Changing manifold gaskets... pitting looks BAD. (1 Viewer)

[Todd Moen]

Hi guys,
I'm in the process of the classic desmog. I've decided to pull the manifold as well and change the gaskets. One big project, trying to knock it out all at once. I've pulled the manifold apart on my 1984 FJ60 and the exhaust manifold after polishing doesn't look that great. I'm not sure what is ok or not as far as the pitting goes. I was on the verge of going with headers but kind of wanted to see how this baby is going to run desmogged with the stock manifolds installed with all new gaskets. Wondering what you guys think of the pitting on the manifolds. I will be buying all new gaskets, springs and rings... plus all new bolts and nuts from Toyota. At that point though I'm at like almost $200.
Thanks a million.

 

[OSS]

The manifold assembly was likely warped before it was disassembled, and if not, it'll never bolt back together flat anyway.
The usual (best) course of action when rebuilding the manifold assembly is to get the whole assembly machined flat after its bolted together — by a machine shop that's worked on these before. After it gets machined, the flanges will be all pretty.

 

[rhah]

Hi guys,
I'm in the process of the classic desmog. I've decided to pull the manifold as well and change the gaskets. One big project, trying to knock it out all at once. I've pulled the manifold apart on my 1984 FJ60 and the exhaust manifold after polishing doesn't look that great. I'm not sure what is ok or not as far as the pitting goes. I was on the verge of going with headers but kind of wanted to see how this baby is going to run desmogged with the stock manifolds installed with all new gaskets. Wondering what you guys think of the pitting on the manifolds. I will be buying all new gaskets, springs and rings... plus all new bolts and nuts from Toyota. At that point though I'm at like almost $200.
Thanks a million.View attachment 2654700View attachment 2654702View attachment 2654703View attachment 2654704View attachment 2654705

felpro manifolds gaskets are thicker. And this going to be your friend

clean it up the best you can (looks like you have)

slap it back together.

fancy washers may be needed, aka cut a bunch in half so you can stack half’s accordingly and tack weld them together so they don’t move on ya.

has worked well on my and my customers rigs

 

[Miloslavich]

It can be machined and corrected.

Felpro is good for nasty surfaces like this.

some good reference material here: Headers vs. refreshing the OEM manifold? (2020 Edition) - https://forum.ih8mud.com/threads/headers-vs-refreshing-the-oem-manifold-2020-edition.1220641/#post-13274150

 

[Seth S]

You’ve done all the work to get it apart I’d just take the intake and exhaust assembly to a machine shop that knows how to machine these matched sets and get all the surfaces done right. Good time to replace or fix bad hardware and redo it it right. It will be good for another 20 years.

 

[Todd Moen]

It can be machined and corrected.

Felpro is good for nasty surfaces like this.

some good reference material here: Headers vs. refreshing the OEM manifold? (2020 Edition) - https://forum.ih8mud.com/threads/headers-vs-refreshing-the-oem-manifold-2020-edition.1220641/#post-13274150

Wow! You did an amazing job on your manifold. I mean... big time nice work.
I’m going to do it right and have a machine shop resurface the manifolds end of this week.

Couple questions
1.Do you recommend going with the solid plate between the intake and exhaust manifold? Right now that plate between the gaskets has that vented opening to it.

2. What type of red copper material do you recommend for the thin layer you put on the main gasket?

Thanks so much. This is my fishing rig and I’m behind getting this all back together. I desmogged the whole thing and am adding a Trollhole carb. Hoping to get this back together in perfect order soon.

 

[Miloslavich]

thanks!

1. Yes I do, because it will help prevent the crack which will eventually form in the intake manifold which will inevitably become a vacuum leak. That one will dive you nuts, so having that insulator plate in there is a good thing. If you really wanted to go over the top "nuts" you could even put a ceramic coating on that block off plate, but lets be realistic, its a Cruiser.

2. Amazon product ASIN B000M8NZ8E. Just a light coat is all you need.

Good luck on your desmog and hope that helps!

- Milo

 

[Todd Moen]

thanks!

1. Yes I do, because it will help prevent the crack which will eventually form in the intake manifold which will inevitably become a vacuum leak. That one will dive you nuts, so having that insulator plate in there is a good thing. If you really wanted to go over the top "nuts" you could even put a ceramic coating on that block off plate, but lets be realistic, its a Cruiser.

2. Amazon product ASIN B000M8NZ8E. Just a light coat is all you need.

Good luck on your desmog and hope that helps!

- Milo

Thanks Milo,
When you installed the plate did you have to trim the rotating heat flapper to work properly or did you just take it out? I have cold temps in the winter and am thinking I need to keep that heat flapper installed? Also, my manifolds are in good shape but the consensus is the heat riser plate should still be installed? Or just keep the stock one (see photo installed) Thanks!!!

 

[Miloslavich]

heat risers are good for cold climates because they heat the intake manifold which in turn helps atomize the fuel going into the head. the problem is that over years of hot exhaust heat cycling onto the bottom of the intake manifold, it can form a stress crack on the bottom of the manifold directly above the heat riser, below the carb. when the truck heats up, you'll eventually have a vacuum leak from that crack. Can make for some seriously difficult troubleshooting !

we just removed the plate you are holding and installed the aftermarket plate, on top of the flapper. I don't recall trimming it, but if you need to shave a little off to get it to fit, I wouldn't hesitate. The plate works, but eventually the intake manifold does get hot. I've not noticed any difference in having the plate installed versus not in cold weather driveability. I like knowing it is installed to aid in preventing that crack in my manifold.

 

[Seth S]

I did the block off plate from cruiser outfitters and used one gasket in the install. I completely removed the old pivot plate and sealed the pivot holes.

 

[rhah]

heat risers are good for cold climates because they heat the intake manifold which in turn helps atomize the fuel going into the head. the problem is that over years of hot exhaust heat cycling onto the bottom of the intake manifold, it can form a stress crack on the bottom of the manifold directly above the heat riser, below the carb. when the truck heats up, you'll eventually have a vacuum leak from that crack. Can make for some seriously difficult troubleshooting !

we just removed the plate you are holding and installed the aftermarket plate, on top of the flapper. I don't recall trimming it, but if you need to shave a little off to get it to fit, I wouldn't hesitate. The plate works, but eventually the intake manifold does get hot. I've not noticed any difference in having the plate installed versus not in cold weather driveability. I like knowing it is installed to aid in preventing that crack in my manifold.

I did the block off plate from cruiser outfitters and used one gasket in the install. I completely removed the old pivot plate and sealed the pivot holes.

If all that work and machine shop to be done why not just get the header install and walk away

no more heat riser to crack the intake

flat surface, no machining needed

 

[Seth S]

If all that work and machine shop to be done why not just get the header install and walk away

no more heat riser to crack the intake

flat surface, no machining needed

I didn’t want to spend $800 for a set of headers that would offer marginal performance increase and also heard plenty of complaints about getting the headers to seal properly. I was planning to install the 3FE exhaust manifolds but I had a matched mated set of manifolds all ready to go. Later if I do a sniper install I plan to switch to the 3fe manifold and use my nicer intake manifold and switch things out.

 

[Todd Moen]

I did the block off plate from cruiser outfitters and used one gasket in the install. I completely removed the old pivot plate and sealed the pivot holes.

Hi Seth,
Did you try both gaskets without success? Is the block off plate thicker than the stock insulator plate? Really curious as it’s seems like you’d want the two gaskets between the manifolds? Thanks!

 

[Miloslavich]

If all that work and machine shop to be done why not just get the header install and walk away

no more heat riser to crack the intake

flat surface, no machining needed

Seth answered this perfectly below. Plus, I wanted to stay OEM, and headers can have their own problems as well. The manifold crack isnt that common, but it can happen and the block off plate should prevent it entirely

I didn’t want to spend $800 for a set of headers that would offer marginal performance increase and also heard plenty of complaints about getting the headers to seal properly. I was planning to install the 3FE exhaust manifolds but I had a matched mated set of manifolds all ready to go. Later if I do a sniper install I plan to switch to the 3fe manifold and use my nicer intake manifold and switch things out.

 

[Seth S]

Hi Seth,
Did you try both gaskets without success? Is the block off plate thicker than the stock insulator plate? Really curious as it’s seems like you’d want the two gaskets between the manifolds? Thanks!

If you are running the block off plate there is no need for two gaskets because there is nothing to seal on the intake manifold side. I was operating under guidance from @ToyotaMatt and even though I was running all nice and machined surfaces I still used the remflex gaskets. I had no issues bolting anything together during the torquing process and no leaks.

 

[ToyotaMatt]

I am a Manifold Purist guy , this should be known before you read my approach below ,

2F headers are simply so passe'

not to mention my 2 forearms are scarred very badly from years of working on header equipped land cruisers , and making a split second contact with them when younger , so much so i have been asked more then once in a hospital emergency room for other reasons and at regular doctors check ups visits like we all normally do , if i am a cutter ?

this is one personal reason i hate headers ...... its my deal , so i deal

manifolds only on my personal rigs ..

on to better topics at hand :

i dreamed up the idea in high school , in VO-TECH that if i removed the heat riser shaft , flapper and related , then inserted 2 12mm diameter stubby SEMS OEM bolts in the holes from the outside , them pre-heated the local area with a OXY torch both very quickly and very carefully , keeping in mind this is cast iron here . then use a NICKLE ALLOY stick welder MED heat range or a MIG welder , with ARGON mix involved and your high end nickle infused wire too , carefully weld up around the 2 hex bolt head , using the 2 SEMS washers as a creative hard core SOLID penetration inside corner welding approach and technique .

why all this step by step ?

i concluded if removed there would be a notable of some kind increase in overall horse power , or fresh air in faster carb intake , exhaust gasses out faster via a less restricted and flapper shaft parts now gone free flowing and running cooler now too factory 2F manifold ....

i also , experimented with porting and polishing a factory intake as much as humanly possible with hand held air tools and longer extensions i shop made to get the small stone bits deeper and deeper inside to the main carb base chamber

i ALWAYS use now the RemFlex system , i have never had a long term issue to speak of

i ALWAYS install the heat riser block off plate system for @cruiseroutfit KURTs gig out in salt lake too , even with the riser gone , i like guarantees in my world i see in black and white sometimes , this is one of those times

i increase my down pipe size one step , i ALWAYS use a BORLA stainless steel 6 cylinder muffler , see a Borla unit is TUNED for a 6 cylinder for proper back pressure , that a 2F need to preform properly , u install a flow master v* monkey business muffler of glass packs your doing your self a huge dis-service period

proper back pressure = more horse power and less emissions hands down ......

this is a internal combustion engine fundamental TECH

lastly , and this may not be for everyone , I install a Single Inlet , DUAL outlets BORLA muffler , i then create or SPEC. to KUSTOM mandrel exhaust shop i use , dual tail pipes set up , one on each side a 45' angle protruding 2" past the rear 1/4 panel to shed any exhaust far away from the chassis and this HUGE LIFE-SAFTEY detail then it gets sucked away and swept with the side breeze of fresh out side air , NEVER a chance to enter the passenger compartment even TOPLESS in summer

of course ALL oem exhaust MODERN TORX Toyota genuine hardware on any kustom multi flange exhaust period

if your chosen kustom exhaust shop will not entertain a hand full of genuine studs , nuts , and most important fact toyota donut gaskets size sppeced in advance ? \

walk the F away , a good shop will do as requested in this detail case .....


does my concept vision steps above result in more horse power gain , even a little bit ?

i indeed think so , every bit helps and there is zero reasons why less restrictions would not

does it will it result in a much kooler running complete exhaust system as a whole HELL yes it does ........

kindly matt

also :

@Miloslavich ........... welcome home brother and thank you so very much