Is this a valve cover issue? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

MattPSU · 05-25-2013, 01:12 PM

I drove my truck (other than around the block) for the first time since I had it apart this fall. When I came back I checked the fluids and I noticed that my freshly repainted intake had stains on both sides. Is this just loose/not sealing valve covers or do I have a worse problem here?

modernbeat · 05-25-2013, 01:17 PM

That is heat staining from the heat riser. It's a port in the manifold that goes into the exhaust port either to heat the manifold, or on some older manifolds, to actuate the choke.

Roninwolf · 05-25-2013, 01:26 PM

x2

MattPSU · 05-25-2013, 02:04 PM

Thanks guys. So no problem? Nothing I need to fix? Just live with the stain till my budget allows for an aluminum intake?

Rufton · 05-25-2013, 02:16 PM

I blocked the heat riser on one car; helps keep carb slightly cooler. MPG still ok. Cold weather performance still ok.

66skylarkpost · 05-25-2013, 02:23 PM

it appears that u are running full time vacumn to ur distributor .... it should be only going to the ported vac fitting in the front left of a quad that u have capped off ...

Rufton · 05-25-2013, 02:31 PM

Pros and cons to running full time vacuum.
Ask 2 people get 2 different answers.
Sometimes easier to just try it both ways.

MattPSU · 05-25-2013, 02:48 PM

Quote:

Originally Posted by 66skylarkpost

it appears that u are running full time vacumn to ur distributor .... it should be only going to the ported vac fitting in the front left of a quad that u have capped off ...

Thanks for the heads up. This is how the carb was set up when I bought the truck, and my knowledge in this area isn't great. So I want to run it to where I have the red circle in the picture below???

Square_78 · 05-25-2013, 03:19 PM

Did you use high heat engine paint on your intake or just normal paint? If its just normal paint then they whole thing may turn that brown color as the paint cooks from the engine heat.
Posted via Mobile Device

MattPSU · 05-25-2013, 04:01 PM

Quote:

Originally Posted by Square_78

Did you use high heat engine paint on your intake or just normal paint? If its just normal paint then they whole thing may turn that brown color as the paint cooks from the engine heat.
Posted via Mobile Device

It's supposed to be high heat paint. I bought it just for painting the intake. Obviously it sucks that it discolored, but I'm more concerned about there being an issue. I can live with the stain (for now) but if there's something I need to do to keep it cooler, I want to take care of that first.

- Matt

**WIDESIDE72** · 05-25-2013, 04:14 PM

As mentioned above, its from the heat riser. There are some little rectangular pieces of metal in your intake gasket set that go over the heat riser he in the head to block the heat from going into the intake. You will give up a little "drivability" when the enhine is cold, but it should solve the issue.
Posted via Mobile Device

**WIDESIDE72** · 05-25-2013, 04:16 PM

I block them off on all of mine, but then i live in Texas, where it hardly ever gets below 20'a and if it does het that cold, we get ice too, so my old stuff is not leaving the place anyway.
Posted via Mobile Device

66skylarkpost · 05-25-2013, 04:34 PM

here's is the port for timing advance . where u cirlcled is where the vacumn line for the door in the original air cleaner snorkel went

MattPSU · 05-26-2013, 02:16 PM

Quote:

Originally Posted by WIDESIDE72

As mentioned above, its from the heat riser. There are some little rectangular pieces of metal in your intake gasket set that go over the heat riser he in the head to block the heat from going into the intake. You will give up a little "drivability" when the enhine is cold, but it should solve the issue.
Posted via Mobile Device

These???

GASoline71 · 05-26-2013, 02:21 PM

Quote:

Originally Posted by Rufton

Pros and cons to running full time vacuum.
Ask 2 people get 2 different answers.
Sometimes easier to just try it both ways.

Yup... some do it, some don't. I've done it both ways as well.

Gary

**WIDESIDE72** · 05-26-2013, 09:04 PM

Quote:

Originally Posted by MattPSU

These???

Yep
Posted via Mobile Device

asolde · 05-26-2013, 09:32 PM

I have the same issue with my intake painted Chevy orange. But felpro gasket instructions did not call for the block off set on my 69 350 so I left them out. I am concerned about too much heat under the carburator. I do not run a insulator spacer either. So far it seems to run ok.

05-25-2013, 01:12 PM	#1
MattPSU Registered User Join Date: Nov 2011 Location: Lyman, SC Posts: 734	Is this a valve cover issue? I drove my truck (other than around the block) for the first time since I had it apart this fall. When I came back I checked the fluids and I noticed that my freshly repainted intake had stains on both sides. Is this just loose/not sealing valve covers or do I have a worse problem here? Attached Images __________________ Matt Criswell - Lyman, SC 1972 Chevy Cheyenne SWB - Build: Porterbuilt State 1 Front & Rear, Bolt in Notch, McGaughys 2.5 Drop Spindles, Boyd Welding Fuel Tank UPSTATE SC GM TRUCK CLUB: FACEBOOK WEBSITE

05-25-2013, 01:17 PM	#2
modernbeat Registered User Join Date: Mar 2011 Location: Dallas, TX Posts: 39	Re: Is this a valve cover issue? That is heat staining from the heat riser. It's a port in the manifold that goes into the exhaust port either to heat the manifold, or on some older manifolds, to actuate the choke.

05-25-2013, 01:26 PM	#3
Roninwolf Registered User Join Date: May 2012 Location: Cullman Alabama Posts: 114	Re: Is this a valve cover issue? x2 __________________ My build thread http://67-72chevytrucks.com/vboard/s...d.php?t=531265 72 Cheyenne Super 90 Z71 S.B. 434 C.I. Stroker 78 Camaro Z28 (gave to wife she is restoring it)

05-25-2013, 02:04 PM	#4
MattPSU Registered User Join Date: Nov 2011 Location: Lyman, SC Posts: 734	Re: Is this a valve cover issue? Thanks guys. So no problem? Nothing I need to fix? Just live with the stain till my budget allows for an aluminum intake? __________________ Matt Criswell - Lyman, SC 1972 Chevy Cheyenne SWB - Build: Porterbuilt State 1 Front & Rear, Bolt in Notch, McGaughys 2.5 Drop Spindles, Boyd Welding Fuel Tank UPSTATE SC GM TRUCK CLUB: FACEBOOK WEBSITE

05-25-2013, 02:16 PM	#5
Rufton Registered User Join Date: Apr 2013 Location: Knoxville TN Posts: 1,170	Re: Is this a valve cover issue? I blocked the heat riser on one car; helps keep carb slightly cooler. MPG still ok. Cold weather performance still ok.

05-25-2013, 02:23 PM	#6
66skylarkpost Registered User Join Date: Mar 2006 Location: kearney,nebraska Posts: 443	Re: Is this a valve cover issue? it appears that u are running full time vacumn to ur distributor .... it should be only going to the ported vac fitting in the front left of a quad that u have capped off ... __________________ '70 k-10 longbox- mid 70's drivetrain 350/350 487x heads 10.1:1 flowmasters ,35's 3.73's auburn posi ,rear shackle flip. '72 short stepside U.S. forestry truck, '73 455 buick,400 turbo,dropped 2"-4 1/4" ,3.07 posi,:'89 silverado 1500 ,OK truck ,5.7 holley tbi ,trick 700r4 3.07 auburn posi ,and my '66 skylark ,'73 centurion and my '84 monte carlo imca stock car

05-25-2013, 02:31 PM	#7
Rufton Registered User Join Date: Apr 2013 Location: Knoxville TN Posts: 1,170	Re: Is this a valve cover issue? Pros and cons to running full time vacuum. Ask 2 people get 2 different answers. Sometimes easier to just try it both ways.

05-25-2013, 03:19 PM	#9
Square_78 Registered User Join Date: Mar 2012 Location: Okanagan Valley, BC, Canada Posts: 1,237	Re: Is this a valve cover issue? Did you use high heat engine paint on your intake or just normal paint? If its just normal paint then they whole thing may turn that brown color as the paint cooks from the engine heat. Posted via Mobile Device __________________ #teamlongbed "I refuse to go disc brakes. I actually love drum brakes. It makes for an adventure." - 50bomb 1978 Chevy shop truck - static 6/8" 1970 GMC 1500 - Accuair eLevel Resto-mod http://67-72chevytrucks.com/vboard/s...d.php?t=537497

05-25-2013, 04:14 PM	#11
WIDESIDE72 Senior Member Join Date: Aug 2008 Location: Cedar Park, Texas Posts: 7,494	Re: Is this a valve cover issue? As mentioned above, its from the heat riser. There are some little rectangular pieces of metal in your intake gasket set that go over the heat riser he in the head to block the heat from going into the intake. You will give up a little "drivability" when the enhine is cold, but it should solve the issue. Posted via Mobile Device

05-25-2013, 04:16 PM	#12
WIDESIDE72 Senior Member Join Date: Aug 2008 Location: Cedar Park, Texas Posts: 7,494	Re: Is this a valve cover issue? I block them off on all of mine, but then i live in Texas, where it hardly ever gets below 20'a and if it does het that cold, we get ice too, so my old stuff is not leaving the place anyway. Posted via Mobile Device

05-25-2013, 04:34 PM	#13
66skylarkpost Registered User Join Date: Mar 2006 Location: kearney,nebraska Posts: 443	Re: Is this a valve cover issue? here's is the port for timing advance . where u cirlcled is where the vacumn line for the door in the original air cleaner snorkel went Attached Images __________________ '70 k-10 longbox- mid 70's drivetrain 350/350 487x heads 10.1:1 flowmasters ,35's 3.73's auburn posi ,rear shackle flip. '72 short stepside U.S. forestry truck, '73 455 buick,400 turbo,dropped 2"-4 1/4" ,3.07 posi,:'89 silverado 1500 ,OK truck ,5.7 holley tbi ,trick 700r4 3.07 auburn posi ,and my '66 skylark ,'73 centurion and my '84 monte carlo imca stock car

05-26-2013, 09:32 PM	#17
asolde Registered User Join Date: Apr 2012 Location: Henderson Nevada Posts: 804	Re: Is this a valve cover issue? I have the same issue with my intake painted Chevy orange. But felpro gasket instructions did not call for the block off set on my 69 350 so I left them out. I am concerned about too much heat under the carburator. I do not run a insulator spacer either. So far it seems to run ok.



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