Heat riser block off plate (1 Viewer)

[Erik Swenson]

1977 Fj40 original owner. Intake manifold leak. Took everything apart. Changing all gaskets and ran across the insulator between the two gaskets in the heat riser. It is cracked ....probably still sort of useable. No other modifications have been made to this vehicle ....still has the smog pump and same carburetor. So when I put this all back together do I install the heat riser block off plate that is available? Does it work? Will I notice anything? Will there be regret? It was quite a job to get this manifold out and I don’t want to go back in on this. The manifolds are good...nothing is cracked....the only thing that is f- -d up is this metal insulator. Anybody running around with this block off plate in there that can look me straight in the eye and say go for it Swenny?

 

[Loomis Blue]

I’ve got the same issue as well as a cracked intake. While the intake is off getting welded I’ve been wondering the same thing. I’ve seen a block off plate available somewhere around here and am hoping someone will give us the “ go for it Swenny “.
Thoughts anyone?

 

[rkymtnflyfisher]

I run a block off plate on my rig, you'll need to trim the flapper inside or remove it all together. I think that in the winter it may need choked a little longer before it starts running as smooth as it should. Other than that I haven't noticed anything unusual.

 

[Erik Swenson]

I run a block off plate on my rig, you'll need to trim the flapper inside or remove it all together. I think that in the winter it may need choked a little longer before it starts running as smooth as it should. Other than that I haven't noticed anything unusual.

Thanks Chief I’ll do the blockoff plate then....seems like a reasonable thing to do

 

[Erik Swenson]

I’ve got the same issue as well as a cracked intake. While the intake is off getting welded I’ve been wondering the same thing. I’ve seen a block off plate available somewhere around here and am hoping someone will give us the “ go for it Swenny “.
Thoughts anyone?

I think if the fly fisherman says it works then I’m gonna seal it up with that block off plate.....good luck with the welding job.... will try to put it all together this weekend....I had to change my steering gear box as it was leaking all the time ....haven’t hooked that together yet.....

 

[Loomis Blue]

Much appreciated input. Thank you all

 

[Erik Swenson]

I ordered the heat riser block off plate with the two gaskets that sandwich it in there and will go for it....if anyone still says that I don’t know....seems fitting here

 

[Loomis Blue]

Got mine!

 

[Erik Swenson]

 

[Erik Swenson]

Thanks Chief I’ll do the blockoff plate then....seems like a reasonable thing to do

So I trimmed the flapper; and put the manifolds back together with the two heat riser gaskets sandwiching the blockoff plate....but now the mating surfaces where the whole thing bolts to the block are not completely flat. I tried loosening the bolts and repositioning ....it’s just not perfectly flat. Do I need to take the manifolds to a shop?.... or will the manifold gasket and just bolting the manifold on take care of the issue....

 

[Loomis Blue]

Still waiting to get my intake back from the welder and my block off plate to show up...
interested in seeing what has to happen. I’m sure I’ll be in the same boat.

 

[Erik Swenson]

Still waiting to get my intake back from the welder and my block off plate to show up...
interested in seeing what has to happen. I’m sure I’ll be in the same boat.

So I have a mechanic friend that knows a good machinist here in one of the Chicago Suburbs and I’m gonna bring the manifold in and have them improve on this.....if they can. I started putting it back last night and it looks like I need to release the exhaust pipe from the anchor further down to get it back in without torchering myself. But I am aborting now till I get this manifold surface right....

 

[Erik Swenson]

So played around with the long bolts on the manifold and got it to lay flat on my shop counter....I had to drill out the other two smaller fasteners that rusted out and when I tapped the wholes I screwed up one of them and it threw things off a bit. I will just put a longer bolt though the one and torque it down with a nut. Should be ok....I bought a new intake manifold from Specter because they had one and their graphite intake manifold gasket. Should be able to get things back together this weekend.

 

[Erik Swenson]

Got everything back together today...sort of a bitch but it started right up and the manifold leak is gone now....the engine idles really fast now....I guess it’s getting more fuel and less air. I’ll need to read up on how to adjust to that.

 

[rkymtnflyfisher]

YouTube some @OTRAMM videos, he has a great video addressing tuning carbs.

 

[rkymtnflyfisher]

Here you go.

 

[Erik Swenson]

Thanks so much....it makes total sense that I’ll need to tweak some things here. You know I bought what I thought was gonna be a good replacement for my rotted choke cable. It works fine but doesn’t have the halfway indent that the OEM cable has and the knob installs with the choke letters vertical....annoying but will half to do for now....I’m worn out and just want to drive around for a while basking in the glow of an abolished manifold leak....overall runs much better already. Thanks for the tips on then flapper and the block off plate.

 

[Erik Swenson]

So I went out and bought a tachometer and the vacuum gauge. Hooked everything up and started to do the "lean drop method" to tune the carburetor and it said my rpms for a 6 cylinder were about half of what they should be. Not sure if I have a faulty tachometer....there was no scale or converstion. ....got numbers like 340....gave it a rest and when to it again and got 120. The vacuum readings were in the good range but I'm not getting any rpm readings from 690 or into the 700s like the Otramm video was describing. I played with the idle mixture and idle speed screws....used my ear a little and I at least got things to idle down a bit and sound better...…... I think I'll see if my buddy has a tachometer that works. Not sure why this Cen-tech device is not working for me....

 

[1911]

You have to set any tachometer for the number of cylinders the engine has; there should be a switch on it somewhere. All it does is count ignition pulses from the coil. It needs to know how many cylinders there are to convert to rpm. Sounds like yours may have been set for 8 cylinders instead of 6.

 

[Erik Swenson]

I set it for 6 but it still displays a reading half of the true rpm....I got 340 hooking it on the #1 sparkplug wire. I think I need to get one isn’t a multimeter ....a dedicated tachometer. Know of a good one? The photo/laser ones look cool but I’m not sure about putting reflective tape and aiming the thing when I’m trying to fiddle with idle screws