Topic: Intake manifold's backing (baffle) plate

[MustangAndFairlane1867]

While I've got the engine out of my '65 fastback (San Jose/February 16, 1965) and the intake manifold off, I plan to remove the manifold's backing plate to inspect and thoroughly clean it out.  I don't know what, if anything, I'll find in there, but after so many years of operation and possible abuse by P.O.s, it seems like a prudent thing to do, and kind of a fun and interesting weekend project to boot (what if a P.O. sand blasted the intake at one point in the past and I've got sand or glass beads under there waiting to wreak havoc on my stamped, original K motor?  I don't want to even think about that!).  But here's the rub:  how do I remove those 4 round-head bolts that attach the plate to the manifold, and how do I re-attach the plate when my cleaning and scrubbing is complete?  I've done some research, but to date I've not come across a technique that makes much sense to me.  Any and all ideas or suggestions will be much appreciated, even from those who might think I'm wasting my time. Lol.  Thanks, Ron

[Bob Gaines]

While I've got the engine out of my '65 fastback (San Jose/February 16, 1965) and the intake manifold off, I plan to remove the manifold's backing plate to inspect and thoroughly clean it out.  I don't know what, if anything, I'll find in there, but after so many years of operation and possible abuse by P.O.s, it seems like a prudent thing to do, and kind of a fun and interesting weekend project to boot (what if a P.O. sand blasted the intake at one point in the past and I've got sand or glass beads under there waiting to wreak havoc on my stamped, original K motor?  I don't want to even think about that!).  But here's the rub:  how do I remove those 4 round-head bolts that attach the plate to the manifold, and how do I re-attach the plate when my cleaning and scrubbing is complete?  I've done some research, but to date I've not come across a technique that makes much sense to me.  Any and all ideas or suggestions will be much appreciated, even from those who might think I'm wasting my time. Lol.  Thanks, Ron

It is not wasting your time . It is always a good idea for the reasons you covered. Those rivets have a twisted ribbing that makes them hard to back out. You have to get under the edge with a thin screw driver etc. and work it under the head. As you tap it under the edge the wedge design works the head up.  You have to alternate sides with progressively thicker screw driver etc utilizing the wedge effect of the tool to work them loose. I know of some that reuse them but most will tap the hole to thread a small bolt and lock tight it in. You can also use a appropriate size self taping screw to hold the shield on in a similar fashion as the factory used rivet.

[MustangAndFairlane1867]

Bob:  Thanks for those suggestions.  The one technique for re-attaching the baffle that appeals to me is to tap the 4 holes and use stainless button-head allen bolts and red Loctite to hold the baffle in place.  I think I'll go with that unless there's a better "been-there-done-that" technique that shows up here.  Thanks, Ron

[jwc66k]

I "removed" the rivets by force and replaced them with AMK supplied rivets. Under the plate was 40 years of crud. It was worth it.
JIm

[66candy]

This is what came out off my intake baffle:

[OldGuy]

I've been successful in removing the rivets by using a fairly large chisel (wider than the head on the rivet).

Make sure that your intake manifold is held down firmly to your work bench by clamping it in place or with the assistance of a helper exerting a lot of "gravity" on the manifold. You want all of the subsequent force to be applied to the rivet and not moving the manifold around the work bench.

Place the chisel edge (on the side of the rivet with the most access) between the base of the rivet head and the sheet metal tab of the baffle. Using a large hammer, give the chisel a hardy "whack". This action should cause the rivet to raise up slightly allowing you to get under the rivet head to continue the spiral-out action of the rivet (using the chisel or, preferably, a pry bar). You may need to repeat this process again from a different angle if the rivet is very stubborn. Don't get in a hurry! You don't want to damage the sheet metal baffle.

Drilling/tapping/securing with screws is my recommendation for re attachment.

I hope this helps.

Frank 

[CharlesTurner]

The chisel method is what I saw a looong time ago by a seasoned mechanic and is what I've always done since.

[Bartman]

Does anyone know what the purpose of this plate is?  My engine builder removed it and told me it wasn’t required.
Aftermarket intakes don’t have it.
Bartman

[rocket289k]

My understanding is the backing protects the bottom of the intake manifold from baked oil / carbon build up. This is because there is a heat crossover that passes hot exhaust gasses from the heads through the bottom of the manifold to help vaporize fuel. It gets so hot that oil cooks on the manifold, causing carbon particles to form and create a mild abrasive in your oil. Even with the pan in place, some oil still gets in and cooks (as illustrated in the picture earlier this thread), but at least it's then trapped in there.

Regards,

Ron

[OldGuy]

Does anyone know what the purpose of this plate is?  My engine builder removed it and told me it wasn’t required.
Aftermarket intakes don’t have it.
Bartman

Your are right, most aftermarket manifolds don't have the baffle plate on the bottom side of the manifold. These same manifolds don't have the hot gas passage porting (that goes from side to side-creating a "hot zone" in the middle of the manifold) either. Therefore, there is no need to keep splashed oil from coming in contact with the base of the manifold because there is no hot zone.

[MustangAndFairlane1867]

Thanks everyone for the advice and the pictures.  I'll be tackling this next week and will post a pix or two of what I find under the baffle.  Ron...

[Chris Thauberger]

Thought it might help to see what the fastener looks like.

Chris

[Hipo giddyup]

 +1 on removing the cover to clean it out. This is a must if your intake has been media blasted as media/sand/glass will definitely get in there.

[MustangAndFairlane1867]

Chris:  Thanks for the great picture.  These appear to be identical to the ones installed on my intake.  Someone told me they are still available after market, but I don't know where.  Not sure I would use them, anyway.  Probably couldn't sleep wondering if they would stay in place, even with locktite.  Probably best to drill, tap and install button-head allan screws with locktite.  But as to the originals, I wonder how they were installed by the intake manufacturer?  Were they self-tapping and pressed in, or driven down with a baby sledge, etc.  Looking closely at the ones on my manifold I see no damage to the heads or perimeter that offer a clue as to how they were seated.  However it was done, must have been somewhat labor intensive.  Ron...

[Bob Gaines]

Chris:  Thanks for the great picture.  These appear to be identical to the ones installed on my intake.  Someone told me they are still available after market, but I don't know where.  Not sure I would use them, anyway.  Probably couldn't sleep wondering if they would stay in place, even with locktite.  Probably best to drill, tap and install button-head allan screws with locktite.  But as to the originals, I wonder how they were installed by the intake manufacturer?  Were they self-tapping and pressed in, or driven down with a baby sledge, etc.  Looking closely at the ones on my manifold I see no damage to the heads or perimeter that offer a clue as to how they were seated.  However it was done, must have been somewhat labor intensive.  Ron...

With the proper shaped anvil tool you would not leave a noticeable mark on the head . Same type is used on most Shelby valve covers and of course necessary to use in the restoration process.