickup or pickups, and plug that internal pickup boss.
 
The oil feed hole that comes up from oil pump to the right hand oil gallery can be slightly off on some blocks where turns. Look in through plug that's in the front of block next to cam. What looking for is if hole from oil pump is lined up with right gallery. On a block I was working in was a little off. Found a ball grinding stone that fit in the hole from the oil pump. Brazed stones metal shaft on to a piece of steel tube. Brazed a shaft on other end. Tube was long enough so it reached to the corn to right gallery. Ground just a little and rounded the corner.
 
for street just detail work
brake master cylinder hone the lifter bores will show any bad spots and put a nice cross hatch to hold some oil
drill between main oil galley and mains I have found partially drilled holes (drill sharpened too often ending up being to short) and even broken drill tips in the oil holes
if hot rod I drill the main oil passage
drill a .040 hole thru the thrust face of the main bearing into the oil feed to pressure oil the thrust especially on a stick shift car and chamfer the partinglines from the center of the thrust bearing main to the rear then make a little pocket in the thrust face and drill the bearing out to 1/16 (slightly bigger than the feed
drill an /040 hole thru the cam thrust into the oil passage to feed the cam thrust also drill the oil galley plugs = not only for timing chain lube but to vent any air bubbles
deburr everything, chamfer the cylinder bottoms-after boring you do not want them to be piston scrapers
bottom tap the mains- again I have found some short threaded if using studs you can drop a little bb size fish weight in the hole then torque the stud in- not really good to torque down on the bottom thread
if using ta fluid flush out with brakkleen or carb cleaner and blow out then brush
install the rocker shafts the correct way- and if reusing pull the plugs, brush out and put in new plugs
if using high spring pressure of if you want super longevity there have been discussions on heavy shafts
I get hard chrome shafts from Rocker Arm Rebuilders in Anderson CA- they can also supply bushed iron adjustable rockers- which work fine (I like to go 1.6 on the intakes)
clearance the block for 3/8 pushrods and check clearance if using 1.6 rockers= heck check anyway
bottom tap the hold down threads and back to oiling
clean the oil feed in the block and heads
I like to use AMC/ Magnum style lifters and hollow pushrods to lube the rockers- most stock rocker failures were when the pushrod pushed through the rocker cup and the mechanical adjusters tend to gall and burn up
Oil pressure spring will depend on your clerances HP and HV are usually not necessary
Windage tray, baffled pan depending on chassis- also threads on this
some drill a squirter for the distributor/ oil pump drive gear interface- and use a aftermarket hard drive shaft spin it up B4 firing the motor
I've never had a problem reaming and tapping for 1/2 suction side makes a big difference
you can also round the corners in the oil passages- it's pretty obvious where the sharp turns are- go with the flow
trace your oil drainback - remove any casting flash you can paint the inside of the clean block with GLYPTOL - DO not use rustoleum, there are other block paints
they not only seal but drain quicker
 
Think this moper was describing . I did this modification, drilled 3/32 hole in gallery plug, running solids. I bought a drill from H Mc it was a foot long approximately . Sweating bullets doing it.
 
I will add,,,I use the AMC style lifters with hollow PRs and NO oil hole on the adjuster.This will prevent ever galling the PR cup.You must restrict the oil hole in the PR or you will lose 15 psi of op.How do I know.......:BangHead:
 
You don't need a foot long drill bit. 9" is sufficient. Did a bunch of blocks with the same bit. No problems but it is nerve wracking !! I always do them slow and dry and I use a low powered drill that will stop before the bit snaps. Use a big strong drill and you're just asking for trouble.
 
Lots of great tech in this thread
how do we get a quality copy of the illustration?
all the little hints add up
What we used to do after drilling the main was to grove the block over to the parting line and feed the oil in there
feeding oil in the top of the bearing where there is the most clearance is the worst you can do
you get the most hydrodynamic wedge feeding somewhere around 4 o'clock feed
Inlines are easy= V8 the ideal place moves around
IMHO, and others make them work but full grooved bearings suck- fix the crank for full time rod oiling
but hey- this is not road race or NASCAR
 
Big pick up with offset is a good idea in book. Imposible to have the feed side to big. As stated check pump passageways for obstructions. The passage mod being discussed is the angled oil feed from the right lifter galley to the mains. NOT the straight feed between the cam a mains. I would not use a drill bit. Get 9/32" reamer. Grind the 1st 1/4" down with a bench grinder so it pilots in the original hole. Slowly no lube. It'll clear the passage. With sloppy lifter bores that are common and as AL stated with pushrod oiling the high volume pump will help oil pressure. Bearing clearance, min of .0025 . Personally my current motor has .003"rod, .004" main, 60 psi idle. Runs to 7100 every pass. Last set of rod bearings looked like new at 300 passes.
Doug
 
If you print that illustration its the best you'll get. That was posted by another Mopar guy on another site a long time ago. I kept it and am just posting for others to use - I claim no credit for any of it.
 
Sounds like your building a 400 - 450 hp 383. If that's the case, you don't need to do any modifications to the pick-up, block or pump. Standard baffled oil pan and a windage try and you'll be fine.
 
Think this moper was describing . I did this modification, drilled 3/32 hole in gallery plug, running solids. I bought a drill from H Mc it was a foot long approximately . Sweating bullets doing it.

The drill bit is the best way. That guy’s 3 hour disaster is quick and easy with a long drill bit.
 
The drill bit is the best way. That guy’s 3 hour disaster is quick and easy with a long drill bit.
No way it takes 3 hours with the reamer. I stepped my reamer instead of tapering it. Did it on a bench grinder in about 2 minutes. I did use the extension he mentioned. Takes maybe 30 minutes at the most. Break that long drill bit off in the block and see how long it takes.
Doug
 
Drills getting stuck and breaking of is all do to rate of feed, type of bit, sharpness and lubrication.
Strange, have broken more backing out after jamming than during the jamm its self.
 
No way it takes 3 hours with the reamer. I stepped my reamer instead of tapering it. Did it on a bench grinder in about 2 minutes. I did use the extension he mentioned. Takes maybe 30 minutes at the most. Break that long drill bit off in the block and see how long it takes.
Doug
I’ve done hundreds and have yet to break a bit. Cast is pretty easy to drill.
 
I will add,,,I use the AMC style lifters with hollow PRs and NO oil hole on the adjuster.This will prevent ever galling the PR cup.You must restrict the oil hole in the PR or you will lose 15 psi of op.How do I know.......:BangHead:
When using pushrod oiling what size oil hole do you recommend in the pushrods so you don't lose too much pressure? Not that I will be changing mine but I am curious since I didn't specify what size hole Trend was supposed to use.
 
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