Dead cylinder on new engine ( what in the he// happened? )

-
duster360 said:
I think you fellas are on to something. I think I may have a problem with the intake sealing at that cylinder.
Click to expand...

If you remove the intake, clean the head surface and put a metal straight edge on both sealing surfaces to check them for flatness.

Use an adjustable bevel that you can get at a home improvement/hardware store to check the angles are correct on the block/head and on the intake.
 
Also when you tear it down, before you clean it up, check all surfaces and gaskets for 'witness" marks to see if there were any leaks. After you clean up the parts, you will destroy any evidence.
 
Originally Posted by duster360
I think you fellas are on to something. I think I may have a problem with the intake sealing at that cylinder.
Click to expand...

That's all nice and well. It should still be doing something. If your intake isn't sealing you should still be pulling some A/F mix into the cylinder and firing. Have you tried starting the engine and putting a timing light on the wire. It may not be firing in the head. It's possible. Have you tried turning off the lights in the garage with the engine running to see if you're arcing elsewhere than the electrode? Jumping from a bad boot to the manifold/header happens all the time.
 
if its leaking around number 6 runner you should be able to take a propane torch and while its running with the torch unlit but on hold it to the runner and if the cylinder starts firing you have a bad leak there,,starting fluid works also if you have no propane torch
 
Did you put a new plug in it? If it had no compression and you ran it, the plug is fuel-fouled. They'll spark without compression but misfire in a cylinder.

Plugs are cheap, don't you be...
 
I think if a person is going to comment on a thread that's been discussed for awhile they should read what's already been posted.

A lot of the recent questions are ones that have already been asked, tested, and answered.

Otherwise the thead ends up being 10 pages long with the same suggestions over and over and over.

If it's too much trouble to do that, then don't get involved.
 
The one on the bottom is the passenger side where the #6 cylinder was not firing. The intake also had oil in the #6 intake runner. The gaskets are drenched in oil and the cylinder head intake ports on all the cylinders are wet. Looks like I might have found the problem, with help from the FABO family of course.
Click on the link below and it will take you to the rest of the pictures of the gaskets.

http://s248.photobucket.com/user/jaimie340/library/?view=recent&page=1
 
I know I hear that from my wife a lot. Does it show a good smash on the gasket right there on #6?
 
I don't have anything to mike the groove in the gasket, but by the eyeball and fingernail test it fells like the bottom of the gasket did not compress as much as the top. With my calipers I measured .038 at the top and .043 at the bottom.
 
place the intake back on the engine with valley surface cleaned. Push all the way to one side and measure the distance between head and intake. You can use a stack of feeler gauges to get the measurement. Take the measurement, add .060 and split that number in half. That's a general thickness the intake gaskets should be to get a good seal.

I'll bet the current gaskets are not thick enough to provide a positive seal.
 
I'm thinking your heads have been cut and the intake wasn't. Did you use a front and rear seal on the block. You might try and set the intake on the engine without end gaskets and see what it looks like.
 
crackedback said:
place the intake back on the engine with valley surface cleaned. Push all the way to one side and measure the distance between head and intake. You can use a stack of feeler gauges to get the measurement. Take the measurement, add .060 and split that number in half. That's a general thickness the intake gaskets should be to get a good seal.

I'll bet the current gaskets are not thick enough to provide a positive seal.
Click to expand...

This evening I ordered a set of .060" edelbrock gasket and they also have the extra sealant around the ports like the mr gaskets do.
 
SGBARRACUDA said:
I'm thinking your heads have been cut and the intake wasn't. Did you use a front and rear seal on the block. You might try and set the intake on the engine without end gaskets and see what it looks like.
Click to expand...

These heads have been in the family since 1975 and they were on the original 340 ( and still are ) they came on. To my knowledge they have never been cut.
I did not use the end gaskets, I used rtv on the ends.
 
duster360 said:
These heads have been in the family since 1975 and they were on the original 340 ( and still are ) they came on. To my knowledge they have ever been cut.
I did not use the end gaskets, I used rtv on the ends.
Click to expand...
Well then You installed the intake the way I do without the end seals. Crackedback I think may be on to the solution. I hope the thicker gaskets do the trick.
 
I have glued 2 felpro gaskets together on some heavily cut intakes some times its cheaper then ordering special gaskets.also remove valve covers before installing intake it can bind up at times.
 
what box (in your wiring harness) do you have, because if your car was originally a slant 6 itll fire only on 6, i made this mistake, check the brain for say make sure its a 8 cylinder 1!! somebody will get you the right answer here, these guys on this board are sharp as hell!!!!
 
muddog said:
what box (in your wiring harness) do you have, because if your car was originally a slant 6 itll fire only on 6, i made this mistake, check the brain for say make sure its a 8 cylinder 1!! somebody will get you the right answer here, these guys on this board are sharp as hell!!!!
Click to expand...

Original V8 car with MSD ignition.
 
You must log in or register to reply here.
-

Back
Top