What valve springs are you using? Is there any possibility your studs are pulling out of your heads? You shouldn't be able to collapse your hydraulic lifters by hand. Your spring pressures are way higher, and even open valves shouldn't collapse your lifters! I can't imagine that your springs coils are binding up with your mild cam, but have you verified you don't have coil bind?

 

Okay it only happened to me ONCE, but even after rechecking my plug wires, two were on wrong; once that was straightened out the engine ran MUCH better

Could the distributor be off enough that the computer can't get it within range?...I mean it sounds like your timing may be close, but not spot on

maybe time for a compression check?

 

Methodically went through and adjusted the rockers arms. Noticed on 2 that the set screw was at least an 1/8” higher from the top of the poly lock nut than the others. Cranked motor over with the remote switch and checked again. Was able to retighten one-the pushrod seat seemed to be stuck on the lifter and not coming back up. Went around and checked it all out again. Seemed ok but still a couple the adjustment seemed way out of line from the rest. Pulled the rocker arm and pushrod and look down at the top of the lifter and the frickin pushrod seat is turned!! Retaining ring is still in place but the cup has literally turned almost 90°. This had actually happened at 2 locations just after I blew the head gasket and figured it could have done something to the lifter when that had happened. I am pulling the whole super ram off to get in and replace but need to know what I am missing. I have messed with at least 10 motors in my lifetime and NEVER had or seen this happen. I don’t want to replace the lifter and have it do it again. HELP

 

Wow ive never seen that happen before. Somehow they got hammered sideways. U gonna need new lifters but take a look at those cam lobes for damage also.
Bud your lifter adj procedure is not correct and from the looks of it damaging. Yes it will be hard to realize u havent done it correctly all these years but u need to keep from going into denial, move on and learn the correct way. U need to study it until u understand the hyd lifter. There are plenty of online diagrams and procedures with great pictures to help you.

First U need to find the base circle of cam. Several ways to do this but u have to be certain of where the lifter is before u adjust it. Dont assume its location - study this until your certain.

Next look at the hyd lifter diagrams and u will see the only drain hole is the feed oil on the side where the oil galley supplies the oil - the installed lifter cannot bleed below this leve unless as Tom said the lifter is pressed down by a open vlv. If the engine has been run then most likey the lifters are full of oil under the internal piston. BTW a lifter bleeds down in milliseconds as it lower down the cam ram to close the vlv so dont expect there is any need to wait until the lifter "bleeds down" to adj them.
Another note is the full lifter preload adj before the internal piston bottoms out is only like <0.030". So if over adj the lifter will hold the vlv open.

Once lifter is on the "base circle" then u need to nail "zero lash". Dont use noise like some old shade tree mechs will say - way too error likely. Use your fingers to roll and feel the p-rod as u tighten the rocker nut. Once the p-rod no longer can move up or down but still roll side to side w/your finger then u are at "zero lash" and can make your preload adj. U need to use the lifter mfr specs for this as the old OEM lifters use 1 full turn (as i recommend) but some new lifters like the LS6 (or maybe the LS7) take like only <1/4 turn - find out what u are using.

Since u are using roller rockers with poly locks u will find they are problematic also. The poly locks are prone to loose if the allen screw and poly nut are not locked up correctly. So u may have everything adj correctly but the poly-locks dont want to do there job unlees u have locked them up correctly. It takes a final snug in the tight direction to do this but look this up untill you are convinced yourself - plenty on line on this if u look. Also some poly locks have a ratcheting feature on the allen screw when it finally locks - look this up for what u have.

Finally any major mod (like the cam w/low restriction exh) really requires a tune. And since u replaced the injectors your a/f maybe all over the place. Each type injector not only has its own operating pressure but its own specs that have to but entered into the ECM. U can change the injectors press but u need to change the ECM injector specs.
U can find mail order tunes or tune it yourself but i recommend a dyno tune. Best tool for this is a quality wide band O2 (HEGO) and u need to install it ahead of the cat(s). The stock narrow band O2 is only good for stoichiometric (14.7) and only used in closed loop but u have to keep it to talk to your ECM as the ECM cannot talk to a wideband (or rather the WB cant talk to the ECM). Sticking the wideband O2 in after the cat in the exh pipe is no longer accurate.

Thats plenty for now, good luck.

 

Hot Rod Roy, these are new AFR 195 heads and I believe these heads are capable of a .600 lift or more. The 74211 cam has a max lift for the exhaust is .534. So I don't think it is a valve spring bind issue. The studs are screw in not pressed.

cardo0, he has not replaced the injectors. They were replaced 2-3 years ago with the same 24 pound injectors that I had in it, I even stayed with the same brand. He replaced the AFR 180 heads with the newer AFR 195's. He went with the small chambers which should have bumped up the compression. The tune is a custom dyno tune for the car by TJ Wong in Vancouver WA.....about 30 miles from Portland. I used to drive the car 800 plus miles up there for the tune. The cam has been in the car for several years, the Lingenfelter 74211 and was in the car when it was tuned. TJ Wong also has the sniffer in the tail pipe when it is on the dyno and dials in the A/F. There is no better tuner in the PNW. It is not a tune issue.

I have questioned him about the poly locks. He did replace the RR's, but they are the same ratio. The RR's I had on there with the AFR 180's had a standard locking nut with the Allan lock. Never had a issue with them. So the poly locks may be contributing to the problem. I was wondering if they were backing off or if the threads in the lock may have been stripped. You may have pointed out an area of concern.

We have discussed this issue with a couple of good Corvette people and the census seems to be a pre-loading issue in their opinion for the lifter issue. The lifters are AC Delco LS7 roller lifters.

 

Well thx for the update John. I always seem to regret giving advice to a fairly new member/owner as they dont profile much/enough and have the most difficult problems. Kinda like in denial from the start. Well at least im onboard with the poly locks and or lifter adjustments.

I apologize for stepping on the "good Covette people" club. Hope they can tolerate a little C3 trash advice.

 

cardo0, not a problem at all. You had pointed to several areas of concern. You are doing the best with the limited amount of information given. I was just trying to fill in the gaps of information. I do the same myself....give advice to solve problems. Sometimes I am spot on and others off a little. But we work with what we are given. I appreciate your response and insight. Don't stop stepping up to give your insight on problems. We still need members that can contribute their experience and help educate those new to the Corvette world.

He is a fairly new member which is true. But the car was mine before he got it. I bought the ZZ4 as a short block and pulled it down to the bare block. Had the rotating assembly balanced and put it back together from the bare block up. The AFR 180 heads were low compression heads but everything in and on this engine complemented the combination and this car moved. I knew every nut and bolt on this engine. He is not new to cars and engines but he has usually worked on carbed engines.

By the way the 85 has the cat half way down the exhaust system in about the middle of the car.

We just learned today from the tuner up in Vancouver that said he thought it was a pre-load issue. On my end I got basically same information (pre-load) from a good friend at a Chevy dealership here in the Bay Area. He had been chasing this problem for awhile now. Not much feedback from the Forum.

 

up and running. runs decent. pretty sure it will need a tune. seems to hit a lean spot just past idle. Parked until i can get it to Wong's
headers run super hot under the hood. doesnt help it was 98° on its maiden voyage. Have to check some things. I will post video when i can.

 

Thx for the update but what was the fix? New lifters?

 

here is what I did:
Ripped manifold back off-not easy on super-ram-broke an ear on the runner(glued it a little too well) Luckily I can TIG weld
Oil seemed "gritty" in the lifter valley.
Pulled apart some lifters and seemed like they were STUCK down on the hydraulic plunger.
ordered a new set from summit.
Poured a gallon of lacquer thinner all over the valley and le it drain out the pan.
Added about half a gallon to pan with plug in and spun JUST the filter with prime tool to get anything out of the mains until it hit the lifter openings.
Completely drained all this.
Soaked new lifters in lacquer thinner for a few days, let them drain and then installed them.
Followed STOCK chevy valve timing procedure for lash
Filled with new clean standard oil and new oil filter and set my drill up with a catch on the handle and started and sat down and had a beer and let that bitch prime itself for about ten minutes. every couple minutes I went and bumped the motor around a couple times
Nothing but clean oil coming all the way up and out the rocker arms-something it wasn't doing when I stopped and parked it.
Put everything back on the top, primed it again, dropped the dist. in and fired it off. Not sure how I got so much "stuff" in the oil. Engine was sitting open for several months but I had covered it with plastic bag while I wasn't working on it.

Best I can figure is something was in the oil and caused the hydraulics of the lifter to bind open and randomly not bind throwing off everything.

 

Hope it works out for u. Good luck and give us updates if u can.

 

Headers make the underwood hot as hell. So far I have had to boost fuel pressure to 45# from 32#. Will tell you how that works on my 30 min drive into work tomorrow. It's been in the 90's and felt so freakin hot on the car. Started cooking the grip off the fram oil filter. Thought the damn car was on fire. That was before I boosted the FP

 

Yea now u see every hi-po V8 from detroit (or where ever they make them now) with functional hood vents. Not just for looks hood ornaments but actual air flowing vents. Something i have wanted to do for a lot longer than before the big 3 started putting them on production cars. Or well now it will look kinda copy cat to put them on my cars. But they do let the hot air out as its much harder to flow down and under the car.

I would rather increase fuel press than install new larger injectors. But u need to change the tune (i think u know this) as u just made the fuel maps a lot richer.

 

Car already has aftermarket injectors-3 nozzle style. I forget what # they are.

Drove to work this morning and thing is a rocket. No off idle stumble. 60-100 pretty fast- I was passing a prius. I am sure a new tune will even it all out. Still running the "smog" tune chip from my last set-up. I am hoping the race version is even better.

 

The plugs must have indicated you were running a little lean.....hence the increase in FP to 45?

The injectors are 24# Accel. The chip should compensate for much of what you did. The difficult part would be when you welded in the bung for the O2 sensor might have changed the O2 readings because of the headers. Probably time to put the "socks" on the other plug wires.

You always were a LEAD FOOT!

And for those un-informed.....had the car tuned originally with two chips that easily change in the computer. One for daily driving using regular 87 gas and the other chip...a ***** out WOT 1/4 race version using premium fuel.

 

Could be a problem....