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Discussion Starter #1
I am at a loss here. I don't know why I don't have any compression after my rebuild.

Here's the skinny. I installed a brand new set of custom AFR 165's, custom FTI cam, HD lifters, lightweight pushrods, Scorpion RRs, Edelbrock Performer RPM, etc.

The starter motor turns the engine. I have power to the ignition, coil, spark plugs, injectors, etc. It makes no attempt to fire up. The starter motor just spins the assembly.

I THINK the problem started when I installed my new lifters, pushrods, and RR's. When I went to set my roller rockers, I still had the lower intake off, so I could watch the lifters. As I am finger tightening the nuts on the rocker arms, the pushrod is pushing down on the center of the lifter. Zero lash came at the point at which the center of the lifter stopped compressing...at which point I gave a 1/4 turn. That 1/4 turn compressed the valve springs a tiny bit.

Now, at this point with the valves moving up and down, I was not getting any compression whatsoever. I had tape on the exhaust port and my finger in the spark plug hole....no air movement. No hissing...nothing.

I am questioning the lifters. Are the lifters supposed to compress down like that? When I give my 1/4 turn, should the valve springs have compressed?

I need some serious help here.
 

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The OASIS Guy
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well im no master tech but....

hey man id look to see if the timing is set right on the car the valves can be opened on the compressin stroke and cause u to have not compression. id look there first.
 

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Discussion Starter #3
That's one of the first things I checked. The valves were definitely closed on the compression stroke. The lifters were seated at the bottom of the cam lobe.

When I installed the cam, I had the #1 piston at TDC and everything dialed in just right according to the cam card.
 

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The OASIS Guy
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ive never had this problem but i know a lotta people

hey i will ask a few of my friends i drag race a lil and i do a lil enging building myself. i might be going into partinership with a good performance guy so i will give him a shout as to what it might be. but til them GOOD LUCK.
 

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zero lash

You stated that you attained "zero lash" when the lifter bottomed out. Then you tighened the RR bolts 1/4 turn more thus opening the valves a little.

You have adjusted beyond zero lash and in fact bottomed the lifters out and opened the valves at all times. As oil pressure builds it will only try to open the valves farther.

Zero lash is attained after all SLACK is removed from the valve train. This will leave the lifter almost fully extended. Then when you proceed to torque the RR nuts down this will then preload the lifters. The lifter plunger should be about mid travel or a little more than 1/2 way down.

When checking for zero lash, move the pushrod up and down between the lifter and the RR as you tighten the RR bolt. Once you can no longer move the pushrod up and down, you have reached zero lash. Then torque the RR bolt to its proper setting. If it takes more than 3/4 of a turn to reach the torque value you will need to shim your rockers..

Hope this helps..
 

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Sounds like you adjusted the valves just right for a typical hydraulic lifter. Did you notice when you put that quarter turn in if the plunger in the lifter moved. You lifters could be stuck or could be solids.
 

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Discussion Starter #7
That's just it. I had all kinds of play in the pushrod until the lifter bottomed out. I mean the rocker arms, themselves, could be wiggled until that point.

What you're saying is making sense, and is why I am questioning the lifters. Brand new out of the box.

Is there some prep to them other than oil and cam lube on the roller bearing?
 

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Go back and adjust them again. This time watch the lifter. Zero lash is when the push rod just touches the lifter. Turn the rocker nut a quarter turn and this will start the lifter plunger down. The rockers are goin to be loose until you pump the lifters will oil pressure.
 

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It seems that if you had play it shouldn't have been compressing the plunger. For it to compress, you would have had to reach zero lash already. It shouldn't feel snug when you hit it......just can't jiggle it up and down anymore. You can usually just feel drag when spinning the pushrod right after that.

Try resetting and stopping as soon as the jiggle stops.
 

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twist the pushrod back and forth(like rolling a spliff) until you have ANY resistance. This is zero lash. Tighten the nut 3/4 turn and lock it. This is how i've set up valves on all the engines ive built. Works like a charm! I did the exact same thing as you did the first time i set valves up. When you crank it over, it sounds like it does when take out your sparkplugs to do a compression test.
Good luck!
 

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sounds like the rr are to tight

if i remember correctly you adjust the exhaust valve when the intake first starts to close and adjust the intake when the exhaust first opens

take it to 0 lash then go 1/2 turn and lock down
 

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Your rockers are adjusted too tight. Adjust them as follows..... working on one cylinder, crank the motor 'till the exhaust valve just starts to open. Then adjust the intake valve for that cylinder by turning the adjuster nut by hand 'till it just takes up the vertical slack in the system..... you'll feel the resistance of the nut change when this happens. DO NOT go by feeling for the pushrod to stop turning and DO NOT compress the plunger in the lifter. If the lifter has no oil in it, you'll be able to pull the rocker back against the spring loaded plunger. If the lifter has oil in it, you won't be able to do this. Then turn the nut an additional 1/2 to 3/4 turn and lock it down. Crank the engine and the exhaust will open all the way, then close, the intake will then open and when it starts to close, stop and adjust the exhaust valve the same way. Do this for the rest of the engine and you'll be in business.

Good luck,
HiTech
 

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Discussion Starter #14 (Edited)
OK. I guess the lifters were not full of oil and is why my lifters were unable to provide any resistance. So, the center of the lifter is not supposed to be compressed....it'll pump up with oil upon start-up. Perhaps this is the problem. I just wasn't getting any resistance on my pushrod when I was twisting it with my finger tips because there was no oil in the lifters?

I was just concerned because the roller rockers could be wiggled around pretty easily. I've set them up on my previous set-up, but obviously, there was oil in the lifters and I could feel resistance. This is a totally new combo, with new parts, no friction, and perhaps is why the 'ol check for resistance with your finger tips method wasn't working for me.

So, I guess I should expect these roller rockers to tick or clack pretty loudly until the lifters get pumped up?
 

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i like to slide the pushrod up and down so i know when it is fully seated. go 1/2 turn more and you are done. follow the comp cams procedure on what valves to adjust and you will be set.
 

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autoxr1

please do me a favor. My car has been in the shop for 6 weeks now because my moron mechanic was installing 1.72 RR's and a cobra intake but somehow he couldnt get the car started when it was all done. Turns out there was no compression. He took the car apart like 3 times and told me he adjusted the RR's the right way but now after reading your post it seems like he most likely didnt. He now thinks that all the fuel that got sprayed into the cylinders while we were cranking it over washed down the cylinders and caused the rings to collapse.....i have a feeling this is completely off base.

Here's a couple questions...did you have compression in any of your cylinders because i didnt. Here's the other thing....when he put oil into the plug holes he got compression but as soon as he put it all back together and tried to start it...it was lost. Do you or does anyone else have any idea what the heck this guy did. I'm desperate here and i want to kill this guy. My car is in FLorida because i had to come home for the summer in MA to work and he cant figure anything out and he want to start pulling heads and make a lot of work for himself...and i just dont trust him.

Thanks for any help anyone can give me
Joe
[email protected]
 

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Discussion Starter #17 (Edited)
1BAD93

It was my lifter adjustment, just like everyone said it was. No, I did not have any compression at all because the valves were always open. I had collapsed my lifters down. I just did what everyone said and I was fine.

She's up and running fine, now. I still have some tuning to do, but that's to be expected with a new combo.

Putting oil into the plug holes is not a way to check compression in this case because all the air was blowing back up my intake. I tested it by placing masking tape over the intake and exhaust ports and over the spark plug hole. It would push and pull air in and out of the intake, not my exhaust port.
 

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is lifter adjustment the same as Roller rocker adjustment???
 

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Discussion Starter #19
Sorry. Mistyped. It was the roller rockers. I had them on too tight. I had cranked the nut down to the point where the lifter was collapsed. As I reported earlier, being a new set up with essentially dry lifters, moly lube, etc....I had mistakenly thought zero lash was the point where the pushrod stopped rotating as I rolled it with my fingers. Zero lash ended up being when the pushrod could no longer be lifted upward, and the rocker arm just touched the tip of the valve. I had to set them correctly, let it run and pump the lifters full of oil, then tear into it again and reset them. A few rockers wanted to clack. Like I said earlier, I have it all worked out now.
 

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This is 1BAD93 posting under a friend's name



thanks for the reply.....i have a pretty good feeling thats what ther problem is with my ride...all the sypmtoms are the same and i know for a fact when he put the RR on he didnt turn the engine over by hand to get the Rockers ajusted at the base circle and all that stuff...i should have done it myself...

later
Joe
 
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