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How Come?

  • Thread starter Thread starter SSSlacker
  • Start date Start date Jul 11, 2015

SSSlacker

Member
Jun 26, 2015
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Houston, Texas
Jul 11, 2015
#1
  • Jul 11, 2015
  • #1
Ok, recently found a vacuum leak on the passenger side lower intake. I used the lower gasket in the picture when I assembled the motor but formed a vacuum leak at the red arrow. Apparently the leak was coming from around a lower intake bolt. The upper gasket in the picture is what came with my Trickflow Street Burner top end kit but I didn't use it. I didn't use it because it didn't have the bolt hole sealing surfaces as the other gasket (red area points at vac. leak and bolt sealing surfaces). The upper gasket has no way to seal those bolts holes. So, how do I make sure those bolt holes don't leak when I reassemble the car next week? I'm going to replace the lower intake bolts with an ARP bolt kit. Is there someway to help seal the lower intake bolts to the manifold so I don't have to screw with this again?
 

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jrichker

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Jul 12, 2015
#2
  • Jul 12, 2015
  • #2
You are pointing to a bolt next to an EGR passage. I am not sure what a leak there and into the crankcase would do, but it should not affect the idle
The gasket above the one with a red arrow should be sufficient to do the job.

Intake manifold installation tips:

Whatever you do, don't skimp on cleaning the gasket surfaces. New gaskets need to seat against bare metal and not the residue left from the old gaskets in order to seal leak free. This is the most time consuming and tiresome part of the job. Put a piece of cardboard in the lifter valley to cover it up. It will reduce the amount that falls down into the valley and hydraulic lifters. I suggest that you make good use of a shop vac while you are scraping and cleaning to avoid getting the old gasket material lost inside the engine. Look for little things that need to be replaced like the short hose from the thermostat hosing to the water pump, damaged vacuum lines and hose clamps that are rusted or broken.

Plan on cutting the thermostat to water pump hose, or removing the thermostat housing. Also plan on removing the distributor to get clearance to remove the intake manifold. Remove #1 spark plug, stick your finger in the spark plug hole and crank. When your finger gets air moving past it, stop cranking. Turn the engine until the timing marks line up with the pointer. Now you can pull the distributor out.

My favorite trick that saves time and effort is the stay in place gasket. Be sure that you scrape (don't use a wire brush) all the old gasket material off, then clean all the surfaces with acetone or MEK.

When the surfaces are clean, use weather strip adhesive on the head to manifold surface. Also use the weather strip adhesive on the side of the gasket that mates to the head. When you are done, the head surface and the gasket surface that mate together will have weather strip adhesive on them. Follow the instructions on the tube or can and when it gets tacky, press the gasket down on the head.

Clean the area where the rubber rails mount to the block in front and in the rear with more acetone or MEK and do the same trick with the weather strip adhesive that you did to the heads.

Coat the rubber seals and the gasket area around the water passages with lots of Blue Silicone gasket sealer and put it together. Bingo! no leaks, and no gaskets that shifted out of place.

If you reuse the injectors from your old setup, a repair kit is available from most auto parts stores if needed. Coat the injector body "O" rings with oil before you use them and everything will slide back together.

Fuel injector seal kits with 2 O rings and a pintle cap (Borg-Warner P/N 274081) are available at Pep Boys auto parts. Cost is about $3.50 - $4.00 per kit. The following are listed at the Borg-Warner site ( BWD - Home ) as being resellers of Borg-Warner parts:

Parts Plus – Premium Auto Parts & Accessories or Auto Value or Pep Boys | Tires | Auto Repair & Service | Car Parts | Car Accessories or Federated Auto Parts

Most of the links above have store locators for find a store in your area.

Use motor oil on the O rings when you re-assemble them & everything will slide into place. The gasoline will wash away any excess oil that gets in the wrong places and it will burn up in the combustion chamber.


Intake manifold to head bolts
--Step 1 96 in/lbs
--Step 2 16ft/lbs
--Step 3 23-25 ft/lbs
 
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