You know your getting old when.........
Thread Starter
Advanced
Joined: Oct 2002
Posts: 59
Likes: 0
From: Houston TX
You know your getting old when.........
You know you are getting old when you take a perfectly running 1985 Vette and screw it up trying to get more HP out of her.
Any help here is appreciated. First Vette, last mistake on it.
1985, 5.7L TBI non-roller engine.
Already had for sometime, TBI Bypass, K&Nm Throttle Body Foil, Aftermarket Exhaust
This past weekend I added made the following changes:
Set of Rhoads Lifters
1.6:1 Roller Tip Rockers
Comp Cams new Conical Springs.
I was hoping to get more seat of the pants torque and maybe a smoother high end.
What I now have is no pedal at all. Almost like hitting a reve limiter or fuel delivery problem. At first is was minor and I did not want to get on it. Now
I am geting vibration and having a hard time getting over 3,000 rpm.
Ligth pressure on the pedal and I drive her all the way to work, any pressure and it bogs down and goes nowhere.
Maybe this was a bad mix? Maybe the conputer does not know what to do with the changes?
I am looking for advice before I strip it all down and throw away brand new parts and go back to stock!
Thanks
Frustrated in Houston!
:banghead:
Any help here is appreciated. First Vette, last mistake on it.
1985, 5.7L TBI non-roller engine.
Already had for sometime, TBI Bypass, K&Nm Throttle Body Foil, Aftermarket Exhaust
This past weekend I added made the following changes:
Set of Rhoads Lifters
1.6:1 Roller Tip Rockers
Comp Cams new Conical Springs.
I was hoping to get more seat of the pants torque and maybe a smoother high end.
What I now have is no pedal at all. Almost like hitting a reve limiter or fuel delivery problem. At first is was minor and I did not want to get on it. Now
I am geting vibration and having a hard time getting over 3,000 rpm.
Ligth pressure on the pedal and I drive her all the way to work, any pressure and it bogs down and goes nowhere.
Maybe this was a bad mix? Maybe the conputer does not know what to do with the changes?
I am looking for advice before I strip it all down and throw away brand new parts and go back to stock!
Thanks
Frustrated in Houston!
:banghead:
Drifting
Joined: Dec 2002
Posts: 1,861
Likes: 4
From: Houston TX
Re: You know your getting old when......... (HoustonBob)
1) How did you set the valve lash when you reinstalled everything?
2) did you check all of the clearances when you installed the new springs and rockers?
2) did you check all of the clearances when you installed the new springs and rockers?
Thread Starter
Advanced
Joined: Oct 2002
Posts: 59
Likes: 0
From: Houston TX
Re: You know your getting old when......... (HoustonBob)
I set the valve lash from zero to one full turn down.
Set the timing at TDC, started at no 1. moved the push rod up and down until it stopped then watched the for the plunger to start to move. From there went one full turn. Rotated the engine 90 deg and went to no 8 and so on.
Clearances? Now you have me worried. No I did not check much on the spring and rocker side. It went together pretty easy. There did not seem to be anything to check?????????
Obviously I missed something here????????????
:confused:
Set the timing at TDC, started at no 1. moved the push rod up and down until it stopped then watched the for the plunger to start to move. From there went one full turn. Rotated the engine 90 deg and went to no 8 and so on.
Clearances? Now you have me worried. No I did not check much on the spring and rocker side. It went together pretty easy. There did not seem to be anything to check?????????
Obviously I missed something here????????????
:confused:
Drifting
Joined: Dec 2002
Posts: 1,861
Likes: 4
From: Houston TX
Re: You know your getting old when......... (HoustonBob)
I set the valve lash from zero to one full turn down.
Set the timing at TDC, started at no 1. moved the push rod up and down until it stopped then watched the for the plunger to start to move. From there went one full turn. Rotated the engine 90 deg and went to no 8 and so on.
Clearances? Now you have me worried. No I did not check much on the spring and rocker side. It went together pretty easy. There did not seem to be anything to check?????????
Obviously I missed something here????????????
:confused:
Set the timing at TDC, started at no 1. moved the push rod up and down until it stopped then watched the for the plunger to start to move. From there went one full turn. Rotated the engine 90 deg and went to no 8 and so on.
Clearances? Now you have me worried. No I did not check much on the spring and rocker side. It went together pretty easy. There did not seem to be anything to check?????????
Obviously I missed something here????????????
:confused:
On the clearances, you need to make sure that the max lift the spring is capable of is more than the net valve lift with the 1.6 rockers. If it's not, the spring coils will bind, the valve will not open all the way, and the springs will break eventually (usually doesn't take too long). Also, if you have non-stock valve seals, this can also affect the max valve lift you can run with a given valve/spring/retainer combo. In my instance, I have Teflon valve seals which limit my max valve lift to ~0.490" intake and 0.525" exhaust before the retainer hits the top of the seal.
Instructor
Joined: Jan 2002
Posts: 221
Likes: 0
From: League city Texas
Re: You know your getting old when......... (HoustonBob)
It sounds like the valve lash is off. After that if you did not check the spring clearance you need to because the 1.6 rr increase your valve lift you could be fully compressing the spring. You mention new lifters but not a new cam this is usually a disaster waiting to happen. When the cam and lifters are new the cam is slightly harder then the lifters and each wears accordingly with both parts maintaining their relative hardness but as these parts wear they each loose some of their hardness. If you put new lifters on an old cam the lifters will be harder then the cam and gradually cut the lobes on the cam, leaving you with what is known as a flat cam. I live in Friendswood and could probably lend a hand if you need it. My email is tupp@swbell.net
Racer
Joined: Dec 2002
Posts: 285
Likes: 5
From: Grass Valley, Ca.
Re: You know your getting old when......... (HoustonBob)
I'll take a wild guess at this since I had run the Rhoads lifters in my 383 for my old 80 pickup. No matter how you adjust them, they always clatter. Rhoads calls it a mild solid lifter sound. This clatter may very well be enough to trigger your knock sensor. See it thinks it is hearing spark knock/detonation, so the computer is pulling out timing from the engine so as to not let it detonate. You can check this by unplugging your knock sensor on the passenger side of the block. It is screwed into the block drain on that side. Just disconnect the wire connector, or if you want, put a timing light on the car and watch to see if it retards as the clacking gets louder. Ideal way to check would be a scan tool that will tell you knock counts detected. If you unplug the sensor and the car runs ok, you've found the problem.
Melting Slicks
Joined: Oct 2002
Posts: 3,193
Likes: 1
From: Cincinnati Oh
Re: You know your getting old when......... (HoustonBob)
and just my take on what Z51 said: I'm more of a fan of the "jiggle up and down" method of adjusting lash- meaning I take zero lash as when I can no longer jiggle the pushrod vertically. I do it that way because I always had such a tough time finding out what the correct "resistance" was! :)
But I have fat fingers, so maybe that has something to do with it?
let us know how it turns out!
:cheers:
But I have fat fingers, so maybe that has something to do with it?
let us know how it turns out!
:cheers:
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Thread Starter
Advanced
Joined: Oct 2002
Posts: 59
Likes: 0
From: Houston TX
Re: You know your getting old when......... (HoustonBob)
The knock sensor may be it!
I was wondering what was going on with my timing. I had a light on it and the mark just kept disappearing. I must have set that thing 10 times!
My son was in the car, holding in drive, est disconnected and each time I could not get it to stay put. It would be okay, shut it down, plug in the EST and then go for a ride, and each time I was either too retarded, (excuse the pun), or too advanced.
I am off to unplug the knock sensor. I will let you all know how it tuns out.
I would agree on one thing, The Rhoads lifters clatter a bit more than I ever thought they would.
I am also going to pull the valve covers again today, and re-set my lash. I was trying to guess if I was too light or loose the old way, "clacking". I may be too tight now.
Thanks again all.
Be back soon.
(L98-Valve Cover Removal is a pain!)
I was wondering what was going on with my timing. I had a light on it and the mark just kept disappearing. I must have set that thing 10 times!
My son was in the car, holding in drive, est disconnected and each time I could not get it to stay put. It would be okay, shut it down, plug in the EST and then go for a ride, and each time I was either too retarded, (excuse the pun), or too advanced.
I am off to unplug the knock sensor. I will let you all know how it tuns out.
I would agree on one thing, The Rhoads lifters clatter a bit more than I ever thought they would.
I am also going to pull the valve covers again today, and re-set my lash. I was trying to guess if I was too light or loose the old way, "clacking". I may be too tight now.
Thanks again all.
Be back soon.
(L98-Valve Cover Removal is a pain!)
Racer
Joined: Dec 2002
Posts: 285
Likes: 5
From: Grass Valley, Ca.
Re: You know your getting old when......... (HoustonBob)
On the Rhoads lifters, adjust them as someone had described above. "Roll" the pushrod with only one finger and slowly take up the lash. Once it stops be able to roll or spin, tighten it your 1/2 to 1 turn down. Using just one finger makes sure you dont start to depress the plunger. Once their is pressure against the lifter the pushrod will stop turning. Do not try to do the lash running as these lifters never quiet down, so you cant tell when you have the correct preload. Like I said I had these lifters in my old truck, and while they work as advertised, they're kind of annoying. My bet is on the knock sensor :banghead:
Safety Car
Joined: Dec 2000
Posts: 3,767
Likes: 5
From: Jacksonville Fl
Re: You know your getting old when......... (trupp)
It sounds like the valve lash is off. After that if you did not check the spring clearance you need to because the 1.6 rr increase your valve lift you could be fully compressing the spring. You mention new lifters but not a new cam this is usually a disaster waiting to happen.
BUT: You are describing a classic symptom of a melted catalytic converter, no power, heavy throttle makes the car stall, won't reach 3000 rpm's...etc...etc
[Modified by BBA, 9:43 PM 3/2/2003]
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: You know your getting old when......... (HoustonBob)
I agree on the clogged cat as a possible cause of trouble.
Also you will likely need an AFPR to add more fuel with the increase in air flow at WOT.
With stock lifters I spin the pushrod and tighten till I just feel drag, then tighten 1/2 turn plus 1/8. But follow directions for your lifters if not stock. The idea is to preload the plunger to about 1/2 of it's range of travel.
The safest though most tedious method is to rotate the crank till the exhaust valve is just opening and adjust the intake; rotate till the intake valve is closing and adjust the exhaust valve.
Also you will likely need an AFPR to add more fuel with the increase in air flow at WOT.
With stock lifters I spin the pushrod and tighten till I just feel drag, then tighten 1/2 turn plus 1/8. But follow directions for your lifters if not stock. The idea is to preload the plunger to about 1/2 of it's range of travel.
The safest though most tedious method is to rotate the crank till the exhaust valve is just opening and adjust the intake; rotate till the intake valve is closing and adjust the exhaust valve.
Le Mans Master
Joined: Jun 1999
Posts: 6,272
Likes: 2
From: Chino Valley AZ
Cruise-In I Veteran
Cruise-In II Veteran
Currently Corvette-less
Re: You know your getting old when......... (65Z01)
There are two ways to adjust hydraulic lifters Dynamic and Static. I agree with the methods that others have described for the Static adjustment..... but I never use it. I prefer the Dynamic adjustment, although it is a bit more messy.
To do so, only remove one valve cover at a time. If you have installed roller rockers, you don't need to worry about the rockers squirrting oil, but line the exhaust header with rags to keep any oil from spilling over the edge.
Star the car and let it settle to a smooth idle. Starting at the front or rear, back off the rocker arm nut until it starts a solid click, then take it down until the click is gone (this is zero lash), the turn the rocker adjustment nut 1/2 turn and lock the nut. Each time you do this the engine will stumble while the lifter adjusts, then it will settle to a smooth ide. Just move down the valve train to the end.
When done with one side, install the valve cover and gasket, then remove the other side valve cover and do the same thing. If you prefer, you can turn the valve adjustment 3/4 turn or 1 turn. I have always gone with 1/2 turn and been happy with the results.
This takes all the guesswork out of the valve adjustment.
~ Purp :thumbs:
To do so, only remove one valve cover at a time. If you have installed roller rockers, you don't need to worry about the rockers squirrting oil, but line the exhaust header with rags to keep any oil from spilling over the edge.
Star the car and let it settle to a smooth idle. Starting at the front or rear, back off the rocker arm nut until it starts a solid click, then take it down until the click is gone (this is zero lash), the turn the rocker adjustment nut 1/2 turn and lock the nut. Each time you do this the engine will stumble while the lifter adjusts, then it will settle to a smooth ide. Just move down the valve train to the end.
When done with one side, install the valve cover and gasket, then remove the other side valve cover and do the same thing. If you prefer, you can turn the valve adjustment 3/4 turn or 1 turn. I have always gone with 1/2 turn and been happy with the results.
This takes all the guesswork out of the valve adjustment.
~ Purp :thumbs:
Thread Starter
Advanced
Joined: Oct 2002
Posts: 59
Likes: 0
From: Houston TX
Re: You know your getting old when......... (HoustonBob)
Again thanks to everyone with the help on this one.
Rhoads lifters are not the way to go! As you said, very annoying, and impossible to set the lash with dynamically.
Removing the knock sensor helped a great deal. I took it around the block, shift points appeared to return to normal, and timing is now stable. So at least I feel like I am heading back the right direction.
I did not imagine spring height would be an issue. The ovate springs from Comp Cams handle up to .500 of lobe lift. I will check all this again Sat.
The whole reason I started this endeavour was the sudden sound of a failed lifter. After a local car meet, I developed a loud rocker on Exhaust #5. I figured if I am changing one, might as well change them all. A good friend recommended the Rhodes.
They are coming out! Anyone want a set of very low use Rhodes lifters :mad
Rhoads lifters are not the way to go! As you said, very annoying, and impossible to set the lash with dynamically.
Removing the knock sensor helped a great deal. I took it around the block, shift points appeared to return to normal, and timing is now stable. So at least I feel like I am heading back the right direction.
I did not imagine spring height would be an issue. The ovate springs from Comp Cams handle up to .500 of lobe lift. I will check all this again Sat.
The whole reason I started this endeavour was the sudden sound of a failed lifter. After a local car meet, I developed a loud rocker on Exhaust #5. I figured if I am changing one, might as well change them all. A good friend recommended the Rhodes.
They are coming out! Anyone want a set of very low use Rhodes lifters :mad
Drifting
Joined: Feb 2003
Posts: 1,976
Likes: 2
From: San Antonio Texas
Re: You know your getting old when......... (HoustonBob)
I think that TPIS has a knock sensor that is not so sensitive, but your best bet might be to just pull the lifters. Rhodes lifters are '70 tech. Crane has some "bleed downs" that are supposed to be quiet,but I have never used them myself so?????
Sorry to hear you have to go back in, that's a big PITA. :banghead:
Sorry to hear you have to go back in, that's a big PITA. :banghead:
Drifting
Joined: Dec 2002
Posts: 1,861
Likes: 4
From: Houston TX
Re: You know your getting old when......... (HoustonBob)
I did not imagine spring height would be an issue. The ovate springs from Comp Cams handle up to .500 of lobe lift. I will check all this again Sat.
Thread Starter
Advanced
Joined: Oct 2002
Posts: 59
Likes: 0
From: Houston TX
Re: You know your getting old when......... (HoustonBob)
Update on this PITA, (stole that one from one of your replies :-)
I am pulling the lifters today. I was so eager to get this together the last time, I did not check installed spring height.
I am off, but to the high side, the stock springs are installed at 1.718 ex, 1.593 in.
All the new Comp Cam springs are installed at the same height, just shy of
of 1.875. This in part is due to the removal of the rotators and oil shields.
I have used the umbrella seals that came in the comp cams kit. Is it possible I have too little seat pressure? I have the numbers on the comp cams springs, but cannot find any on the stock configuration in my books.
Anyone know what the pounds pressure is on a stock 85 C4?
Hopefully I get this resolved once and for all. About that time I will need a new cam from breaking in new lifters! :confused:
I am pulling the lifters today. I was so eager to get this together the last time, I did not check installed spring height.
I am off, but to the high side, the stock springs are installed at 1.718 ex, 1.593 in.
All the new Comp Cam springs are installed at the same height, just shy of
of 1.875. This in part is due to the removal of the rotators and oil shields.
I have used the umbrella seals that came in the comp cams kit. Is it possible I have too little seat pressure? I have the numbers on the comp cams springs, but cannot find any on the stock configuration in my books.
Anyone know what the pounds pressure is on a stock 85 C4?
Hopefully I get this resolved once and for all. About that time I will need a new cam from breaking in new lifters! :confused:
Le Mans Master
Joined: Nov 2002
Posts: 7,080
Likes: 0
From: Corvette valley Georgia
St. Jude Donor '06
Re: You know your getting old when......... (Widebody)
I'll take a wild guess at this since I had run the Rhoads lifters in my 383 for my old 80 pickup. No matter how you adjust them, they always clatter. Rhoads calls it a mild solid lifter sound. This clatter may very well be enough to trigger your knock sensor. See it thinks it is hearing spark knock/detonation, so the computer is pulling out timing from the engine so as to not let it detonate. You can check this by unplugging your knock sensor on the passenger side of the block. It is screwed into the block drain on that side. Just disconnect the wire connector, or if you want, put a timing light on the car and watch to see if it retards as the clacking gets louder. Ideal way to check would be a scan tool that will tell you knock counts detected. If you unplug the sensor and the car runs ok, you've found the problem.
:iagree:
Burning Brakes
Joined: Feb 2000
Posts: 958
Likes: 1
From: SF Bay area, CA USA
Re: You know your getting old when......... (HoustonBob)
Did you put new lifters in with an old cam? That can and usually does cause the cam to go flat. Lifters and cams should break in together. When you put new ones in with an old cam you could have problems.
I also prefer to adjust the valves with the engine running. It is messy but I think it gives you the best chance at finding zero lash.
I also prefer to adjust the valves with the engine running. It is messy but I think it gives you the best chance at finding zero lash.