Manifold machining/repair in Colorado?

[mattcheston]

Does anybody know a shop/specialist that has experience machining 2F manifolds in Colorado?

I just took my set off and looking to have them refinished before re-installing with a new gasket.

Any additional tips on restoring any part of the manifolds would also be appreciated. Trying to be as thorough as possible.

 

[OSS]

Tips when the manifold comes off and the machine shop mills the assembly flat:

Have them carefully examine the top of the aluminum intake manifold directly under the carb for any hairline crack. If there's a hint of a crack, have them weld it.

The Heat Control Valve (that rusty flapper valve inside the exhaust manifold that has a rusty bi-metal spring on the outside of the manifold) can jamb open because it's a rust bomb. I recommend getting rid of it entirely. It's an intake cracker waiting to happen.

Replace the stainless steel heat deflector (and all the gaskets)

Replace the manifold arm inner sealing rings & underlying tension spring and clean up the inner bore of the ex manifold where the arm slides into so that the ring seals nicely & it doesn't bind when inserting.

Replace the two small outer manifold bolts with brand new Toyota bolts. Don't reuse those two bolts. (Big bolts & nuts ok to reuse).

 

[Infinity00]

Don’t use MHP, they weren’t able to plane mine together, and I had a huge gap because they did them separately - even though I asked them to do them as a unit. Also didn’t face the bolt locations to help with gapping issue. They are great for anything else, but expensive. Try the other well known place in Denver. Sorry I don’t remember their name but if you search it will come up. Basically the only two places I found that knows 2F engines well.

 

[Spike Strip]

Not only must the halves be done as a unit, but it's important to tack-weld, or otherwise secure the 'horns' so they do not move when planing.

 

[mattcheston]

So far I've split my manifolds since the insulator between was definitely cracked in pieces. Lucky for me both halves came apart without much trouble.

Although my exhaust flap is currently not frozen, I think I'm going to preemptively remove it.

How much trouble am I seeking since I do frequent driving in cold weather? I am not opposed to a slightly longer warmup before I take off.

Any advice on removing it? the bolts holding the plate to the shaft look welded and very difficult to remove.

Additional question: I'm guessing I should have the manifolds machined before I disassemble again to install new gaskets around the insulator? Or should I have these already in place when the entire assembly is machined together?

 

[UGA2018]

I don't know a shop in Denver but I did this same job a few months ago so I'll throw out some things to think about.

1. Find out who the LC experts are in the area and call them. Ask them who they use for machining manifolds. That's what I did in Atlanta and they put me right onto the machine shop. Specificy you need the machine shop for manifolds because I found that they used different machine shops for different work. The manifold requires special equipment because of its size.

2. Have the machine shop look for cracks and repair they can.

3. You have to have a machine shop that will tack weld the swivel arms on when they machine the manifolds. If they don't do this then don't use them. You need all parts attached together when the work is done. This will make sure that you have an even surface and prevent leaks.

4. I pulled the swivel arms off and replaced the springs and rings that are in them. It would be a pain to do all of this work and then not far down the road have a leak in the swivel arms. It's worth doing while you are in there. I also sanded the arms some where they connect together as there was some build up.

5. I also pulled my exhaust and intake manifolds apart like you did. Make sure you get all of the old gasket material off that was between the two manifolds. I replaced the gasket that goes between them that has a shield on it. I didn't replace the spring and plate that opens and closes between the two. It seemed to be in good shape to me.

6. Bolt the two manifolds together with the new gasket before you take it to the machine shop. Or have the bolt them together. Regardless, they MUST be together before the surfaces are machined.

7. Use OEM parts and gaskets for all of this.

8. Torque to specs. After about 200 miles retorque. I had a small exahaust leak happen just with the bolts loosening. After retorquing I was all set.

10. Also, replace the "O" ring that goes between the exhaust manifold and the exhaust downpipe.

I documented a good bit of my work in my build thread if you want to check it out. The link is in my signature line.

Good luck!!

 

[Spike Strip]

Don't remove the flap. If you do, you'll have to weld up the holes. Just cut the flap, or lock in the position that sends exhaust to the down-pipe IF you're going to use a block-off plate. If not, leave it alone, since it's working. You can lube the shaft with some v. high temp lube, like graphite so it doesn't freeze up. Bi-Metal thermo springs for old J**ps are available on ebay, etc that work if yours is rusted out...

Since you're in snow country, I'd leave it, and replace the insulator - they're available.

The assy should be machined as a unit, but get the new gaskets installed before machining. If your machinist is familiar with this setup ask them how they want it.

Block off plates are available from @cruiseroutfit

 

[UGA2018]

The gaskets and plate that @Spike Strip shows in the picture is exactly what I installed between my manifolds.

 

[Tancruiser]

If your ever up in steamboat I will machine them for you.

 

[mattcheston]

@Tancruiser I may take you up on that if I cannot find someone closer. I hear you guys just got a nice storm that I could take advantage of too.

Thanks for the offer.

 

[mattcheston]

@Spike Strip

I mostly worry about the longevity of the bushing that the shaft rotates with. I'd hate for it to become a future leak if I don't remove and plug/weld it.

Thanks for the block off plate source, I was planning on a Cruiser Outfitter or a SOR block off plate if I eliminate the riser flap and don't use the OEM clearanced insulator.

 

[Infinity00]

I welded mine shut and I live above boulder and haven’t had any problems with the warm up. People also say to tack weld the swivel ends before machining. The machine shop might do that for you. Then cut off the tack welds after its machined flat. Also, I agree with everything said above.

There is a heater that SOR sells and maybe others, that will help with warmup if you remove the flap and are worried about warm up...

 

[OSS]

I live in So Cal so typically we don't get super cold weather. But the machine shop that repairs all the manifolds for 2Fs for TLC4x4 (Johnathan Ward's shop) removes the heat control flapper valve inside the exhaust manifold from every single manifold they work on. It's an emissions component, not an engine performance component. In fact technically, if the valve isn't there, a car will fail a visual smog test- but they modify it so you can't tell. I say get rid of it. Old rusty ones are the number one cause of cracked and warped intakes. It only takes one time for it to stick closed to mess up your manifold.
My cruiser engine heats up just as fast without it (as far as I can tell). You definitely need the split heat shield that Spike showed though.

When the heat control flapper is in its hot position, diverting exhaust downwards, it's not really diverting it down into the exhaust pipe like the drawing in the FSM wants you to believe. Plenty of hot gas is still flowing up to the intake - same as when the flapper is removed.

Once my heat control flapper valve was removed, my exhaust sounded a LOT different- much better breathing. That sucker constricts the flow.

 

[daytonadogie]

Colorado Automotive Machine (CAM). Terry really knows his stuff, and is a good guy to work with. What you want done should be a piece of cake for him.

 

[mattcheston]

Colorado Automotive Machine (CAM). Terry really knows his stuff, and is a good guy to work with. What you want done should be a piece of cake for him.

Thanks for the referral. I will probably hit this up in any case but do you know if he specifically has experience with these manifolds?

 

[FJ60Cam]

I just had a manifold worked over for various issues. They cut the flapper out, tapped the holes and plugged with a nice bolt & copper crush washer. This is for an earlier 40, but same concept:

 

[Spike Strip]

Now that's the way to do it!

Mine is cut, and on those occasional cold mornings (S. Cal - it does get down in the 30s sometimes) I just pull the choke out all the way and fire it up, then let idle for a min or so, then push the choke in half-way, another min, then take off...

 

[mattcheston]

The more of the thread-and-plug fixes I see, the more I like that over welding. I think that will be my preference, with a blockoff plate and some additional choke time on cold warmups.

Now....hoping those exhaust horn ring seals are still available? Looks like I need two per horn?

 

[UGA2018]

Now....hoping those exhaust horn ring seals are still available? Looks like I need two per horn?

They are still available. more expensive than they should be but you can get gem.

 

[mattcheston]

They are still available. more expensive than they should be but you can get gem.

Man, if this weren't true of nearly the entire OEM 60 parts catalog these days. I dropped about $1k on my OEM clutch refresh earlier this summer. Went to an OEM 3FE alternator? $300. I'm used to it.