OK, been a while since I updated. Yanked the monster apart this january. It was literally leaking from every gasket and seal possible.head gasket, rings, front/rear seals, valve covers, oil pan, timing cover,etc.... Here's the nasty old engine before I got it out:





So much crap in the intake it was ridiculous. Got the engine torn down and found 3 broken pistons, and all 8 intake valves had the keepers so loose it should have dropped a valve. So had the heads milled, new intake valves, cut the exhaust, 3 angle valve job, bored the block.030 over, decked, polished the crank, popped in a new Comp Cams cam with .500/.510 lift, new valve springs, min ram, 24lb injectors, etc. So today I put her together:





Also shot thebare heads, block and the valve covers with a couple coats of hi-temp clear while the block, oil pan and majority of the valve covers with hi-temp gloss black.

Still need to drop the headers off at Pro-Kote and tomorrow I'll drop in the lifters, bolt down the oil pan and install the pushrods and rocker arms and then yank the rack out and get it rebuilt this week.

 

Looks awesome. I'll bet she'll be a beast

 

Dropped the headers off to get coated. Yanked the rack out to get rebuilt this morning.... This is like the "never ending story!"

 

Just picked these up at Pro-Kote at lunch:




They are soooo shiny!

Last night I fought the rack back in as well.

 

 

PLans are to stab the engine/trans back in on Sunday. With any luck I can hear it run again in another week.

 

OK, 2 months later and I'm still fighting this damn thing.


car starts,runs and drives great..... on 5 cylinders. I've changed injectors from good cylinders, injector connectors, plugs, wires no change on any of it. There is fuel on the plugs, and spark at the end of the wires. I've changed to good plugs multiple times. No change.

Fuel pressure was low (38psi KOEO, 35psi engine running with the AFPRcranked to the max) so I installed a new Walbro 255 in tank pump. Pressure is where it should be factory and I can still turn it up if need be. There is fuel to the dead cylinders, you can smell it on the plugs. Like I said before, I swapped injectors (new Accel 24lb) from good cylinders and no change. Tried changing the injector plugs no change. The good cylinder still fires, the bad cylinder does not.

Ran a compression test. Worst cylinder was 150psi dry, best was 158psi dry. Best was one of the dead cylinders, worst was one of the good ones. Ran a coolant system pressure test. Had a slow leak down(10 minutes to lose 5psi) that I later tracked down to a loose hose clamp off the t-stat housing.

So what the hell am I missing? I've got fuel, spark and compression but I am still running dead on 3 cylinders. What did I do wrong? Thoughts? Suggestions? I'm at a loss here.... completely lost.

 

How do you know they are dead cylinders? Just to clarify, since you said it runs great...though probably sarcastically?

 

runs rough, engine shakes, exhaust has a flat note, IR probe shows that 4-5-6 are running ~90-100* while 1-2-3-7-8 are running 190-200* on the header. I can pull the injector plugs on 4-5-6 and there is no change to the idle. Pull an injector plug on 1-2-3-7-8 and the idle changes and it gets rougher. I can pull the plug wire off of 4-5-6 and no change, again 1-2-3-7-8 gets worse. 4-5-6 are still wet with fuel while the other 5 are not.

And yes, it is definitely down on power.

 

Valvetrain good? (pushrods, rockers, springs)
Full roller or stock stuff?
If flat tappet, did you break it in correctly? (Wiped lobes?)
I'd hand crank it and make sure you are getting good valve movement on those cylinders.

If fuel truly good and spark is good, you just need air. If the compression is good, the valves are closed...are they opening?

 

Recheck your distributor. It might be 180 degrees out. Car will run but rough with that problem. I helped a guy rebuild a 350 in high school and he had the same problem after the build. My buddy tore his hair out for weeks with it. Shop teacher figured it out in 5 minutes.

 

OK, two weeks later, still fighting it. 4-5-6 are still no go. What I've done:

Swapped injectors.
Swapped injector wiring (no change, dead cylinders still dead, good cylinders still good)
changed wires (new Accel custom fit wiring run to not touch anything)
checked, rechecked and checked again firiing order
readjusted the rockers
checked for bent pushrods.( none bent}
Measured valve openings (all matched)
Changed plugs
checked plugs
changed the timing
turned the dist 180*
put in new 255lph fuel pump
checked compression
checked fuel pressure

I'm pretty much out of options/ideas. I'm down to wondering if the cam is not installed correctly or.......

 

I think I would pull the cam to check the lobes for damage and then reinstall. Outside of that you've done just about everything.

 

I've never heard of a roller cam weariung the lobes off. On top of that after measuring the rocker movement they all measured roughly the same.

 

It sounds like you have a massive vacuum leak. How many inches of vacuum at idle, and is the needle steady?

 

That I have not tested. I will try and check that tonight or tomorrow.

 

The cam is not a 4-7 swap is it?

 

Nope. Many reasons why that theory won't fly, but the main is #7 still fires. 4-7 swap literally swaps those two cylinders only. Since 7 fires and 5-6 are dead as well as 4 it's not it. That and I grabbed the cam card and double checked.

 

You didn't leave rags stuffed in the intake ports did you? (reaching for an answer now...)

If you have fuel at all cylinders, have spark at all cylinders, it has to be air right?

Keep at it, that is frustrating for sure.

EDIT: You said you turned the distributor 180* did it run a lot worse? Physically turning the cap doesn't mean much, if you drop it in with the same alignment you can still be 180* off. The key is putting it so the rotor is right before/at the #1 plug terminal at the top of the compression stroke, not the exhaust stroke. Your balancer will read TDC for both but if it is on the exhaust stroke it is 180* off, you want spark on compression.

 

Yeah, I turned the engine to TDC, pulled the distributor and set the cap and rotor to #1. Tried to fire, no go. Engine didn't start but did backfire throught the intake. SoI turned it back to TDC, and then turned the dist 180 again and it fired up instantly.