Broke timing chain - How screwed am I?

[Dr. Jeckel]

OK, I finally got back to my computer and boy was it an interesting day. First off when I drained the oil I noticed it looked like caramel......not good. I pulled the pan to make sure all water/coolant contaminated oil would be removed. Question is since I primed the engine with this crud the first time, did this hurt my motor? What do I have to do to clean out all the water or does my engine need new bearing and be rebuilt?

Also I checked all the pushrods and the #3 exhaust and #5 intake were bent. #3 was bent pretty bad. On the crank gear four teeth were partially broke off and the chain broke clean. I found all four peices of the crank gear in the pan. I wonder if i put it on and didn't get the chain seated on the crank gear properly
I did notice the dot on the cam gear but didn't notice a dot on the crank gear....is the "dot" the notch in the gear?

I am about to just pull the motor and trans and take off the heads, replace them with some ported irons, replace the cam, lifters, pushrods. I don't have the money but mr discover does and I am to the point of just doing it all since I've nearly got it all apart.

Anybody have advice for me. Say in the way of heads cam package, and head gaskets. I am going to search on all this stuff tonight and tomorrow but anything helps. I am also going to put on a new chain/gears and do a quick compression check on the #3 cylinder at least.
Thanks for all the help, I really appreciate the support!

 

[Roc87]

The guy who wrote the article on GnTtype.org, Erik is a friend of mine, AKA FuzzyGN (here) Even after reading his article, I didn't trust myself to do it. I drove down there and had him do it! He knew what he was doing when he wrote the article. Glad I had it done when I did!

 

[TRENT THOMPSON]

don't feel bad bro! I have done the same thing in the past ( caused by alcohol consumption while assembly ) and bent every single intake valve in a set of brand new champion irons....... took everything back apart and popped in new manley valves from jegs fired right up! sucks huh!

 

[1badTTA]

Well since nobody has mentioned it yet, I will. Look at the box from the new chain and see if it is the correct one and not for an engine that has been line bored. It is possible you got a short chain for a line bored engine (line boring raises the crank requiring a shorter chain). If this did happen it would explain why the chain was so tight and broke. As for replacing the chain in the same position as the old chain, it could possibly work but you would still need to rotate the engine to make sure the dots did line up once you have the chain back on. You are better off just turning the engine to TDC before you take it apart.

 

[TR Custom Parts]

Originally posted by 1badTTA
Well since nobody has mentioned it yet, I will. Look at the box from the new chain and see if it is the correct one and not for an engine that has been line bored. It is possible you got a short chain for a line bored engine (line boring raises the crank requiring a shorter chain). If this did happen it would explain why the chain was so tight and broke. As for replacing the chain in the same position as the old chain, it could possibly work but you would still need to rotate the engine to make sure the dots did line up once you have the chain back on. You are better off just turning the engine to TDC before you take it apart.

Think you might have hit the nail on the head. That's makes sense. In my many years of hot rodding I have never seen a timing chain itself break. Wonder if that is what happened?

 

[musclecar neal]

seen many break from mechanical interference. It is so rare to find undersize chain sets ( most are special order). from the way he installed the set it is very clear what happened.

Neal

 

[scottyb]

That sucks.

When you get the next set on and ready to go, bolt on the balancer without the front cover and rotate by hand to make sure everything jives. I even did a compression test on mine like this.

 

[Dr. Jeckel]

Well all I have to do now is get the converter bolts and bell housing bolts off and out she will go. I am going to have everything checked and have a port job and 3 angle valve job done. Then put it all back together on an engine stand, put it all back in and hold my breath while I turn it over.
Once I get ready to put the new cam in how do I make sure that I'm on TDC on the compression stroke. I know I can set the piston to TDC #1 but how do I know I'm not going to be 180* out with the cam installed?

 

[musclecar neal]

If you line up the dots you will be set. If the crank gear is at 12 its where you want it.

Neal

 

[Scott231]

Originally posted by Dr. Jeckel
<snip>I wonder if i put it on and didn't get the chain seated on the crank gear properly I did notice the dot on the cam gear but didn't notice a dot on the crank gear....is the "dot" the notch in the gear?

Uh, You didn't install the crank gear backwards did you? The dot is pretty obvious if you are looking at the correct side of the crank gear. That too, would be a problem.

 

[Scott231]

Originally posted by Dr. Jeckel
I know I can set the piston to TDC #1 but how do I know I'm not going to be 180* out with the cam installed?

If you examine the cam lobes for #1 when you install it, then make sure the lobes are not in the position that they would be opening a valve. You want Top Dead Center on the Compression stroke. If you do this correctly then the "dots" on the gears will line up correctly.

And another little trick (its been a while so correct me if I am wrong here people) but I believe the cam gear will only go on the front of the camshaft one way...the correct way.

 

[musclecar neal]

Scott is correct. Good thinking.

 

[Dr. Jeckel]

Well you hit the nail on the head. I can't beleive I put the crank gear on backwards My carelessness cost me alot of time and mula.
Oh well. I got the heads off and the #3 & #5 pistons were nicked and the valves were as well, but you couldn't hardly tell.
Can I use Carb cleaner on the pistons to get the carb build up off without hurting the cylinder walls? Is it going to hurt if the carb cleaner gets in oil ports or in coolant ports since the car will be sitting open for atleast 4-5 days. The carb cleaner should just dry up by then, shouldn't it. I have everything off the engine. I went ahead and did it in the car, no problem at all. The only thing left is the crank,rods,pistons. Everything else is on the table. There is a little bit of play in each piston at TDC for each one.

 

[Scott231]

Originally posted by Dr. Jeckel
Well you hit the nail on the head. I can't beleive I put the crank gear on backwards.

Never thought I would say this but, sorry I was correct.

Oh well. I got the heads off and the #3 & #5 pistons were nicked and the valves were as well, but you couldn't hardly tell.

After you clean the piston tops, you can "polish" the nicked portion of the piston domes with a Dremel tool...if you are looking for a quick and easy way to get back on the road.

Can I use Carb cleaner on the pistons to get the carb build up off without hurting the cylinder walls? Is it going to hurt if the carb cleaner gets in oil ports or in coolant ports since the car will be sitting open for atleast 4-5 days. The carb cleaner should just dry up by then, shouldn't it.

The Carb cleaner will be bad for the bearings and the oil. Simply spray the cleaner on a rage and wipe off the piston domes. The minimal amount that might get on the cylinder walls will evaporate without doing any damage.

I have everything off the engine. I went ahead and did it in the car, no problem at all. The only thing left is the crank,rods,pistons. Everything else is on the table.

What is left to do to the crank, rods & pistons? You do not need to disassemble the motor...unless you are planning on big HP.

There is a little bit of play in each piston at TDC for each one.

Huh???