The honeymoon is over – Broken timing chain?

Locktite is your friend there. Don't look bad at all

 

My thoughts exactly. I think I got really lucky.

 

You'll want grade 8 bolts

 

Unfortunately, I pulled the crank gear without paying attention to which keyway was used. The gear has 9 keyways and looking at some pictures I took while I was disassembling the timing chain it appears the 2nd to last keyway on the left side of the gear was used when the cam was installed (but I’m not positive). (See pictures. Note: the key on the crank is just below 9 o'clock) In addition, I thought the car had a Lunati H230-245 cam because I found the cam card and some other info in the previous owner’s documentation; however, after looking through the info again I found info that’s making me question the cam grind. So that leads to a couple of questions:

1. Are there typically marks on the cam that identify the grind? I didn’t see any on the front of the cam. Is it worth pulling the cam so I can see if there’s anything on the back of the cam? I’m asking because I’m wondering how to degree the cam without knowing the grind. (I’m just now learning about degreeing cams and I need to read through JW’s writeup again.)
2. Do I use the degree wheel to figure out the grind? (I'm assuming this can be done.)
3. If I can’t determine the grind what do I do? Install it straight up? Install it the way I THINK it was (2nd last keyway on left) and check piston-to-valve clearance? Do something else?

Also, regarding the timing chain purchase, I stumbled across an invoice that has billing for align honing. Originally, I was going to buy a standard timing set, check how tight the chain is, and order an oversized set if need be. Now since I THINK the block was align honed:

1. Do I follow that same process?
2. If the standard chain is too loose, can I measure the deflection and use that info to determine the correct size timing set?

Thanks!

 

I think you can get just the chain.

Someone correct me if I am wrong, but isn't an oversized set just a difference in the gear size and not the chain itself?

If I remember correctly Lunati stamps the cam ID on the back.

I would just out it back the way it was if you can positively confirm what it was at. If you are not sure, you need to degree it to make sure it doesn't get damaged.

Oh, and the cam bolts are special (very thin head). These are not just a hardware store special. TA has them in ARP if you can't get originals.

 

yes the difference in an undersized timing set is the gear diameter not the chain

 

Looking at the pics I would also think it is the second to last keyway. To confirm, I would install the gear, using the two keways before and after the one you think is the right one and take pictures with a similar camera position like you used before. I am pretty sure it will show very obviously which keyway is the correct one.

 

Unfortunately, the teeth on the cam gear were damaged when the chain broke, but I guess I can measure the diameter of the gears and then contact one of the manufactures to see what size set I need.

I like the idea about installing the set and taking pictures to confirm the keyway used.

Thanks for all the help! It's good advice and I'd be struggling without it.

 

I would degree the cam anyway. In theory the timing sets should be the same but i would check it anyway.

 

I would like to degree it, but I'm not sure about the cam's specs. That's why I was considering just installing it the way it was previously installed. Do you think it's worthwhile to pull the cam to see if there's something on the backside that would identify the grind?

 

Have you checked to see if any of the valves were bent yet?

 

Not yet. I was going to pull the rockers and do a leakdown test, but then decided to do the test after I install the timing chain so I don't have to pull the rockers.

 

So I’m still struggling a bit to determine the correct size timing set. I spoke with TA today and they said there’s no good way to determine the proper size without knowing specific engine info. However, they did say if I order a set from them they would replace it for free with a different size set if the chain is too loose. Before I go down that path I’m just wondering if the info I just found (shown below) provides any guidance as to what size set I should use. Thanks!

 

Sorry nothing really there to help.

 

Okay. Thanks! Plan B it is.

 

Wow! I did not realize that. Thanks for letting me know! I haven’t had a chance to enjoy the car since I bought it. I’m anxious to get the car back together and see how it runs.

 

P.C. Automotive in Oberlin, OH. It was built in 2010. I just contacted him. He remembers the car but not the specifics of the build. I figured it was a long shot, but worth a try.