exhaust manifold fit

[ukboneman]

I am in the process of rebuilding the F engine on my '73 FJ40. The original exhaust manifold had a frozen/corroded heat riser, do I decided to replace it. I found a nice intake/exhaust manifold set here on MUD. I dry fit them when they arrived and they fit fine. I then sent them off to be sandblasted and ceramic coated in the case of the exhaust manifold. Just went to fit them and this is what I found: any ideas? can I just grind that corner of the EM that so that it will fit over the stud? Makes me think that somehow it warped during blasting? seems hard to believe but it definitely fit. I did replace the studs.

 

[erics]

on later models I believe there are a couple thick gaskets sandwiching a deflector plate deal in between the two manifolds - something like that would "raise" the intake and largely fix your alignment issue.

 

[OPMACHINE]

looks like you are missing the gaskets and heat riser/block off plate, that go between the two manifolds.

 

[ukboneman]

yeah, I have not installed those yet because I am trying to figure out this issue. I don't think it will effect how the mounting sites line up on the head, but I am going to try and see.

 

[Steamer]

When I got my 74 the exhaust manifold was warped just like that and maybe slightly worse. It was prone to exhaust leaks at the bottom of the 1 & 6 ports since there is not much contact surface there to begin with. I made my own stainless block off plate, but it was too thick, where it the brought the ends into alignment but resulted in the center ones being staggered. So, I ditched the plate and came up with a thicker gasket that evened up the stagger between the outer and center mounting points. I had to split washers in half so they would fit in the recess with the stagger.

I got it to work but it was finicky. Luckily at the time (20 years ago), I found out that new manifolds were still available and so I bought one. Wish I had bought 2.

 

[KY Longhunter]

It’s been recommended that you mount intake/exhaust manifold to head finger tight BEFORE tightening the intake and exhaust manifolds together. And the block off plate.

I failed to do this and now regret it.

 

[firemanj92]

I am in the process of rebuilding the F engine on my '73 FJ40. The original exhaust manifold had a frozen/corroded heat riser, do I decided to replace it. I found a nice intake/exhaust manifold set here on MUD. I dry fit them when they arrived and they fit fine. I then sent them off to be sandblasted and ceramic coated in the case of the exhaust manifold. Just went to fit them and this is what I found: any ideas? can I just grind that corner of the EM that so that it will fit over the stud? Makes me think that somehow it warped during blasting? seems hard to believe but it definitely fit. I did replace the studs.

View attachment 2731367

View attachment 2731368

View attachment 2731370

looks like you are missing the gaskets and heat riser/block off plate, that go between the two manifolds.

The gaskets will help align the holes better. I had mine machined, they assembled them with the gaskets then machined 'em. So assemble them on a flat surface if possible for better surface alignment.

 

[Spike Strip]

Gaskets !

 

[ryanwk628]

Gasket will push the manifold down bringing that half of the circle more into alignment. You can get a heat riser block off plate from @cruiseroutfit .

 

[cruiseroutfit]

Gasket will push the manifold down bringing that half of the circle more into alignment. You can get a heat riser block off plate from @cruiseroutfit .

Yup

Heat Riser Block Off Plates for your F/2F

Suffering from a cracked intake manifold on your F or 2F engine? Many F/2F equipped Land Cruisers suffer from a cracked intake causing a major vacuum leak and poor running conditions. It's possible to have your intake professionally tig-weld repaired but we have a much cheaper alternative...

forum.ih8mud.com

 

[ukboneman]

You guys are just too freaken' smart. I put in the heat riser gasket and just finger tightened the bolts so that the manifolds could "settle" flat. I did use one of the expensive SOR thick gaskets for the manifolds. I did have to grind away less than 1mm of exhaust manifold at that stud. Everything did fit much better with the gasket intact. I then rebuilt the heat riser spring mechanism. I live in Maine and would like to have a functioning heat riser. Isn't the block off plate used if there is a crack? Now, if I could figure out how to rotate these photos so they aren't 90 deg off.

 

[ukboneman]

Thanks everyone for your help. I could never do this project without MUD. BTW, I rebuilt the transmission, transfer case, knuckles and rear axle using Cruiser Outfitter kits. The kits were all top notch.

 

[Jadavm]

You guys are just too freaken' smart. I put in the heat riser gasket and just finger tightened the bolts so that the manifolds could "settle" flat. I did use one of the expensive SOR thick gaskets for the manifolds. I did have to grind away less than 1mm of exhaust manifold at that stud. Everything did fit much better with the gasket intact. I then rebuilt the heat riser spring mechanism. I live in Maine and would like to have a functioning heat riser. Isn't the block off plate used if there is a crack? Now, if I could figure out how to rotate these photos so they aren't 90 deg off. View attachment 2732237View attachment 2732238

I am having the same problem that you had, and have follow this forums advice, but a very small portion of the exhaust manifold is still blocking the stud hole, while the intake is sitting fine. When you said you removed some of the metal of the exhaust manifold, where did you remove the metal from? From the C shaped portion blocking the stud or from the ports?

 

[73FJ40]

I am having the same problem that you had, and have follow this forums advice, but a very small portion of the exhaust manifold is still blocking the stud hole, while the intake is sitting fine. When you said you removed some of the metal of the exhaust manifold, where did you remove the metal from? From the C shaped portion blocking the stud or from the ports?

A recommendation I followed was to bolt the manifolds to the head first, and then insert and tighten the bolts connecting the manifolds to each other.

 

[Jadavm]

A recommendation I followed was to bolt the manifolds to the head first, and then insert and tighten the bolts connecting the manifolds to each other.

Good know, the problem I have run into is that I cannot get the exhaust manifold on all of the studs (ex: Front most stud will kick out if every other stud including the rear most stud is making contact with the exhaust and vice-versa). Pictures 1,3, and 4 show that best. As of now, I took the front most stud out to see how the hole is aligned, and it is still partially blocked, and I can't get the stud back in. While the last picture show the manifolds before I tightened down the middle connectors. It looks slightly better now, but no dice with the stud. (sorry for picture quality but the lighting isn't great in the old garage).

Also ignore the 2F sticker, this is the original 6/72 F engine, which was put on before I caught the 2F part...

 

[Pighead]

I am having the same problem

Are you installing a factory-mated set of manifolds or are they strangers to each other?

 

[peesalot]

Jadavm, have you put a straight edge on that exhaust manifold ?

 

[Grayscale]

Is it possible to mate the exhaust to the head with just two studs in the middle, then install the last four studs after the manifold holes are parallel / perpendicular to the head?

I've heard of people replacing the outside four studs with screws so it assembles easier. Maybe cut a groove on the face of the stud with a grinder so it can be installed with a screwdriver, or use a pair of nuts compressed against each other on the stud to drive it with a socket or wrench.

 

[Jadavm]

Are you installing a factory-mated set of manifolds or are they strangers to each other?

This is the factory set of manifolds.

 

[Jadavm]

Jadavm, have you put a straight edge on that exhaust manifold ?

I have not yet, though I have no doubt there is at least a slight warp. Where would you suggest that I check?