Chevy Impala SS Forum banner

1 - 20 of 23 Posts

·
Registered
Joined
·
25 Posts
Discussion Starter #1
I know this has been talked about on here before, but I figured I would take some photos and post some info about the infamous home plate and first base delete with some information along with questions that I have.

Here is a before shot of my engine bay; I need a good washing. I was at the beach and things look a bit dirty. That will be another thread. It's unreal how much heat home plate holds after driving the car; it's lighter than I expected, too.



The two bolts on top of home plate are 12mm. I used an impact wrench and they zipped right off. The left stud came right off, but the right is still stuck on there.

Here is the replacement. A nice rubber hockey puck. 8mm socket or a flat head screw driver will loosen the hose clamp. Once those are loose, it slips right out. Drop in the puck and tighten the hose clamp. I decided to loosen the first base connection to make sure the puck was sitting 100% flush on the inside of the hose to not disturb airflow. Tighten the worm clamp nice and snug and you're all set.



I neglected to get a good shot of the after, so I will update with that information.
 

·
Registered
Joined
·
25 Posts
Discussion Starter #2
Once the resonator has been removed, you now have access to some wires that are attached to a bracket. Below are two photos of the hoses I am pointing to.

I'd like to remove the metal bracket on top of the engine - I've read that the screws need to be put back in once it's removed or else you'll have trouble.

My question is, once I remove that bracket, where/how do I zip tie the wires so that they are protected from heat and moving parts?


Below is the bracket I am looking to remove. It seems like it's just 4 bolts attached to the top of the motor.

 

·
Registered
Joined
·
25 Posts
Discussion Starter #4
Bump. Any ideas on where to place the extra wires/harness once you remove the metal bracket that is currently holding them? Also, what is that empty screw space for on the right hand side?

Thanks!
 

·
Registered
Joined
·
3,729 Posts
My wires are just laying there. Some folks get them all moved out of the way and secured. Being thin and weak when new I didn’t want to mess with them at 200k miles and over 2 decades of engine heat later.

When you take that bracket off be sure and put the bolts back in because they hold the fuel rails in place.

The extra hole is just that, extra. Nothing on the B body uses it. This same intake was also used on Camaro, Trans Am, Cadillac and Corvette. I believe it is used for the throttle cable cover that the FBody uses because it doesn’t have the ugly silencers on it.
 

·
Registered
Joined
·
25 Posts
Discussion Starter #6
My wires are just laying there. Some folks get them all moved out of the way and secured. Being thin and weak when new I didn’t want to mess with them at 200k miles and over 2 decades of engine heat later.

When you take that bracket off be sure and put the bolts back in because they hold the fuel rails in place.

The extra hole is just that, extra. Nothing on the B body uses it. This same intake was also used on Camaro, Trans Am, Cadillac and Corvette. I believe it is used for the throttle cable cover that the FBody uses because it doesn’t have the ugly silencers on it.
You lay them on top of the engine when you remove the bracket? Wouldn't the heat damage them from laying right on top?

I wouldn't mind moving mine, Just not sure how flexible or extra length they have to be zip tied elsewhere. Where would one even put them? I can't find good photos of an engine bay without home plate to see where they go.

I did read about the fuel rails; can do.

That is perfect, I had read that, just wanted to be sure.
 

·
Registered
Joined
·
92 Posts
Though mostly out of the frame in all my pics, you can kind of see that I left my bracket in place after removing home plate in my thread here:
Turning scraps into a… hockey puck?
Was always planning to fab a nicer looking bracket, but never got there.
 

·
Registered
Joined
·
1,704 Posts
I get the aesthetic concerns, but til you figure out how to secure those wiring looms, the bracket can wait.
 

·
Registered
Joined
·
3,729 Posts
You lay them on top of the engine when you remove the bracket? Wouldn't the heat damage them from laying right on top?

I wouldn't mind moving mine, Just not sure how flexible or extra length they have to be zip tied elsewhere. Where would one even put them? I can't find good photos of an engine bay without home plate to see where they go.

I did read about the fuel rails; can do.

That is perfect, I had read that, just wanted to be sure.
Yeah, they are just laying there. Heat is a moot point because bracket or not they are still under the hood laying on the engine. 3 years so far with this one and 6 years with a previous one set up like this. No destruction no terror no mayhem due to it. One day I will move it and secure it because I have more than enough slack with the ABS system no longer in the way.

Pay no attention to the filth, lol. Car is a daily and I park it behind the shop in a gravel/dirt lot and customer trucks drive through there as well. I keep visible areas clean but it isn't a show car so the hood is closed unless something breaks.



If memory serves a lot of folks would disconnect the fuel lines and put the harness under them and secured behind the intake manifold.
 

·
Registered
Joined
·
25 Posts
Discussion Starter #10
Thank you all for the posts. Sounds like they are just going to have to either stay there attached to the bracket or remove the bracket and let them lay on top.

@Sinister ah, removing the fuel lines and putting them under makes sense. Out of the way on top of the engine at least! I have no idea how to remove fuel lines without blowing myself up, so I don't know if I'll go that route :)

I do wish I could remove the one (of two) upright bolts that used to hold home plate on. Seems like it's fused nice and tight to the bracket itself.
 

·
Registered
Joined
·
1,503 Posts
There's the hole you brought up and a second at the rear injectors. Fab up two big 'wire clamp' and screw into those two holes.
 

·
Registered
Joined
·
3,729 Posts
Bleed pressure off of the fuel system and then disconnect the lines the same way one does to replace a fuel pump. Move harness and reconnect lines.

If I motivate myself to work on it this weekend I will come up with a solution.

There's the hole you brought up and a second at the rear injectors. Fab up two big 'wire clamp' and screw into those two holes.
That is a pretty good idea.
 

·
Registered
Joined
·
207 Posts
Hi, Caddyshack95,

Good job on the homeplate delete—easier access, less baking underneath!

1. I have no homeplate but still have the bracket. The tall stud stuck in your bracket will
come out with rust penetrant and vise-grips.
IMG_20200521_2001246.jpg


2. Bracket removal
If you remove the bracket and re-install the fuel rail hold-down bolts, be careful. When removing the bracket, hold down the fuel rails with one hand and do not disturb them. That S-shaped tube at the front has a couple of o-rings and will leak gas if the fuel rails are disturbed when removing the bracket.
IMG_20200521_2005019.jpg


3. Air pump system
As shown on Sinister’s engine and mine, we removed the AIR pump and hardlines that go to each exhaust manifold and plugged the holes with a couple of well-sealed threaded pipe plugs. This gets rid of an unneeded system and simplifies future engine work. Rust penetrant and tapping the wrench with a hammer will loosen the manifold fittings. Don’t try to remove the metal tubes in one piece—the assembly wraps under the engine---start cutting them and remove bit by bit. The air pump has an electric plug to it—just unplug it, tape off the plug, and remove the pump. A bracket piece can go in the trash as well. You will also have to hose-clamp a large rubber cap to the aircleaner opening to seal it when you remove the rubber tube to the air pump.
IMG_20200521_2003025.jpg


4. AIR delete label
To deal with possible emissions inspections, you should get the silver label shown in the picture specifying that the air pump system has been deleted. Someone on the forum sells them—check back in time in the parts for sale section.
IMG_20200521_2000425.jpg


5. PCV valve grommet
The driver-side close-up shows the PCV valve and other vacuum lines. If you pull the PCV valve to shake/check it, I’ll bet it just slides out. The rubber grommet has been cooked and probably is hard as a rock. Removing it will take patience and pliers and will destroy it. Since it is a source of vacuum leaks, you can still get a replacement from Rockauto or others. It’s a weird-shaped piece, not just a round grommet. The two other vacuum lines there are probably baked as well.
IMG_20200521_2004302.jpg
 

·
Registered
Joined
·
80 Posts
With home plate gone, I noticed this; right hand side of the engine (while looking from front of car to back). What is the purpose of the extra screw hole?
As far as I know, that extra hole was primarily used for the Corvette Dress mounting posts on the Corvette LT1/LT4.

vette-dress3.jpg

vette-dress2.jpg

The aforementioned "posts" seen in the first pic screw into the holes in the intake manifold and then snap in here on the underside of the Corvette dress.

vette-dress1.jpg

And don't worry about heat with the wiring. I ran that Corvette dress for 20 years with the harness sandwiched underneath. You can see the routing I used. This is on my daily driver 9C1 Caprice. No problems.
 

·
Registered
Joined
·
25 Posts
Discussion Starter #16
Thank you guys for all of the information; very helpful and good to digest.

Have any of you ever made homemade penetrant with acetone and ATF 50/50 mix? I have read that it's an excellent penetrant (and cheap).


Hi, Caddyshack95,

Good job on the homeplate delete—easier access, less baking underneath!

1. I have no homeplate but still have the bracket. The tall stud stuck in your bracket will
come out with rust penetrant and vise-grips.
View attachment 193740

2. Bracket removal
If you remove the bracket and re-install the fuel rail hold-down bolts, be careful. When removing the bracket, hold down the fuel rails with one hand and do not disturb them. That S-shaped tube at the front has a couple of o-rings and will leak gas if the fuel rails are disturbed when removing the bracket.
View attachment 193741

3. Air pump system
As shown on Sinister’s engine and mine, we removed the AIR pump and hardlines that go to each exhaust manifold and plugged the holes with a couple of well-sealed threaded pipe plugs. This gets rid of an unneeded system and simplifies future engine work. Rust penetrant and tapping the wrench with a hammer will loosen the manifold fittings. Don’t try to remove the metal tubes in one piece—the assembly wraps under the engine---start cutting them and remove bit by bit. The air pump has an electric plug to it—just unplug it, tape off the plug, and remove the pump. A bracket piece can go in the trash as well. You will also have to hose-clamp a large rubber cap to the aircleaner opening to seal it when you remove the rubber tube to the air pump.
View attachment 193742

4. AIR delete label
To deal with possible emissions inspections, you should get the silver label shown in the picture specifying that the air pump system has been deleted. Someone on the forum sells them—check back in time in the parts for sale section.
View attachment 193743

5. PCV valve grommet
The driver-side close-up shows the PCV valve and other vacuum lines. If you pull the PCV valve to shake/check it, I’ll bet it just slides out. The rubber grommet has been cooked and probably is hard as a rock. Removing it will take patience and pliers and will destroy it. Since it is a source of vacuum leaks, you can still get a replacement from Rockauto or others. It’s a weird-shaped piece, not just a round grommet. The two other vacuum lines there are probably baked as well.
View attachment 193744
I plan on soaking some penetrant to get that stud out. It's much cleaner under there and the heat sink from home plate must have been unreal. Didn't let the engine breathe with fresh air!

I plan on doing the air pump delete (another thread). I have the necessary bolts to screw in along with a plug for the air cleaner. I have been waiting until I have a day when the engine is dead cold so I can work around and not have to drive it after work. Did you seal the bolts in any way? The ones that plug the old air cleaner lines?

I plan on either using penetrant or using just an air impact wrench to blast that puppy off. It's a 7/8 fitting, so I am going to cut close to the bolt so I can fit a socket on and let it rip. I am not going to cut anything until I can physically remove/get to the air pump and the associated 10mm and 14mm sockets holding things on.

I won't need the emissions sticker (for my current registration) and I don't think MO would require it either, but I am not sure.... Calling @96 Black.

Dumb question, what is the PCV valve and what does it do? I am afraid to tear things apart because it's my daily driver.


Here is a video of how to re-route your wiring after removing home plate, et. al.
View attachment 193811

Very helpful upon first (quick) viewing. Seems like a fair amount of work to cut and remove some things, but the end result is beautiful. I am not sure I'll tackle this until I know more.

As far as I know, that extra hole was primarily used for the Corvette Dress mounting posts on the Corvette LT1/LT4.

View attachment 193813

View attachment 193814

The aforementioned "posts" seen in the first pic screw into the holes in the intake manifold and then snap in here on the underside of the Corvette dress.

View attachment 193815

And don't worry about heat with the wiring. I ran that Corvette dress for 20 years with the harness sandwiched underneath. You can see the routing I used. This is on my daily driver 9C1 Caprice. No problems.
I am really surprised that the heat from the engine (contact with the plastic) doesn't melt anything or damage the wires! Isn't that plastic tubing just laying on the engine?

Did you cut everything apart like the video above, or did you have enough slack to move things around?
 

·
Registered
Joined
·
412 Posts
I have used the acetone/ATF penetrant, seems to work. You can double nut the stud to get a better grip for removal.
All the parts of the AIR system can be removed intact, I have done 4 of them and have 4 complete tubes. It is more effort than chopping the tube in half.
PCV system brings fresh air into the crankcase and meters crankcase fumes into the intake manifold for burning. Maintain it and you will be fine.
 

·
Registered
Joined
·
80 Posts
I am really surprised that the heat from the engine (contact with the plastic) doesn't melt anything or damage the wires! Isn't that plastic tubing just laying on the engine?
GM used high-temp plastics under the hood. On 9C1 cars that idled all day, the looming does get stiff and brittle, but I've never seen it melt. The wires are clearly also hi-temp rated.

B-body cars with a mechanical fan stay cooler under the hood than cars with only electric fans due to the constant air flow. The stock electric fans come on pretty late (225 degrees F if I recall from memory), but many people reprogram their PCM to lower this down. I never recommend turning on fans below about 195 degrees F though. They will run too much and stress the fan motors and electrical system for little gain. Even if you go with a 160 degree stat, you need to let the engine internally heat soak to at least 212 degrees F to boil off water/moisture in the oil. Running an engine too cool (in a street vehicle) has longevity and emissions side effects. There is a sweet spot. GM engineers knew this.
 

·
Registered
Joined
·
80 Posts
The AIR pump delete thread is long. Unsure if this tip is mentioned there, but I've struggled with getting the nipples out of the manifolds due to rust and seizing. The earlier design ('94 and early '95) are especially cranky because of the thinner walls of the nipple. Impact guns and breaker bars destroy them before they budge. So the trick I learned is HEAT. And the easiest source of heat is the engine itself. I've done different techniques here, but the fastest one is to cut off pipes at the nipples, thread in a bolt to close off the hole (large lag bolts work well), and run the engine at 2000 RPM for a few mins. Remove the bolt, and then crank the nipple with an impact wrench and/or breaker bar within 1 minute of shutting off the engine. Another technique would be to run the engine without closing the hole (loud and obnoxious but should work nonetheless). Either way, you have to work fast after shutting off the engine. A plumbers torch will not get the nipple hot enough due to the manifold acting as a heat sink, so don't bother. However an oxy torch should work if you have one.
 

·
Registered
Joined
·
1,704 Posts
PCV system brings fresh air into the crankcase and meters crankcase fumes into the intake manifold for burning.
Maintain it and you will be fine.
There are three optional things that can be done to the PCV system:
1. Splice a NAPA 3299 fuel filter into either or both PCV lines.
2. Replace silly lil pasta elbow atop the passenger side valvecover with a
AC Delco FB131 / Baldwin SA4137 / Deutsch BF412 / Fram BA6592 / Hastings CB36 / Motorcraft FA 1118 / Purolator B23165 / WIX 66501 PCV breather filter.
3. Replace old style PCV valve with Gen4 SBC PCV thingy (12572717).
B-body cars with mechanical fans stay cooler under the hood than cars with only electric fans due to the constant air flow.
Stock electric fans come on pretty late (225°F if I recall from memory), but many people reprogram their PCM to lower this down. I never recommend turning on fans below about 195° F though. They will run too much and stress the fan motors and electrical system for little gain.
Even if you go with a 160°F stat, you need to let the engine internally heat soak to at least 212°F to boil off water/moisture in the oil.
Pretty much stipulate to the gist of the above, except that motor oil typically runs hotter than coolant, even in top-down cooled LT1s.
Mech fans cost 10 peak horse. Before programming became a thing, some people would use the AC to turn the fans on sooner than 225°F & 232°F. (F- & Y- LT1s are a lil bit hotter even.)
OEM GM programming left much room for improvement besides excessively hot fan-on temp thresholds; there's plenty of untapped potential in quite a few other areas. It's an underappreciated bang for the buck that STILL doesn't get done often enough, especially for 2.93 & 2.56 B- & D-cars.

Excessive radiator fan duty cycles tend to cause the fan relay seats in the underhood fusebox to get melty.
GM halfassed it when they addressed it with a TSB to relocate ONE of the fan relays outside the fusebox for 9C1s only.
Cadillac Fleetwoods' OEM fullass solution locates BOTH relays outside the fusebox; Innovative Wiring sells a wiring kit that does this.
Both fans should be on before 212°F.
 
1 - 20 of 23 Posts
Top