Doing the intake manifold this weekend - tip & hints

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dave silva

New member
Oct 2, 2009
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We've diagnosed a cracked intake and i have a good to install. I have done this job before but it was long time ago.

I have Jim k's gasket kit with blockoff plates.

I know about cuting the head of a bolt to make alignment pins.

Any other tips?
--
Dave & Ellen Silva
Hertford, NC

76 Birchaven, 1-ton and other stuff

Currently planning the Great american Road Trip Summer 2021

It's gonna take a lot of Adderall to get this thing right.
 
This is what I do. And the products I use successfully.
1. Clean the gasket surfaces and the ends of the intake manifold and the
block and cylinder heads "Operating Room Clean" I use Carb cleaner in a
spray can and green scotchbrite pads. And Blue paper towels made for
automotive use.
2. Invert the manifold on a clean work surface where it is well lighted and
not easily disturbed. Using bolts that snugly fit the hold down holes in
the manifold, place the gasket dry where it will eventually live, and place
the block off plates in place with the gasket, and see if any trimming is
necessary on the gasket to prevent overlapping onto the block off plates.
If there is interference, trim and mark the gaskets so that they pair up
with the plates. I usually use DyChem blue marker dye and paint the
manifold surface where the block off plates fit. After all is in position
and safely trimmed, scribe around the blockoff plates in the dye.
3. Remove the gaskets and using Permatex high tack spray adhesive, spray
the intake manifold end to end where the gaskets go. Let it tack up and
spray it again. do the same thing to the down side of the gaskets, and
while still tacky, place the gaskets exactly in place drop the bolts down
through the gaskets and intake manifold to hold position overnight.
4. Do the same thing to the plates.
Leave it overnight.
On each end of the manifold where the water passages are, squeeze out a
ribbon of "The Right Stuff" sealant. I use a can like a redi whip can but
the tubes will work as well if you are not going to have more use for it
later.
5. If you are very sure that your engine has not had it's head surfaces
milled or the intake manifold surfaced, then the OEM Neoprene dams at the
ends of the block are your best bet. DO NOT USE ANY SEALANT OF ANY KIND ON
THESE DAMS, THEY WILL SLIP AND LEAK OIL IF YOU DO.
6. If your block or manifold have been milled and there is not enough space
for the dams, then use a copious bead of "The Right Stuff" on each end of
the block. Let it tack up so that it does not stick to your clean
fingertips, but is not completely cured, Then with the help of an
assistant, place the intake in place without moving it around and align the
manifold with taper punches on four corners. Start the hold down bolts and
studs and run them down until they touch the intake manifold.
7. Finally, using the torque sequence pictured in the GMC shop manual,
torque the intake down to the specified torque in three stages. Then leave
it to heck alone for a day. If you do it like I have outlined here, you
will have an intake that will not leak anything.
It works for me.
Jim Hupy
Salem, Oregon

> We've diagnosed a cracked intake and i have a good to install. I have
> done this job before but it was long time ago.
>
> I have Jim k's gasket kit with blockoff plates.
>
> I know about cuting the head of a bolt to make alignment pins.
>
> Any other tips?
> --
> Dave & Ellen Silva
> Hertford, NC
>
> 76 Birchaven, 1-ton and other stuff
>
> Currently planning the Great american Road Trip Summer 2021
>
> It's gonna take a lot of Adderall to get this thing right.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
 
> If you do it like I have outlined here, you
> will have an intake that will not leak anything.
> It works for me.
> Jim Hupy
> Salem, Oregon

Ok then, that's what I'm gonna do.

Thanks

--
Dave & Ellen Silva
Hertford, NC

76 Birchaven, 1-ton and other stuff

Currently planning the Great american Road Trip Summer 2021

It's gonna take a lot of Adderall to get this thing right.
 
> \
> 3. Remove the gaskets and using Permatex high tack spray adhesive,

Jim,

Not wanting to deviate the slightest from this sacred scroll (i hired a monk to transcribe it onto goat skin)

But I am not able to source the permetex high tack- there is regular permatex spray and other spray adhesive, is that a critical part?

--
Dave & Ellen Silva
Hertford, NC

76 Birchaven, 1-ton and other stuff

Currently planning the Great american Road Trip Summer 2021

It's gonna take a lot of Adderall to get this thing right.
 
They also make an identical product that is a screw top can with a brush
attached to the cap. Messier to use, but will yield the same results.
Slower, though."Permatex" brand, should be available at nearly any GOOD
auto parts store. NAPA, too. Professionals use the stuff, so it should be
available and fresh.
Jim Hupy
Salem, Oregon

> > \
> > 3. Remove the gaskets and using Permatex high tack spray adhesive,
>
> Jim,
>
>
> Not wanting to deviate the slightest from this sacred scroll (i hired a
> monk to transcribe it onto goat skin)
>
> But I am not able to source the permetex high tack- there is regular
> permatex spray and other spray adhesive, is that a critical part?
>
> --
> Dave & Ellen Silva
> Hertford, NC
>
> 76 Birchaven, 1-ton and other stuff
>
> Currently planning the Great american Road Trip Summer 2021
>
> It's gonna take a lot of Adderall to get this thing right.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
 
Get a cheap shop vac and dedicate it to this job. The mess under the intake I used a shop vac extensively, but such a mess the shop vac ended up in
dumpster in end.

Take time to make a good lifting handle. I have basically a 1” square tube with some holes drilled in. Washers and bolts to catch the carb base.
Or make a way to lift and set intake gingerly. They are heavy!!! You dont want to be banging it around.

Also helps to lift up while you carefully pry to break seal on old one.
--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
 
And if Jon threw something out, it was trash. The man can fix anything
________________________________
From: Jon Roche
Sent: Thursday, February 10, 2022 9:23 PM
To: gmclist
Subject: [GMCnet] Re: Doing the intake manifold this weekend - tip & hints

Get a cheap shop vac and dedicate it to this job. The mess under the intake I used a shop vac extensively, but such a mess the shop vac ended up in
dumpster in end.

Take time to make a good lifting handle. I have basically a 1” square tube with some holes drilled in. Washers and bolts to catch the carb base.
Or make a way to lift and set intake gingerly. They are heavy!!! You dont want to be banging it around.

Also helps to lift up while you carefully pry to break seal on old one.
--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
 
> should be available at nearly any GOOD auto parts store.

Hah, you guys would be jealous of my auto parts store- at least two generations, fan belts hanging on 12 foot walls, and an ashtray on the counter-
That guy told me he was having trouble getting permatex prodicts.

I ended up getting high-temp spray adhesive at Car Quest.

Correct me if i'm wrong, the spray adhesive is just to hold everything in place during assembly- right?

--
Dave & Ellen Silva
Hertford, NC

76 Birchaven, 1-ton and other stuff

Currently planning the Great american Road Trip Summer 2021

It's gonna take a lot of Adderall to get this thing right.
 
> Hah, you guys would be jealous of my auto parts store- at least two generations, fan belts hanging on 12 foot walls, and an ashtray on the
> counter- That guy told me he was having trouble getting permatex prodicts.
>
> I ended up getting high-temp spray adhesive at Car Quest.
>
> Correct me if i'm wrong, the spray adhesive is just to hold everything in place during assembly- right?

Dave,

There are actually two critical areas.

The MOST critical is the coolant ports at the ends. If those leak, you end up with coolant in the lube oil and that is very bad.

The second critical area is below the intake ports. If there is leakage there, ingesting lube oil will be a problem and so will vacuum loss at idle.

When I had to do mine, I put a sawhorse in the cab and rigged tackle to lift/lower that thing and was glad I did.

Matt
--
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
 
I put a 2” dia pipe across the seats and used a come along connected to a two x four across the aisle behind the bath and the closet. This allowed me to lower the manifold alone.

Emery Stora

>

>> Hah, you guys would be jealous of my auto parts store- at least two generations, fan belts hanging on 12 foot walls, and an ashtray on the
>> counter- That guy told me he was having trouble getting permatex prodicts.
>>
>> I ended up getting high-temp spray adhesive at Car Quest.
>>
>> Correct me if i'm wrong, the spray adhesive is just to hold everything in place during assembly- right?
>
> Dave,
>
> There are actually two critical areas.
>
> The MOST critical is the coolant ports at the ends. If those leak, you end up with coolant in the lube oil and that is very bad.
>
> The second critical area is below the intake ports. If there is leakage there, ingesting lube oil will be a problem and so will vacuum loss at idle.
>
>
> When I had to do mine, I put a sawhorse in the cab and rigged tackle to lift/lower that thing and was glad I did.
>
> Matt
> --
> Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
> Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
> SE Michigan - Near DTW - Twixt A2 and Detroit
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
 
All good advice.
I will add,

go back and retorque the intake bolts 2-3-4 times some I have seen relax the torque after a
few heat cycles.

watch puke tank like a hawk; particularly if you have to retorque bolts

some have used fish line to hold gasket to manifold through the bolt holes,

--
1977 Eleganza II
Ogden NY
 
> T3. Remove the gaskets and using Permatex high tack spray adhesive, spray
> the intake manifold end to end where the gaskets go. Let it tack up and
> spray it again. do the same thing to the down side of the gaskets, and
> while still tacky, place the gaskets exactly in place drop the bolts down
> through the gaskets and intake manifold to hold position overnight.
> 4. Do the same thing to the plates.
> Leave it overnight.
> On each end of the manifold where the water passages are, squeeze out a
> ribbon of "The Right Stuff" sealant. I use a can like a redi whip can but
> the tubes will work as well if you are not going to have more use for it
> later.

I'm a little unclear- at this point i have glued the gasket and plates to the manifold with spray adhesive and let it sit.

Then step 4 says "On each end of the manifold where the water passages are, squeeze out a
ribbon of "The Right Stuff" sealant."

Am i putting a bead of sealant in the gasket, only at the water passages?
--
Dave & Ellen Silva
Hertford, NC

76 Birchaven, 1-ton and other stuff

Currently planning the Great american Road Trip Summer 2021

It's gonna take a lot of Adderall to get this thing right.
 
No. Both sides of the gasket, as well as the heads where the gasket mates.
The "Right Stuff" only needs to seal the water passages. Sorry if I was a
bit vague, there.
Jim Hupy
Salem, Oregon

> > T3. Remove the gaskets and using Permatex high tack spray adhesive, spray
> > the intake manifold end to end where the gaskets go. Let it tack up and
> > spray it again. do the same thing to the down side of the gaskets, and
> > while still tacky, place the gaskets exactly in place drop the bolts down
> > through the gaskets and intake manifold to hold position overnight.
> > 4. Do the same thing to the plates.
> > Leave it overnight.
> > On each end of the manifold where the water passages are, squeeze out a
> > ribbon of "The Right Stuff" sealant. I use a can like a redi whip can but
> > the tubes will work as well if you are not going to have more use for it
> > later.
>
> I'm a little unclear- at this point i have glued the gasket and plates to
> the manifold with spray adhesive and let it sit.
>
> Then step 4 says "On each end of the manifold where the water passages
> are, squeeze out a
> ribbon of "The Right Stuff" sealant."
>
> Am i putting a bead of sealant in the gasket, only at the water passages?
> --
> Dave & Ellen Silva
> Hertford, NC
>
> 76 Birchaven, 1-ton and other stuff
>
> Currently planning the Great american Road Trip Summer 2021
>
> It's gonna take a lot of Adderall to get this thing right.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
 
> No. Both sides of the gasket, as well as the heads where the gasket mates.
> The "Right Stuff" only needs to seal the water passages.

So I'm sealing the gasket around the opening with the Right Stuff and the spray adhesive is just to hold everything in place?
--
Dave & Ellen Silva
Hertford, NC

76 Birchaven, 1-ton and other stuff

Currently planning the Great american Road Trip Summer 2021

It's gonna take a lot of Adderall to get this thing right.
 
Still need clarification on the application of sealant.

The spray adhesive glues the gasket and block off plate to the manifold, right?

The only other sealant apllied at the gasket is around the coolant openings?

And i do this on BOTH sides of the gasket?

I have not begun removing the old one yet (today)

I am fairly certain it is original.

How can tell if the heads have ever been milled?

Would the presence of the turkey tray be a good indicator?

We have been blocking the crossover and tossing the turkey tray for a long time, right?

--
Dave & Ellen Silva
Hertford, NC

76 Birchaven, 1-ton and other stuff

Currently planning the Great american Road Trip Summer 2021

It's gonna take a lot of Adderall to get this thing right.
 
Yes, the Paterson gaskets and block off plates replaces the turkey tray.
Many of us have used this upgrade for a very long time. The fix is battle
tested and works very well.
So, to clarify my instructions a bit.
Yes, both surfaces of the gasket are supposed to be sprayed with hi tack.
Only do the side that mates with the manifold first, then, mount the gasket
to the manifold, align the holes and leave it sit overnight.
Just before you place the manifold, apply the "right stuff" and spray
both the heads and gasket with high tack, then with assistance, place the
manifold without sliding it around and line up the holes and bolts.
You use the neoprene dams if room exists for them. If there is not
enough room for them, then more than likely, something has been milled off
either the heads or manifold or both. In this case, do as I have already
directed and use beads of sealant in place of the dams. If this isn't
clear, call me. I will walk you through it.
Jim Hupy five 0 three, nine thirty one-49eighty eight.

> Still need clarification on the application of sealant.
>
> The spray adhesive glues the gasket and block off plate to the manifold,
> right?
>
> The only other sealant apllied at the gasket is around the coolant
> openings?
>
> And i do this on BOTH sides of the gasket?
>
> I have not begun removing the old one yet (today)
>
> I am fairly certain it is original.
>
> How can tell if the heads have ever been milled?
>
> Would the presence of the turkey tray be a good indicator?
>
> We have been blocking the crossover and tossing the turkey tray for a long
> time, right?
>
>
>
> --
> Dave & Ellen Silva
> Hertford, NC
>
> 76 Birchaven, 1-ton and other stuff
>
> Currently planning the Great american Road Trip Summer 2021
>
> It's gonna take a lot of Adderall to get this thing right.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
 
Dave, You have enough questions that I am going to answer in-line**

Still need clarification on the application of sealant.

The spray adhesive glues the gasket and block off plate to the manifold, right? **This will work. I hope it holds that stainless well enough.

The only other sealant apllied at the gasket is around the coolant openings? **There and the China walls at the ends of the valley.

And i do this on BOTH sides of the gasket? ** At the coolant ports - Yes

I have not begun removing the old one yet (today)

I am fairly certain it is original.

How can tell if the heads have ever been milled? **Can you see the edge of the cylinder head gaskets? Are they 0.017 steel shim? If yes, the heads
have probably not been off or milled. If the cooler parts of the engine are still all the Olds metal flake blue, I would bet it hasn't been apart.
Are the China Walls still close with rubber gaskets??

Would the presence of the turkey tray be a good indicator? **No, that would have been replaced no mater what else was done.

We have been blocking the crossover and tossing the turkey tray for a long time, right? **GMCers and jet boat racers have been filling and/or plugging
that cross over for decades.

**If these are not all the answers you need or some are not clear, try again.

Matt

--
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
 
When you install the crossover block, you'll need to install a electric
choke.
I see all type of junky electrical connectors that fall off and not work.
We have the correct connectors on our web site to use.

> Dave, You have enough questions that I am going to answer in-line**
>

>
> Still need clarification on the application of sealant.
>
> The spray adhesive glues the gasket and block off plate to the manifold,
> right? **This will work. I hope it holds that stainless well enough.
>
> The only other sealant apllied at the gasket is around the coolant
> openings? **There and the China walls at the ends of the valley.
>
> And i do this on BOTH sides of the gasket? ** At the coolant ports - Yes
>
> I have not begun removing the old one yet (today)
>
> I am fairly certain it is original.
>
> How can tell if the heads have ever been milled? **Can you see the edge of
> the cylinder head gaskets? Are they 0.017 steel shim? If yes, the heads
> have probably not been off or milled. If the cooler parts of the engine
> are still all the Olds metal flake blue, I would bet it hasn't been apart.
> Are the China Walls still close with rubber gaskets??
>
> Would the presence of the turkey tray be a good indicator? **No, that
> would have been replaced no mater what else was done.
>
> We have been blocking the crossover and tossing the turkey tray for a long
> time, right? **GMCers and jet boat racers have been filling and/or plugging
> that cross over for decades.
>
> **If these are not all the answers you need or some are not clear, try
> again.
>
> Matt
>
>
> --
> Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL,
> GMCES
> Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum
> Brakes with Applied Control Arms
> SE Michigan - Near DTW - Twixt A2 and Detroit
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>

--
Jim Kanomata ASE
Applied/GMC, Newark,CA
jimk
http://www.gmcrvparts.com
1-800-752-7502
 
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