Engine Concensus....lower intake manifold install

Gs1987GT

Active Member
Sep 25, 2019
301
99
38
MidAtlantic
Hello Gents, Good Morning,

I will be removing the lower intake manifold soon and cleaning and preparing it for reinstallation. I purchased the felpro gasket kit with the silicone end gaskets.

Typically when I install the lower intake I run a bead of black rtv on the front and back of the block and I do not use the gaskets. It's been awhile and back in the day those end gaskets were cork (no good, leaked)

I am sure there are many here who do this work frequently. Is the consensus to use the silicone end gaskets, or still to use the bead of silicone on the front and rear of the intake?

Thanks for your thoughts.

-Greg
 
  • Sponsors(?)


Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
36,391
12,296
224
Massachusetts
You'll get folks who have done it both ways with success

I've always done them with the Felpro gaskets with the blue silicone end seals and even with the older cork gaskets. I dab RTV only in the corners and seal up the intake. Never had an issue that way. I've never done the RTV only method.

I also get a pair of long bolts that fit into the block and cut the heads off. I used them as guides in each corner to lower the intake down without having to wiggle it once it's in place.
 
  • Useful
  • Like
Reactions: 1 users

John Dirks Jr

there is enough sticking out to grab on to
5 Year Member
Jun 28, 2013
2,872
1,227
174
57
Maryland
Just a heads up here. Felpro had more than one gasket set for these engines. The one laminated with steel core is highly recommended. Do you know which one you have?

Here's the ones I use.

 
  • Like
Reactions: 1 user

Gs1987GT

Active Member
Sep 25, 2019
301
99
38
MidAtlantic
Just a heads up here. Felpro had more than one gasket set for these engines. The one laminated with steel core is highly recommended. Do you know which one you have?

Here's the ones I use.

I believe the set with the silicone end gaskets have the main gaskets with steel core. It's the set recconemeed by Tmoss.
You'll get folks who have done it both ways with success

I've always done them with the Felpro gaskets with the blue silicone end seals and even with the older cork gaskets. I dab RTV only in the corners and seal up the intake. Never had an issue that way. I've never done the RTV only method.

I also get a pair of long bolts that fit into the block and cut the heads off. I used them as guides in each corner to lower the intake down without having to wiggle it once it's in place.
Much appreciated Sir, thanks for your thoughts. I will probably stick with what has worked for me but have not decided yet 100%

Great tip for the temporary studs for the lower intake install.

I looked recently and still have the set I made 20 plus years ago for just that purpose.

Thanks again
Just a heads up here. Felpro had more than one gasket set for these engines. The one laminated with steel core is highly recommended. Do you know which one you have?

Here's the ones I use.

This is the kit from lmr I purchased. Says they are metal core

 
  • Like
Reactions: 1 user

jrichker

StangNet's favorite TOOL
SN Certified Technician
Mar 10, 2000
27,441
2,772
234
75
Dublin GA
lowendmac.com
Some other help for you...


Intake manifold removal and replacement.

Revised 8 Jul 2017 to add diagrams and bolt torque information
Here's some help...

Vacuum line connections:

One large vacuum line from the upper front goes to the carbon canister

One large vacuum line from the rear goes to the vacuum tree.

One small line in the front feeds the Smog pump solenoid control valves on the rear of the passenger side wheel well..

One small line in the rear goes to the fuel pressure regulator.

One small line in the rear goes to the EGR suction regulator.

One large line in the rear goes to the PVC valve.

Diagram courtesy of Tmoss & Stang&2birds - Typical Vacuum Routing for a Fox stang 5.0:
mustangFoxFordVacuumDiagram.jpg





Diagram courtesy of Tmoss & Stang&2birds - Intake manifold bolt tightening sequence for a 5.0 Fox stang:

FordIntakeTorqueSequence.gif




Intake manifold to head bolts
--Step 196 in/lbs
--Step 216ft/lbs
--Step 323-25 ft/lbs

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/

Here's some tips...

Tools: a good torque wrench is a must have item. A razor blade scraper that holds a single edge razor blade from Home Depot or Ace hardware is another handy thing. Get a Chilton or Haynes shop manual - you'll need it for the bolt torques and patterns. The intake manifold has an especially odd pattern. You'll need access to a timing light to set the timing after you re-stab the distributor. Look in the A/C repair section for the fuel line tools. They look like little plastic top hats. You will need the 1/2" & 5/8" ones. The hat shaped section goes on facing the large part of the coupling. Then you press hard on the brim until it forces the sleeve into the coupling and releases the spring. You may need someone to pull on the line while you press on the coupling. Put some motor oil on them when you put the line back together.

The A/C Compressor comes off with lines still connected. Mark all the electrical, smog and vacuum lines with tags to help you remember where to re-connect them. If you have a digital camera, take several pictures.

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. When all the surfaces are free of dark specks and are smooth enough that when you run your fingernail over the surface, you don't feel any raised places, then it is clean enough.

Put some cardboard in the lifter valley to help catch the gasket scrapings. Have a shop vacuum handy to suck up the scrapings and any coolant that leaked into the lifter valley.

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. Be sure to put a rag or cap in the block where you removed the distributor. It will save you trouble if something falls into the empty distributor hole.

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. TADA! no leaks, and no gaskets that shifted out of place.

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-$4 per kit. The following are listed at the Borg-Warner site ( http://www.borg-warner.com ) as being resellers of Borg-Warner parts:

http://www.partsplus.com/ or http://www.autovalue.com/ or http://www.pepboys.com/ or http://www.federatedautoparts.com/

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


Putting the distributor back in and setting the timing.

Revised 15-Apr-2016 to add fix for TFI hitting the thermostat housing while trying to set the base timing at 14°.

You can forget about anything beyond this point if you don't have access to a timing light. You will never get the timing set right without one.

Note:
If you don't have access to a timing light, most of the larger auto parts stores will rent or loan one if you have a credit card or leave a cash deposit.

Putting the distributor back in is fairly simple. Pull #1 sparkplug, put your finger in the sparkplug hole, crank the engine until you feel compression. Then line up the TDC mark on the balancer with the pointer on the engine block.

The distributor starts out with the #1 plug wire lined up at about 12:00 with you facing it. Align the rotor to about 11:00, since it will turn clockwise as it slides into place.

Align the distributor rotor up with the #1 position marked on the cap, slide the distributor down into the block, (you may have to wiggle the rotor slightly to get the gear to engage) and then note where the rotor is pointing.

If it still lines up with #1 position on the cap, install the clamp and bolt. If not, pull it out and turn 1 tooth forwards or backwards and try again. Put the #1 spark plug back in and tighten it down, put the clamp on the distributor, but don't tighten it too much, as you will have to move the distributor to set the timing. Note that there is no such thing as one tooth off on a 5.0 Mustang if you follow the spark plug wire order on the distributor cap. If it doesn't align perfectly with #1 position, you can turn the distributor until it does. The only problem is that if you are too far one way or the other, you can't turn the distributor enough to get the 10-14 degree optimum timing range. If the TFI prevents the distributor from being turned enough to get 14°, there is a simple fix. Pull the distributor out and turn the rotor 1 tooth counterclockwise Don't move the wires from the positions shown on the cap on fuel injected engines!!!! The #1 position cast into the cap MUST have the spark plug wire for #1 cylinder in it. Do it differently and the timing for the fuel injectors will be off. The computer uses the PIP sensor to time injector operation by sensing the wide slot in the PIP sensor shutter wheel. If the injector timing of #1 and the firing of #1 do not occur at the right time, the injector timing for all other cylinders will be affected.

Setting the timing:
Paint the mark on the harmonic balancer with paint -choose 10 degrees BTC or 14 degrees BTC or something else if you have NO2 or other power adder. I try to paint TDC red, 10 degrees BTC white and 14 degrees BTC blue.

10 degrees BTC is towards the drivers side marks.

Note: setting the timing beyond the 10 degree mark will give you a little more low speed acceleration. BUT you will need to run 93 octane to avoid pinging and engine damage. Pinging is very hard to hear at full throttle, so it could be present and you would not hear it.

Simplified diagram of what it looks like. Not all the marks are shown for ease of viewing.

ATC ' ' ' ' ' ' ' ' ' '!' ' ' ' ' ' ' ' ' ' BTC

---------------- > Direction of Rotation as viewed standing in front of the engine.

The ' is 2 degrees.

The ! is TDC

The ' is 10 degrees BTC

Set the timing 5 marks BTC. Or if you prefer, 5 marks towards the driver's side to get 10 degrees.

To get 14 degrees, set it 7 marks BTC. Or if you prefer, 7 marks towards the driver's side to get 14 degrees.

The paint marks you make are your friends if you do it correctly. They are much easier to see than the marks machined into the harmonic balancer hub.

At this point hook up all the wires, get out the timing light. Connect timing light up to battery & #1 spark plug. Then start the engine.

Remove the SPOUT connector (do a search if you want a picture of the SPOUT connector) It is the 2 pin rectangular plug on the distributor wiring harness. Only the EFI Mustang engines have a SPOUT. If yours is not EFI, check for a SPOUT: if you don’t find one, skip any instructions regarding the SPOUT

Warning: there are only two places the SPOUT should be when you time the engine. The first place is in your pocket while you are setting the timing and the second is back in the harness when you finish. The little bugger is too easy to lose and too hard to find a replacement.

Start engine, loosen distributor hold down with a 1/2" universal socket. Shine the timing light on the marks and turn the distributor until the mark lines up with the edge of the timing pointer. Tighten down the distributor hold down bolt, Replace the SPOUT connector and you are done.

The HO firing order is 1-3-7-2-6-5-4-8.

Non HO firing order is 1-5-4-2-6-3-7-8

https://www.stangnet.com/mustang-forums/attachments\51122 [/img]

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. Heat the pintle caps in boiling water to soften them to make them easier to install.

Plan on doing an oil change within 2 hours of run time on the engine. This will get the debris and coolant out of the oil pan.

Consumable items:
Upper manifold gasket
Fel Pro 1250 or equal lower manifold gasket set.
Short formed hose between thermostat hosing and intake manifold
6 ft 7/64" or 1/8" vacuum hose
2 ft 1/2" heater hose
1 1/2 ft 5/8" heater hose
Blue Silicone sealer
ARP antiseize or equal for the bolts
4 each 3/4" hose clamps (spare item in case the old ones are bad)
4 each 1/2" hose clamps (spare item)

What can happen if you don’t use the stay in place gasket…
Ask Nicoleb3x3 about the intake gasket that slipped out of place and caused idle and vacuum leak problems that could not be seen or found by external examination. Spay everything with anything you have, and you won't find the leak...

photodisplay.php
 
Last edited:
  • Like
Reactions: 1 user

mikestang63

SN Certified Technician
Aug 27, 2012
10,458
7,232
204
In the garage
My suggestion is to line up the intake gasket against the heads and intake to make sure they match and are the right size. Felpro makes a 1250 and 1262 which are different port size. Personally I would never use their Print O Seal gaskets as they leak. Use either the 1250S or 1262S that have the steel reinforcements. Regarding the China walls, I have always used a nice thick bead of Right Stuff and let it tack up and then carefully laid the intake on. I run the bolts down hand tight and walk away for a few hours before torquing them down. It also helps to use a dab of right stuff on the intake gaskets just to hold them in place so they dont slide around.