Bent Intake Valve?

[bd]

Ron, figure out what you can w/o spending any money.  Specialty tools that will make your job easier often are available from the larger chain stores on a loan basis when secured by a refundable deposit.  So, test and teardown until you have a complete picture of both the extent and cause(s) of failure.  Be methodical.  Target each day with exactly what you intend to accomplish.  Manage your time.  Remain flexible, but don't get ahead of yourself.  Avoid making assumptions and drawing premature conclusions.  Take the time to look!  Observe all that is available to be observed.  Take plenty of digital images.  Scribble notes in your repair manual!  You get the idea?  Ensure that you can correctly reassemble all the pieces in their proper locations, orientations and sequence if the job becomes protracted.  If you are new to auto repair, keep all of the bolts, screws, clamps and fittings organized.  Keep your tools wiped clean and organized.  Maintain a safe, clean work environment.  Pick up clutter.  Wipe up spills.  Wear eye protection.  Watch out for razor sharp edges, especially at the margins of machined castings!  The job is largely just nuts and bolts, so don't be intimidated.  But, by the same token, don't be reckless!  Stay focused.

As for repair scenarios, guessing from the bleachers is not very productive and often introduces new and unnecessary confusion or predisposes an unexamined conclusion that distorts or negates the facts.  You cannot create a realistic repair plan until you actually know what's wrong.  And, you won't know what's wrong until you look.  So make your observations, post your discoveries and pose your questions as they arise.  Help will be forthcoming.  Bear in mind that your primary focus early on is to determine exactly what failed, how and why.  Let the immediate failure guide your approach.  What components were directly involved in the failure that brought you to this point?  How encompassing was the failure?  Once those issues are clearly defined with cause(s) identified, broaden your scope to include any other components that show evidence of wear to achieve a complete evaluation.  Depending on what you discover, your best option maybe installing a new powerplant rather than fixing the existing engine.  You really won't know until you compile more information.

[gunrac]

Maybe, I'm reading to much into this, but....."What's yall's take on the Exhaust Manifold Spreader?"  Replacing manifold studs is a must, so they will see heat, while being off.

[bd]

Exhaust manifolds were installed without flange gaskets at the factory.  Typically, I don't use gaskets when servicing exhaust manifolds.  I check the sealing surfaces for flatness and alignment, and smear a thin even coat of Ultra Copper on the flange faces during assembly.  If the manifolds are badly warped, gaskets won't really help.

When removing an old manifold that you intend to reuse, it is good practice to install "spreaders" before loosening the bolts - two per manifold. 



The 'spreaders' help maintain the flange spacing and greatly ease reassembly.  Otherwise the cast manifold can distort, making its reuse a frustrating proposition.  Once the manifolds move, the spreaders are virtually useless.  They won't restore flange position or alignment.

So, if you are removing both exhaust manifolds at the same time...

...pick up and install four Lisle 13000 manifold spreaders BEFORE you unbolt the manifolds from the heads!

[roundhouse]

A new crate engine won't cost much more than what you're gonna spend to have this one fixed


Sent from my iPhone using Tapatalk

[gunrac]

I can't remember what this is called. Can someone tell me how to check it?

[LTZ C20]

That's an EGR valve, (E)xhaust (G)as (R)ecirculation valve. It is opened by vacuum and allows exhaust gases to pass back thru the intake system and be reburned again. On the bottom side of the unit, there is a small pin shaped piece called a pintle, it's in the middle of the circular hole in the cast iron base. So press the pintle down into the canister valve, then plug the vacuum line port with your finger and then release the pintle, if it stays down, it's working, if it pops back up, it's not working right.

[gunrac]

THX......I read about it a while back. Just making sure I got it right......It also needs replaced.

[gunrac]

#5....#7 Is rt. of 2 valves. 7 is sucked in the center towards stem. Piston, cyl. walls r good to go. Lifters also good. Still need measurement on v. spring and cam just to be sure. Replacing the EGR valve. Head shop on Mon. check for hair line cracks. Nothing visable to my eye. Hoping to get away w/a single valve replacement and seat and grind the rest. See what the man says.

[gunrac]

Got the heads back yesterday. I got lucky, just the 1 intake valve had to be replaced. Felt good about price, cleaned and resurfaced both heads even cleaned up all the hardware, while throwing in a new valve....110 bucks. I already had them dissembled and still have to lap/grind and reassemble. Couldn't salvage the left exhaust manifold tho, 80 bucks at Jegs. good deal there to, I thought.

[gunrac]

1st. lap job. Guess I'm gettin the hang of it. 1 head done, checkin myself using brake cleaner, so far so good. Beautiful day down here in TX. workin outside w/just a pair of shorts on.....all good!

[gunrac]

Am I missing something? As mentioned, this is my 1st. rodeo.
After watchin some videos, I'm not so sure I'm gettin this lapping down correct, even tho it passes the seal tight test using brake cleaner.
I'm using the compound by Permatex. Supposedly, they use multiple grades of grit in there formula. I just don't see the same flat shine on my valves, like I do in the videos. It appears that the top and the bottom of the valve are polishing out to a shine. But there is a thickness between the 2 that is a dull gray in color, it just won't polish out to a shine. I see and feel w/my thumb nail, very fine lines between the 2 polish surfaces. Both heads are done to where they pass the leak test. But wanted to hear input before install.

 

[bd]

The face of a properly ground valve will be somewhat shiny.  Lapping will dull the area of contact, indicating where the valve face meets the seat.  The resulting ring (witness mark) should be equal width throughout its arc and centered roughly one third of the way in from the valve margin.  Be sure that the valve faces and seats are totally clean of abrasive before final assembly.

Edit:  Referring to the diagram, the valve "face" is mis-labeled as the "seat."

[gunrac]

It all makes since, but I notice the fine circular lines. Normal?

[bd]

Follow up with fine lapping compound, clean all abrasive residue from valves and seats, apply a smear of light engine oil and call it done.  I should add, assuming at least a three-angle valve job, the seats should have witness marks similar to the valves.

[gunrac]

Gasket an parts showed yesterday. The EGR valve has my concern. Advance web site says this is an exact fit. All is the same as the old one except the pintle, "as I understand it is called".
The original protruded an 1/8" from base. The new one protrudes 3/8" w/the housing around it is 1/2" off base. Is this just a upgraded version or did I receive the wrong one?