Return to the home page...

Go Back   Moyer Marine Atomic 4 Community - Home of the Afourians > Discussion Topics > General Maintenance

Thread Tools Display Modes
  #1   IP:
Old 10-31-2017, 11:16 PM
CamaroMan CamaroMan is offline
Join Date: Oct 2017
Location: San Pedro, CA
Posts: 42
Thanks: 3
Thanked 10 Times in 5 Posts
Pics on me doing my 1st a4 head + unsticking stubborn valves ++

(wd u nice chaps hold off comments till I'm done, just so the post is contiguous tx

Hi all - so finally got down to doing some of the real nitty gritty today -

I decided to write a thread aimed at novices / first timers - hope it helps someone! I might have missed sth but I hope not!

This motor was running great/bad/great/bad - eventually found some stuck valves.. tried MMO, tapping with a allen key / etc - NOTHING worked, not even close.. these puppies were stuck!

Comp test showed #1 and #2 on 0 compression so I thought it was a head gasket..

Here are some pics and tips I picked up regarding stuck valves (alot of it from the very knowledgeable threads/ppl on this site!)

It's quite easy getting to the head. Remove manifold with carb and exhaust flange and cooling connections. Plug wires and few small things..

Removing the head was tricky - took about 3 hours!

For those that dont know - the head nuts go on to studs (3/8 coarse in the block and 3/8 fine on top).

A heat gun will DRAMATICALLY help u get the nuts off (this will be the first challenge!).

I had a new impact cordless drill and on the lowest settings worked mine out with kroil and patience. The really tight ones need to be worked out/in/out/in to break loose grit/rust and let the oil soak deeper - LEAVE overnight if they are real bad.. Good time to do this is while u wait for parts..

Heres a pic showing the head bolts (undo them in a clockwise pattern starting from the outside - if possible!)

Once u get the nuts off (sometimes the whole stud will come out - thats fine for now)

To get the head loose it probably the hardest part - unless it was recently put on! Rust builds up between the head and studs - expands and that sucker will stick like theres no 2moro!

Penetrating oil! A trick (from Don Moyer) is to put a nut on the stud and give it a few firm taps to break the crud loose. I found the stud will usually sit against one side of the hole leaving the other side open for oil to get in. Take a note where the open side of the stud is and tap the stud (with nut on) in that direction.

When the oil soaks down thats good - Now get 2 (or 4) strong scrapers, not the flex painters type - Harbor freight sells strong ones with a angled edge.

Wedge these in between the head to get a gap.. from there move on to something stronger (blunt chisel as per Don - I used screw drivers gently prying)..

Eventually I got my head loose - but a LONG way from off.. depending on where its stuck - mine was in the middle, and I rocked it backwards and forwards for 45 mins prying.. knocking the head it back down and up over and over -

U can pop plugs in and buzz starter to assist, but not too much, few spins to see if she breaks looser..

All the time keep an eye on the studs - soon u will be able to see which ones are loose and not - focus on tapping / oiling the stuck ones.

Do Not try lift head up from one side - it has to come up level.

Once its off go grab some cold beers - I hope u didnt break any studs off and the worst is hopefully over!

Head off:

Now is the time to clean the head and block - if you havent done this, remove the big flaky bits gently.. as the dirt gets smaller be careful not to mess it anywhere. There are many ways to do this - and cast iron is forgiving, just donit gouge at it.. a hack saw blade has always worked very well cleaning up small gasket pieces - go over it 10 times, trust me u will always find more pieces u missed..

If some of your studs came out - get a 3/8-16 coarse tap and run it thru each hole - cleaning between each pass. These go thru the block into water passages so about 1/2" deep shd be fine.

Use high quality taps!! Craftsman, blue point, UK, Japanese etc are usually very good. No Chinese!! U will damage the threads,esp the fine ones!!

The stud tips are 3/8-24 FINE threads - If the rust is bad - use the "start from this side" facing the stud, then flip the die over and run it again - with some oil. You should now have nice clean studs/holes.

Now you also have to clean the studs themselves, the shafts get very rusty.. Wire brush on a drill or scraper - get as much of it off.. Wd40 and steel pot cleaner. U won't get it all off..

This is all head gasket prep done. If you arent doing valves then from there u can do a final clean and assemble (the heads are torqued in 3 stages 20/30/37 ft lbs) - in a circular pattern from the CENTER working outwards in a criss cross spiral.

Light oil is suggested but since there's a chance of steam and water making its way up the studs, I might opt for a non hardening gasket sealer or something similar under the nut heads.

*** if u pulled a whole stud out you HAVE to put thread sealer on threads,it goes down into water jacket.

After the motor has run warm - torque it again. If any of the nuts move slightly repeat this step.

An idea of what lurks in the old threads!

You can also use a machinist straight edge and a feeler gauge to check the block / head for straightness (this is quite easy.. just do a criss cross pattern from various angles - sometimes shining a light from behind the straight edge can reveal gaps).

I almost always put a very thin gasket sealer around all water ports/jackets - its very common for old cast iron to develop pits so this is just a measure ive taken over the years.

(to be continued in next post)...

Last edited by CamaroMan; 11-01-2017 at 11:39 AM.
Reply With Quote
The Following 2 Users Say Thank You to CamaroMan For This Useful Post:
cdhickey (11-01-2017), TimBSmith (09-09-2020)
  #2   IP:
Old 10-31-2017, 11:16 PM
CamaroMan CamaroMan is offline
Join Date: Oct 2017
Location: San Pedro, CA
Posts: 42
Thanks: 3
Thanked 10 Times in 5 Posts

Now for the valves:

(*** SEE post #4 - MOST IMPORTANT - block the 4 oil drain holes tight with tissue so you dont drop a keeper down there :0 )

You need a special valve tool with a specific "toe" to fit around and in between the spring and lifter on these. Sounds like some ppl have had bad luck using the lisle cheapos - I would personally buy a vintage used tool on ebay for this - or make your own (like I did) from a $3 harbor freight clamp and a 9/16 spanner (basic wire/stick/braze welding required)..

Also - you dont need to follow the diagrams - just look at the lifters, you compress the springs when they are at their longest length/least compressed (logical ey?). A rule of thumb is if u can spin the lifter with ur finger its prob loose enough to remove valve.

The tool:
I took some measurements and it seems a 1/2" (tight) to 9/16 open crescent wrench end is a perfect fit for the job (u can buy one for $1 at a swap meet/store) and slice it up. Buy quality steel!

Heres my my home made tool - worked perfectly. Snip off the clamp end, weld on the piece IN LINE with the clamp so it comes together with the screwing part.

Here is my tool in action:

Now one MAJOR issue with tools breaking is the keepers/retainers being stuck to the valve - most ppl will over tighten the tool and break it.

Heres what you do - take a needle nose pliers, and set it on top of the lifter with the tips on both sides of the valve retainer like so:

Now give the valve a hard tap - not a hard whack (unless multiple attempts fail of course). The valve should bounce - the keepers are now un stuck - proceed to use the tool.

If u have stuck valves (u prob do).. heres a technique i used - grab the outside of the valve with vice grips (a tiny bit of damage here wont affect anything) - its the seat area about 1/8-1/16th behind it you want to protect) -

Now put another wrench on the vice grip and twist sideways. As it starts to loosen (use atf/kroil, kroil and more kroil - down the stem).. you will have to pull up as u twist - this is tiring and tough, but it gets VERY stuck valves out. ATF is a fantastic thing to use (beats anything hands down) - mixed with some acetone its prob the best.

Right - where are we, a few beers down the road!

(2 be continued)...

Last edited by CamaroMan; 11-01-2017 at 11:43 AM.
Reply With Quote
The Following User Says Thank You to CamaroMan For This Useful Post:
cdhickey (11-01-2017)
  #3   IP:
Old 10-31-2017, 11:19 PM
CamaroMan CamaroMan is offline
Join Date: Oct 2017
Location: San Pedro, CA
Posts: 42
Thanks: 3
Thanked 10 Times in 5 Posts

Now to clean up the valve guides - a nifty tip is go get a 1/2" pipe cleaner from home depot, snip off the grey handle - PERFECT for a cordless drill (DONT USE REVERSE! the wire will unwind and strew it everywhere!)

Uses this tool to clean the valves - stems and faces. I use a paint scraper to get the tough crud off the stem (dont worry, unless u sit there scratching non stop fr maybe 3 months u MIGHT leave a scratch). Work you way around the stem - dont fuss too much about some carbon right at the bottom of the stem where it joins the flat part - focus on the straight stem part (this is what travels up and down as the motor is running).

Valve before:

Valve after cleaning:

Right - almost ready - take the wire brush in the drill and buzz it around the valve seat (on the engine block).. about 5 seconds / seat shd be good. Now poke it gently down throat and spin it on the valve guide with the piece of wire down the valve guide - this will clear out gunk near the guide leaving it shiny.

Now grab a 3/8 drill bit, insert it into each valve guide (not sure if they vary but check whatever drill bit goes in snug).

I use a slow reverse to get it down the hole straight - then I switch to fwd, give it a few spins (use lube oil) - this will clear out/unlodge any gunk in the valve guide- DONT angle it/muck it up, let the hole/drill guide your hand and keep the drill in the whole guide (make sure u dont go down too far and damage sth). 5 secs / hole shd be plenty

Blast out holes with spray cleaner and oil. Clean everything up real well.

Your valves/valve seats/guides are ready for another 50 years (i hope!).

I have done this on many engines and never had issues - One valve that was stuck and took 30 mins to get out slides in and out effortlessly now - thats exactly what u want.
Reply With Quote
The Following User Says Thank You to CamaroMan For This Useful Post:
cdhickey (11-01-2017)
  #4   IP:
Old 10-31-2017, 11:25 PM
CamaroMan CamaroMan is offline
Join Date: Oct 2017
Location: San Pedro, CA
Posts: 42
Thanks: 3
Thanked 10 Times in 5 Posts
Here is a pic of the thermostat after soaking it in muratic acid. I did this with the head nuts as well. You have to degrease first (acid doesnt penetrate oil) / soak in acid for 15-30 mins / rinse in fresh water / dry and OIL immediately.

The muck from threads:

**** i FORGOT THIS - U HAVE TO plug the oil drain holes when removing the valve keepers to stop them falling down engine!!

All the valves cleaned and ready for assembly!

Final notes:

Cast iron rusts - after cleaning keep the surfaces oiled. Spritz some wd40 in cylinder bores to keep rings from rusting too. Check for cracks in head/block. Grease the studs on assembly - and use a thread sealer on the studs (if they came out) so water doesnt corrode studs.

Ill take some more pics Friday when Everything goes back together (incl setting the valves / torquing procedure and a short vid).
Reply With Quote
The Following 5 Users Say Thank You to CamaroMan For This Useful Post:
cdhickey (11-01-2017), DDO (04-07-2021), GregH (11-01-2017), Nahart (11-03-2017), Surcouf (11-05-2019)

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
head removed and valves loosened but what next? heinz Troubleshooting 5 09-20-2016 09:53 AM
unsticking valves? overez General Interest 5 05-08-2014 11:08 PM
Would you reinstall this cylinder head? (Pics) Launchpad McQ Overhaul 17 03-16-2014 02:04 PM
Cleaning valves while head is removed Jeremy Thompson Overhaul 3 10-17-2008 08:00 AM
more photos in the manual JarrettF The Wish List 16 01-15-2008 07:04 AM

All times are GMT -4. The time now is 02:24 AM.

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2023, vBulletin Solutions, Inc.

Universal® is a registered trademark of Westerbeke Corporation

Copyright © 2004-2023 Moyer Marine Inc.

All Rights Reserved