Timing Chain Jumped?
#21
Registered
Join Date: Apr 2005
Location: KENT ISLAND, MARYLAND
Posts: 2,675
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
I have to agree with JJ like I said before very unlikely you jumped timing chain........
go back and readjust valves if you do it as I posted the merc book procedure its pretty much fool proof just take your time
go back and readjust valves if you do it as I posted the merc book procedure its pretty much fool proof just take your time
#22
Registered
![Default](/forums/images/icons/icon1.gif)
We need more diagnostic work.
You:
removed intake manifold
removed cyl heads
Had the heads done
replaced the camshaft / lifters
So, you had a lot apart. Wires where removed, ignition removed, etc/etc/etc
Basically - a lot has been removed and replaced.
Let's do compression test first, electrical, ignition, and then carb.
Impossible for a good guess at this point.
You:
removed intake manifold
removed cyl heads
Had the heads done
replaced the camshaft / lifters
So, you had a lot apart. Wires where removed, ignition removed, etc/etc/etc
Basically - a lot has been removed and replaced.
Let's do compression test first, electrical, ignition, and then carb.
Impossible for a good guess at this point.
#23
Registered
Join Date: Apr 2005
Location: KENT ISLAND, MARYLAND
Posts: 2,675
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
SB,
I agree with you but first need to get the valves right as of now we do know it was done incorrectly, then we can move on to the std routine
I agree with you but first need to get the valves right as of now we do know it was done incorrectly, then we can move on to the std routine
![Drink](/forums/images/smilies/drink.gif)
#24
Registered
![Default](/forums/images/icons/icon1.gif)
Edited: I caught it - don't respond to mwhat I just typed here.
Doh.
Doh.
#25
Registered
Thread Starter
![Default](/forums/images/icons/icon1.gif)
Results are in. Pulled Timing cover and marks (dots) were off a bit. Removed valve covers, put a straight edge across valves, intake valves no good. Pulled head on left bank, all intake valves were hit by pistons. Pistons have marks from valves. Exhaust valves ok.
Those valves had a short life, about 30 minutes.
Next question, would it be ok to just put new intake valves in, and run it for another month or two?? The pistons have marks on them from the valves, but not too bad. A full rebuild on the motor would be great, but that would mean that the only chance I got at being on the water in 2006 was for 15 minutes
Timing chain had about 1/4 inch of slop on one side, and 1/2-5/8 inch on the other side. When I realigned the cam gear and crank gear, I lined the dots as follows; cam dot at 6 oclock, crank at 12 oclock. When I rotated engine the crank gear was at 12 oclock, cam gear at about 1230 position.
I learned a valuble lesson here. Never take shortcuts, especially when it involves a 50 dollar timing chain, and everything was apart already, and now i had to take it all apart again!!!!
![Mad](/forums/images/smilies/mad.gif)
![Mad](/forums/images/smilies/mad.gif)
Those valves had a short life, about 30 minutes.
![Roll Eyes (Sarcastic)](/forums/images/smilies/rolleyes.gif)
Next question, would it be ok to just put new intake valves in, and run it for another month or two?? The pistons have marks on them from the valves, but not too bad. A full rebuild on the motor would be great, but that would mean that the only chance I got at being on the water in 2006 was for 15 minutes
![Frown](/forums/images/smilies/frown.gif)
Timing chain had about 1/4 inch of slop on one side, and 1/2-5/8 inch on the other side. When I realigned the cam gear and crank gear, I lined the dots as follows; cam dot at 6 oclock, crank at 12 oclock. When I rotated engine the crank gear was at 12 oclock, cam gear at about 1230 position.
I learned a valuble lesson here. Never take shortcuts, especially when it involves a 50 dollar timing chain, and everything was apart already, and now i had to take it all apart again!!!!
#26
Charter Member # 55
![](https://www.offshoreonly.com/forums/images/icons/charter_member_star.gif)
![Default](/forums/images/icons/icon1.gif)
I have had the valves just lightly hit the pistons due to a brain fart during assembly. Bent every intake valve and broke half the intake rockers. Slight half circles on the pistons. I fixed the brain fart, replaced the valves and all was good. Ran the boat for a 60 hrs and the next owner ran it for 150 or so. Never had any issue with the pistons. Just make sure its not deep enough that it creates a hot spot.
#27
![Default](/forums/images/icons/icon1.gif)
Originally Posted by GOODT
what makes you think the chain jumped ?????????
very rare on bb chev mtr, possible dist off after all you did just have it out ??????
very rare on bb chev mtr, possible dist off after all you did just have it out ??????
![Mad](/forums/images/smilies/mad.gif)
Thread
Thread Starter
Forum
Replies
Last Post
tomas_wallin
General Q & A
7
05-26-2005 02:06 AM