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Help! -intake/Exchaust flange trueness -- need feedback asap
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Author:  shadango [ Thu Apr 13, 2017 8:36 am ]
Post subject:  Help! -intake/Exchaust flange trueness -- need feedback asap
Hi all

So we just pulled the intake/exhaust manifold stack.

Using a steel yard stick, the best straight edge I have...

I can see light across much of the surface of the flanges, when the yardstick is centered across the ports.

Intake 1 and Exhaust 1 and 6 are the high points.

The biggest gap I can measure anywhere is about .011"-.012"......

Using a remflex gasket this time ....think the remflex will make up for that amount ? The remflex claims it can take care of 1/16" gaps.....true?

.011" is a fifth of the 1/16" gaps they claim to be able to seal.

Or should I pursue having the stack planed, which will hold us up for who knows how long? no one local can do it....

As an aside....The green gasket failed at all the exhaust ports. It also cracked down the longitudinal center, and a small piece broke off at the very back.
Author:  Dart270 [ Thu Apr 13, 2017 9:40 am ]
Post subject: 
Sounds like your exh manifold was held away from the gasket by hanging up exh pipe, or torqued "joining" bolts for int/exh before torqueing the int/exh to the head first.

Lou
Author:  shadango [ Thu Apr 13, 2017 9:57 am ]
Post subject: 
Quote:
Sounds like your exh manifold was held away from the gasket by hanging up exh pipe, or torqued "joining" bolts for int/exh before torqueing the int/exh to the head first.

Lou
When we assembled, we had the exhaust pipe hanging free, no where near...

We torqued up the bolts at the head before tightening the bolts that join the two pieces together.

Seems there is a high spot at each end of the new exhaust from what I can tell....so the ports in the middle have the leaks.

The green gasket doesnt have any give from what I can tell when its new...of course neither does a standard metal gasket I guess.

Plus, that green gasket was cracked in NUMEROUS places and was hard as a rock.....making the other leaks at all the cracks :x

If I separate the two halves I dont think that will change.....and the hotbox gasket isnt leaking...looks nice and solid sealed.

I am leaning towards giving the remflex the chance to do what it says it will do....I called Remflex and told them of the situation and the tech I talked to believed we would be Ok due to how the Remflex gives and compresses and bounds back etc.....reassemble the stack as-is with the remflex and see what happens.
Author:  jcc [ Thu Apr 13, 2017 10:22 am ]
Post subject: 
Not sure where you live, but a plane jib would resolve your entire issue it seems to me. It doesn't require near the accuracy of milling a head or a block, but seems to me to be the same process, and takes certainly no more time, are you sure you have explored all the possibilities for this solution?

Let me know if I have oversimplified this option.
Author:  shadango [ Thu Apr 13, 2017 10:50 am ]
Post subject: 
Quote:
Not sure where you live, but a plane jib would resolve your entire issue it seems to me. It doesn't require near the accuracy of milling a head or a block, but seems to me to be the same process, and takes certainly no more time, are you sure you have explored all the possibilities for this solution?

Let me know if I have oversimplified this option.
Shop called us back -- able to do a walk in , uses what you are talking about! Thanks!

The remflex may have done the job fine but this way I will feel much better knowing its perfectly flat to start with.
Author:  Dart270 [ Thu Apr 13, 2017 11:06 am ]
Post subject: 
Good choice. Happy Slanting...

Lou
Author:  DusterIdiot [ Thu Apr 13, 2017 2:42 pm ]
Post subject:  well put...
Quote:
The remflex may have done the job fine but this way I will feel much better knowing its perfectly flat to start with.
The street hyperpak I put together eventually used a remflex and was able to hold up with 3 different thicknesses of manfold flanges, but if tightened too much they'd crack and fail... What you are doing is best insurance overall whether you use the remflex or not...
Author:  shadango [ Thu Apr 13, 2017 7:24 pm ]
Post subject: 
Well we got it all together and wow does it sound so much better.

The green gasket was bad....cracked in multiple areas.....

Image

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Remflex ...big improvement.

[Image

Car is nice and quiet now....no more locomotive sounds under the hood....lol

Several of you said "go remflex" from the start......yeah, probably should have taken that advice...lol

I have no doubt that others , in other situations, have had good luck with the green gaskets......but I guess we weren't that lucky. Of course our flanges were out too.....

Hopefully we are done with intake exhaust gasket issues for a while....

Think we should recheck the torque at some point? The gaskets advertise no need to retorque...what do you all say?
Author:  Brian [ Fri Apr 14, 2017 7:15 am ]
Post subject: 
Sorry to hear about your luck with those gaskets. I have never seen one fail like that around the exhaust ports.
Author:  Rick Covalt [ Fri Apr 14, 2017 11:23 am ]
Post subject: 
I always cut those lugs off the front and rear of the block. They can hold the gasket away from the head and even when torqued, hold the gasket away along the bottom edge causing bad leaks.

Glad you was able to get it sealed up!

Rick
Author:  DusterIdiot [ Fri Apr 14, 2017 4:11 pm ]
Post subject:  And...
Quote:
They can hold the gasket away from the head and even when torqued, hold the gasket away along the bottom edge causing bad leaks.
And some headers and dutra fronts/rears.... on my rebuilds, it's the first thing to go before I send the block to the machine shop....
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