I ruined my old cam, the lifters, and pushrods. I'm not really sure why, except that I had the valves tightened way too much for a few days which could have collapsed the lifters. So I got a new cam almost identical to the old one, new lifters, new pushrods. Installed the cam dot to dot so the engine would be at #6 firing. The dots lined up absolutely perfectly so I know I did it right. Put everything back together and the car will not start. I've put my finger in #1 spark plug hole and cranked the engine over until it gets blown out, the balancer was at the 0 degree mark, I put the distributor in with the rotor facing number one, and I've turned the cap as far as I can in both directions. I've even taken the dizzy out a few times and turned it a little bit in both directions to see if that would help. The car will just crank and crank. Every once in a while there is a really small backfire, but changing the timing doesn't seem to make it backfire any more. I have spark and fuel (shocked one of my friends testing for spark and when i pull plugs there is a little bit of fuel on them). I'm assuming I have compression because the engine ran when I took it apart. I have a feeling that it still might be just the timing, but I'm afraid when I ruined the cam I ruined something else on the bottom end that won't let it start. When I crank it over with the valve covers off, the valves open and close like normal. What do you guys think I should do?

 

Are the valve covers off?set the timing mark at tdc and make sure both valves on #1 are closed. recheck your rotor posiion.

 

okay I'll try that. I didn't have the driver side valve cover off to check that both valves on #1 were closed, but at TDC on the timing mark the rotor is facing #1. Anyone else have any ideas? I'm really worried that I toasted the whole motor.

 

You're not sure why?

It's in backward. Take out the dizzy, and put it back in facing the OPPOSITE way. For instance, if the rotor is facing towards the number one cylinder when you remove the distributor's cap, pop up the dizzy, and put it back in facing number six....

 

LOL about the "not sure why."

I know that dot to dot is #6 firing. After everything was installed, I turned the engine over to #1 firing, put dizzy in facing #1, and tried to start it. I figured I might have messed up, so I tried turning the dizzy 180*. It didn't really change much of anything.

 

It might not have helped starting the car (as it sounds like you're valves might still be a little too tight), but did it at least eliminate the popping back (back-firing)?

 

No, it seemed to increase the backfiring a little bit if anything when I switched it 180.

So the valves could be too tight now? This would cause the car not to start? When I put in the lifters and pushrods, I tightened down the rocker arm nuts to zero lash plus 1/4 turn. However, the lifters were not "pumped up" because the Comp Cams instructions said to just coat them in oil and put lube on the tappet. This seems like it would make the valve lash inaccurate, but thats what the instructions said to do.

 

If it increased it, then yes... put it back the way you had it.

I honestly wish I was there with you, but since I'm not, try doing it the old way. Loosen you're rockers individually (when the lifters are at their lowest point), and tighten them to where you can hear the rocker arm 'clack' slightly (slightly loose). Do not tighten anymore than this...

Once their all set that way, start the car.... and tighten them down while the engine is running. Tighten until the 'clack' goes away, then go 1/4 of a turn for each (no more).

 

Of course it will....

 

okay i'll try loosening them up a bit and putting the dizzy back how i had it. thanks for your help so far.

 

lol, no compression and probably bad timing man

 

I'm starting to think I have no compression, I'll do a compression test tomorrow. Maybe I bent some valves?

Loosening the rocker arm nuts and having the distributor in the right way has made the backfiring somewhat louder, but it still doesn't seem close to starting.

 

You very well could have. How exactly are you setting lash? My guess is that you're doing it wrong. I fussed with my car not starting for a good 2 weeks before I realized I was setting lash improperly.

 

I had a friend sit in the car and bump the engine over. When both valves on a cylinder were closed on the compression stroke, I tightened the nut while jiggling the pushrod up and down. When it wouldn't move up and down anymore, I tightened it 1/4 turn more. Isn't this the right way to do it, assuming you can't do it hot with the engine on?

 

Do a compression test.

 

tomorrow morning bright and early

 

Getting back to you're original post;

Followed by;

If the engine ran before-hand, then why did you tighten (over-tighten) them in the first place? Were they 'clacking'? Were you trying to re-adjust them?

Just curious...

 

I tightened the valves too much probably about two months ago because I thought zero lash was when you couldn't spin the pushrod anymore, not move it up and down. I drove like this for a few days, maybe a week tops, realized what I did wrong, and loosened them to correct lash. Engine was fine for almost two months. Then I overrevved the engine a few times (once during a burnout, once missed a shift). I'm guessing the combination of having been too tight and overrevving ruined everything. However, it ran fine until about a week ago when I noticed a ticking noise and a severe loss in power. I pulled the pushrods and they were bent, so I went deeper and found the ruined lifters and cam. The motor still ran, but was very very difficult to start the last time I started it to drive it into the garage.

edit: At this point, I think I'm just going to pull the heads tomorrow and see how the valves and pistons look. Something is definitely wrong down there.

 

I took off the intake this morning and all of the intake pushrods were horribly horribly bent. All of the exhaust ones were straight. What on earth is going on here?

edit: The car never even started with the new pushrods in! I turned it over quite a few times, but it never fired. Why are all my intake pushrods bending but not the exhaust ones?

 

This is why I mentioned it again above, that it still sounded like the valves were being set too tight again. This also explains the backfiring, and the non-starting...

Trial and error. Get yourself some used pushrods from a junkyard (don't waste money on quality pushrods until you get the right feel for setting valve-lash). I really wish I was there with you my friend.

If I were you (and I know you don't want to hear this), but after you try adjusting them again with some used (or donated, anyone?) pushrods, and it still doesn't start (and they still get damaged), I would go back to the beginning, and carefully inspect all of my work starting by removing the timing chain cover. Make sure the timing chain is still lined up properly, for starters...

Pushrods simply don't bend for nothing like that. Either the pressure between the rocker and lifter is that great, or you're pistons are banging into them (this is why it's imperative you check and see if you're timing chain is properly lined up)....

 

Okay I got more pushrods and I cranked it over a bunch of times and the pushrods didnt bend. I set the valve lash with the lifters pumped up this time. It still won't start though. It sounds exactly the same, and adjusting the timing all over the place slightly changes the sound of the backfiring, but it's still not even close to starting.

I also tried to do a compression test, but it's hard to get the fitting screwed into the spark plug holes. Two easy cylinders were around 110 psi, but then two hard to get to cylinders were only about 55 psi. I don't know if I didn't have the fitting screwed in all the way tight or if I really have bad compression. The compression tester is also very old and could be faulty. I still think I have good enough compression for it to run if everything else was right because it ran with the bad cam in it.

Any other ideas?

edit: I don't think the pistons are hitting the valves. Can't you usually hear that when that happens, "piston slap?" I am 100% sure that the timing chain is lined up properly, but I guess I might have to take off the cover and check if nothing else helps.

 

If all of you're intake valves (not just three or four) were bent, then there's no question that you're pistons were making contact with them. Between the noise of the starter, and the distributor.... it'd be a little harder to detect any slap.

This depends. I'm not questioning if you lined up the marks correctly, as I'm sure you did. But the question is, did you intall a double-roller timing chain, with a three key-way bottom sprocket?

It really sounds like you're timing. Turning you're distributor will do absolutely nothing to correct this, you need to double check you're timing chain's position (cam, in relation to the crank)...

This will cause you're intake valves to bend, and you're timing to be completely off.... regardless of how much you try to advance, or retard the dizzy to correct it...

 

The intake pushrods were all bent, not the valves. At least I don't know if the valves are bent yet. Tomorrow I'm going to do a cylinder leakdown test.

I left the old timing set on there. It is a double roller chain. I did not touch the bottom sprocket at all. I put the cam in the top sprocket the only way you possibly can with the little dowel then lined up the dots. I know its recommended to get a new timing set when you do a cam swap, but this timing set is less than a thousand miles old. This was a brand new crate engine this spring, so I figured the timing set was still fine. There were no obvious signs of wear on any of it.

 

I honestly meant to write pushrods, not valves, as they are the weaker link (being that the valve stems are both housed and supported by the head casting, while the pushrods are exposed). Either way, the valves might be a little bent as well, and don't be surprised if you see a little damage on the top of each piston (this is only if the timing chain is not lined up properly, which is what it sounds like)...

Followed by;

Right, but how did you line up the bottom sprocket? Are there three settings to choose from? You might want to take another peek....

 

I thought there was only one dot on the bottom sprocket...I guess I'll have to pull off the cover and take a look. Thanks a ton Street Lethal you've been a huge help. This certainly sounds like this could be the problem.

 

Certain double roller timing chains come with three keyway positions, 4 degrees before, 0, and 4 degrees after. This is definitely the culprit, it has to be...

 

Remember though, you're looking for three keyway positions on the crank sprocket, not dots.

 

Okay...so which one do I want to line up the dot on the cam sprocket with?

 

First, remove the timing chain cover, and with the crank bolt placed back into the crank snout, rotate the crank until both dots (the one on the cam sprocket, and the one on the crank sprocket), are facing each other. With both of them now facing each other, carefully inspect the keyway on the crank's snout (there is only one keyway on the crank snout, but you will find that there are three notches in the crank sprocket itself that ultimately alter the cam's position in relation to the crank's stroke). Find the notch in which is being occupied by the keyway, and observe which way it is facing....

With the two dots still facing each other, the keyway should be facing towards to the 2:00 position. In you're case though, you will see that the keyway is occupying one of the other two notches found on the crank's sprocket, and facing the wrong way.

After you verify this, remove the timing chain from the engine.... and using the same crank bolt, rotate the engine until the keyway found on the snout is facing the 2:00 position.

Now, put the timing chain back on, and without moving the crank, keeping the keyway facing 2:00, MAKE SURE YOU INSTALL THE TIMING CHAIN SO THAT THE DOT ON THE CRANK SPROCKET IS FACING STRAIGHT UP, then you can rotate the cam sprocket until the dots align themselves up with each other again.

Remember, keep the keyway facing 2:00, as you align the dots on the cam and crank sprocket's...

You're all set...

 

I have to remove the crank sprocket to do this right?

If I remember, I believe the keyway was at the 10 or 11 oclock position, so this sounds promising.

How was the original cam installed but worked fine with the keyway in the wrong place?

 

That's not strictly true; close, but not quite right.

The keyway is EXACTLY IN LINE WITH the #1 & #2 rod throw of the crank. Therefore, when it points EXACTLY IN LINE WITH the #1 cyl, the #1 piston is at TDC. Since a V8 motor has the 2 banks of cyls at 90° from each other, the banks are each exactly 45° from straight up (12:00), which means that the keyway should be at 1:30 (halfway between 12:00, straight up, and 3:00, staright to the side).

Sounds to me like what has happened here, is you have one of those 3-key crank sprockets, where you put it on an any of three places to get either retarded, straight-up, or advanced cam timing with respect to the crank. There are also 3 "dots"; one probably a triangle, one a square, one a circle. Depending on which slot you use, you have to use the coresponding "dot".

Locate the carnk such that the keyway points directly up the front of the block, at the center of the #1 cyl. Put the crank gear on the crank using the slot that results in the CIRCLE dot being straight upwards. When you do that, you have the # piston at TDC. Now rotate the cam such that its dot is straight down; and align the crank and cam to where the dots are together. Put the chain on. The engine is now at #6 firing, which is distinguished from #1 firing by the cam position. #1 firing and #6 firing are EXACTLY THE SAME THING as far as the crank and pistons are concerned. Now rotate the crank ONE FULL REVOLUTION, which will bring the piston back around to TDC again, but will rotate the cam ½ revolution; this position will be #1 firing. Install the timing cover and the crank damper WITHOUT MOVING THE CRANK; verify that the timing mark on the damper is correct (it probably isn't). If not, mark a new mark on the damper with white paint, White-out, white tape, or whatever. Drop the dist in with the rotor pointing at the #1 plug wire terminal (should be the one just barely to the driver's side of straight ahead). Reach in the window and start your car, and set the timing with a light, using your new mark.

 

I honestly didn't want to make it any more difficult for him by telling him it needs to be in an exact position. He might get a little frustrated.

In respect to that general area (area between 1:00 to 2:00), you're absolutely right... but as long as he uses this keyway angle (facing that particular area), and provided he lines up the dots on both sprockets accurately, then there really is no way he can miss 1:30...

 

Not at all, you can see the keyway if you carefully inspect the area behind the crank sprocket, as well as by inspecting the notches in the crank sprocket itself (whichever one out of the three is being used, you'll see it in there... as the other two will be vacant).

Yes, and the third keyway should be facing the 6:00 position. Whoever had the car before you did not set the timing straight up...

Again, whoever had the car before you did not set the timing straight up. Three keyway timing chains come with a diagram explaining how to position the cam in respect to the other two keyway positions (4 degrees before, and 4 degrees after)...

As RB explained, the sprocket will more than likely have pictures that accompany each keyway; (triangle, square and circle).... some of them will also have numbers instead; (-4, 0 and +4).

Utilize the keyway that's facing toward the 2:00 position, then position the timing dots on both sprockets facing each other...

 

Turns out that my crank sprocket had two different dots on it. One was a little bigger than the other, I didn't even see the second dot when I first installed the chain. I just used the wrong dot. When I lined it up using the second dot, the keyway was in the 2 oclock position. Car fired right up.

Thanks RB and Street Lethal this had me going crazy for a few days.

 

ok this problem sounds a lot like my problem, one thing being different is when I set my crank sprocket it was at the 2:00 position with the dot straight up. I had the dowel on the cam at the 9:00 clock position with the dot straight up. Could I have screwed up the cam timing too?

 

The origional poster stated that his car would not run at all. Not even start. The crank pulley being 4* advanced or retarted would not cause this. The only reason his car runs now is because he installed the timing set incorrectly the first time. Right?????? Please tell me if I am wrong. I am having a similar problem but my car starts and runs just horribly! Wondering if it could be timing set issues.

 

It wasn't 4* off, It was more like 60* or so.