Dead cylinder??

[RCSConstruction]

Re: Dead cylinder??

Drum Roll..... dududududududududududududdudu,









Ting!



Ting!







Pulled rocker stud! Doh!
Seems the number six intake valve rocker stud pulled up but not out.
He says he can fix it but I kinda wanted to just have all the studs threaded.
He got another stud and put loctite on it and said he had to bang it on pretty good, so I guess we will see.
He feels strongly enough about it to warranty his work, so....
Thanks for the great replies and converstaion in this thread!

 

[FreeBeeTony]

Re: Dead cylinder??

Why would that cause low/no compression?

 

[RCSConstruction]

Re: Dead cylinder??

Intake valve isn't letting air into the chamber....

 

[QC]

Re: Dead cylinder??

Single cylinder throttle . . .

 

[RCSConstruction]

Re: Dead cylinder??

Single cylinder throttle . . .

What does that mean QC??

 

[FreeBeeTony]

Re: Dead cylinder??

If the stud was pulled out of the head..........then the valve would not be opened by the rocker arm...........and would be closed all the time........this would not cause low/no compression. The cylinder would be "dead" but not from lack of compression..........from lack of intake mixture. Did he really perform a compression test?

What did Raul say about this?

 

[QC]

Re: Dead cylinder??

No air in, nothing to squeeze . . . A throttle is a device that limits air in. It is not an accelerator or governor control . . .

 

[RCSConstruction]

Re: Dead cylinder??

No air in, nothing to squeeze . . . A throttle is a device that limits air in. It is not an accelerator or governor control . . .

I am feeling pretty dumb..
So your saying a valve is a throttle. When the valve doesn't work it's like having no throttle?
Is that what you are saying?


I never called raul. I figured, why? Unless the mech. had to take the head off and there was a busted piston or something.
Cost me 50.00 to ship and probably have to wait 2 weeks for the head and locally a head is only 225.00. Not worth my time.

 

[QC]

Re: Dead cylinder??

No. I am saying that the valve acted as a throttle. In today's highest tech camless engines and VVT stuff, that is some of what they can do. Use an intake valve as a sort of single cylinder throttle (air choking device). Anyway, I probably confused the whole discussion for all, but the fact is that valve closed air off from getting in, effectively "throttling it down" and allowing no fuel in.

 

[RCSConstruction]

Re: Dead cylinder??

No. I am saying that the valve acted as a throttle. In today's highest tech camless engines and VVT stuff, that is some of what they can do. Use an intake valve as a sort of single cylinder throttle (air choking device). Anyway, I probably confused the whole discussion for all, but the fact is that valve closed air off from getting in, effectively "throttling it down" and allowing no fuel in.

Roger that QC.
Thanks for the explanation

 

[FreeBeeTony]

Re: Dead cylinder??

Still not sure how this caused no compression.

 

[bomar76]

Re: Dead cylinder??

the mechanic just called and said I am not getting spark in number 6!!QUOTE]


....and so much for this statement....

 

[SuperNova]

Re: Dead cylinder??

Still not sure how this caused no compression.

If your intake valve is not opening you can't draw any air in, so the downstroke of the piston just develops a strong suction above it and the upstroke (which would normally be the compression stroke) only serves to alleviate the vacuum it created on the downstroke, thereby creating......NOTHING. It is a very common failure and the Dodge HEMI with MDS works on this principle to cut FOUR cylinders in such a way as you can't tell it's been done.

 

[SuperNova]

Re: Dead cylinder??

If you don't do something more than loctite to repair that stud, this is going to end up with a repeat performance. IMHO
--
Stan

 

[RCSConstruction]

Re: Dead cylinder??

the mechanic just called and said I am not getting spark in number 6!!QUOTE]


....and so much for this statement....

Semi-true...
Plug was fouled, although if not getting fuel, how?

 

[RCSConstruction]

Re: Dead cylinder??

If you don't do something more than loctite to repair that stud, this is going to end up with a repeat performance. IMHO
--
Stan

I said the same thing but he assured me that the new stud went in as good as any. He said he did something to the shank so it didn't fall in line with the old studs groove??
I will run it hard and it's going to be under warranty..
He also said that you can't tap a head while bolted? At least the vortec head he said. Something about it going all the way through (the stud hole)?
I would much rather them get this thing done and if there are any other issues I will stud the heads myself.
No since in paying them 100. an hour to do non-boat specific work.

 

[SuperNova]

Re: Dead cylinder??

As long as he's going to warranty it and any damage it may do, then it's just your "downtime" you'll have to deal with. I don't know about the vortecs, but I used to tap heads for screw in studs on the engine a fair amount. As a side note, I usually find that there was a reason the stud pulled in the first place. A short run at about 4500 rpm should tell if it's going to hold or not, maybe 15 or 20 minutes. Hope it works out for you.
--
Stan

 

[SuperNova]

Re: Dead cylinder??

Semi-true...
Plug was fouled, although if not getting fuel, how?

It was sucking oil up past the rings, probably. Might be pretty easy depending on a few factors that if I went into might be construed as disparaging Rapido, and I don't want to do that.

 

[RCSConstruction]

Re: Dead cylinder??

It was sucking oil up past the rings, probably. Might be pretty easy depending on a few factors that if I went into might be construed as disparaging Rapido, and I don't want to do that.

RapidO, who said anything about them?? Acme motor company built my motor.
For the sake of education, could you elaborate? If not, I understand.
Thanks!

 

[SuperNova]

Re: Dead cylinder??

Simple stuff, really. Just little details like ring end-gap alignment and cylinder finish. Of course, if the engine wasn't completely broken in yet, meaning the rings weren't fully seated, it would be easy to suck oil right past them as well. That would depend on whether moly-faced rings were used or plain cast-iron rings, how long it would take to seat them. I have heard plenty of things both ways about Acme motors, but I haven't had a chance to see one first hand, so I reserve judgement, although you were a case in point....on several points. I am still going to wait and see what your final outcome is. By the end of this season, you'll have formed your final opinion one way or the other, I think. I would be interested in your thoughts.
--
Stan