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Manifold Crack - Need New S2MS Intake

Started by greekz, October 18, 2021, 04:09:36 PM

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greekz

Discovered this crack in my intake manifold at #8 cylinder intake port.  I believe I am now in the market for a S2MS intake manifold.  Do not really want to buy a reproduction. Hopefully, someone has a good used one or NOS piece.

Thanks,

Greek
SFM 6S1134  '67 GT-350 #2339

Dan Case

Dan Case
1964 Cobra owner since 1983, Cobra crazy since I saw my first one in the mid 1960s in Huntsville, AL.


Bob Gaines

Bob Gaines,Shelby Enthusiast, Shelby Collector , Shelby Concours judge SAAC,MCA,Mid America Shelby

s2ms

Quote from: greekz on October 18, 2021, 04:09:36 PM
Discovered this crack in my intake manifold at #8 cylinder intake port.  I believe I am now in the market for a S2MS intake manifold.  Do not really want to buy a reproduction. Hopefully, someone has a good used one or NOS piece.

Thanks,

Greek

Could that just be a casting flaw? I've seen similar on other OE manifolds that looked more like flaws, plus yours seems "inward" from the "typical" location...
Dave - 6S1757

1109RWHP

Does not look like a crack to me. Just sloppy casting.

SFM5S000

#6
Take it off and test it and see if it's actually cracked! Try either brake Kleen or solvent and see if it bleeds through. If it is, fix it!

~E

GT350AUS

Yep looks like a casting mark not a crack.

Have you noticed a change in the the way the engine runs since discovering the image?

greekz

Thank you all for your replies and suggestions.  Have been told it might be a casting flaw.  While searching Ebay, I found a manifold for sale and it had a line/crack in the same place.  I plan on getting tested, but will try the solvent test as well.

The engine was running great before I took the car(6S1134) apart for painting.

Greek
SFM 6S1134  '67 GT-350 #2339

shelbydoug

That manifold, unfortunately, is very susceptible to breaking off that ear. I don't know if there is anything that you can do about it?

That corner is also where the engine has a tendency to develop a water leak.

Maybe just use silicone back there on that corner and just drop the bolt in and make it just a little more then finger tight?

Under NO conditions ATTEMPT to use the cork "s" gaskets under it. Use ONLY silicone.
68 GT350 Lives Matter!

pbf777

Quote from: shelbydoug on October 19, 2021, 10:06:32 AM
That manifold, unfortunately, is very susceptible to breaking off that ear. I don't know if there is anything that you can do about it?

     The engineering of the unsupported flange in this area (260/289 cylinder heads) was based on the iron component which was fine; but with the substitution of the less rigid aluminum material for the intake manifold, and as a nonstandard production component probably didn't receive the engineering discover effort typically warranted, failures began to result.  Later Ford changed the intake face casting profile of the cylinder heads to provide support, but I wonder if this was thru observation of the difficulties experienced with the aluminum intakes, or due to similar failures of even the cast iron units with the propensity of air impact wrenches in use in the assembling of such items at the dealership service departments?    :o

     Don't over torque the bolts (particularly the end ones') and you won't have any problems; but remember, the torque values listed in the repair manual is based on the cast iron component!    ???

     Scott.

shelbydoug

#11
Quote from: pbf777 on October 19, 2021, 11:39:32 AM
Quote from: shelbydoug on October 19, 2021, 10:06:32 AM
That manifold, unfortunately, is very susceptible to breaking off that ear. I don't know if there is anything that you can do about it?

     The engineering of the unsupported flange in this area (260/289 cylinder heads) was based on the iron component which was fine; but with the substitution of the less rigid aluminum material for the intake manifold, and as a nonstandard production component probably didn't receive the engineering discover effort typically warranted, failures began to result.  Later Ford changed the intake face casting profile of the cylinder heads to provide support, but I wonder if this was thru observation of the difficulties experienced with the aluminum intakes, or due to similar failures of even the cast iron units with the propensity of air impact wrenches in use in the assembling of such items at the dealership service departments?    :o

     Don't over torque the bolts (particularly the end ones') and you won't have any problems; but remember, the torque values listed in the repair manual is based on the cast iron component!    ???

     Scott.

It in fact may be an unfair statement from me but in all honesty I question the quality of the casting itself.

The close ups of the break to me show a lousy grain pattern and again, it's easy for me to criticize but exactly what alloy was Buddy Barr using?

Don't go ANYWHERE near these manifolds with any kind of an impact wrench or for that matter even a torque wrench. Use a 6" box wrench and just snug up the freakin' bolts otherwise...


The only thing I can think of that's worse is the likeliness of breaking the center on a Cragar on the old tire mounting machines. That HAS TO BE the worst but this is a close second?
68 GT350 Lives Matter!

pbf777

Quote from: shelbydoug on October 19, 2021, 11:59:11 AM
.......................or for that matter even a torque wrench.


     Well,...........maybe I would disagree here.  That is, a properly used torque wrench!   ;)

     Scott.

S7MS427

One thing is for sure, you can't just go cranking down on those unsupported corners. Use a good torque wrench and creep up to the specified value in small increments.  When you get to the nominal value, go around the torque sequence as many times as you need to until the readings are all the same.

I agree with others that you are probably looking at a casting anomaly and not a crack.
Roy Simkins
http://www.s-techent.com/Shelby.htm
1966 G.T.350H SFM6S817
1967 G.T.500 67400F7A03040

shelbydoug

Torque wrench? OK. What are the recommended values for the aluminum manifold vs. iron?

Considering the replacement cost of the manifold I wouldn't torque anything on it more then 15-20 which is snug with a box wrench.

I would wager that more manifolds have been broken in attempting to use the cork s pieces, because you need to COMPRESS them,  then anything else and I'd double or nothing that NO ONE exceeded the recommended torque when they broke.

Stay away from it. If you drop it, you can hurt your foot.  ;)
68 GT350 Lives Matter!