Missing on one cylinder - 351C

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boilermaster

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Dude,

I had a oil leak somewhat like stanglover, mine ended up being the oil pressure sender, it was brand new and I have the proper socket to install it.

I ended up breaking down my tee for my mechanical gauge and used some hobby type clay to build a small dam around the base of the new oil sender to verify it was not a rear intake leak, clean the area super good and re try.

Another thing that happens when engines get rebuilt and machine work gets done is the dimensions at the intake valley actually change when cylinder blocks are decked and cylinder heads get trued or shaved.

if you find that the rear of the intake is leaking and the manifold has to come off, you might find where there is a low spot of silicone where it did not fully seal.

find a spot where it did seal and measure it's thickness with your dial caliper for future reference.

this distance will be the minimum bead of silicone needed to re seal.

like stanglover states, a little extra on the 4 corners.

Dude, you have showed great patience in finding and repairing your misfire and your end goal is very close, slow and deliberate will see you there.

Boilermaster

 
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I'm glad it is firing on all 8 again. Any idea of what was causing the mis-fire? Chuck

 
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72 Fastback - 351C-4V, Fitech EFI, T56 Magnum 6 Speed
Thanks guys. From your description, I have to think I didn't go far enough up the side. I'm going to clean it up and run it for a but and see if I can spot where' it's coming out. Of course a neighbor walking by told my to just pile on a bunch of RTV on the outside "it'll be fine". No thanks. 

Hunting for some new valve covers now as these still have that clearance problem and they are ugly as sin. Tight budget at the moment though with tax season here. 

@Stanglover I cut out a small piece of thin sheet metal to go over the port under the gasket. Big enough to stay put not thin enough not to mess with the gasket or seal. 

@c9zx It had a blown gasket around that port. 

https://lh3.googleusercontent.com/D1dCqQTkJ0p8v9z5Q13I9HKdEVRALNO9iPoaNYhdDSuLrQjBc1fr3QGMjNh1pqlBzs07DVNDnBlGFxwFoH-at96UYn4mRoUd87m-lZuWMpNeBP8GUKVFHt--rycnr0mOdyv6xkEZKAE=w1222-h916-no[/img]

 
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Thanks guys. From your description, I have to think I didn't go far enough up the side. I'm going to clean it up and run it for a but and see if I can spot where' it's coming out. Of course a neighbor walking by told my to just pile on a bunch of RTV on the outside "it'll be fine". No thanks. 

Hunting for some new valve covers now as these still have that clearance problem and they are ugly as sin. Tight budget at the moment though with tax season here. 

@Stanglover I cut out a small piece of thin sheet metal to go over the port under the gasket. Bit enough to stay put not thin enough not to mess with the gasket or seal. 

@c9zx It had a blown gasket around that port. 
 Dude, I guess you'll find out if the intake gets hot under the carb base. If not, job done!

 Geoff.

 
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Another new gasket later and so far so good. All 8 are hot and no leaks and so far cool under carb!

Car still seems to have less power than I think it ought to, but that's clearly another issue for another thread. 

Thanks much to everyone for all the help. Looks like the mystery is solved and the problem fixed.

 

EvilPuppetMaster

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Thanks guys. From your description, I have to think I didn't go far enough up the side. I'm going to clean it up and run it for a but and see if I can spot where' it's coming out. Of course a neighbor walking by told my to just pile on a bunch of RTV on the outside "it'll be fine". No thanks. 

Hunting for some new valve covers now as these still have that clearance problem and they are ugly as sin. Tight budget at the moment though with tax season here. 

@Stanglover I cut out a small piece of thin sheet metal to go over the port under the gasket. Big enough to stay put not thin enough not to mess with the gasket or seal. 

@c9zx It had a blown gasket around that port. 

https://lh3.googleusercontent.com/D1dCqQTkJ0p8v9z5Q13I9HKdEVRALNO9iPoaNYhdDSuLrQjBc1fr3QGMjNh1pqlBzs07DVNDnBlGFxwFoH-at96UYn4mRoUd87m-lZuWMpNeBP8GUKVFHt--rycnr0mOdyv6xkEZKAE=w1222-h916-no[/img]
He he he ... What did I tell you on the second page post 11?

I was chasing same issue for months it was gasket between heads and manifold except in my case tightening manifold bolts closed the gap and fixed the issue

Cheers

Alex

 
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Yup, absolutely right. I did try tightening the bolts (and broke one) per your suggestion, but obviously the gasket was blown out. But that was ultimately the problem.

Thanks

 
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