TKR 88 GTA

ok well i did an AFR 195 cc head swap, HSR swap, and a XFI 268 cam swap... it doesnt look like im gettin compression. we took out a spark plug n checked the whole while we cranked the engine n there was no air coming out tryin to force the finger away n out of the hole. and on top of that when we took the plug out it didnt smell like fuel so im not sure if the pluh is even gettin fuel or not? its gettin spark for sure tho....


anybody have any idea wat would be causing this kind of problem? any info would be great

toomany

Did you adjust the valves correctly? Check the gemometry? Having a valve stay open will give no compression across all cylinders.

Do you hear the pump priming when you turn the key on? Might want to find some noid lights to see if the injectors are opening.

rgarcia63

I would like to make an anology here, A valve staying open is equivalent to not having a spark plug in the cylinder so even if no valve was staying open a missing spark plug will not affect the compression of other cylinders. One valve staying open will not affect the compression of other cylinders unless it's causing all the valves not to close properly on the compression stroke.

TKR 88 GTA

ok well we tore it apart again n checked everything well it ended up being that the cam and crank timing gears werent were they were suppose to be both the dots were pointing up.

the valves im not sure how those were cuz my grandpa knows that not me so im not sure how it was done i should ask..

and the push rods werent long enough for the cam i guess.. so it was hitting something and it bent the push rods so i got to order the news ones that r .100 longer.

should this fix the problem or no??

JakeJr

"and the push rods weren't long enough for the cam i guess.. so it was hitting something and it bent the push rods so i got to order the news ones that r .100 longer. should this fix the problem or no??"

You're right, you're guessing on the pushrod length. If length is a concern, you need to use an adjustable pushrod length checking tool to determine the correct length you need.

When adjusting lifter preload (sometimes referred to as adjusting the valves) the most important part is to make sure the lifter is riding on the base circle of the cam lobe when ZERO LASH is found.

When addressing bent pushrods, you need to CAREFULLY check for interference. There are a number of different places where this can occur; pushrod to head, underside of rocker arm to retainer, retainer to valve guide, coil bind and some others I can't think of off the top of my head.

"Both dots pointing up" requires a more detailed explanation since there are two different directions the dots can point - both at 12 o'clock position or cranks gear dot at 12 o'clock and cam gear dot at 6 o'clock. Both are correct. The first is when the #1 piston is on the compression stroke and the second is when there #6 is on the compression stroke. Many get confused on this.

Jake

SeanW

As long as your cam timing wasn't so far out that the valves were smacking the pistons your should be good to go.
What was your pushrod hitting? Be sure to get the .080 wall pushrods.

TKR 88 GTA

well ya they were both pointing at the 12 o clock direction now the cam gear is at 6 o clock. but i think i may have figured out another problem my cuzin tightened the rocker arms to tight i guess n also the rocker arms dug into the bolt that holds down the guide plate if. i was told that im only suppose to put them finger tight and then 1/4 more after that???

im lost on this for the ppl that have done this swap before have u guys ran into this problem that i have. but man im lost n i hate seeing my car not running like this. so all the help the better thanx.

TKR 88 GTA

and well im not sure if its hitting the piston or not i dont think it i. and so now im guessing the pushrods wasnt the problem..

JakeJr

I can probably figure this out but I need to know what you did and how you did it. The part about "finger tight" and "1/4 turn more" leaves out a lot of valuable information. Without it I can't figure out what you did. No way for me to know.

How about posting the step by step procedure you used?

Jake

TKR 88 GTA

first i started taking the intake manifold off. while i was doing that my grandpa starting taking the front of the car apart to get to the cam bolts. then once i got the manifold off i moved to the heads by this time my grandpa had the radiator, air conditioner condenser off and all the puller from the front off. he also had the balancer off the block. next the heads came off. we took the lifter guide plates and the plate that holds the guides in place out. then once that happened we moved to take the cam out. we took it out and put the new cam in with the assembly lube. after the cam was put in we put the heads on and torqued them down to the specs that came with the heads. we put the intake manifold on next and assembled the manifold fuel rails and attached them to everything that needed to such as fuel lines and sensors and vacuum lines. next we put the timing chain on with both dots pointing to 12 o clock(its not like that anymore the cam gear is now at 6 oclock) then we put the front end back to gether with balancer all the pulleys and put the air conditioner in and the radiator in. connected all the lines to them. next we put the pushrods in the heads (standard length) and the 1.6 rocker arms. we tightened them down to snug. the springs went down a lil bit. then connected all the wires to the distributor and the ground to the blocks and the alternator and everything to get the spark to the engine. connected the headers and the starter. after that i went to try and start the motor and it would turn but it sounded weak. we checked for compression by taking the plug out and seeing if there was air trying to force our fingers out of the hole. there wasnt. this is when we took the timing cover off to the check the timing and this is when we changed the gear to point at the six o clock position. we then tried to crank it again n when we did we heard a clunk sound and thats when we noticed the pushrods were bent so we took all the rocker arms off and noticed the rocker arms were digging into the guide plate studs the push rods were bent and pulled them out and put 2 new ones in on the #1 cylinder and now we turned it by hand to see and it looked like the spring was collapsing against it self from being over tightened. now today we r going to try and start it with the rocker arms only being 1/4 turn after being tightened by finger while moving the push rod untill it showed resistance and thats the 1/4 turn past that.

the cam is 570/565 lift and the rocker arms r 1.6 and the heads r the AFR 195cc p/n 1040 and its the holley stealth ram intake. thats the swap we did was intake manifold cam and heads.

SeanW

Just read that through. Just so you know you need to use sealant of some sort on any headbolt that goes into a water jacket.

ok next thing i am noticing is you mention tightened rockers, the springs went down a little. That shouldn't be happening. That means your valves are opening. You can't adjust the valves like this. Of course at any given point some valves are open. They are the ones you don't adjust. haha

If you have f'd it up start by loosening them all off.

The easiest method of valve adjustment is exhaust opening/intake closing. Rotate the motor by hand. When you see an exhaust valve starting to open on a cylinder then you adjust that cylinders intake valve. When you see an intake valve closing then you adjust the exhaust valve on that cylinder. Do this one by one until every valve is adjusted. You can use a paint marker or felt pen to mark each rocker after you adjust it so it is easier to keep track.
To adjust the rockers spin the pushrod. As soon as there is drag that is 0 lash. Now tighten 1/2.

Your cam gear mark should be at 6 and the crank at 12.

Just to clarify i didn't recommend buying .080 wall pushrods because i thought there was an issue with the pushrods themselves.

TKR 88 GTA

ok well yesterday we got the engine ready to crank and the rocker arms on there are tightened to wat u said. but everytime the engine turns it loosens up the rocker arms and i go bak in there and tighten them but everytime we try to start the engine they come loose. i dont want to over tighten them again, how can i stop this from happening.

but now the engine tries to crank and then it will give a big pop so im guessing its back fire. so this is probably due to the timing being off right? the rotor points at the driver side head light it looks like its at one and mark on the balancer says it on about 7 BTDC when the rotor on the distributor is facing that way. so should it be facing that way when its at Top Dead Center?

JakeJr

One of the basic problems is how you set the lifter preload (tightening the rocker arm adjusting nut).

In order to correctly set lifter preload, each rocker MUST be set individually, one at a time. Each time one of the time is set, the lifter HAS TO BE riding on the base circle of the camshaft lobe.

In order to ensure the lifter is riding on the base circle of the cam lobe, as already recommended by SeamW, is to use the Intake Closing/Exhaust Opening method. You watch what the Intake pushrod is doing in order to set the Exhaust; then watch what the Exhaust pushrod is doing to set the Intake.

You turn the engine over, manually, while watching the EXHAUST pushrod and as soon as the EXHAUST pushrod just beings to move UP, you stop turning and THEN SET THE INTAKE.

Then you begin to turn the engine again, manually, and as you do watch the INTAKE pushrod. As the INTAKE pushrod goes to max lift and then goes ALMOST ALL THE WAY back down, you stop turning and then SET THE EXHAUST.

That's why it's named the Intake Closing/Exhaust Opening method.

Once you've stopped manually turning, you find ZERO LASH by slowly tightening the adjust nut until all pushrod slack is removed between the lifter and the rocker. When all the slack is removed, you THEN set the preload. I use 3/4 turn from ZERO LASH; others may use a different amount of preload. I've found 3/4 turn results in a quieter running valve train with no downside.

I have a long "How-To" posted as a STICKY on the LS1LT1.com site on the LT1/LT4 board.

Once you properly set the lifter preload, all your problems will probably be cured at the same time.

Hope this helps.

Jake

rgarcia63

TIMING:
To clarify the confusion both dots at 12 O'clock is the correct alignment for #1 compression stroke, but is difficult to properly align so 6 O'clock dot to dot for #6 compression stroke is used because it's easier to align since they're so close together.
VALVE ADJUSTMENT:
If the rods were loose the wrong method was used, or improperly applied. After all lifters are adjusted and after a couple manual turns they shouldn't be loose, don't bother starting the engine and risking damage try another method.

TKR 88 GTA

ok well i tried the Intake Closing/Exhaust Opening method and it seemed to work while going down the drivr side. but the rockers still came loose but i realized its cuz i dont have those allen head locking nuts.. guess they didnt come with the rockers.. so today i have to go to the hardware store and get them.. if they come loose that would keep the engine from kicking over to start right? and we were turning the engine over manually havent tried to start it yet... this is stressin me out lol i miss driving the car lol

InfernalVortex

iTrader: (4)

What do you mean they're coming loose? Are the nuts physically backing off?

The rocker arms arent bolted into place the way other components are. They are adjusted via that nut, not tightened down. That's probably why you bent that pushrod - if you tighten down the rocker so far it's compressing the spring even on the base circle it's going to cause serious problems when it starts hitting valve lift.

The nuts are a setting. Leave it alone. If you have to get a marker or something non permanent and mark a line on the side of the stud and the side of the rocker nut and see if it's actualyl moving - if the nut isnt backing off, leave it alone. You're setting preload from the spring against the cam base circle. You take the slack out of it ONLY WHEN THE LIFTER IS ON THE BASE CIRCLE OF THE CAM, and then tighten 1/2 to 3/4 of a turn and leave it. It's set. The only complicated part is remember which ones you've already set and finding the base circle, which is why you turn the engine over to watch the valves moving - hence the EOIC method they just told you about.

TKR 88 GTA

yes there physically backing off.. its cuz we set the #1 intake and exhaust right. then when we go to do #3 intake and exhaust from the turning that we to do see what the pushrods are doing they come loose, like i can use one finger to back the nut off. and thats after a 3/4 turn like JakeJr said. and once they come loose the whole rocker arm moves and if i dont re tighten that bolt i can move the rocker arms in circles ..

JakeJr

It seems you're still doing something wrong. I suspect you're not correctly identifying the INTAKE and EXHAUST rockers. If the adjusting nut is actually loosening, you would be able to SEE it turn - I strongly doubt that's what's happening.

You are aware of EIIEEIIE right? That's the arrangement of the valves; front to back or back to front - same/same. You watch E to set I and then watch I to set E.

Jake

TKR 88 GTA

ya but i think i am lol i went to ur long post on LS1LT1.com and printed it out and followed it as i was doing the steps. but its the nut that goes onto the stud that the rocker arm slips on.. then u got the bolt looking thing that has the allen head that goes inside the rocker arm nut thats screwed on to the stud.

InfernalVortex

iTrader: (4)

You're not doing something right then.

IF YOU'RE DOING IT RIGHT, then they should NEVER get looser than they are when you set the preload. Again, WATCH THE ROCKER NUT. If the rocker nut itself isnt rotating itself loose, then you're doing something wrong.

You're setting preload... you're setting how tight the rocker is on the spring when it's at zero lift. When the cam has lowered the lifter all the way and it's as far down as it can be, that's when you set preload. That's the minimum pressure on the spring at any spot in the engine's rotation. It should be more than enough to keep it from backing off. You're setting the minimum spring tension - or pre load.

It shouldn't be necessary, but you can always grab 16 nuts taht fit your rocker studs and use them as jam nuts and tighten them against your rocker nuts.

Try this...

1 8 4 3 6 5 7 2

That is the firing order. The pistons are numbered from right to left and front to back in the engine.




Rotate the engine until the number 1 cylinder's exhaust valve opens, and then set preload on the intake valve. Then rotate it again until the intake valve starts to open, and then set the preload on the exhaust valve. And make sure you're turning the engine clockwise.

Then do the number 8 cylinder... then the 4....

This is the longer way to do it, but it's difficult to screw it up this way.

If you have rocker nuts that are supposed to have set screws inside them, but dont, then you need them. Normal rocker nuts fit snug enough it aint a problem. But I know my Pro Mags with their set screws dont really feel solid until you tighten the set screw against them.



Here watch this:
http://www.youtube.com/watch?v=BgIzn2neiuY

You most likely have a hydraulic cam, so go with that.

TKR 88 GTA

no there not normal rockers, there rockers from jegs. there 1.6 aluminum roller rockers

JakeJr

I deliberately made my STICKY post long so as to include more detail in the hope of helping first timers really understand what to do and how. Maybe I need to make it even longer.

You're using what we refer to as a poly-lock. It consists of a long nut (they come in different lengths depending on the rockers being used) which screws down onto the rocker arm STUD.

The second part of the poly-lock is an allen head set screw which locks the setting in place once the correct preload is found. The purpose of the set screw is to prevent vibration from loosening the setting over time.

It's obvious to me that you're still doing something wrong, but because I can't actually "see" what you're doing, I can't tell what it is. It could be anything from installing the rocker arm incorrectly to identifying the wrong pushrod by (thinking it's an intake when, in fact, it's an exhaust.)

Perhaps you can find someone who has done them before to give you a hand, someone who can walk you through the procedure. After someone walks you through the procedure you'll see how easy it is.

Jake

TKR 88 GTA

dang ok.. well to install the rockers, u jus slip them over the the stud and make sure the push rods are in the little cup on it right? then from there u follow the steps u showed me right.

but idk im asking around town and i cant find anyone that has really done an aftermarket heads cam and intake swap i think i have to go out of town.

JakeJr

The trunnion of the rocker arms have two differently shaped side, one is rounded and the other is flat. Flat side goes UP.

I've done an aftermarket heads/cam swap many, many times; as recently as last summer on my son's 96 LT1. So since I've made those swaps so many times it's second nature to me. I'm trying to list all the things I can think of tht could possibly be done wrong to help you solve your problem.

Jake

Confuzed1

iTrader: (4)

You can't use "Jam nuts" to keep poly lock type nuts in place. The allen head screws lock them in place. If you're not using the allen head screws to lock them in place, I can easily see the nuts backing themselves off the stud after he adjusts them and is cranking the engine.

There's a few different ways to set lifter preload, and they all work if done properly. If you don't learn how to lock up your poly locks properly, they'll come loose every time. You can just do what InfernalVortex said, and just get a set of regular rocker arm nuts and use those instead of the poly lock nuts.

Unless YOU KNOW you're setting the lash correctly and the rocker arm nuts are not backing themselves off the stud, DO NOT continue to try and run the engine because YOU CAN cause damage.

EDIT: And when I said regular rocker arm nuts, I don't mean regular nuts you get at the hardware store. Rocker arm nuts are a self locking type.

TKR 88 GTA

ya i made that mistake with the trunnion the first time but my grandpa noticed before anything lol.. but every since then the rockers have been goin in with the flat side up..

i wish there was someone around here thats done them at least once on my type of car.. my grandpa has done them before but it was with the old school cars that used mechanical parts not the hydraulics i have, and the were fords at that so he doesnt really kno about the valve pre loading stuff lol

im jus stressin over this stuff already but i think im following ur sticky post but i dont thinkso cuz the car hasnt started yet. i re read them over and over and re read over each step as i was doing the the pre load on the lifters but idk what else i could be doing wrong right about now lol

TKR 88 GTA

but i got after market 1.6 aluminum roller rockers those use a different type of nut thats like 3/4 of an inch to an inch long and the space for the nut to go on the stud is very narrow and i dont think a regular rocker arm nut will hold them in place?

and there is a certain way to lock up poly locks?

JakeJr

No, you can't merely swap poly-locks, you should use the ones that came with the rockers. I recently read a caution that merely swapping poly-locks can cause valve train failure. The caution went on to say that it matters how the poly-lock loads the rocker arm trunnion.

#1: Are you backing out the allen head set screws to allow the outer nut to be able to be screwed down as far as needed?

#2: Once the lifter is on the base circle of the cam lobe, are you screwing down the outer nut to a point where the pushrod can no longer be pushed down or pulled up?

Once you've done #1 and #2 correctly, are you then setting the 3/4 turn preload by turning the outer nut 3/4 turn more?

Are you then screwing down the allen head set screw until it's really tight?

Unless you can post a video of exactly what you're doing, you have to post THE DETAILED, SPECIFIC STEP BY STEP procedure you're using. I'm emphasizing DETAILED/SPECIFIC for a reason.

If you mis-state or leave something out of the procedure that'll hurt our ability to see where you're going wrong. You've got to be thorough and accurate in what you post.

Jake

Confuzed1

iTrader: (4)

Ahhh. Ok then. You have full roller rockers then. I could change mine to regular rocker nuts because I only have roller tips instead of full rollers like you. You'll need to use the polys then. Setting them isn't hard.

-Once you have a cam lobe on base circle, ensure the allen head is backed off almost till almost the last thread. Spin the pushrod back and forth with one hand between your thumb and forefinger and slowly turn the rocker poly nut down on the stud with the other hand until you feel a VERY slight resistance in the pushrod you are spinning with the other hand. This should be the point of "zero lash".

- Now, "preload" needs to be set. Then turn the poly nut down further with a wrench one half turn.

- Then screw the allen head in the center on the nut down until it just touches the top of the rocker stud. Using a wrench on the poly nut, and an allen wrench, turn down both the nut and the allen screw at the same time until the poly nut "locks". If done correctly, you shouldn't be able to tighten down the poly nut any further. This should only add an additional 1/4 to 1/2 of a turn to the poly nut.

JakeJr

Confuzed1 gave you excellent advice.

In addition to what he wrote, I'm now beginning to suspect you're not correctly locating the base circle. As I've written many, many times before, correctly locating the lifter of the base circle of the camshaft lobe is THE MOST IMPORTANT step in setting lifter preload.

Finding it is often confusing to a lot of guys, so let me try to make it easier for you:

Stand on the driver's side of the engine with the valve cover removed

Reach down and grab the very first rocker arm; that's the #1 EXHAUST

Now reach farther down and grab the pushrod between your two fingers and hold that pushrod

Now manually turn over the engine in the clock-wise direction while paying attention to the movement of the pushrod

A ratchet/socket can be used to turn the the engine using one of the damper bolt or even the center hub bolt

When you FIRST FEEL MOVEMENT OF THE PUSHROD, pay attention to which direction it moves:

If it moves UP KEEP TURNING THE ENGINE MANUALLY until the pushrod MOVES ALL THE WAY UP, THEN ALL THE WAY BACK DOWN and JUST AS IT BEGINS TO MOVE UP AGAIN, STOP!!!

That position means the #1 INTAKE is now on it's BASE CIRCLE and it's time to set the #1 INTAKE You're through with the #1 EXHAUST FOR NOW.

Now, move over to the #1 INTAKE pushrod, which is the one right next to the #1 EXHAUST

Grab the #1 INTAKE PUSHROD and begin tightening its poly lock nut.

As you tighten that NUT, move the pushrod up and down.

As you reach the point that the pushrod can NO LONGER be moved UP or DOWN, STOP TIGHTENING THE POLY-LOCK NUT - YOU'VE FOUND ZERO LASH

Now's the time to set the preload by turning the poly-lock NUT the amount you want for preload - I use 3/4 turn.

Once that's done, tighten down the allen head set screw really tight.

Once I think I've tightened the allen head set screw really tight, I give the poly-lock NUT (the bid NUT) an additional 1/16th turn just to be sure the setting is locked in place and won't loosen over time.

The #1 INTAKE IS NOW SET!

Setting the #1 EXHAUST IS SIMILAR and I can post how to do those if you need me to. The difference is you stop manually turning the engine when the #1 INTAKE (Yep, the one you just set) pushrod goes all the way UP and returns to ALMOST ALL THE WAY BACK DOWN.

Notice the difference? Just beginning to move UP Vs ALMOST ALL THE WAY BACK DOWN.

Hope this helps.

Jake

TKR 88 GTA

ok ya that helped clear up a few things. when feeling for the pushrod on the exhaust side i would stop on the first movement i felt it going up not on the second time. maybe thats where i messed up. but lately the weather has been bad so i havent had a chance to get to it again maybe sunday ill be able to get it. and ill do it exactly the way u told me and ill make sure to note what im doing as im doing it to post it on here n let u know exactly what im doing.

and im gonna try and get some guys that race at the track here that build 10 and 11 sec cars. hopefully they can help and watch wat im doin. hopefully i can get them to help lol

TKR 88 GTA

alright guys well i figured out the problem i had the racing team around here that builds chevy motors look at it... they ended up finding that there was bent valves in the heads after my cuzin had tightened the rocker arms way to tight the first time dam. so ya i pulled the heads and sure enough 6 intakes were bent so i have to send it off to the machine shop and see how much that'll cost.
anybody know a estimated figure on how much it would be?

InfernalVortex

iTrader: (4)

Ouch... that's rough man. That'll definitely throw off everything you do.

Valve are expensive, but it's not so bad if you only have to repalce a few. A set of 16 gets pricy quick.

As long as the valve guides are fine it shouldnt be TOO awful. Tearing down the heads and reassembling them will cost you a bit in labor though.

Machine shop prices vary wildly... I would guess around $250. Could be a lot less, could be a lot more. Just depends.

TKR 88 GTA

took the heads in n its gonna cost #350.. 10 valves were bent 8 intakes and 2 exhaust. so ya should have them back by friday so hopefully everything goes good with the re install.