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Block party [message #145734] Thu, 06 October 2011 15:08 Go to next message
Charley is currently offline  Charley   United States
Messages: 116
Registered: September 2010
Location: Magnolia Texas
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Senior Member
I am getting ready to block my crossover on my intake. I am using a product "Hard Blok 860228-Hard Blok Engine Block Filler" along with block off plates and gaskets. I had to order more than what was needed so if some one would like to fill theirs as well let me know. I am in Magnolia Texas near Houston. I hope to do it this weekend but will wait if some else would like theirs done as well because I have not yet pulled my intake.

Charley Harris Magnolia Texas 1976 Edgemont
Re: Block party [message #145754 is a reply to message #145734] Thu, 06 October 2011 19:43 Go to previous messageGo to next message
midlf is currently offline  midlf   United States
Messages: 2212
Registered: July 2007
Location: SE Wisc. (Palmyra)
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Charley wrote on Thu, 06 October 2011 15:08

I am getting ready to block my crossover on my intake. I am using a product "Hard Blok 860228-Hard Blok Engine Block Filler" along with block off plates and gaskets. I had to order more than what was needed so if some one would like to fill theirs as well let me know. I am in Magnolia Texas near Houston. I hope to do it this weekend but will wait if some else would like theirs done as well because I have not yet pulled my intake.



I mentioned to a performance engine builder that I was thinking of using HardBlok to block the crossover. He advised me that it was not suitable as the oil temps get the crossover to exceed the max temp of HardBlok. I have not checked this for myself yet. You might wish to check with HardBlok.


Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI
Re: [GMCnet] Block party [message #145760 is a reply to message #145734] Thu, 06 October 2011 20:40 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
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Registered: July 2007
Location: Sydney, Australia
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Charley,

Please document the process with pictures, we have discussed using this product for this job but I don't remember if anyone has
actually used it and what the results were.

If the manifold has not been removed before it probably will be stuck to the turkey tray and the turkey tray stuck to the heads. Do
your best to remove both items as gently as possible. Tap a narrow paint scraper between the manifold and turkey tray at the four
corners to break the seal on both heads then lift it off. Do the same thing with the turkey tray if it's stuck. The reason I mention
this is there WILL be HEAPS of oil baked on the bottom of the manifold and turkey tray. The gentler you remove it the less will fall
into the lifter valley.

http://www.gmcmhphotos.com/photos/showphoto.php?photo=10758

The bottom of my turkey tray was WAY worse than this:

http://www.gmcmhphotos.com/photos/showphoto.php?photo=17730

John Sharpe and I were careful when we removed my cast iron manifold to install the Aluminum RPM manifold but a fair amount of crud
fell into the lifter valley anyway. We wound up vacuuming the bits out. The problem is that crud winds up in the oil pump inlet.

http://www.gmcmhphotos.com/photos/showphoto.php?photo=10860

Here's a link to the stuff Charley is using:

http://www.summitracing.com/parts/HNH-860228/

As you can see its $89 if you add the $45 for the block off plate gasket kit it's a cheap fix!

http://www.appliedgmc.com/prod.itml/icOid/799

Along with the gasket kit you might want to consider installing one of these:

http://www.mondellotwister.com/VT-581.gif

Tips on re-installing the manifold:

1) Review the procedure in MM X-7525
Section: Engine
Page: 6A-29 - 31
Paragraphs: INTAKE MANIFOLD - Removal & Installation

Note: disregard the torque sequence in Figure 17 - Reverse it starting with 12 and work back to 1. It is the general consensus that
this is for a turkey tray type gasket not a fiber type.

2) Cut the heads off a couple of bolts and screw them in one head to guide the manifold on to the heads

3) The cast iron manifold is HEAVY, bolt a chain to the carb mounting holes. You can stand over the engine hatch and a helper can
guide the manifold straight down left/right - fore/aft

4) Permatex Ultra Black PermatexR Ultra BlackR Maximum Oil Resistance RTV Silicone Gasket Maker in an aerosol can makes it very easy
to get a nice bead at the front / rear of the lifter valley

http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=BK_7653009_0006382638

5) Allow the Black Max to "skin over" before you drop the manifold down as that will form a perfect gasket and prevent silicone
drips into the engine

6) Glue the gaskets to the cylinder heads using Gorilla Snot (3M Super Weatherstrip Adhesive)

http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=MMM08011_0006436278

7) Re-torque the manifold after the engine has been run to operating temp and cooled several times.

If I've missed anything or screwed something up PLEASE correct me!

Regards,
Rob M.

-----Original Message-----
From: Charley Harris

I am getting ready to block my crossover on my intake. I am using a product "Hard Blok 860228-Hard Blok Engine Block Filler" along
with block off plates and gaskets. I had to order more than what was needed so if some one would like to fill theirs as well let me
know. I am in Magnolia Texas near Houston. I hope to do it this weekend but will wait if some else would like theirs done as well
because I have not yet pulled my intake.

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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] Block party [message #145761 is a reply to message #145754] Thu, 06 October 2011 20:41 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Steve,

Following sent to Hard Blok:

Hi,

I have a 1975 GMC Motorhome that is powered by an Oldsmobile 455 Toronado engine. It has a crossover under the carburetor that
channels exhaust gases to warm the carb.

This crossover causes vapor lock problems with the new Ethanol fuels and most owners fill it with aluminum or zinc. I would like to
try your product.

In conjunction with Hard Blok I will install stainless steel block off plates between the heads and the intake manifold to keep the
Hard Blok from being exposed to exhaust gases.

Do you think your product will work in this application?

Please advise.

Thank you,
Rob Mueller

Regards,
Rob M.


-----Original Message-----
From: Steve Southworth

I mentioned to a performance engine builder that I was thinking of using HardBlok to block the crossover. He advised me that it was
not suitable as the oil temps get the crossover to exceed the max temp of HardBlok. I have not checked this for myself yet. You
might wish to check with HardBlok.
--
Steve

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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] Block party [message #145764 is a reply to message #145761] Thu, 06 October 2011 20:53 Go to previous messageGo to next message
midlf is currently offline  midlf   United States
Messages: 2212
Registered: July 2007
Location: SE Wisc. (Palmyra)
Karma: 1
Senior Member
Robert Mueller wrote on Thu, 06 October 2011 20:41

Steve,

Following sent to Hard Blok:

Hi,

I have a 1975 GMC Motorhome that is powered by an Oldsmobile 455 Toronado engine. It has a crossover under the carburetor that
channels exhaust gases to warm the carb.

This crossover causes vapor lock problems with the new Ethanol fuels and most owners fill it with aluminum or zinc. I would like to
try your product.

In conjunction with Hard Blok I will install stainless steel block off plates between the heads and the intake manifold to keep the
Hard Blok from being exposed to exhaust gases.

Do you think your product will work in this application?

Please advise.

Thank you,
Rob Mueller

Regards,
Rob M.






I'll be interested to hear their answer.


Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI
Re: [GMCnet] Block party [message #145769 is a reply to message #145764] Thu, 06 October 2011 21:40 Go to previous messageGo to next message
Charley is currently offline  Charley   United States
Messages: 116
Registered: September 2010
Location: Magnolia Texas
Karma: 0
Senior Member
Thanks for all the information. Rob I will have to order one of those trays tomorrow thanks for the link. I know there was a hot rod shop out east that was using this stuff on intakes with no issues but it will be interesting to see what the company actually says. I did find this where this guy used it on his GMC to fill the crossover as well http://www.gmcmhphotos.com/photos/showphoto.php?photo=18183&cat=4537
I will document what I do and let everyone know how it turns out. If there are any more brave souls in the area that would like to try it or have a spare they want filled I still plan on trying it but may wait as I do want to order that tray that Rob posted.



Charley Harris Magnolia Texas 1976 Edgemont
Re: [GMCnet] Block party [message #145774 is a reply to message #145769] Thu, 06 October 2011 23:01 Go to previous message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Charley,

You're welcome.

Good find!

I knew I saw this somewhere but for the life of me I couldn't remember.

However, this does not appear to be the same product; note the name "Durabond" on the receipt:

http://www.gmcmhphotos.com/photos/showphoto.php?photo=18167

Here's a link to Cotronics:

http://www.cotronics.com/vo/cotr/index.htm

It appears that 950 is no longer sold, however, there is 960 which appears to be a similar product.

I have sent the same email to Cotronics that I sent to Hard Blok so we can see what both of them say.

On the receipt I noted: Contact: Mike Kilroy and a phone number.

Is Mike still a GMC owner? The receipt is dated 07/22/06 and if Mike is still owns this GMC we could find out how the Durabond
worked.

Regards,
Rob M.

-----Original Message-----
From: Charley Harris

Thanks for all the information. Rob I will have to order one of those trays tomorrow thanks for the link. I know there was a hot
rod shop out east that was using this stuff on intakes with no issues but it will be interesting to see what the company actually
says. I did find this where this guy used it on his GMC to fill the crossover as well
http://www.gmcmhphotos.com/photos/showphoto.php?photo=18183&cat=4537
I will document what I do and let everyone know how it turns out. If there are any more brave souls in the area that would like to
try it or have a spare they want filled I still plan on trying it but may wait as I do want to order that tray that Rob posted.

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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
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