HEAD REPLACEMENT

[ArtJ]

I rcvd a used head a couple of days ago thanks to the generosity of Jack Wright

Removed head from spare engine today took couple of hours, 1 hr prep with pbblaster and liight tapping of head bolts. Half came out stud and nut together
(all had good threads) A couple of nuts needed vice grips as they had rounded heads

Gentle use of screwdrivers wedges and blocks of wood persuaded the head\off
in 2o minutes,

I noticed that all of the oval holes in the block nearest the manifold were
blocked completely, I tried to clean them out briefly. The companion
oval holes in the old head were not blocked. I assume they are for cooling
the head??
Suggestions on clearing them appreciated.

The cylinder walls and tops of pstons looked great as do the valves.

I have ordered head gasket etc and studs nuts from MMI
Thanks

Art

[Mo]

Did about 4 heads this past summer on both my old engine and a few friends. Those blocked holes are generally superficial blockages, meaning they don't extend far. What I did was use a shop vacc (running) and positioned right over each hole as I disturbed the grud with a screw driver. You will note it will suck right out of there and you will also see it is only about one quarter to a half inch deep. Of course also check the head (which you did) Have a good look for cracks in the block there, like weak or thinned out areas. I've found that if it's brownish it's usually gunk building up because (of what I think) is heat. I've noticed it on cyl 1 and 2 on engines that slant rearward with the No 1 cyl forward and high. Not real sure of the correlation. Have seen black as well which I thought was a build up of carbon from an exhaust port crack leaking into the water jacket area or perhaps around manifold studs etc.

What you were looking at is the reason I do muriatic acid flushes of my engine every 2 to 3 years. When I took the head of mine, nothing of the sort was there but the other 3 sure did. So clean them out the best you can, see if you can blow compressed air through after, then reinstall the head. Once you run up the engine, check or leaks on your hoses etc. Once convinced there are no leaks I'd do a muriatic acid flush and continue to do one every couple to 3 years. I'll post Mr. Don Moyer's link beneath.

Hope that helps and perhaps others have an even better idea of how to deal with it.

https://www.moyermarineforum.com/for...20the%20engine).

[Al Schober]

Yes, those small coolant passages by the valves need to be cleaned out. They go down a short way, then fore/aft, then down again. A small hammer and chisel work well, also a Dremel tool with a diamond burr. Get out what you can. Open is better than closed!
Once you get those passages flowing, then an acid flush will do some good. When they're blocked off an acid flush does nothing.
Once they're opened up and clean, think about glycol cooling. If you want to keep your A4, it's the way to go.

[ArtJ]

Thanks Al & MO

This engine is a spare which I fill with afreeze after running did not know
about blockage till now. will try to pick and vac out. Once back together
I will do a acid flush.

Other questions Re studs and nuts

Since the threads on the studs that came out look fine I assume that
I can Torque the ones that stayed in? Is there a separate spec for
torque of the studs alone (using 2 nuts?) or use stud remover to torque??

For the ones that came out all with great threads like new if
reused I must first remove the - old good but frozen nuts maybe soak in mmo?
then clamp stud other end with 2 nuts in vice and remove or heat nuts
with torch?
I have some new studs on boat which I can retrieve and ordered a couple from MMI but at $$ per stud would like to reuse some studs

I assume it is a no no to simply reinstall studs with frozen nuts on them
both for further removal in future and to have ability to torque stud and
nut installed .

Are the nuts simply grade 8 which I can get locally?

Thanks Guys

[Al Schober]

You've got to get the nuts off the studs and clean up the threads. You don't want the stud turning when you try to torque the nuts.
As to how hard to seat the studs, I don't know of a published number. When you torque the nuts to 35 ftlb, some of that goes into friction between the nut and the head. The rest goes into the stud. Hence the seating torque for the stud can be less than 35 ftlb. Giving a number would be a guess. But if the stud turns while you're torquing the nut, you didn't get it tight enough.
The nuts do not need to be Gr 8. Some folks have used stainless washers and stainless acorn nuts - makes things 'pretty'.

[ArtJ]

I have successfully remove the nuts from all studs and cleaned up the
threads

NUTS could not locate a local source for the large head nuts the smaller
ones are available I ordered a new set fro MM of the large nuts
Why do the small nuts exist? only found one location using them??

STUD PLACEMENT

I plan to clean the holes of removed studs wiht a 3/8 coarse tap
as recommended in MMI manual apply AV Permatex to threads and
install till bottoms out using snapon stud tool
This is a spare engine which I may or may not need to use

Still installed studs I would like to look at exposed threads i(f any)
and check tightness with snapon tool
I dont wish to remove them unless someone has a strong reason
why I must.

OVAL HOLES

plan to clean out withj pick and coat hanger bent.
Do they travel toards each other ?
How much must be cleaned out to allow muratic flush to work?

MANIFOLD
I don't want r remove unless I must in order to clean flow
What is the coolant flow from block to manifold to head

When I got this engine I nwas told it had been rebuild as mentioned
the studs, valve heads cylinder walls and heads look great\
the head was very crusty

Best Regards and thanks Art

[ArtJ]

The left hand thermostat stud (end closest to lifting eye) is
3 1/4 inches long .
While installing this stud found it would not really tighten until
in so far that only a couple of threads show above the housing
If I really torqued it in I could probably make it flush on housing.

Why does this one go in so far? f I get a 3/1/2 stud and use it
will it do damage to the block?
The alternative is to not iinstall the stud so deep
What is the best thing to do?

Thanks Appreciated Art

[ArtJ]

Originally Posted by ArtJ

The left hand thermostat stud (end closest to lifting eye) is
3 1/4 inches long .
While installing this stud found it would not really tighten until
in so far that only a couple of threads show above the housing
If I really torqued it in I could probably make it flush on housing.

Why does this one go in so far? f I get a 3/1/2 stud and use it
will it do damage to the block?
The alternative is to not iinstall the stud so deep
What is the best thing to do?

Thanks Appreciated Art

I looked at the local hw store studs as well as on line dont seem to fnd anything longer than 3 inches. I noted that the nut on this stud had to be
cut off . PO must have been using that may.
Looks as though I may have to resort to not fully seating the stud and let the nut tghtening torque take care of thngs?

[jcwright]

Hello Art.

Here is a link to the 3.31" stud I believe you are trying to replace. I think Moyer sells them in pairs.

https://moyermarine.com/product/stud...lk_01_110-2-2/

Jack.

[ArtJ]

Hi Jack

The stud I have is one of those 3.31.I believe 3,25 as only a rough estimate
one possible problem is that the head is only finger tight now and will compress down a little when torqued exposing a few more threads for the nut

I suspect it is common for a stud to come out with the nut on
thermstat housing.

[ArtJ]

Guys


Just noticed that the manifold studs are 3.6 inches just the right length
for the thermostat !!!!!


https://moyermarine.com/product/stud..._01_110-2-2-2/