manifold ?

[1979fj40]

My 79 had a header on it when I got it. I got a new exhaust manifold from a mudder here. The heat riser is in working condition. Question, is there supposed to be a plate in between the riser and the intake , or is that just if you remove the flapper? Saw a SS plate on SOR but it looked as if was in there to it would stop the riser plate from moving.

 

[1979fj40]

no one knows?

 

[Degnol]

If your heat riser is working, you do not need the plate. It is a block-off plate that deflects the hot exhaust gasses away from the intake.


ED

 

[D'Animal]

I take the broken plates out of mine.

 

[1979fj40]

thanks guys, thats what i needed to know, being turkey day no time to work on it . maybe tommorow I,ll get it running again. The PO put a header on and forced SAE bolts in so I had to tap out to the next size up (gotta love PO rigging).

 

[mudnyreye]

Make sure you check the face of the manifold. If it is warped it will have to be milled for flatness (otherwise it will leak and ruin expensive gaskets) Any machine shop can check it.

 

[handcannon]

Make sure you check the face of the manifold. If it is warped it will have to be milled for flatness (otherwise it will leak and ruin expensive gaskets) Any machine shop can check it.

I agree on this, but you need to go one step further. The intake and exhaust bolt together. If there is a mismatch in the head mounting surface after bolting the manifolds together (which is very likely) they should be machined as a unit.

 

[1979fj40]

Make sure you check the face of the manifold. If it is warped it will have to be milled for flatness (otherwise it will leak and ruin expensive gaskets) Any machine shop can check it.

Had them surfaced yesterday. They were bolted together just wasnt sure if there was supposed to be a plate also.

 

[Pighead]

There may not SUPPOSED to be a plate there...but it might be a good idea. I've seen more than one intake manifold develop a crack in that area. Not sure I would trust the flapper to last and work properly to protect the underside of the intake manifold.
Just my two cents.

Had them surfaced yesterday. They were bolted together just wasnt sure if there was supposed to be a plate also.

 

[FineWynsFJ40]

Yes, a plate goes in there, but substituting a couple gaskets can fit, the shim height is important so the bolt holes line up and the seal is maintained. That's what I did, just a thought.

Brian

 

[1979fj40]

Yes, a plate goes in there, but substituting a couple gaskets can fit, the shim height is important so the bolt holes line up and the seal is maintained. That's what I did, just a thought.

Brian

So the heat flapper AND a plate go in ?

 

[Pighead]

So the heat flapper AND a plate go in ?

I'm thinkin yes. All the heat flappers I've ever seen have been worn down to the nub. I'm thinking a plate might help. Couldn't hurt. Sorry I can't be more help, I got headers.

 

[1979fj40]

The manifold I got has a flange that is like new. If I put a plate on top it wouldnt be able to move but about a 1/4 in or so before it hit the plate ,would that be right?

 

[FJ40Jim]

The stock plate is stamped up so it just clears the arc of the heat riser flap.

Without the plate, the exhaust gass will have more contact w/ the bottom of the intake, leading to carb boiloff problems and (eventual) intake manifold cracking.

Either order a new plate from Toyota, or remove heat riser altogether & install SOR stainless blockoff plate.

 

[FineWynsFJ40]

What I did was go from headers back to intake/exhaust manifold for efficiency and driveability reasons. I talked with Vic at Hadley Industries, and what he recommended was remove the plate on the heat riser assembly, as well as the plate in between manifolds. I stuck in an extra gasket to maintain the spacing, and it's worked good so far. I will let you know if cracking becomes an issue. If you remove both pieces, then the exhaust is free to flow out of the manifold while heating up the intake like it is supposed to do. That's my $.02 Good luck!

Brian

 

[FJ40Jim]

If there is no plate then there will be plenty of heat (too much?) on the bottom of the intake.

I don't get the whole heat riser apparatus. the aluminum intake is bolted to the flaming hot exhaust manifold w/ 5 big bolts. Were they afraid that not enough heat would transfer through the intake? C'mon, that thing is scorching hot in 3 minutes, just from contact w/ the ex manifold.

Whenever I'm dealing w/ a stuck valve, or a buttrfly that's rusted off the shaft, i prefer to trash the whole apparatus and use the SOR style plate (I make 'em out of 16ga stainless), to reduce (?) the heat to the intake. It's simple, and the intake still gets hot as hell.

 

[1979fj40]

I have a big sheet SS from a ice machine cabniet I trashed at work, guess i,ll cut out a plate to go in there too.

 

[1979fj40]

Ok , so I got my manifolds on and fired her up after sitting for 3 weeks waiting on parts. drove across town to the muffler shop (sounding like a log truck) and had them tie into my exhaust where i cut the header out. on the way home I hear a loud metalic bang then steam pouring from under the hood. Called a buddy with a strap to come tow me home. pulled the radiator and lo and behold I found my 17mm wrench.....so did the fan as it slung it into the radiator and broke a vein. (note to self,... after rebuilding engine account for ALLLLLL tools). Took it to the radiator shop ,he bypassed the one vein then pressure checked it where in he found a leak around the top hose solder joint and one in the top tank. Had to leave it over night ,said he would take it apart clean it and repair for $60.00. Guess it was a good thing or one of those other leaks would have stranded me somewhere for sure. One day im gonna get this thing back on the road. Am I the only one with this much bad luck?

 

[D'Animal]

That is not bad luck, You are just getting the bugs worked out of it.

Am I the only one with this much bad luck?