Rough idle, compression test... head gasket at 3 and 4? (1 Viewer)

OSS

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If you've got the time and a little extra cash - nickel plate those air injection nozzles-- and if your air injection manifold isn't horrible, get that nickle plated too. Guaranteed smiles
 

DFXR

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If you've got the time and a little extra cash - nickel plate those air injection nozzles-- and if your air injection manifold isn't horrible, get that nickle plated too. Guaranteed smiles
I probably won't, but I will admit to looking lustily at the photo of your nickel-plated dream rail that has been circulating on this forum!
 

DFXR

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Manifold is next.

I have a question for @Spike Strip -

I have new rings and springs for the manifold horns. I remember you saying that you used some Permatex ultra copper in your horns with good results. Did you just apply it over the rings in their grooves or what?

I have no reason to think that my new hardware won't seal... but I will happily reduce risk wherever I can.
 

NeverGiveUpYota

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Manifold is next.

I have a question for @Spike Strip -

I have new rings and springs for the manifold horns. I remember you saying that you used some Permatex ultra copper in your horns with good results. Did you just apply it over the rings in their grooves or what?

I have no reason to think that my new hardware won't seal... but I will happily reduce risk wherever I can.
No sealer. Are you using new rings?
 

DFXR

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No sealer. Are you using new rings?
Yes, I have brand new rings and springs that will be going in all 4 grooves.

I had a leak past the rings from one of the horns up until this head gasket thing came up and took over. This manifold was NOS when I put it on, so the rings and springs already in it may have been old but were not used. They still managed to leak.

So I really don’t want that to happen again. Spike Strip mentioned using hi-temp sealer in his once upon a time and I am all for that if it adds an extra layer of insurance. If I can just get one good year of no exhaust leaks...
 

Spike Strip

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Manifold is next.

I have a question for @Spike Strip -

I have new rings and springs for the manifold horns. I remember you saying that you used some Permatex ultra copper in your horns with good results. Did you just apply it over the rings in their grooves or what?

I have no reason to think that my new hardware won't seal... but I will happily reduce risk wherever I can.
Yes, high-temp RTV smeared around the rings and horn before assembly. It was a recommendation by the guy who used to rebuild all of MAFs engines and manifolds before MAF was sold and moved to NV. I had to remove and replace that manifold about a year ago because one of the J-tube studs broke and I couldn't replace it with the manifold on engine. That high-temp stuff that everyone said would burn off had held up amazingly well after 10 years, and hadn't even discolored.

But do you really need it? I dunno, but worked for me, or at least didn't hurt anything

This was the one I used:

1601914861090.png
 

NeverGiveUpYota

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I thought that there was supposed to be some allowance for those rings to move inside the horns. Adding sealer will affect any movement. Are your horns out of round? I suppose that could be a reason to use sealer...
 

DFXR

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I agree, those horns are free for a reason. But how do the rings move? Expand out with heat and then back in? Maybe I put the sealer in there everywhere except the rings. I am probably overthinking this.
 

NeverGiveUpYota

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I agree, those horns are free for a reason. But how do the rings move? Expand out with heat and then back in? Maybe I put the sealer in there everywhere except the rings. I am probably overthinking this.
Mine is attached to the truck now and I’m having a hard time recalling the way they look when installed.
is there two shoulders or landings, (whatever they’d be called)? One for the bendy one and one for solid? If you put sealer you’d need to not add it to those gaps only to the solid ends. And you couldn’t add until right before install because the horns need to shift as you tighten down the bolts.
 

DFXR

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Here’s what they look like. This is the rear (j-pipe) end, and these are the original rings. You can see the the rings, and hidden underneath each of them is a spring (the bendy piece).

I will probably put the sealer on close to the area where the two sections butt each other. It stays tacky for a little while so I could do it and then wrestle the thing on with some movement. Sounds good on paper at least.

2E0B05BA-B44E-4318-8931-92BB98299C93.jpeg
 
Last edited:

NeverGiveUpYota

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Here’s what they look like. This is the rear (j-pipe) end, and these are the original rings. You can see the the rings, and hidden underneath each of them is a spring (the bendy piece).

I will probably put the sealer on close to the area where the two manifolds butt each other. It stays tacky for a little while so I could do it and then wrestle the thing on with some movement. Sounds good on paper at least.

View attachment 2457073
Ok so my feeling is this... any sealer that potentially becomes goopy chunks during manipulation of the horns into the manifold can/could be sucked where you don’t want it. Personally I wouldn’t do it.
 

DFXR

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Manifold is in and torqued to the Remflex specs. 25 lbs feels weird.

Comparing new horn rings to old, makes me realize why some of the old ones weren't sealing. They were old and flat from all the years, even though they were essentially "new" (old stock). The new rings rise out from the grooves and should do the job of actually sealing that area. I put a little bead of ultra copper around the flange on the horn anyway, because I couldn't help it.

IMG_2082.JPG




IMG_2078.JPG
 

DFXR

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It lives...

Finally got all the smog stuff buttoned back up, fluids back in, and fired it up this AM. Choke and some serious pumping and then a nice solid start.

Burped it with a Lisle funnel contraption, drove for 20 minutes. Nothing seized, leaked or exploded.

Observations: it’s purring, probably too well. I think I did my cold initial valve lash setting a little tight, because I’m not hearing that industrial sewing machine sound.

Vacuum is a steady 18, but I would like it to be a steady 20. Can tight valves give lead to a lower vac reading? None of the charts I have say so.

It could use a lean drop to dial in the idle, but I will do that after the valve adjustment. I’ll do an oil change and re-torque the head bolts at the same time. After that it just needs driving to shake out the bugs.

8465974C-5E96-4FE6-89B2-3D118008F964.jpeg

F7123929-87AC-4B95-9C69-A7B61852AAF8.jpeg
 

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