Engine won't turn over after cam install

Engine is a 53 olds 303.
Stock bottom end. Stock heads. I recently replaced the camshaft ( regrind from fusick) timing chain and lifters. I had the engine at tdc #1 in firing position and replaced the cam in the same position as the old one cam out ( fuel pump eccentric in the same orientation) and did not turn the crank at all.

New lifters. Torqued everything down. And when I went to to start the engine it turned over once and then would not turn any further. I can NOT turn the engine over by hand. In either direction.

So my question..... Am I experiencing some sort of bind in the timing chain? Engine was running prior to the cam swap. I had worn down a lobe and a few lifters weren't pumping up causing it to run really rough and down on power.

I plan on pulling the timing cover to get a look at it and see... But if anyone has any ideas or has experienced this before please let me know.

Thanks
Brian

 

Wow, that is weird. I would start by removing the rockers and pushrods on both banks and see if that frees it up. If not, you will have to remove the timing chain and see if the cam spins free and if the crank will turn now. Since it only happened after the cam change my guess is that it is in the cam or valvetrain. Possibly something in the distributor drive too, like the gear not meshing with the cam for some reason.

Don

 

is it possible that the original cam had jumped a tooth (or 2) on the chain without you realizing it? if so, then the new cam may not be in the correct position. Do your timing gears have index marks? sometimes its best to start from the beginning....

 

I don't know if the Olds is an interference engine (I'd guess it isn't) but if it is and the cam isn't installed properly, you may have a piston jammed against an open valve.

I know it's too late, but before closing up the surgery I always rotate an engine by hand multiple times to make sure the timing marks line up and that nothing is interfering. I learned that lesson the hard way.

 

I am certainly not Mr Olds but it doesn't sound like valve to piston problem to me. It would turn away from the interfering valve if it were.

Brian,
I have to ask this as I am just Mr Curious, please excuse my dumb question. Do you have adjustable rockers and if so did you run into any problems when you ran the valves?

Here is another dumb question. Did you replace the cogs or just the chain? When you installed the cam did you line up the timing marks on the timing sprockets (gears).

If you did not replace the timing sprockets or even if you did there is a chance that one of them broke or lost a tooth, the piece may have fallen and is lodged.

Also this is totally unrelated but I have had totally unrelated stuff happen to me before. What are the chances that the starter is stuck and engaged. That is your easiest check, take a hammer and larrop it, or pull the starter then try and roll the engine by hand. That will cost you about 15 minutes before you tear into your engine.

Just some things to think about.

 

Thanks for all the ideas and thoughts!

The rockers are non adjustable. However is there a chance that I I've torqued the rocker shaft? I noticed that the upper bolts on the shaft are also the head bolts so I torqued them accordingly. I will loosen them up tho and see if that frees up the engine. Easier to start there than opening up the timing cover.

The timing chain and cogs are all new cloyes units. I had the crank in #1 firing position and installed the cam straight up in the same position it was in when I had located tdc.

The distributor dropped in without Too much trouble. I looked to make sure the gears were meshing but it may be worth another check.

The starter in acting normally. I can hear it engaging and disengaging. It actually grinded out once when I was trying to start it. I will post results once I get back into it.

I will start at the valve train and work for there.

Thanks again !

 

Also when I installed the crank gear and cam gear the cam gear "o" was at 12 o clock.

I had seen somewhere where you install the crank and cam hear with the o together crank at 12 and the cam at 6 and then rotate the engine 180*.

I didn't think about this since I figured I was replacing the cam in the exact same position as it had come out.....

 

Stupid question, did you leave a tool behind, hey doctors do it on ocassion?

 

When crank on tdc wheres the rotor

 

I can never remember timing marks on anything, after 40 years you would think that I could. I either look at a manual or look at one of my old notebooks. Makes me sound dumb doesn't it, what it does is keeps me from second guessing myself.

Tell you a story, twin cam lambo has an adjustment for cam timing. You turn a screw while the engine is running. You can retard your timing or advance it. Fine tune it so to speak. The Ol' Man was forever getting it wronng and crashing the valves. he was considered to be the best. the last time he did it I was in my 20s. he called me at about 5:00 AM on a saturday morning and told me i had to go over to oakland to pick up some valves for a Lambo and told me where to go. So I fired up my old hawg and headed to the east bay.

When I got to the shop he said he handed me a donut and and a cup of coffee. And we finished pulling the head on the lambo. I said what happened and he said I started to turn the screw clockwise and then thought to myself I always get this wrong and turned the screw counter clockwise. So I made him a picture and stuck it on his tool box.

Doesn't matter how long you have been doing something it never hurts to look at a reference. never ever.

LAMFAO, I got a wrench I found in the pan of a 283 a long time ago. I don't think the heads had ever been off of that engine. Bet when it was new it was at the shop a ton, "my engine rattles when I'm on a dirt road." " You're nutz there's nothing wrong with this engine."

 

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That is one thing I always do too and have caught at least one engine that was a tooth off when I had rotated the engine two revolutions. The crank has to rotate twice to rotate the cam once.

Going back to the problem. Not all cams are installed with the #1 piston at tdc. Did you follow the manual's instructions for installing the cam in that engine and aligning the timing marks?

You might want to pull the pushrods or rockers first and see if it will turn over then and go from there.

 

Another happy little definition of an "interference engine" that I am familiar with is one when the cam and crank are not in proper time, the crank knocks lobes off the cam.

 

Forgive me, I don't know Old's 303s much, but is it possible that you got water down into a cylinder and hydrolocked the engine? (even though I can't imagine a scenario where the engine would lock in both directions...)


Might want to remove the plugs and eliminate this possibility anyway.....

 

I'm pretty sure I got all the tools outta there. Made sure to check And double check before the valley pan went on.

I will start with the rockers to see if she frees up. If no luck there I'm prolly gonna pull the timing cover and make recheck the alignment of the cam and crank. I fugure it's one or the other at this point.

When the crank is At tdc I had the rotor in position for cylinder 1. Might take a day next week to muck around with it and retrace all my steps.

 

Sounds like you have the timing way off start over get you a manual and see how the timing marks on crank and cam gear line up. Somebody on here for sure builds the Olds engine and can tell you how they go.

 

My money is on, you're 180* out of time. You say you've had it set at TDC....How did you check to be sure it was #1 on TDC? By looking at the rocker arms and viewing the valves? Double check by seeing where distributor rotor was? Firing at #1.

Timing on the 303 is intake opens 14* before TDC and exhaust closes 14* after TDC.

Timing using the tab on the crankshaft pulley the leading edge of that notch is 5* before TDC. The trailing edge of that notch is 0*. Normal setting is 5* before TDC.

#1 is front drivers side piston....1 3 5 7....passenger side 2 4 6 8

The dots you described are correct. Big sprocket dot lines up with little sprocket dot. When you lined up the dots, did you just eye ball them or did you use a straight edge ruler to be sure the dots were in alignment?

Next, crankshaft MUST be rotated 360* when distributor is installed. (this is where I think you might be 180 out since you said you only rotated it 180 degrees instead of the full 360 degrees.)


Since you didn't get to fully crank it over. Look and see where your crankshaft timing mark is. (that timing tab on the crank pulley) Then pull off your distributor cap and see if it is either firing on #1 or getting ready to fire.


HellRaiser

 

Another good reason to degree a cam

 

If you still have the old cam,you can compair it to the new one.
I would guess you have the wrong camshaft.What i had happen on a 235 chevy the position of the lugs were off spacing and when turn it hit the block.When you remove the chain,
see if the camshaft can turn one full turn.

 

I always pull the plugs and roll a motor over by hand, watching the valves and checking the spark plug holes for compression as I do it, whenever I make a change like this. I've caught many problems early that way. Just did a '67 Olds 425 motor, where I put in a beefier cam and hyd. roller lifters, a new timing chain, and new roller tip rockers. Turned out the cam timing was way off, and to fix it I had to advance the crank sprocket a bunch of teeth on the chain (six teeth if I remember right, it was try it and check it) before I got it right, it is spot on now. But the marks on the sprockets don't line up now,even though I know the valve timing is correct, never did figure out why it was that way!

2Loose Willy

 

Here is the fastest way to tell what you are dealing with.
Should only take a few minutes to confirm your worst fears.
Hope this turns out negative!!!

Remove valve covers and spark plugs.
Visually look for the open valves,
Use a small probe in the spark plug holes to feel for the tops of the pistons.
The pistons shouldn't be anywhere near tdc with open valves. There are also small camera scopes you could stick in the plug hole and look around.

Regardless of what happened, if you find the top of a piston in a cylinder with a open valve , you are going to be pulling the heads

" And when I went to to start the engineit turned over once and then would not turn any further. "
^^^^
If the valve hit a piston, its bent. That starter motor isn't going to be stopped easy.

"I can NOT turn the engine over by hand. In either direction"
Got jambed up pretty good, you would need to exert the same force as the starter in the other direction. An easy test would be to loosen the rockets, if a valve hangs open, its curled up and jambed on a piston.

Let's say that turns out negative and you are jumping for joy. process of elimination would rule out, starter, flywheel, chain, crank jamb.

 

I'm trying to remember if that engine uses a plate between the camshaft and gear. I've seen them lock up if the spacer on the cam or gear isn't the correct thickness or the eccentric for the fuel pump turns.

I doubt that you have a valve hitting because you would be able turn it backwards.

 

Thanks for the info. Hellraiser I think I do have the camshaft 180* off. I will check tomorrow to see how much damage I've done.

I had found tdc by making sure the #1 piston was in firing position and also that the rotor on the distributor was in "about to fire" position. When I put the cam in both the dots on the crank and cAm gears were at 12 o'clock. This was the orientation of the cam when I took it out. However now I'm thinking that even though the crank was at tdc, that wouldn't necessarily mean that the cam was at tdc.
Wish me luck......

 

Crank @ 12 - cam @ 6

The line going up should be : crank c/l - crank gear dot - cam gear dot - cam c/l

Good luck

 

Since the crankshaft turns twice per one turn of the camshaft, as long as the crankshaft sprocket alignment mark is up and on the centerline, the camshaft sprocket alignment mark can be either up or down on the centerline and won't cause any valve problems. When you turn the crankshaft one turn, the camshaft turns 1/2 turn so if you start with it up, it would be down. If the cam is out of time causing valves to hit pistons, they will hit every piston.

If you took it apart with the cam sprocket alignment mark up and put it back together the same way, the distributor should be close. The distributor should not stop the engine from turning. Even if valves hit pistons, it usually bends the push rods and keeps turning with the starter.

 

I was looking at and old book and says dots are facing each other.So crank at 12 ,cam at 6 oclock.I also found that there is and early cam for 49 and later 49 thur 54.Something to do with can end play.Lobes must be hitting block.

 

I would start with removing the rockers and spark plugs too. If that doesn't fix it, pull the cam sprocket. Eliminate one thing at a time until you find it.
And I'll agree that 180 out won't hurt anything. In fact if that was all that was wrong you could pull the distributor, turn the rotor 180 and the engine should fire up.
Larry T

 

Please excuse my old geezer attitude, and this applies to everybody, if you have an old style engine from days gone by and you are attempting to work on it or service it you should be using a service reference book as an aid.

News flash the best thing you can do next time you are at the swap meet, look for some one selling a used Motors Manual repair reference books. They come in editions by year and the older ones have all the info you need if you have an old style engine like a 303, Caddy, Pontiac, flathead or Rambler. Most of the time the old ones from the 50's and 60's cover 10 years or more previous to the edition date.

This book is the cheapest thing you can purchase at the swap meet or used book store they usually go for $20 or less and save you the expense of costly mistakes.

My belief regarding your problem is that you have the cam indexed incorrectly its not 180* out its actually 90* out and the valves hit the piston preventing it from turning over. Somethings bent for sure and you should follow the suggestions of "31 vicky" .

Here is the section on Olds engines that shows the timing marks aligned.

 

Nothing better than a good Motors shop manual, I have my dads and these books are packed with the real deal.

 

Dick Spadaro's comment regarding obtaining a manual and reading it before you act is probably one of the best pieces of advice ever posted on the HAMB. However, if you have been following the "Ready, Shoot, Aim" method of processing tasks, it is difficult to make the transition. The change is tough, the results are worth it.

 

My shop's bookshelf is full of old Motor's manuals from the 50's through the 80's, as that's pretty much all I work on. They are thorough and accurate. Pick'd em up over the years from my Dad and the Uncles and swap meets. Even if I find duplicates I grab 'em and pass 'em on to friends....

If you find 'em anywhere, pick 'em up!