TBucket Engine Project (Dart SHP)

Indycars said:
I'm going to run a compression test first, since I'm already setup. I'm not ready to jump in and change the intake manifold
gaskets, I went to great pains cleaning 15-20 times, getting the sealer just the right thickness on the rails front and back.
Grumpy says its a quick and easy task, but it's an all day job for me with my OCD.

Charging the battery with my trickle charger at 4 amps before the compression test.

But something like that is on my mind, what should I expect with WD40, will it rev up some if there
is a vacuum leak?

I just tried another carburetor that has been on the shelf for 30 years. I did spray carb cleaner with the
red tube stuck into the air bleeds and blew it out with air. Filled the bowls thru the vent up to the site plug
and made sure the pump worked. Since my fuel lines coming in will not connect, I filled the bowls again
thru the vent up to the site plug. It should run long enough to see a difference if the carburetor is the
problem.

No difference to even worse, therefore that's why I'm getting ready to do a compression test. It back fires
thru the carburetor during many of the different tests, wondering if I have a intake valve staying open. I
noticed and so did Brian that that fuel cloud above the carburetor in the video just as the engine starts.

View attachment 9835
Click to expand...
Yes Rick.
Spend Sunday Diagnosing.
I agree do a compression test.
Plausible an intake valve is not seating and staying open.
Readjust the offending cylinder valves.
Retest.
I Don't like that Fuel Standoff.
Should only be present On Race Cars with full drag race cams with 100-120 degrees valve overlap.
Idle speeds on such cams are 2000-2500 rpms.
 
Loves302Chevy said:
You have to be careful Rick, but the CLEAN way of testing for a vacuum leak is with an UNLIT propane torch.
The leak will suck the propane gas in and the engine will smooth out. Nothing liquid sprayed on your engine.

So you are not using PCV, or are you connecting it somewhere else?

Rick, within the last 2 days, I just read on another site about connecting a gauge to your dipstick tube to test for an intake manifold leak.
I will see if I can find it again.

Do you have your stud girdles installed yet? Any interference issues?
Are they up high enough on the studs as to not interfere with the rockers?
The girdles should be the only real difference between this time and last.

Were your heads surfaced when this latest valve job was done?
That might account for your intake not fully seating, IF that's the problem.
Click to expand...

Here ya go Rick.

A smoke test will work if there is a vacuum leak anywhere downstream of the throttle blades.

If the leak is from the intake runners to the valley of the motor, you still need to smoke test to see if the front or rear china walls of the block are sealed.
If the aren't, you've likely found your leak(s). If they are, now you can check the PCV system to see if the engine block is under vacuum.
Do this by plugging the breathers on the valve covers and putting a vacuum gauge on the oil pan dip stick.
If it pulls vacuum - yeah your intake isn't sealing to the heads.
 
Loves302Chevy said:
So you are not using PCV, or are you connecting it somewhere else?
Click to expand...
Yes I do have a PCV in one valve cover and a breather in the other, didn't change any thing there from earlier.

Loves302Chevy said:
Do you have your stud girdles installed yet? Any interference issues?
Click to expand...
No stud girdle yet, not until I have a final adjustment on the valve lash.

Loves302Chevy said:
Were your heads surfaced when this latest valve job was done?
Click to expand...
No the heads were not surfaced, but good question to ask.
 
Finished the compression test this morning. Test was done at ambient temp and no carburetor
installed. For reference I also included the test done in 2014 with the engine hot.

CompressionTestAfterRepair.JPG
 
Told Ya The RTR Was what caused the extreme valve float & Keeper coming loose and bent valves.
Triggering firing at the wrong time.
 
Seen it before.
Long before I was on Grumpys site.
Never took photos then.

Why I am A Vertex Magneto Guy.
High Cost is Ok.
Worth it to me.
 
I tried the propane torch to test for a vacuum leaks. I couldn't tell any difference in RPM, but then
again I'm trying to keep it running at over 3000 RPM. It's not like you let it idle and then flow
propane along the gasket surfaces.

I then started it again and kept it running long enough to get to 190°F. The AFR was running between
14.5 and 15.5. The trans puked fluid out the vent tube.

This is getting depressive!
 
Indycars said:
I tried the propane torch to test for a vacuum leaks. I couldn't tell any difference in RPM, but then
again I'm trying to keep it running at over 3000 RPM. It's not like you let it idle and then flow
propane along the gasket surfaces.

I then started it again and kept it running long enough to get to 190°F. The AFR was running between
14.5 and 15.5. The trans puked fluid out the vent tube.

This is getting depressive!
Click to expand...
Thinking Rick
 
I forgot to mention this earlier before the propane test that I found a spark plug on #5 with
a cracked outer porcelain. Since I bought 9 plugs when I replaced the Champions with the NGK's,
so I already had one and just replaced it. Made me wonder about the other plugs so I pulled all
of them again and checked for cracks and set the gap at .040 inches.
 
Sure appears to be a major vacuum leak.
Intake gasket ripped sucked inward.

Or the intake manifold cracked in a runner.
Underside of it towards valley of engine.
 
Best way to test is with a modern Shop Smoke machine.
Have one at work to use.
They are $1,000 to buy.
Use it for Evap emission diagnostic repair work.

Other way is to use Cigarette smoke.
You dont smoke Rick.
I do.
 
The plausible way to test is fill the engine with smoke through one valve cover breather hole.
Make the crankcase air tight.
Watch for smoke coming out the carburator or not.
 
Do You still have your Boroscope Tool Rick ?
Remove the Demon Carb.
Look down the intake ports .
See if a gasket is sticking in it.
Of course that means an intake gasket failed.
 
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