1985 Zz4 with heads, lingenfelter 211/219 cam with 1.6 rockers a. Blew a head gasket on ZZ4. Had AFR 180 with 74cc and put new 195 with smaller 65cc chambers to raise compression and added long tube headers. Thing should be lightning fast but it's not. Going to check fuel pressure and maybe check for vacuum leaks tomorrow. Seems sluggish or almost a lean spot in the low end. Maybe just need to burn a new chip. Any additional ideas welcome

 

Are you 100% confident in lifter preload ?

 

I was until you brought it up. i will pull covers and go back through. I use the "when exhaust starts moving up adjust intake and when intake is almost all the way down adjust the exhaust" method. Then I went 1/2 turn

 

ORMARKER -

Did you replace the distributor gear?

Sure you have the plug wires on correct?

Did you checking timing?

It is the 74211 cam.

Back off the lock nut all the valves a couple of turns. Align timing mark to zero with compression in #1. The try this......from Forum member JoeC...

BTW, I tried something a little unconventional on adjusting hydraulic lifters. one thing that always bothered me is the statement "spin the pushrod until resistance is felt" that seems a little too subjective to me. So I tried this: I set "zero" lash with a .0015" feeler gauge while slowly turning the adjusting nut. When I felt the feeler gauge grab, I was fairly confident I was about .001 from zero lash. at that point, I turned the adjusting nut 3/4 turn. I recently read that one turn is equivalent to .040" because of the thread pitch on the threaded rocker arm stud, so 3/4 turn should give you about .030" adjustment. I also read that within a hydraulic lifter there is .060 total plunger Movement, and ideally you want to be just about in the middle of that range, or .030 inch. I don't know if I’m out in left field on what I did, but I feel I got a really consistent valve adjustment across the board. if you think you might have a tight cylinder, maybe give this a try - it seemed to work for me... Works better than twisting the rod.

Just follow the standard GM adjusting sequence... it will work fine with this cam. Intake #1, 2, 5 and 7 then adjust Exhaust 1, 3, 4 and 8.

Turn the engine 360 degrees and line up the timing marks again. Now adjust the following:
Intake 3, 4, 6 and 8 then adjust Exhaust 2, 5, 6 and 7.

CAMARKER

 

Are you sure your not running into a knock problem with that much more compression. I was told bumping the compression too much would cause a problem with the knock sensor. Replacing 74cc with 65cc would bump it about 1.5 to 2 points points, maybe around 10.5:1 stock is 9:1. Did you use a stock thick gasket or did you go thinner ?

 

Stop driving it at full throttle. You will blow it up. When I put my AFR 195 heads on my '85 my air/fuel ratio at wide open throttle was 16:1 before I tuned it.

Get yourself an AFR gauge and start doing some research on tuning. Full throttle tuning is one of the last things you want to tune.

Just make sure you have no misfires, no vacuum leaks, and no sensor problems before you start tuning. You don't want to tune over a broken component because you will have to tune it again when the component is fixed.

 

I think you are over stating the risk. The 211 cam is pretty mild. The AFR heads alone will not require a tune. They are CA smog legal. This engine should be OK. I would invest in a $60 data logging cable and download a free version of Tuner Pro RT and see what's going on. Look at the BLMs to see if a tune is required. The data log might even point to the real problem.

 

This isn't a high performing 2 stoke here.

I also agree that some data logging is a good idea.

 

TJ Wong's tune should be good for the head change. He can fine tune it once you have it up and running.

 

If you know someone with access to a smoke machine its a great way to test for vacuum leaks. Even the smallest one will rear its head quick.

Ive had a few on another car and it really made it sluggish

 

Update:
Been sitting since the first post to see where to start. Tried starting today and rocker arm noise all over the place. When I parked it not even a tick. Pull the covers and every god damn arm seems like it's out of adjustment. This isn't my first rodeo. With the locking nuts it's easy to set lash. Turned them till zero lash and then half a turn. I had soaked lifter in oil but all the lifters you could push the rocket arm and make the plunger go down- this is the way I set up before the lifters we're pumped full of oil. I am dumbfounded they could be this far out. No bent pushrods or anything so I hope this is it. Going to reset tomorrow. We will go right through Falkens Maze and start there.

 

Lifters bleed down, but should not bleed that much. Could they have been too tight? Very strange.

 

And really, the only lifters that should ever bleed down are the ones holding a valve open. Not all of them.

 

hopefully doing again will be the trick or I am stumped.

 

Nate.....do you want to pull the distributor and prime the oil system again before trying to set valves.....although I think that with the engine running even with the noise that they should pump up. Are you getting oil to the RR's? As soon as you start it, there should be some oil start to flow quickly.

CAMARKER

 

went through and meticulously set all the rocker arms again. Am concerned because the center locking screw is at a different HEIGHT above the head of the nut on a few cylinders-sticking out an extra 1/8" where the other are flush or slightly recessed into the nut.
Turned over and started up. still runs like crap. turned off and went around and 4 of the rocker arms had enough slop you could feel the lash by hand.
To reiterate, I went to zero lash and a half turn more.
My real concerns is WHY would the lash suddenly go from zero to slop and why would the adjusting nut set screw heights be different. By eyeing it, these rocker arms seem to sit DEEPER on the side where the pushrod contacts. Makes no sense to me whatsoever.

Going to try and do some research and see WTF is going on before I throw a match into the gas tank and walk away

 

Just a thought....the one(s) that have slop after zero lash. Back off the nut and turn the RR 90 degrees and use vice grips with perhaps tape or a rag so you don't screw up the rod. Clamp it on the top of the rod and see if you can keep pressure on the lifter ...want to know if the lifter bleeds down...can you push the rod down by hand so the lifter deflates? You should not be able to.

Wondering if there are bad lifters? Over the years had a bad lifter or two on the Blazer engine rebuilds. But they were standard hydraulic.

Another thought....are the ones that are sloppy the same holes that there prior lifters had messed up? I know that you sent pictures at one point....still have them?

CAMARKER

 

You are setting the lash on each one while at the lifter is on the low side on the cam ?

 

Exhaust starts up adjust the intake and when the intake is almost back down adjust the exhaust per comp cams settings.

 

http://www.centuryperformance.com/va...procedure.html

Intake Valve Adjustment: ENGINE OFF!

with #1 cylinder Intake Valve at full valve lift .... Adjust #6 Intake Valve
with #8 cylinder Intake Valve at full valve lift .... Adjust #5 Intake Valve
with #4 cylinder Intake Valve at full valve lift .... Adjust #7 Intake Valve
with #3 cylinder Intake Valve at full valve lift .... Adjust #2 Intake Valve
with #6 cylinder Intake Valve at full valve lift .... Adjust #1 Intake Valve
with #5 cylinder Intake Valve at full valve lift .... Adjust #8 Intake Valve
with #7 cylinder Intake Valve at full valve lift .... Adjust #4 Intake Valve
with #2 cylinder Intake Valve at full valve lift .... Adjust #3 Intake Valve


Exhaust Valve Adjustment: ENGINE OFF!

You will notice that this is the same procedure and sequence as the intake valves listed above. Only now you are adjusting ONLY the exhaust valves the same way.

with #1 cylinder Exhaust Valve at full valve lift .... Adjust #6 Exhaust Valve
with #8 cylinder Exhaust Valve at full valve lift .... Adjust #5 Exhaust Valve
with #4 cylinder Exhaust Valve at full valve lift .... Adjust #7 Exhaust Valve
with #3 cylinder Exhaust Valve at full valve lift .... Adjust #2 Exhaust Valve
with #6 cylinder Exhaust Valve at full valve lift .... Adjust #1 Exhaust Valve
with #5 cylinder Exhaust Valve at full valve lift .... Adjust #8 Exhaust Valve
with #7 cylinder Exhaust Valve at full valve lift .... Adjust #4 Exhaust Valve
with #2 cylinder Exhaust Valve at full valve lift .... Adjust #3 Exhaust Valve