Good Leakdown with Bad Compression

Ima Doit · Mar 19, 2017

Okay. So, she's putting again. Replaced the bent pushrod and pulled all rockers. All valves appear to be sitting correct with a strait edge laid across the tops. Re-torqued rockers down. Pulled fuel rail. Injectors were nasty. Replaced with a newer set. Cranked it up with valve cover removed and waited for oil to reach the rockers. Runs great.

Problem solved for now.

Saudade · Mar 19, 2017

Ima Doit said:
Okay. So, she's putting again. Replaced the bent pushrod and pulled all rockers. All valves appear to be sitting correct with a strait edge laid across the tops. Re-torqued rockers down. Pulled fuel rail. Injectors were nasty. Replaced with a newer set. Cranked it up with valve cover removed and waited for oil to reach the rockers. Runs great.

Problem solved for now.

AWESOME!! Thanks for the followup and nice work!

Ima Doit · Mar 19, 2017

The one thing I'll say is that I put gasoline on the new o-rings on the injectors. Made it easier to install. However, they sprayed a good bit of fuel out and didn't seat properly. I'm guessing the gasoline didn't allow for a good seal.

After a few starts it got better. Assuming after the fuel cleaned off the vasoline. I'll start it again tomorrow to be sure. Also, does smell rich anymore. Really running better than before. Might swap the injectors for the 4 hole sprayers in the future. But, for now, she's good.

And yea, thanks. I hate reading threads and never seeing a conclusion or follow up.

Ecomike · Mar 19, 2017

md21722 said:
What did the spark plugs look like? Picture? Intake valve sticking? Collapsed lifter? I would pull the valve cover and whack the valve stems with a hammer. Inspect for bent push rods, etc.

If the intake valve is not opening on #2 that would cause this data right?

Edit, I see after reading the rest of the posts, you all already figured it out, no Mojo on opening the #2 intake valve. I have a lot of slop in my 291,000 mile push rods, from wear, guess its time to do that head job and replace everything before I get a bent rod.

Hypoid · Mar 20, 2017

Mike, if your hydraulic lifters can maintain "zero lash," life is good.

Saudade · Mar 20, 2017

Ima Doit said:
The one thing I'll say is that I put gasoline on the new o-rings on the injectors. . . . . .

After a few starts it got better. Assuming after the fuel cleaned off the vasoline. . . . . .

And yea, thanks. I hate reading threads and never seeing a conclusion or follow up.

Good thing I read your entire reply.

Ima Doit · Mar 20, 2017

Damn autocorrect.

Ecomike · Mar 20, 2017

Hypoid said:
Mike, if your hydraulic lifters can maintain "zero lash," life is good.

They are a wee bit loose when the cam lobes go to their lowest height due to Wear on the rod ends and rockers. I read somewhere they should not have zero lash at that point that you should be able to rotate the rods then. Mine are loose enough to be obvious, and loose enough to tick just a wee bit.

Unless I do not understand zero lash? That is zero movement of the rocker, zero gap, at BDC of the piston? I may have as much 1/16" on some. Definitely 1/32" I think. I did not measure it.

I have an entire new set of parts already, and spare head for the engine shop to prep, its a roundtoit thingy.

cherokeefan_1 · Mar 20, 2017

Pushrods and rockers won't wear enough without failure to cause that slop but a cam and lifters will. Zinc is missing from modern oils that our flat tappet cams desperately need to live.

Ecomike · Mar 20, 2017

cherokeefan_1 said:
Pushrods and rockers won't wear enough without failure to cause that slop but a cam and lifters will. Zinc is missing from modern oils that our flat tappet cams desperately need to live.

You have not seen my rod ends and rockers and pivots, LOL, or the valve guides for that matter. I guess we will know about the Cam once I have replaced everything but the cam.

I have enough zinc and additives in mine to gag a maggot LOL. I wrote the book on the ZDDP issue here over 10 years ago. Probably why mine is still running.

Good Leakdown with Bad Compression

Ima Doit

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Saudade

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Ima Doit

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Ecomike

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Hypoid

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Saudade

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Ima Doit

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Ecomike

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cherokeefan_1

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Ecomike

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