Confirmation for KenB on two topics

[Matt Colie]

Hey Ken,

Remember we were talking about how Mobil1 can make glass-hard deposits in the combustion chamber??

Well #7, the one that broke out the rings has a nice case. Fortunately most of the deposit is over carbon and a shot with a center punch can break it
up. It is tedious, but I will finish tomorrow.

And - Valve Cover Gaskets.....
The guy that put my engine together glued them to the head. Looks like Fel-Pro rubberized cork and it only comes off with a sharp wood chisel, about
an inch at a time. Man, am I glad I am not trying to do this over a belly-board and working in the hole.

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

 

[Jim Hupy]

Bad enough when it is a rocker cover, but my LEAST FAVORITE gasket is the
water pump and followed by the timing cover. That is a belly board
operation, and it truly SUCKS.
Jim Hupy
Salem, Or
78 GMC ROYALE 403

> Hey Ken,
>
> Remember we were talking about how Mobil1 can make glass-hard deposits in
> the combustion chamber??
>
> Well #7, the one that broke out the rings has a nice case. Fortunately
> most of the deposit is over carbon and a shot with a center punch can break
> it
> up. It is tedious, but I will finish tomorrow.
>
> And - Valve Cover Gaskets.....
> The guy that put my engine together glued them to the head. Looks like
> Fel-Pro rubberized cork and it only comes off with a sharp wood chisel,
> about
> an inch at a time. Man, am I glad I am not trying to do this over a
> belly-board and working in the hole.
>
> Matt
> --
> Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
> Electronically Controlled Quiet Engine Cooling Fan
> OE Rear Drum Brakes with Applied Control Arms
> SE Michigan - Twixt A2 and Detroit
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[Ken B]

What are you chipping on, the head? If it is the piston I would just replace it.

On the airplane engine we had here that used Mobil One, we tried everything. Including sand blasting. Finally we scrapped the cylinders and pistons
and got new ones. You can get by with Mobil one on a GMC engine if you are NOT USING OIL. If you are burning oil (one quart per thousand or more),
Do NOT USE any Synthetic oil.

Why use synthetic oil on a 50 year old design engine?

Yes, I agree on the valve cover gaskets. Glue them to the cover only. It is much easier later to put the covers in the parts washer and clean them
up there.

Finally got the cooling system back together on this 403 I'm working on. I was able to get the engine up to temperature (around 180). I ran it up
and let cool down three times today. Engine starts and runs beautifully. After a total of about 1.5 hours in 3 runs I dumped the oil / Rislone /
gasoline mix. It came out medium black and still has traces of that brown stuff in it but it is no where near what it was before. I was using 5W20.

I filled it again for a second flushing. This time with 5W30. We will run it again a few times and flush it out also. It was interesting how much of
that brown crap was trapped in the filter. Using this thinner oil I have to watch the oil pressure very carefully. I run it until the pressure drops
to around 25 and engine temp is 180. Then I shut it down. After this next flushing I plan to use 15W40 conventional oil with another can of Rislone.
Then put 500 or 1000 miles on it.

Good luck on the engine rebuild. Thanks for the confirmation. Hopefully others are watching.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[Matt Colie]

> What are you chipping on, the head? If it is the piston I would just replace it.

Ken,

I am chipping the glass out of the head casting. One smack at a time, but it is going.

The #7 piston lost rings and lands for about 120°.
The rest are so good after 80K of Mobil1 with moly, that if the piston were whole, I would just screw it back together. I kind of have to replace all
8 pistons (well, one was a given) but I can't find who made the others and they are not stock bowl. That means I could not match compression
volumes.....

The bores have so little wear that I am going to go back with 30 over pistons. The cam followers do show some wear, do that is getting replaced. The
mains and rods all seem to have embedded some aluminum dust. But, the crank has no threading and so that gets new shells only. I am not going to
worry about debris in the oil cooler. It seems that the only thing that got circulated was that small amount of AL dust. There is actually less
damage in the lube oil pump than I would have expected in 80K miles and there was nothing in any of the lash adjusters that I opened that was not
black but clean oil.

The timing chain was so slack (1-1/2")that I could almost pull it off the crank. I am doing a whole valve job just on general principle. I am still
trying to decide on a stock or high volume oil pump. The only reason I might replace that is the wear on the pump drive shaft.

Well the rebuild is going well. Parts are coming in and I have too much apart for there to be any surprise hiding in there.

Matt

--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

 

[terry1]

Matt,
I think you still have a surprise left in there, that thought stemming from the lack of wear in the engine in general, yet the timing chain is
slack enough to skip a beat since you can almost remove it and leave the sprockets. What's up with that? Isn't there an orifice at the end of the
lifter run specifically for lubing that chain? Haven't taken mine apart (yet) and don't have books in front of me now, but I remember reading about
the racers plugging that orifice for more/faster lifter fill or overall pressure or something like that. If trash or metal filings blocked that
orifice/leak then maybe flushing the oil cooler would be a good idea...
--
Terry Kelpien

ASE Master Technician

73 Glacier 260

Smithfield, Va.

 

[Jim Hupy]

On the front end of the engine, the cam gallery has a plug with a hole
drilled in it to lube the timing chain set. The other end of that gallery
also is drilled and tapped with a plug. On agricultural applications, which
our motor home engines are, that plug is also drilled to lube the
distributor gear. Many passenger car blocks do not have that hole. Also,
passenger car engines frequently have "Cylent" cam sprockets which are
coated with nylon or some other plastic to minimize noise. They usually
only last 80 k or so before they self destruct. The factory heavy duty set
was the "Hyvo" chain which is not a roller chain, but a series of
tri-angular links pinned together. They loosen over time. The ultimate set
is a true double roller chain and sprocket set. The best ones have loose
rollers that have axles on the rollers and only the axles are pinned or
staked to the side plates. The rollers are free to rotate on the axles.
Cheap copies do not have loose rollers. Buyer beware.
Jim Hupy
Salem, Or

> Matt,
> I think you still have a surprise left in there, that thought stemming
> from the lack of wear in the engine in general, yet the timing chain is
> slack enough to skip a beat since you can almost remove it and leave the
> sprockets. What's up with that? Isn't there an orifice at the end of the
> lifter run specifically for lubing that chain? Haven't taken mine apart
> (yet) and don't have books in front of me now, but I remember reading about
> the racers plugging that orifice for more/faster lifter fill or overall
> pressure or something like that. If trash or metal filings blocked that
> orifice/leak then maybe flushing the oil cooler would be a good idea...
> --
> Terry Kelpien
>
> ASE Master Technician
>
> 73 Glacier 260
>
> Smithfield, Va.
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[LarryW]

Matt,
Just rebuilt my 500. Now have 1100 miles on it. Oil is pretty darn clean at 1100 change and burning no oil so far. I attribute this to several
things.

1.) new valve guides with PC type seals on the intake and umbrellas on the exhaust. Exhaust gets quite hot and has exhaust pressure on it which helps
limit the amount of oil that can get to guides, thus umbrellas to allow a little more oil to the guides.

2.) tighten up and make sure the PCV system is working properly, including baffled valve cover on the vacuum side of the PCV system.

3.) On assembly, used "Total Seal" "Gapless rings" on the pistons.

http://015ef8d.netsolhost.com/TechPage.aspx

I researched this and saw no reason not to use these. Didn't find any negatives other than they are expensive. Hopefully this is a one time upgrade.

4.) Use this method of mounting rings on pistons.

http://www.gmcmhphotos.com/photos/g4104-putting-rings-on-pistons.html

Just what I did. Maybe will help you.

--
Larry
78 Royale w/500 Caddy
Menomonie, WI.

 

[Ken B]

Duh! What was I thinking when I suggested replacing the piston? Of course you are going to be replacing it. The old one is broken.

I also wonder what is happening with the stretched or worn timing chain and sprockets.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[kosier]

Larry,

I've missed something here. What happened that caused the need to rebuild
the 500?
Last I knew you were trucking down the pike, carefree and happy.

Gary Kosier
77PB w/500Cad
Newark, Ohio

--------------------------------------------------
From: "Larry"
Sent: Thursday, March 15, 2018 11:36 AM
To:
Subject: Re: [GMCnet] Confirmation for KenB on two topics

> Matt,
> Just rebuilt my 500. Now have 1100 miles on it. Oil is pretty darn clean
> at 1100 change and burning no oil so far. I attribute this to several
> things.
>
> 1.) new valve guides with PC type seals on the intake and umbrellas on the
> exhaust. Exhaust gets quite hot and has exhaust pressure on it which helps
> limit the amount of oil that can get to guides, thus umbrellas to allow a
> little more oil to the guides.
>
> 2.) tighten up and make sure the PCV system is working properly, including
> baffled valve cover on the vacuum side of the PCV system.
>
> 3.) On assembly, used "Total Seal" "Gapless rings" on the pistons.
>
> http://015ef8d.netsolhost.com/TechPage.aspx
>
> I researched this and saw no reason not to use these. Didn't find any
> negatives other than they are expensive. Hopefully this is a one time
> upgrade.
>
> 4.) Use this method of mounting rings on pistons.
>
> http://www.gmcmhphotos.com/photos/g4104-putting-rings-on-pistons.html
>
>
>
> Just what I did. Maybe will help you.
>
>
> --
> Larry
> 78 Royale w/500 Caddy
> Menomonie, WI.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

 

[Ken H.]

Now I'M confused! I thought Matt still ran one of those ol' 455's and it
shed a piston ring & lands.

Ken H.

> Larry,
>
> I've missed something here. What happened that caused the need to rebuild
> the 500?
> Last I knew you were trucking down the pike, carefree and happy.
>
> Gary Kosier
> 77PB w/500Cad
> Newark, Ohio
>
> --------------------------------------------------
> From: "Larry"
> Sent: Thursday, March 15, 2018 11:36 AM
> To:
> Subject: Re: [GMCnet] Confirmation for KenB on two topics
>
>
> Matt,
>> Just rebuilt my 500. Now have 1100 miles on it. Oil is pretty darn clean
>> at 1100 change and burning no oil so far. I attribute this to several
>> things.
>>
>> 1.) new valve guides with PC type seals on the intake and umbrellas on
>> the exhaust. Exhaust gets quite hot and has exhaust pressure on it which
>> helps
>> limit the amount of oil that can get to guides, thus umbrellas to allow a
>> little more oil to the guides.
>>
>> 2.) tighten up and make sure the PCV system is working properly,
>> including baffled valve cover on the vacuum side of the PCV system.
>>
>> 3.) On assembly, used "Total Seal" "Gapless rings" on the pistons.
>>
>> http://015ef8d.netsolhost.com/TechPage.aspx
>>
>> I researched this and saw no reason not to use these. Didn't find any
>> negatives other than they are expensive. Hopefully this is a one time
>> upgrade.
>>
>> 4.) Use this method of mounting rings on pistons.
>>
>> http://www.gmcmhphotos.com/photos/g4104-putting-rings-on-pistons.html
>>
>>
>>
>> Just what I did. Maybe will help you.
>>
>>
>> --
>> Larry
>> 78 Royale w/500 Caddy
>> Menomonie, WI.
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>