1986 454 Headers

[zMadMechanic]

Question for you folks - what is my best option for replacement headers? Short? Long?

Mine are cracked and leaking badly (smells in the cabin with engine running).

1986 Chieftain 27 with a smogged 454. I'm not opposed to removing the smog stuff...

Thanks for any input!

[Eyez Open]

Long tube will work best, improved flow of both gases and heat.

[RockwoodMike]

Long tube will work best, improved flow of both gases and heat.

Totally agree..If you have the original cast iron ex manifolds, you will really like the difference when the install is complete..dual exhaust system helps too..In other words, don't have all the exhaust feeding into a single output..And make the exhaust as short as possible..Out the sides in front of the rear tires work well..

When you have a long tube going all the way back to the rear of the coach..The engine has to push all that exhaust the full distance..loosing power to the engine..When the exhaust is shorter, the engine needs less effort to get rid of the exhaust..MORE POWER!!..Cooler running too

[zMadMechanic]

Thoughts on these? think they would hang too low?

https://www.ebay.com/itm/224298679096

[RockwoodMike]

You are on your own for that question..

I am having some problems on my header install..The problem wit a set of headers is they are designed to fit trucks and cars..Without any attempt to show anything in regards to fitting a Motorhome..

I am in the middle of working my headers for my 73 D22 with a 440..Completely different frame and engine from you..

And I am having some fitment issues..A couple of notches to be cut in the frame..But the problem that might stop all of this is the collector dumps right at the leaf spring shackle..

As for hanging down too low, here is a picture of mine..It hangs below the frame, but I don't think that will be a problem..

The left side always seems to be the problem side and I didn't think there would be a problem..Most of the time it is the steering gearbox that gives issues because it is located on the inside of the frame..

But my steering is mounted on the outside of the frame..

Like I said, headers are designed for trucks and cars with no thoughts for motorhomes..

Soooo..that is my story!!

[Eyez Open]

Due to the ever present fitment issues with headers i would stick with summit racing as a vendor and support site. Ebay is does not have the depth that Summit has.

Is your RV sitting on a p32 GM chassis?

Now the above is strictly a opinion.

[zMadMechanic]

Thank you both for the feedback! For the cost, I can't justify Summit racing (all options $750+).

The $250 eBay headers arrive Saturday. I will report back on my progreess!

[RockwoodMike]

I will report back on my progreess

If you can, please show some pictures..

[RockwoodMike]

Here is a preview of what you might be up against

[zMadMechanic]

Made some progress. Loosened 7 of the 8 manifold bolts on drivers side. The last one requires removing the brake master cylinder, which I was trying to avoid, but probably best to replace anyways based on appearance.

https://imgur.com/a/WpKbhKD

Video is from before I got 3 more loose today. The problem child is the one towards the front of the engine, behind the brake master.

[RockwoodMike]

The problem child is the one towards the front of the engine, behind the brake master.

If you get frustrated, just walk away from it for a while..And while you are away, you can think more clearly..
Then you will come up with better ideas to get it apart, besides getting a bigger hammer!!

Plenty of You Tube videos on handling bad bolts and other things..

You are doing Great!!  

[RockwoodMike]

You mentioned in your video, that the engine has 2 smog pumps and all that tubing that you cut away..

Will you be eliminating that equipment??

Here in Taxifornia, you would not pass the bi annual smog inspection..thus not getting a registration to drive it

[Eyez Open]

Oh boy I have the same setup, the valley of death comes to mind. My own approach will be...having a fire suppression systems close, clean engine&bay, one hot torch and some instant freeze spray.

Made simple quick heat and sudden freeze, shock therapy. Lol and gentle hand on the strong arm bar..or maybe a light setting on the impact wrench..slowly walking the bolt in and out.q

[zMadMechanic]

RE: smog deletion/EPA concerns - I have no comment  but I will say my state does not do emissions testing on older vehicles 

RE: the heat and freeze method - that's interesting! I'll have to buy a can of the freeze stuff for the passenger side.

As of today I'm working on removing the brake master cylinder to access the last manifold bolt. Got 1 of 2 mounting bolts free, and both brake lines free (miracuously), leaving only 2 other mounting bolts for the support bracket and 1 more for the master itself. I'm letting them soak with penetrant overnight before making a final push.

With an ounce of luck, tomorrow I'll get the drivers manifold out...

[Eyez Open]

Yes it works quite well, but keep in mind there are two points of locked/frozen points in a stud. One being the outer manifold point and the stud in the block.

Shocking the stud loose may take a few attempts, and walking the stud out of block can be slow and tedious. Walking means loosening it a tad then tighten it back up. Some times it easy peasy and sometimes...it's mind bending.

[zMadMechanic]

Got the drivers manifold off without breaking any of the bolts! 

For the first time in my 28 years (lol), an extractor socket worked to remove one bolt that was rounded off. Annoyingly, it was one of the 7 I had previously loosened. I'm just happy it's out. They were all heavily rusted, only one rounded off, and none snapped - that's a massive win in my book!

Pictures or video coming tomorrow...

[RockwoodMike]

Good Job!!  

In preparation to reinstall, you need to get a bottom tap to clean up the hole threads in the cylinder head ..All sorts of rusty residue in each hole

And take it easy with the tap..You don't want to jam it or break it in one of the holes..

Compressed air to blow them out clean..

When bolts are going back in, some anti seize grease on the threads will have a good result..Especially if and when you need to take the bolts back out for what ever reason..

[zMadMechanic]

Drivers side was certainly a battle with the added annoyance of having to remove the brake master cylinder and needing a bolt extractor, but it could've gone much worse: https://imgur.com/gallery/CGJYM0X

[RockwoodMike]

It is going to be very interesting to see how things go when you install the new headers

[Eyez Open]

Since the job at hand is a GM chassis and mid 80's class it should be a breeze. Basically a 1 ton chassis two wheel drive.

Now with that being said the reality will soon set in. Starter placement and spark plug issues are just part of the drama...BFH is required in most scenarios.

[zMadMechanic]

Making progress! https://imgur.com/gallery/UlGBMWp

Slow going because I'm only working weekends, weather permitting, and I want to be thorough.

Surprisngly the new headers fit without issue! I am waiting to install them after painting the frame rails (much better access sans headers).

[RockwoodMike]

The more you look, the more you find as your video shows,,It is a lot of work keeping these old things up and running..

The parts that you are replacing, where do you find good replacement parts?? Junk yard or NOS if they can be found..??

[RockwoodMike]

https://www.rockauto.com/en/catalog/chevrolet,1986,p30,7.4l+454cid+v8,1059252,suspension,control+arm,10401

[zMadMechanic]

The more you look, the more you find as your video shows,,It is a lot of work keeping these old things up and running..

The parts that you are replacing, where do you find good replacement parts?? Junk yard or NOS if they can be found..??

https://www.rockauto.com/en/catalog/chevrolet,1986,p30,7.4l+454cid+v8,1059252,suspension,control+arm,10401

Exactly! Mine only has 50k miles, runs great, and previous owner had the interior professionally painted + rear drum brakes replaced.

Plus I've already wasted, I mean invested, a ton of time into restoring the fuel tank/rear shocks/rear sway bar/re-sealing the roof.

Parts so far have been a mix of Advance Auto for brake components and Rock Auto for the suspension goodies (+ eBay for rear shock mounts... they are NLA but still sold as forklift shock mounts). Bilstein HD shocks + steering stablizer, Energy Suspension polyurethane sway bushings, Carquest Premium calipers/brake pads + master+ rubber hoses, Mevotech Supreme upper control arms, Moog lower control arms, new Firestone airbags, and LESJÖFORS heavy-duty springs. I'm still debating buying a super steer bellcrank...

After the front end is rebuilt and headers buttoned up, I'll move on to replacing transmission filter/fluid + differential fluid and finish properly painting the frame/undercarraige before getting out on the road. I have some minor body work to repair too (delamination, but the water leaks have long since been fixed).

[Eyez Open]

Oh I have fond memories of that part of my rebuild. Almost tore my rotator cup out grabbing a hub slipping/ falling off a temporary perch/mount.

All I have to say is grease you coils generously on the mounting points, they can be very difficult to mount/lock into place on the lower control arm.

Moog is a brand preference speaking for myself, it's just a nostalgic thing.