Exhaust manifold pitting thoughts?

[Trialsallday]

Hi everyone. This little bit of pitting going on here is a little bit of a concern to me. I ordered the OEM gasket which I think will be fine. Do you guys think I should order a remflex as a backup just to have in case it leaks? That way I don’t have to wait another five days for it to arrive. What do you guys think?
Separately, I ran a straight edge across the whole thing. Everything looks nice and straight.

 

[JohnnyC]

bring to a machine shop to have it decked... have them do it with the intake attached... might as well do it now

 

[cstav86]

The previous advice is solid, I would not use that until it's been machined flat.
My thoughts after chasing leaks in a factory manifold is to consider using a new header. Factory manifolds are 50ish years old and leak through the ears on the end, through the heat riser bushings, have old bolts that the down pipe secures, are brittle from so many heat cycles, and in your case rusty. Just a throught before you go spending money on a 50 year old piece, consider replacing it.

 

[Trialsallday]

The previous advice is solid, I would not use that until it's been machined flat.
My thoughts after chasing leaks in a factory manifold is to consider using a new header. Factory manifolds are 50ish years old and leak through the ears on the end, through the heat riser bushings, have old bolts that the down pipe secures, are brittle from so many heat cycles, and in your case rusty. Just a throught before you go spending money on a 50 year old piece, consider replacing it.

Have you all had good luck running header? What about the flapper valve that heats up the fuel on the OEM set up? I keep hearing that they run rougher and have a harder time warming up with a header. How true is that?

 

[pb4ugo]

How long does it take to warm up?

 

[rlong]

Headers have pluses and minus’s, (yours does look “crunchy”) the heater riser issue can be overcome. I ran something like this that I fabbed that bolts to bottom of intake.

 

[Trialsallday]

Headers have pluses and minus’s, the heater riser issue can be overcome. I ran something like this that I fabbed that bolts to bottom of intake.

Is it an issue always or only during really cold weather?

 

[JohnnyC]

I've been running a header in the upper north east for 30+ years... its my DD... warms up just fine... use a block off in front of the radiator to cut down on airflow

 

[charliemeyer007]

I made a fluid heat riser to replace the flapper. No more carburetor ice in the fog. You could plane that manifold with sand paper on a big sheet of glass. I install the gasket after I soak it in warm water for like a half an hour - lets the high spots dig in easier. Let engine heat up to dry it. Retorque then after several heat cycles retorque it again.
+1 for a curtain in front of the radiator. Easy to move up or down to adjust.

 

[Mytmousemalibu]

There is some evidence of rust jacking going on there. Over time along with all the heat cycling a manifold goes through, I'd bet my lunch that manifold is warped. Its certainly pitted enough that if used as-is, those gaskets probably aren't long for this world. That manifold needs to be surfaced to be reused if you want it to reliably seal. With this shared design like a lot of uniflow inline engines, the intake needs to be surfaced with it. Probably more cost effective to replace it or put a header on it. You could put a heat blanket on a header but I wouldn't wrap it unless it is stainless. Header wrap will rust a mild steel header fairly quickly.

 

[Trialsallday]

Headers have pluses and minus’s, (yours does look “crunchy”) the heater riser issue can be overcome. I ran something like this that I fabbed that bolts to bottom of intake.View attachment 4139217

Hey, that’s pretty nifty. Do you sell those? How does it work? Decent?

 

[rlong]

Is it an issue always or only during really cold weather?

In my case it was many years ago in Colorado at single digit or very cold days.. ice would actually form on the venturi (SD40). I made mine out of a block of aluminum. If you never drive below freezing or very much you would probably be fine as long as you have a manual or automatic choke that works.

 

[Trialsallday]

what headers does everybody like?

 

[charliemeyer007]

Fluid Heat Riser Kit for 1975-1987 Toyota Land Cruisers with 2F-Engines - Landcruiser Parts

Fluid Heat Riser Kit for 1975-1987 Toyota Land Cruisers with 2F-Engines. Designed to be used with aftermarket exhaust manifolds. Helps with cold starts.

manafrelv.com

 

[JohnnyC]

my header is the SS header from sor.... I don't know if they still make it.... but trimeki? that is a Mark A/Downey header is also SS

I highly recommend a SS header.... been through several steel ones over 30 years... they all rot


just checked and no more sor SS headers.... but here is Trimeki:

Thread '2F Header - Downey/Mark's Design - Stainless Steel'

Nov 1, 2024

Here's some Fall Friday Fun for y'all!

We have been working long and hard to bring you a header for the 2f (and F) engine that is worthy of your attention.

This all started in early 2022 when @gonzopancho purchased the rights to the header that was originally designed and manufactured by Jim @Downey and then sold to Mark @65swb45 : FJ40 Mark/Downey Header - https://forum.ih8mud.com/threads/fj40-mark-downey-header.1267016/page-3#post-14293492

We painstakingly did the work of evaluating the original design, test-fitting multiple versions of the header on various...

• Fe3
• Replies: 17
• Forum: 60-Series Wagons

• 
• 

TRIMEKI

TRIMEKI

shop.trimeki.com

 

[igotta40]

Headers have gotten crazy expensive

 

[JohnnyC]

Wow I didn’t even check the price… that is crazy

The sor one is ceramic coated steel … but you can get the header pipe muffler and tail pipe and everything a complete system for less … almost half that price … how times have changed when Sor is the cheaper option

 

[JohnnyC]

I done know about these guys …but… this one is also SS it looks like and only 500

Exhaust Header Manifold for Toyota Land Cruiser FJ40/FJ45/FJ55/FJ60 (1

Maximize Flow and Power for Your Toyota Land Cruiser 4.2L Who Is This For? This is built for the dedicated Land Cruiser enthusiast owning an FJ40, FJ45, FJ55, or FJ60. If you are restoring a classic 2F engine or looking to improve the breathing of your off-road rig, this 6-into-1 header is...

performancechiptuning.com

 

[JohnnyC]

And another just found for 400 … also says SS

https://www.ebay.com/itm/267131863948?mkcid=1&mkrid=711-53200-19255-0&siteid=0&campid=5337589904&customid=&toolid=10001&mkevt=1

 

[Pighead]

I've been running the Downey header for about 25 years now. Maybe more, I forget exactly. My original exhaust manifold cracked and broke in 1989, I tried a couple different headers before I got the Downey, I find it superior to the others available at the time. If it showed any sign of failure I would replace it with the Trimeki. Had it surfaced, along with the intake, when I got a valve job couple years back. Still solid.
I have not had a problem with cold weather operation. Naturally, I block off some of the radiator with a piece of cardboard in the wintertime. I always leave time to warmitup and don't move it until the temp gauge needle moves.