# Intake valve not opening!!!



## OrbitOrange (Jul 5, 2010)

So i have a terrible miss on #7 cylinder. I've changed the plug and wire. Ive had a tick for a while now. I had pulled the valve cover off and found that #7 intake valve rocker is looser than all the others. Checked to see that it was tightened down all the way and it is. Turned the engine over by hand and watched both #7 valves. Seen the exhaust valve open and shut 2 times and the intake valve never open or close either time. So what is going on here? Lobe worse slap off the cam or lifter dead? This is a stock Poncho 350 hydraulic flat lifter engine. I pulled the push rod and checked its not bent either.

Never seen this happen before.


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## Rukee (Feb 8, 2007)

Intake lobe worn, time for a new cam and lifters!


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## BearGFR (Aug 25, 2008)

:agree Sure sounds like a wiped lobe on the cam to me.

Bear


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## BatmanGTO (Jun 18, 2011)

Is it usually a wiped lobe when only 1 or 2 valves need adjustment? I'm wondering because when I had to adjust mine all the noise was coming from 1 on each side, the rest were all close to specs. I was able to adjust them, but now I'm wondering if this is my misfire. I swapped the dizzy thinking that was it, but still a misfire.


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## geeteeohguy (Feb 2, 2008)

Yep. It's usually a wiped lobe. This never happened until the last 8 years or so. The ZDDP was removed from engine oil due to emissions warranties on cat converters, and the new oil is not up to the task of protecting the camshaft lobes in a flat tappet engine. You will need to replace the cam, and run appropriate oil or upgrade to a roller set-up that doesn't need the ZDDP.


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## OrbitOrange (Jul 5, 2010)

ok so suggestions on a stock 350 cam? maybe something that will wake it up. has #94 heads, th400 and I think 3:08 gears, something close to that anyhow.


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## BearGFR (Aug 25, 2008)

Power brakes and/or factory a/c? If needed, would you also be willing to replace valve springs and pull the heads to have the spring seats machined (to allow for taller springs)? Would you be willing to replace the rocker studs? Convert to a fully adjustable valve train? (poly locks) Different rocker arms? Different length push rods?

(Just trying to get a feel what your limits are in terms of how much "wake up" you could tolerate  )

Bear


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## OrbitOrange (Jul 5, 2010)

Bear, that would be a big NEGATIVE LOL ! I will save all that work for the 400 build thats on the stand. The 350 thats in the GTO is my "get me by" motor. So I'll probably stick it with a stock bumpstick and keep on cruising.


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## OrbitOrange (Jul 5, 2010)

Well the lifter is out.!!!


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## gjones (Oct 8, 2012)

*Double D*

You might say it's "a little bit cupped".


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## OrbitOrange (Jul 5, 2010)

you could eat soup out of the bottom of this lifter LOL. Got the cam out its gone too. Looks like Im getting a new one.


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## gjones (Oct 8, 2012)

*pep*

On the plus side, a new cam/lifters/timing chain & gears/roller rockers/etc, etc, etc... will definitely make her "perk up", I suspect! How far are you going to take it? Might have to invest in a couple of cases of ZDDP, I assume?


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## OrbitOrange (Jul 5, 2010)

Im not going all out on this 350. Its just my "get me by" motor for now. I have a 400 on the stand right now I am gonna build asap. But I dont want to just junk the 350 since its in the car and before this actually ran. 

The cam looks to have a small D or possibly an O stamped in the end of it. Trying to see what cam it had.


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## gjones (Oct 8, 2012)

*Doubletake*

^^^As was stated previously. (Slap to the forehead!). Good luck. Should be an easy fix!


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