New crate engine oil priming/ ignition timing impact if the distributor is mis-installed

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Bennyt

Full Access Member
Joined
May 17, 2019
Posts
1,202
Reaction score
1,856
Location
Surprise
First Name
Ben
Truck Year
1977
Truck Model
C10
Engine Size
350
WHY would you need to prime a new engine ???? it should have assembly lube on everything so lube at startup would be a non issue...
The assembly lube is for "assembly". Most of it wipes off in the first half second of rotation. Priming ensures you have oil pressure, pump up lifters, and ensures you have lubrication.
 
Last edited:

Bextreme04

Full Access Member
Joined
May 13, 2019
Posts
4,439
Reaction score
5,581
Location
Oregon
First Name
Eric
Truck Year
1980
Truck Model
K25
Engine Size
350-4bbl
WHY would you need to prime a new engine ???? it should have assembly lube on everything so lube at startup would be a non issue...
Assembly lube keeps the parts from grabbing and spinning the first time, but is not a replacement for priming. Having a mechanical gauge on a newly rebuilt motor, you can see that it can take 30-40 seconds of priming at 700rpm before you start to see oil pressure build. You want to fill in all of those large oil galleries and purge the air out. Your bearing are not supposed to be making contact with the rotating parts, they are suspended by a thin layer of pressurized oil. If you fire the engine up for cam breakin straight to 2200RPM like you are supposed to, with no oil in any of the galleys, you are going to score the hell out of the bearings and open up the possibility of one of them grabbing and spinning. Assembly lube is there to help mitigate the few seconds its going to take for the final prime and purge once things start spinning, not to take the place of engine oil for 30-45 seconds.
 

RanchWelder

Full Access Member
Joined
Jan 14, 2023
Posts
798
Reaction score
1,144
Location
Earth
First Name
--------
Truck Year
87
Truck Model
Blazer
Engine Size
355ci
On the 87' Blazer, the distributor is so close to the firewall, inserting a long handle screw driver is nearly impossible to locate the drive shaft for the oil pump.

When you use the tool, the locating ring aligns the shaft, so it drops at the correct angle, directly over the drive notch. I use a paint marker to draw a line on top of the end where the drill mounts. After priming, remove the drill, relocate the shaft and align the shaft using the mark on top of the tool towards cylinder #1.

Then pre-rotate your distributor gear enough so when it drops the gear rotates into the correct slot and drops all the way down to the block, with the electrode pointed the same direction, towards #1 cylinder.

Now you are primed and your distributor is aligned for ignition. If it does not drop to the block, you are off a tooth. Pull the distributor, realign with the tool and try again.

Most people screw up by not allowing the distributor gear to wind into position, or they grab the electrode instead of the housing. This prevents the gear from rotating into place and causes the shaft to turn out of alignment.

It's frustrating with your head into the hood, with freezing cold hands or sweat pouring down your face. Buy a 9/16" Matco or Snap-On distributor wrench from fleabait and save yourself the hassle of trying to wrench or get a socket down onto the distributor.

The cheapo 2-piece set from the auto parts store is a rip-off. Save up for the correct bent handle tool from ebait.

Like this one S8176:
You must be registered for see images attach


This version, with the handle bent back towards the distributor, will stay on the bolt, while you tune, without having to hold it.

Loosen, set your light, rotate to time, tighten and try not to eat the fan with your jacket or timing light wires.
 

59840Surfer

Full Access Member
Joined
Oct 8, 2020
Posts
206
Reaction score
335
Location
Montana
First Name
Joe
Truck Year
1986
Truck Model
K5
Engine Size
350 Stroker to 383 with a 400 crank, Crane Cam, Q-Jet, single 3.5" exhaust..
There's a lot of discussion about the correct way to drop the distributor into the cam and the oil pump - ostensibly trying to get both of them in the right position to just fall into place.

It's easier than that and there's a much smoother process that I have used professionally for over 55 years in shops (my own and working for other people) and even now - once in a while - I get to do it again, retired now since 2004.

Pre-oiling aside - and that's a chapter in itself - just use a starter button to bump the starter with a finger in the #1 spark plug hole to feel the compression build - (I built a whistling spark plug that lets me know when I'm getting to TDC #1) - and now watch for the harmonic balancer to stop at the 0-degree pointer.

You must be registered for see images attach


Once there --- just point the distributor rotor to the space between #1 and #2 cylinders in the cap/wire position. This is usually at the 6:00 clock position - looking straight down at the rotor.

You must be registered for see images attach


Then drop the distributor into the drive hole and let it slightly spin into the #1 position even if it stops short of going all the way down. This will usually be at the 6:30 o'clock position after the slight rotation.

If it didn't drop all the way down, it will be sitting on top of the oil pump drive - but that's good.

Now while keeping a little down-pressure on the distributor housing (not the rotor) --- just gently bump the starter button until the distributor drops into the pump drive.

Install the hold-down clamp loosely and set the timing with a timing light.

Simple. Easy.

When it's in correctly --- the vacuum advance nipple will point very close to 45 degrees to the left of center and #1 wire tower position will be at the 5 o'clock position - more or less.

This whole process takes 3-5 minutes.
Really!
It takes longer to talk about it than to do it.

Beware that SOME GMs set their timing on #6 cylinder and that may be confusing, so it's just easier to say that they shift the wire positions 180 degrees and that's all there is to it.

You can shoot the timing on either #1 or #6 on a GM with the 1-8-4-3-6-5-7-2 firing order anyway.

0 degrees TDC #1 is the same as 180 degrees ATDC for #6 cylinder.

I think I got all this right. I'm old - make exceptions for me.





/
 

RanchWelder

Full Access Member
Joined
Jan 14, 2023
Posts
798
Reaction score
1,144
Location
Earth
First Name
--------
Truck Year
87
Truck Model
Blazer
Engine Size
355ci
What he said ^^^^^^

With 2 important warnings:
Buy a quality bump switch from somebody like OTC, with properly insulated clips that stay on and a UL rated 12v switch with THICK WIRES. The amp load on a cheap switch can burn up on first use with cheapo bump tools. This works without starting a fire or electrocuting you.

This unit is $58.00. That's a fair price for a tool you will not burn your rig up under normal use. You can remote start your fireworks display with it too!
The light turns red when you have power.

When adjusting your valves, it's indespensable. This thing loves the fan...
You must be registered for see images attach


The only reason I do not advise new guys to use a bump switch is the risk of electrical shock/damage, shorting out the starter fuse-able links and the B/S quality of the vast majority of the bump switches out there.

I recommend to new builders to use a D-Cell timing light... especially with any computer controlled 7 wire ignition module.

The D-cell light is isolated and does not pick up static from the electronics, which your Dad's old timing light is susceptible to.

This unit is $95.00. You will not get a ghost reading because it is isolated from the electrical system. Same situation as the bump switches. Get the right one for the proper money the first time.

If you read this and buy the cheapo knock-off version of this light, with the sub-standard pickup and wire gauge, non insulated wires and it grenades the first time you plug in.

You are forewarned, the cheapo electrical tools, for this application, will ruin your day. You are paying for the very expensive black pickup in the picture.
You want the expensive pickup. The other's are a joke, when tested for accuracy.

You'll want to wrap electrical tape around the battery cap to keep from dumping them during use. Remember to take the batteries out when you are done using it, or they will corrode and ruin the light. This thing loves the fan too.
You must be registered for see images attach



******* Please Remember,
There is lots of DC current and 700-800 cold cranking amps, flowing through your battery hot lug to your starter.

You are going to want to preserve your soft fleshy bits, as they will be next to the GROUNDED frame, while attaching the clips for the Bump Switch.

You can easily weld your hand to the frame or ruin stuff down there if you are not positive, what you are clipping on to.

If this scares you, (and it should), try removing the ground wires from your battery, then attach your welding switch, then carefully put your ground back on the battery.
If you see lightning, remove the ground connection immediately.

Do NOT skip the ground removal step, when the clip falls off three or four times in a row.

You will think you can skip it, when you're angry they fell off.
Resist the stoopid urge to die.

You absolutely can stop your heart wiring a bump switch, if the DC voltage goes from one hand through your heart to your other hand on an active ground.

A properly installed Battery Disconnect switch on the ground side works well for this type of repeated work on your engine. The $95 300A rated one, (not the cheapo). Now you can switch your battery ground off when these situations arise.

"IF" you show up at the hospital with your fingers welded, your surgeon will know exactly what you did to yourself, before he even speaks to you in the ER.
 
Last edited:

BlazerBill

Full Access Member
Joined
Mar 24, 2023
Posts
103
Reaction score
83
Location
Texas
First Name
Billy
Truck Year
1983
Truck Model
Chevy K5 Blazer
Engine Size
350
Thanks, everyone for all the good advice! I’m a couple of weeks away from installing the engine and am glad to have you all for good information. This Blazer restoration has taken me about 5 years. Health issues, family, lack of facilities, other priorities and projects have prolonged my Blazer build but it is finally getting close to coming to life. Thanks, again! This is the best forum!
 

JBswth

Full Access Member
Joined
Jan 24, 2022
Posts
225
Reaction score
184
Location
Vallejo, California
First Name
James
Truck Year
1973
Truck Model
C25
Engine Size
292 cubic inches
I’ll be installing a new GM crate 350 into my ‘83 Blazer soon. While the engine is on the stand, I’ll need to pull the distributor to prime the oil system. I’ve not done this before although I’ve watched videos of the process. I’m just curious how the engine will operate in the truck if I don’t get the distributor reinstalled in the same position. Will I be able to correct the timing with just turning the cap after the engine is installed and running or will I need to pull the distributor back out and reposition it? Is there a different way to oil prime the engine that doesn’t require pulling the distributor? Thanks!
What I do with GM engines from the mid 50s on is use a large screwdriver that I removed the handle from. I put that screwdriver shank in an electric drill and use it to spin the oil pump, which I first pack with vasoline. Much easier to prime that way. You can tell when the oil system is pressurized because the electric drill will slow down some. For the distributor, I first turn the engine so the timing marks line up, then pop the cap and note where the rotor is pointing, and match-mark that to the cap exactly. Then I match mark the distributor body to the crankcase or intake manifold, depending on what type of engine I am working on. For older GM engines and all Chrysler engines, You can't do that because the drive gear is on the oil pump shaft, not the distributor shaft.

J. B.
 

mavtricks71

Full Access Member
Joined
Jun 29, 2016
Posts
222
Reaction score
60
Location
az
First Name
mike
Truck Year
1986
Truck Model
k10
Engine Size
350
I’ll be installing a new GM crate 350 into my ‘83 Blazer soon. While the engine is on the stand, I’ll need to pull the distributor to prime the oil system. I’ve not done this before although I’ve watched videos of the process. I’m just curious how the engine will operate in the truck if I don’t get the distributor reinstalled in the same position. Will I be able to correct the timing with just turning the cap after the engine is installed and running or will I need to pull the distributor back out and reposition it? Is there a different way to oil prime the engine that doesn’t require pulling the distributor? Thanks!
Im actually gona be firing up my GM crate 350 as well pretty soon. I hope just using Royal purple break in oil is good enough for the flat tappet..... also im not sure what weight oil to use. some say 10-30 others say sae straight 30 cuz it protects the cam better. I dont know.
 

59840Surfer

Full Access Member
Joined
Oct 8, 2020
Posts
206
Reaction score
335
Location
Montana
First Name
Joe
Truck Year
1986
Truck Model
K5
Engine Size
350 Stroker to 383 with a 400 crank, Crane Cam, Q-Jet, single 3.5" exhaust..
What he said ^^^^^^

With 2 important warnings:
Buy a quality bump switch from somebody like OTC, with properly insulated clips that stay on and a UL rated 12v switch with THICK WIRES. The amp load on a cheap switch can burn up on first use with cheapo bump tools. This works without starting a fire or electrocuting you.

This unit is $58.00. That's a fair price for a tool you will not burn your rig up under normal use. You can remote start your fireworks display with it too!
The light turns red when you have power.

When adjusting your valves, it's indespensable. This thing loves the fan...
You must be registered for see images attach


The only reason I do not advise new guys to use a bump switch is the risk of electrical shock/damage, shorting out the starter fuse-able links and the B/S quality of the vast majority of the bump switches out there.

I recommend to new builders to use a D-Cell timing light... especially with any computer controlled 7 wire ignition module.

The D-cell light is isolated and does not pick up static from the electronics, which your Dad's old timing light is susceptible to.

This unit is $95.00. You will not get a ghost reading because it is isolated from the electrical system. Same situation as the bump switches. Get the right one for the proper money the first time.

If you read this and buy the cheapo knock-off version of this light, with the sub-standard pickup and wire gauge, non insulated wires and it grenades the first time you plug in.

You are forewarned, the cheapo electrical tools, for this application, will ruin your day. You are paying for the very expensive black pickup in the picture.
You want the expensive pickup. The other's are a joke, when tested for accuracy.

You'll want to wrap electrical tape around the battery cap to keep from dumping them during use. Remember to take the batteries out when you are done using it, or they will corrode and ruin the light. This thing loves the fan too.
You must be registered for see images attach



******* Please Remember,
There is lots of DC current and 700-800 cold cranking amps, flowing through your battery hot lug to your starter.

You are going to want to preserve your soft fleshy bits, as they will be next to the GROUNDED frame, while attaching the clips for the Bump Switch.

You can easily weld your hand to the frame or ruin stuff down there if you are not positive, what you are clipping on to.

If this scares you, (and it should), try removing the ground wires from your battery, then attach your welding switch, then carefully put your ground back on the battery.
If you see lightning, remove the ground connection immediately.

Do NOT skip the ground removal step, when the clip falls off three or four times in a row.

You will think you can skip it, when you're angry they fell off.
Resist the stoopid urge to die.

You absolutely can stop your heart wiring a bump switch, if the DC voltage goes from one hand through your heart to your other hand on an active ground.

A properly installed Battery Disconnect switch on the ground side works well for this type of repeated work on your engine. The $95 300A rated one, (not the cheapo). Now you can switch your battery ground off when these situations arise.

"IF" you show up at the hospital with your fingers welded, your surgeon will know exactly what you did to yourself, before he even speaks to you in the ER.
12V @1K Amps can kill, but it's usually the fields collapsing in the starter motor that generate the high Amps - much like an ignition coil that uses field-collapse to induce high voltage to the cap/rotor/plug wires and spark plugs.

I've never had so much as a tingle while bumping a starter - even with a screwdriver --- in and under very adverse, side-of-the-road situations.

Sparks? Yup - because a screwdriver will not work as well as a starter button --- as I use my Snap-On MCB version that I've had for almost 50 years now - so I may be somewhat spoiled that way.

I also use the Snap-On induction timing light that can go 360 degrees positive or negative. I bought it for diesels but it also works for gasoline engines.

(The diesels use a photo probe that fires an induction loop for setting the diesels - that and a monolithic probe on the holder for the timing notch --- but that's not for this post).

The timing light induction pickup in no way induces any transients back into the ignition module (talking the 4-wire units in the HEI caps) - so I don't know what troubles you had - I have never seen such a thing.

You are right --- cheap tools are for loaners and being thrown in anger only.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,464
Reaction score
8,729
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
I bump them with a quarter in my bare hand,all the time. The points in solenoid,do all the heavy work. The solenoid exciter lead draws almost no current. Why do I use a quarter? Because I normally have one in my pocket,but rarely have a remote start switch in my pocket.
 

RanchWelder

Full Access Member
Joined
Jan 14, 2023
Posts
798
Reaction score
1,144
Location
Earth
First Name
--------
Truck Year
87
Truck Model
Blazer
Engine Size
355ci
Slide down the page of the first link, and read the post by a Guru named "Tuner".
The thread starts off with a guy specifically stating the Snap-On timing light is giving him false readings, because it is receiving delayed impulse from the SLEW RATE. (See the second link).

https://www.speed-talk.com/forum/viewtopic.php?t=36678

Here's the SLEW link:
https://en.wikipedia.org/wiki/Slew_rate

Anyways, from what I have read, by eliminating the current slew between the battery, aftermarket HEI modules and low budget timing lights with poor quality dials and internal electronics, or even high priced timing lights that rely on the on-board battery for power; the solution is to use a D-Cell style timing light.

The circuitry cannot be effected from ghosting or surge voltages and the slew phenomenon can be avoided.

Pardon me for trying to advise people not to burn their fingers and stop there heart or saving a few bucks by purchasing a relatively inexopensive D-Cell timing light.

Often, when I try to advise non-professionals on safe behavior on this forum, every Professional mechanic who cheats death and probably owns top quality tools, flames me. Knee jerk reaction and flame thrower blazing.

You can bet your weekly salary on it. Darn near every thread.

"I've been doing it wrong for years and it ain't killed me yet". You gentlemen are PROFESSIONALS.

Do you really want the father of a 16 year old boy or girl, who gets burned trying your ridiculous "trick" and have him see your name on this forum telling him/her it's OK?

"I do it wrong all the time!" -Professional

First time I seen you do that on my worker's comp insurance, in any shop I was in charge of, you'd be fired and leaving with double coupons.
You know darn well one slip by someone without a $6000.00 lift on a hot sweaty day and it's french fried fingers.

The cheap D-Cell light is better. Less slew, zero interference, no chance the battery circuit is effecting the readings.

By isolating the circuit to the number one wire, you reduce the chances of being wrong.
If the $600 Snap-On light can defy physics, it's worth every penny!

The guy from MT who trains the children's robotics team to the US National Championships (with an unusual number of consecutive wins), had his face burned off from a battery bursting while he jump-started his truck. Not everybody gets to make that mistake twice.

All due respect to all of you Expert Mechanics out there.
Several of my co-workers are dead from electrical installation mistakes.
They were the top paid lighting designer's in the world.

Dead.
 
Last edited:

1lejohn

Full Access Member
Joined
May 14, 2012
Posts
325
Reaction score
749
Location
texas
First Name
john
Truck Year
1985 , 2004
Truck Model
k-1500, 2500 HD
Engine Size
350, 6.7
Im actually gona be firing up my GM crate 350 as well pretty soon. I hope just using Royal purple break in oil is good enough for the flat tappet..... also im not sure what weight oil to use. some say 10-30 others say sae straight 30 cuz it protects the cam better. I dont know.
Lucus makes an ZDPD additive that you can add to the oil. It's in a 16 ounce bottle. I would add this to the oil every oil change. The RP oil should be fine for start up.
 

ChuckN

Full Access Member
Joined
Nov 8, 2022
Posts
1,323
Reaction score
4,064
Location
Bellinham, WA
First Name
Chad
Truck Year
1981
Truck Model
C10
Engine Size
350
@1lejohn @mavtricks71 I was about to say Royal Purple break in oil would likely be fine, but I went and looked up the ZDDP content (the part that is critical for flat tappet cams) and it was surprisingly low, 1150 ppm zinc. Lucas Break in oil is comparatively higher at >3600 ppm. There may be more to the picture, but something like the Lucas additive would be of great benefit. I myself would choose something with a higher ZDDP dose.
https://www.speedwaymotors.com/amp/...hart-high-zinc-oil-list-brand-breakdown/32479
 

Craig Nedrow

NADAR UNDER THE RADAR
Supporting Member
Joined
Sep 1, 2018
Posts
1,042
Reaction score
2,188
Location
Washington State
First Name
Craig
Truck Year
1973 (have two), 1985
Truck Model
K10, K20, C20
Engine Size
350, 454, 6.2 Detroit
Schaffer oil has the highest zinc content, but use any break in specific oil. When we first start an engine at the machine shop, we use basically what has been said here. The most critical thing in my opinion is not doing a lot of cranking. We use a holly carb couple pumps timing right, starts first turn over. Engine dyno program does the rest. On occasion, If there is very high spring pressure, we will take the inner spring out and break in the cam. This is time consuming, but so is a flat cam. Your GM crate motor will not need this. Gm has break in oil. Doing this at home vary the rpm between 1600- 2500 rpm for twenty minutes, vary rpm, shut down, DRAIN the oil, and replace with a good zinc oil like Valvoline, change the filter, cut it open, look at the drained oil, there should be almost no filings to be seen. Then run that oil for 500 miles and do it again using any oil you like. Run that baby for another 200,000 miles.
 
Last edited:

Latest posts

Forum statistics

Threads
44,185
Posts
951,089
Members
36,310
Latest member
BLAKMAX
Top