Intake exhaust manifold repair

[FishTacos]

I have the manifold removed and both exhaust horns pulled.


A few questions:

1: A pair of springs and a single ring sits in the groove in each horn. Or perhaps there are two groves with a ring in each and the springs (which appear to be wavy shaped objects in the Specter Off Road diagram) have been disintigrated by exposure to exhaust gasses.

It seems like I need 4 rings and 4 springs for a complete replacement but I don't really want to order too many and end up spending an extra $75.

2: I ordered a remflex gasket set which is considerably thicker than the OEM version and it seems like instalation between the intake and exhaust would misalign the holes where the studs protrude from the head. Has anyone replaced these gaskets with remflex? Do they crush enough to end up in alignment or not?

3: I need to machine the mating surface on the manifold. Should the horns be removed and machined separately to the same thickness?

Pictures will follow.

 

[FishTacos]

Horn:

Rings and (nonexistent?) Springs:

 

[FishTacos]

One more thing,

There is a helicoil in the intake manifold:

Forward outboard bolt.

This makes me a little hesitant to separate the two halves.... I considered painting them...but....scope creep..... and I'd be 6 months down the road painting a naked frame.

 

[gregnash]

@FJ40Jim @OSS should be able to answer this..

As for the machining, you are going to want to find an OLD SCHOOL shop that does multi-piece manifolds like this. If I remember correctly, the manifold should be done as one piece with horns tack welded to main intake to hold in place during the process. Do you believe that the manifold mating surface is untrue?

 

[OSS]

Each of the two grooves in each horn gets one spring installed underneath one ring.
Yes you'll need to buy 4 rings and 4 springs.

The manifold needs to be machined as a complete assembly as Greg said with everything installed. Only take it to a machine shop that's done these exact manifolds before. Don't let them practice on yours.

If the manifold gets machined flat, the OEM gasket is fine and recommended

 

[FishTacos]

Thanks for the quick replies folks.

@FJ40Jim @OSS should be able to answer this..

As for the machining, you are going to want to find an OLD SCHOOL shop that does multi-piece manifolds like this. If I remember correctly, the manifold should be done as one piece with horns tack welded to main intake to hold in place during the process. Do you believe that the manifold mating surface is untrue?

The third and fourth cylinder's exhaust mani mating surfaces are at least .055 below the surface of the intake manifold. There is some pitting where the exhaust leaks existed as well. I think it is clearly time to give it a shave.

I put a post up in the Wisconsin Clubhouse looking for a referral to a machinist that has done one. We'll see if that bears fruit.


It makes sense that they would have to be tack welded together (or that would be a suitable method at the very least). I was trying to wrap my head around that.

Thanks

 

[FishTacos]

Each of the two grooves in each horn gets one spring installed underneath one ring.
Yes you'll need to buy 4 rings and 4 springs.

The manifold needs to be machined as a complete assembly as Greg said with everything installed. Only take it to a machine shop that's done these exact manifolds before. Don't let them practice on yours.

If the manifold gets machined flat, the OEM gasket is fine and recommended

Thanks for the clarification on the springs & rings.

I have a Machinist recommendation from a friend that runs a Ford dealership service department locally. If this shop hasn't done a similar I/e manifold before I want to arrive with as much helpful info as I can. I am going to have it shaved while I'm waiting for the rings and springs to arrive. I'll just leave the existent rings in there....doesnt seem like that should affect fit.

I don't think I'm going to separate the two halves at this time for a paint job either. That helicoil creeps me out.

 

[micruz60]

I will suggest making sure the heat riser / flapper is not stuck in the closed position, it is up in the exh manifold. You can check the condition of the triple gasket set, see if it's warped by the heat. It appears to be a desmogged intake manifold? Eastwood makes an exhaust manifold dressing. Also check the place on the intake (right below the carb) that is known for cracking from excess heat.

 

[FishTacos]

The flapper moves freely.

No cracks below the carb

 

[OSS]

If you can't find a shop nearby who's done it before and don't mind shipping the whole assembly across the country, there's a shop in CA that's done dozens of these and also does machine shop work for SoCA Toyota Dealers and all the work for TLC4X4. They told me that customers ship cruiser engines and manifolds and cylinder heads to them from everywhere.

 

[macdaddy59]

OSS what is the name of the shop for future reference?

 

[OSS]

Bob's Automotive Machine Shop
3621 Foothill Blvd
Glendale CA 91214

 

[3_puppies]

the local guy who has done several for me thru the years, doesn't tach weld them. he is able to lock it all into the chuck on his table.

just curious what the charge is in CA, mine cost between $200 and 250

 

[FishTacos]

the local guy who has done several for me thru the years, doesn't tach weld them. he is able to lock it all into the chuck on his table.

just curious what the charge is in CA, mine cost between $200 and 250

I'm hoping that welding is not required.

I'm going to try to get a machinist to let me film the process. If I can, I will post it here.

 

[FishTacos]

The manifold is at my friend's machine shop. He has a large run of parts to make for a client so he is building a fixture to hold it in fits and starts when he has free time.

Meanwhile, I got a stud/bolt kit from SOR.

Two nuts and my preferred method for jambing them together. I find that using grip strength with two box end wrenches gives the best feel and vitually eliminates skinned knuckles.

And a lifetine supply of nickel anti-seize.
Available on Amazon for $20 shipped.

I had some standard duty anti-seize but figured it was worth the expenditure.

Is there any reason (other than cost) not to just use hi-temp in all situations that demand anti-seize?

 

[FishTacos]

Head is a little rough:

A razor blade and:

Add elbow grease....

 

[LAMBCRUSHER]

ih82fmanifolds... only headers are worse... have it disassembled to mill flat the heat riser mating surfaces- both sides, replace the heat riser baffle and gaskets- use OEM gaskets- your welcome... do not tighten the manifold together without bolting them to a head first- or at the same time, as that is really how its done...you snug up the heat riser bolts, but don't torque till both manifolds are in position on a head. I recommend finding a competent machinist who is able and willing to replace the heat riser flap bushings. Only use stainless fasteners to hold the plate to the shaft and repeen the screws after assembly of the plate to the shaft. have all the studs pulled, threads repaired and cleaned as needed, and reinstall new studs. Once the exhaust manifold heat riser area is rebuilt, and the heat riser mating surfaces milled flat, and your halves re-married while positioned on a head, and torqued to spec, fixture the horns with new rings and springs to the body, and have the whole thing milled at the head mating surface together. Then, counterbore the fastener wells to a set flange thickness spec- the depth of the bore set by the milled surfaces and the thickness of the flange at each well... clear as mud?

 

[FishTacos]

Thanks @LAMBCRUSHER .

I'm a little apprehensive about separating the halves of the mani at this point. Helicoil in the one bolt hole and.....well...i dont have a leak there.

Studs installed.

Edit:

I AM going to follow your suggested install procedure. The "wells" will see a light cut with an end mill and the rings and springs will be installed prior to mounting it on the milling fixture as one piece (so to speak).

 

[Spike Strip]

IIRC, that manifold fastener 'kit' from SOR has two fasteners for the very end of the flanges that are not OEM and not very good. Post a pic of the kit, they may have changed it from when I bought it.

 

[FishTacos]

IIRC, that manifold fastener 'kit' from SOR has two fasteners for the very end of the flanges that are not OEM and not very good. Post a pic of the kit, they may have changed it from when I bought it.

Funny you say that....

I was not real impressed with the look of the 2 m10 bolts in the kit. I'll take a pic next time they're in front of me.

I'm considering putting a stud in the firewall end of the head to alleviate some of the trouble of getting a bolt to thread into the head back there.

Anyone done that?