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Engine noise, then no-start

JerzNick

JerzNick

SE Level Member
Finally finished the build! :cool:

HOWEVER, I'm not very happy about this... after finalizing every nut & bolt, I fired her up! Started immediately, Cam sounded awesome and idle was perfect for the most part... I let it run for about 10 mins and turned it off.

Next day, finish up the mufflers and fire it up again, this time a lot of smoke in the engine bay from the paint burning off the headers. After running about 2 minutes, a loud knock started getting louder and louder... I whipped out my phone to film it then shut it off right away. I double checked just about everything, rocker arm torque etc.

Now it won't start at all. If I hold WOT when starting it I get a tiny backfire.

Any insight??!!

First Start: http://youtu.be/uF4ZXJUpEr8

Day 2 after mufflers: Motor noise gtp - YouTube
 
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Was it a brand new cam or did you buy it used? Definitely sounds like something wrong with your valvetrain. If some spec was off on the cam then your valve train it will chew itself out.
 
buickman104 said:
Was it a brand new cam or did you buy it used? Definitely sounds like something wrong with your valvetrain. If some spec was off on the cam then your valve train it will chew itself out.
Click to expand...

Brand new cam. According to ZZperformance anyway.
 


Listened to it on the phoner.

Fill us in on all the parts.
Rockers?
Pushrods?

Pull the plugs and see if any show anything out of the ordinary.

Triple check your plug wire routing/order. It sounds like two cylinders may be swapped. Then fire it back up wtih vid running and give it a couple of revs. That's how you can really tell if a bearing spun etc. So far..I'm not thinking a bearing.
 
Bill: Double then Triple checked the Plug wire routing. Perfect. Pulled plugs (APP-606's) gap is fine, plugs are a little wet though.

Have to pull the cover to get to the timing dots (which I think is the issue) Not sure how it went out of time on it's second start?!

Matt: Compcam lifters, stock rockers, stock pushrods, XP-Cam, 105# springs.
 
BillBoost37 said:
Why comp lifters?
Always..take a picture and if you did it right..it can't change time.
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Needed new lifters, went with comp but I think that was a mistake.

I remember the dots lining up perfectly, I should of took a pic! Maybe sprocket came loose?! I'm baffled!
 


After re-torquing the rockers (cause it sounded valve related) I get NO start at all! Only WOT during start gives me a backfire, That's why I'm thinking timing issue btw
 
Something to look into as well. Verify that the crank pulley is aligned properly. I remember Thrasher demonstrating how easy it was to install a cam when they were first available in the parking lot at GPG. They installed the crank pulley with an impact, and it made it's own keyway. The timing was off enough that the car never could quite fire. If your crank pulley slipped a little, it could cause what your seeing.

-Rob
 
RivMan said:
Something to look into as well. Verify that the crank pulley is aligned properly. I remember Thrasher demonstrating how easy it was to install a cam when they were first available in the parking lot at GPG. They installed the crank pulley with an impact, and it made it's own keyway. The timing was off enough that the car never could quite fire. If your crank pulley slipped a little, it could cause what your seeing.

-Rob
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Funny you say that, I watched the shop put my crank pulley on with a impact as well. I will look at that as soon as I get home, thank you.
 


Bill, Attached is a picture of the timing marks... Also a picture of what might be the culprit.

IMG_0105.jpg


FML...IMG_0106.jpg
 
A dinged up cam keyway can cause issues. I don't think timing would be that far out at this point. Definately something that has to be addressed.

Putting a balancer on with an impact isn't a bad thing. However if you sit the balancer on the crank w/o rotating it and pushing to seat it on the keyway, that's when you screw up the keyway/balancer if you torque it. I've seen people do this with and without impact. Not sure why they wouldn't line it up, it has a groove and the crank has a key to fit in that groove.
 
Your first photo shows that the timing gear isn't lined up properly with the gear behind it. Probably your issue there.

-Rob
 
BillBoost37 said:
A dinged up cam keyway can cause issues. I don't think timing would be that far out at this point. Definately something that has to be addressed.

Putting a balancer on with an impact isn't a bad thing. However if you sit the balancer on the crank w/o rotating it and pushing to seat it on the keyway, that's when you screw up the keyway/balancer if you torque it. I've seen people do this with and without impact. Not sure why they wouldn't line it up, it has a groove and the crank has a key to fit in that groove.
Click to expand...

I hope Compcam will warranty this. The cam is brand new! Turns out the balancer was lined up on the crank with no issues.

RivMan said:
Your first photo shows that the timing gear isn't lined up properly with the gear behind it. Probably your issue there.

-Rob
Click to expand...

How is it off? They look perfectly lined up to me...
 
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