Intake/Exhaust manifold question. (1 Viewer)

[Judger]

Morning everyone,

I'm in the process of trying to get my body off resto buttoned up (or at least drivable) and I'm in the process of replacing the carb (thanks @Racer65 ) and I wanted to make sure I'm removing all possible leaks/issues. I'm replacing the fuel filter, new hard line to the carb, new remflex manifold gasket.

I just took the gasket off and here are a few pictures of my manifold. The intake seems oily and the exhaust, seems to be very carbon rich with deposits. Is this normal? Or should I be looking at another problem(s) with the motor after I get the new carb and lines hooked up?

Thanks as always.

 

[Dizzy]

The header is probably thicker at the studs than the milled section of intake manifold. Measure it with a micrometer, or calipers. You definitely have had leaks at this connection. The need fixing.

How do the valve stems, and the tops of your valves appear?

 

[77mustard40]

Looks like oil has leaked from the head cover gasket and you may have had a vac leak too, but I don’t think that can be diagnosed from pics. Pull the header and take it with the intake and have the flanges milled to the sale depth. Or you can measure the intake and exhaust flanges adjacent to common bolts and see what the differences are. On mine I was close but not perfect at each bolt, so I bought some heavy machine washers and filed half of each washer equal to the difference between the two flanges. Each one is unique so I did them one at a time and marked the opposing side of the washer with a sharpie so I could get them oriented in the correct spot when assembling. Used a stock gasket, dry and torqued to spec. This eliminated my vac leak and she’s been rock solid since.

 

[Judger]

The header is probably thicker at the studs than the milled section of intake manifold. Measure it with a micrometer, or calipers. You definitely have had leaks at this connection. The need fixing.

How do the valve stems, and the tops of your valves appear?

Thanks, I don't know about the valve stems, but I did just buy those as a job for the future, is there anything I should be looking at for the stems? They're difficult to see through the springs, do I have to remove them to have a good inspection?

I've got some decent machine rules in the shop the measure the flatness of the manifold side, and will use the method @77mustard40 suggested for getting the bolts on the same level. Thank you for that suggestion, I definitely would have just put it back on the way I took it off.

Thanks!

 

[77mustard40]

The problem is that the intake and exhaust manifolds / header share bolt locations half and half. If one is thicker than the other then your are only torquing the thicker manifold at that bolt location. The thinner side won’t get torqued properly and may leak.

 

[Dizzy]

You can only see caked on oil on the valve and valve stem thru the port. The springs need removal if you want to see much.

I have two 2F intakes that are a 'swoosh' 10mm, the previous mechanics, and Toyota used washers to keep the nuts from chewing at the aluminum, so they are like new. I bought a header that was manufactured with 1cm plate.

 

[77mustard40]

OP, I think I documented my vac leak ordeal and solution in this thread.

 

[Judger]

OP, I think I documented my vac leak ordeal and solution in this thread.

Which thread?

 

[77mustard40]

Going Aisin-details, details, details

I made the commitment some time ago to ditch the aftermarket carbs and get back to stock, or as near as possible. Down the torpedos with Holley and Weber. My 77 FJ40 has never had its original carb in the years I've owned it so here is what I have pulled together: 1/76 carb - just completed a...

forum.ih8mud.com

Sorry about that

 

[Curt]

Replace with Remflex gasket.

 

[Judger]

Replace with Remflex gasket.

That's the plan.

Quick question, when putting the studs in for the carb, do you all seal the studs? Could that be a source of vacuum leaks in the future?

 

[flee]

That's the plan.

Quick question, when putting the studs in for the carb, do you all seal the studs? Could that be a source of vacuum leaks in the future?

Maybe because of the age of the manifold the studs fit a bit loose on mine. A good use for LockTite.