Atomic 4 rebuild - Head removal

Atomic 4 head - bolts out

 As a non-mechanic, removing the Atomic 4 head had a very high nifty-factor. This is my first glimpse into the belly of the beast!

Removal of the head was somewhat difficult. There may be a better way to do it than mine!

I attempted to remove the remaining twelve nuts holding on the head. Only about half of the nuts came off easily. The other half brought the studs (threaded on both sides) with them because they were seized on.

Atomic 4 head - Half off

My plan, once I have more stripped off, is to take the block to an engine mechanic for some general advice on whether to extract those remaining pins and how to generally proceed.


The head was difficult to remove because of the remaining pins. I had to pry around the edge with a large screwdriver (trying not to damage the head surface) and then I used a wooden block placed under the thermostat housing to beat the head upwards. As I said, there is probably a better way to do this!

Atomic 4 - Headless

There are two gaskets, both of which were destroyed in the removal. I had planned on replacing them anyways though.

Since the engine is seized, from many years of not being used, I took the opportunity to thoroughly soak the top of the pistons with WD40 to try to get things moving again.

Atomic 4 head - off

[All of the posts associated with this rebuild are available under the search label Atomic 4 Rebuild.]

Atomic 4 Rebuild - Transmission cover and housing - Part 1

Transmission - Pre-dissasembly

Removing the transmission cover and housing was a bit of a challenge...and continues to be.  I also don't think that I did it correctly. Hopefully I didn't cause myself grief down the road when I try to put things back together.

I removed the four 3/4" bolts (1/2") holding the transmission cover, exposing the transmission.

Cover plate removed

I the removed the thrust bearing (the round plate at the back of the transmission). This is held on my six 1" long bolts (1/2").

Rear of transmission before removal

I have since discovered that I should have first removed the tail shaft nut first.

Removing the transmission housing was difficult, as it was securely stuck by gasket goop and decades of rust.

I first removed the ten bolts holding it in place. These include four 1 7/8" (1/2"), two 2 5/8" (1/2"), and six 3/4" (1/2").

I was apprehensive about beating too hard on any particular piece because I wasn't sure how solid they were. In the end I used a knife, large screw driver and hammer to poke, pry and beat the housing until it dislodged. No damage done. (except the gasket)

Removing that nut is now much more difficult (I haven't actually figured out how to do that yet) since the nut spins on the bearing (surprise surprise).

I thought it would be easier to find something to pry on once I removed the whole housing and transmission. Not so much...

Housing and transmission removed together

Here is the finished product.

Atomic 4 without transmission

[All of the posts associated with this rebuild are available under the search label Atomic 4 Rebuild.]

Atomic 4 rebuild - removing flywheel housing

Atomic 4 flywheel cover

The flywheel cover is held on by nine 1" (9/16") bolts around the perimeter on the back side of the cover, each has a lock washer. There are also 2 similar bolts on the top front of the cover.

All except the bottom two are easy to get at and remove. Those I couldn't get at with a socket but was able to eventually free with a short wrench. Removing two of the boards from the bottom of the wooden stand made the job somewhat easier.

The cover is also held in place with several alignment studs. A rubber or wooden mallet can be used to tap the cover off once the bolts are removed.

Have a container ready when you take the cover off because you will lose some oil.

[All of the posts associated with this rebuild are available under the search label Atomic 4 Rebuild.]

Atomic 4 flywheel cover removed

Atomic 4 rebuild - removing the waterpump and thermostat

The next step in the disassemble process was to remove all of the cooling related pieces. All of the cooling lines are going to need to be replaced as they are disintegrated.

Water pump to thermostat hose 

• Remove rubber cooling hoses.  There are 4 hoses that are involved in the cooling system:
•  Thermostat to manifold - 1/2" hose - 4 3/4" long
• Mid-block to thermostat - 1/2" hose - 7" long
• Water pump to mid-block - 1/2" hose - 10 1/4" long
• Manifold loop - 1/4" hose - 18" long

• Remove thermostat - The thermostat is held in place by two 9/16" nuts. There was no gasket on the thermostat. I tested and cleaned the thermostat. 

[All of the posts associated with this rebuild are available under the search label Atomic 4 Rebuild.]

Atomic 4 rebuild - Removing water pump and accessory drive

The water pump is attached directly to the accessory drive bracket with two 9/16" (1" long) bolts.

I removed the impeller for inspection (and because I haven't had a good look at the impeller housing before since my current engine's is crammed in the worst ungodly position in my engine compartment).

The impeller was in good condition but I will replace it since it is old. The impeller is held on with 4 flat head machine screws (1/2" long). There is a full description of each part in the impeller system on the Moyer impeller parts page. The o-ring gasket on the impeller plate is missing, or so disintegrated as to not be recognizable. I will replace that on reassembly.

There is a gasket on the drive side of the assembly. It will need to be replaced.

The accessory drive is held on by two 9/16" bolts (2 7/8" long). One of these bolt heads is stripped and will need to be replaced. I couldn't remove the other bolt fully yet because the engine mount is in the way.

The Moyer site has a great page on the accessory drive. http://www.moyermarine.com/access_repair.htm



[All of the posts associated with this rebuild are available under the search label Atomic 4 Rebuild.]

Atomic 4 rebuild - Helpful resources

As I go through the rebuild process of my engine I will use this post to keep track, and propagate, useful information sources and links.

General Links

Moyer Marine - The definitive source of parts and information about the A4.

http://www.moyermarine.com/

The Atomic Four Marine Engine  and  Replacements - http://pearsonvanguard.homestead.com/files/atomic4.htm

Atomic 4 Manual [Download]

http://l-36.com/Atomic4/a4manual2.pdf

Atomic 4 parts guide [Download]
http://www.cncphotoalbum.com/atomic4/partslist.pdf

Alberg 30 site- The Care and Feeding of the Universal Atomic Four Engine

http://www.alberg30.org/maintenance/MechanicalPropulsion/Atomic4/

Atomic 4 Repair and Maintenance Manual [Download]
http://www.fdlaudubon.org/page19/assets/A4RepairMaint.pdf

Atomic 4 rebuild - removing manifold and accessory brackets

The manifold is held on with three threaded pins with 9/16" nuts, these nuts are missing from mine.

Manifold removed

 There is a gasket behind the manifold. The gasket appears to be in reasonable shape but I will probably replace it.

Manifold gasket

 The manifold is in fairly rough shape. It has been previously repaired, there is some rough braising along the top-front. I will explore the part more thoroughly before deciding on replacement or re-use.

Atomic 4 Manifold

I removed 3 other brackets at the same time:

• Side alternator bracket (the alternator was not installed when I got the engine) - One 1/2" bolt holds this on.

Alternator bracket

• Some sort of bracket at the back that I'm not sure what it was use for. This was bolted to the back with two 1/2" bolts (2" long). I may or may not replace this depending on what it turns out to be for. 

Miscellaneous bracket at back. What is it?

• Top alternator bracket - This bracket is held on by two 11/16" nuts on threaded studs. One of the bolts broke off while removing. I will have to remove and re-tap this bolt hole.

Top alternator bracket

Top alternator bracket with broken-off stud

•  I also removed the breather hose - The breather hose is tapered from 3/4" to 1/2" (inside diameter) and is 4" long.

Breather hose

[All of the posts associated with this rebuild are available under the search label Atomic 4 Rebuild.]

Atomic 4 rebuild - Removing coil and distributor

I am continuing to remove the miscellaneous pieces from the outside of the engine. I have started making detailed labels and notes and pictures for each piece that I am removing since I am not comfortable yet in my ability to remember where things should go and what fasteners are needed. I have been grouping like-parts into large ziplock baggies and organizing these in order. So far this has minimized the chaos of miscellaneous bits and pieces in my [cluttered] garage. 

• Labelled, and removed ignition wiring. I left the spark plugs in for now since they provide some protection from grime and they aren't in the way. 

• Removed the coil from the back side of the engine. Two 1/2" bolts hold the coil bracket in place. One was missing. I will need to re-tap the corroded thread of the missing bolt before re-assembly. 

Ignition coil

• Removed the distributor cap. Both screws will need to be replaced.

Distributor without cap

• Removed the distributor. There is a bracket midway up on the distributor that holds it in place. Once the bracket is removed (single 1/2" bolt) it slides easily out. The distributor on my engine is the Delco variety, as opposed to the pre-1969 Prestolite ones. 
  
  
  

  

  Delco Distributor 

  
  

  

  Delco Distributor with bracket

[All of the posts associated with this rebuild will be available under the search label Atomic 4 Rebuild.]

Atomic 4 rebuild - Removing and testing the starter

Starter on engine

The starter is held on with two 9/16" bolts. Remove these to remove the starter.

There is a great video on bench testing a starter here:

Following the directions in the video, these are the steps that I took to test:

• Attach a switch between the ignition terminal and the positive terminal on the solenoid.  The ignition terminal is the one with an "S" beside it. 

• Attach jumper cables from the battery to the positive terminal on the solenoid and the negative to a bolt on the body of the starter. 
• Test

My starter tested fine. Here is the video of my test:

[All of the posts will be available under the label Atomic 4 Rebuild.]

Atomic 4 rebuild - Removing the flywheel

Atomic 4 front view

 Removing the flywheel is straight forward.

1. Remove the front cover of the engine by removing the six 7/16" bolts around the cover.
2. Remove the flywheel by removing the six 9/16' bolts. You might need to secure the flywheel from turning by bracing it with a large screwdriver. (mine came off easily) 

Keep track of all pieces and bolts by placing them in individually labelled bags or trays!

[All of the posts associated with this rebuild will be available under the search label Atomic 4 Rebuild.]

Flywheel cover removed

Flywheel removed

Atomic 4 engine identification - Serial number and build date

In order to find parts and details on the specific setup of the Atomic 4 it is important to know the date that the engine was manufactured as well as the serial number. Parts guides and tutorials will usually reference one of these numbers.

Example from Manual

Both are located below the breather hose, on the right side of the engine. The build date is the top number and is in the format MMDDYY. The serial number is the 6 digit number directly below.

Atomic 4 serial number and build date

[All of the posts associated with this rebuild are available under the search label Atomic 4 Rebuild.]

Atomic 4 Rebuild - Introduction

Recently I came into possession of an Atomic 4 engine. A local sailor upgraded to a new boat and had a spare engine from his old boat that he had intended on rebuilding. I am taking over the rebuild project.

Goals

I have a few goals for this project:

1. Increase knowledge: Increase my knowledge of Atomic 4 engines so that I am more capable of troubleshooting and repairing my boat when needed. I am not mechanically inclined but need to be more self sufficient given my desire to cruise further in this boat.
2. Spare: Given that my current A4 is 42 years old, a spare is important to avoid lengthy losses in precious summer boat time.
3. Upgrade: Assuming that I am successful in this build, my plan is to eventually swap this new engine with my old one to provide more reliability and performance.  Not that my engine has been particularly problematic, it has been reliable for the most part.

Mechanical ineptitude 

Ineptitude may be a little strongly stated, however, I have very little mechanical experience. Over the last few years I have tried to increase my knowledge of engines and marine systems and I have successfully done some maintenance and repair jobs on my A4 (thermostat and exhaust manifold were the big ones).

All of this is to say that this engine rebuild will be completely new ground for me. While this is a great experience for me, it does mean that you should take my techniques, suggestions and recommendations with a BIG grain of salt. Talk to a mechanic if you want real advice!



My primary resources, initially, for this project will be:
THE COMPLETE OWNERS & SERVICE MANUAL FOR THE 
UNIVERSAL ATOMIC 4 GAS ENGINE

Engine Builder's Handbook

I will chronicle this rebuild as detailed as possible so that others might find something useful out of it. All of the posts will be available under the label Atomic 4 Rebuild.