Hi all,
putting my 330 stroker together now and upon dialing in the cam, when we have found desired lift@tdc, we put the double row timing chain that was on the engine when we got it back on. However as it sits, it has alot of slack, we have the dial guage hooked up and there is .006" play in the cam gear measured from the dial indicator guage to the lifter. Does this mean that the chain has stretched, and also is it advisable that I get a new timing chain?
many thanks,
brad.
Holden V8 loose Double row timing chain
Started by
_Brad1979UC_
, Jan 16 2010 08:54 PM
18 replies to this topic
#2
_Bomber Watson_
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Posted 16 January 2010 - 09:40 PM
Im no expert, but i dont like the sound of that.
Personally i would be replacing.
Cheers.
Personally i would be replacing.
Cheers.
#3
TerrA LX
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Posted 16 January 2010 - 10:14 PM
Maybe trace the manufacture of replacement chains and ask them for their wear figures.
#4
fuzzypumper
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Posted 16 January 2010 - 10:18 PM
Im with Bomber, putting in a new cam, put in a new chain.
Is that play in the locating pin on the cam gear or are referring chain stretch?
Im not a expert either I would suspect there always gonna some slack in the chain.
I suppose as long you dial it in rotating the crank the clockwise direction,
Experts please shed some light.
Is that play in the locating pin on the cam gear or are referring chain stretch?
Im not a expert either I would suspect there always gonna some slack in the chain.
I suppose as long you dial it in rotating the crank the clockwise direction,
Experts please shed some light.
#5
_Brad1979UC_
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Posted 16 January 2010 - 11:18 PM
Yeh ive decided to replace it...actually writing .006" seems like nothing, but it feels like alot of movement in the cam gear, the chain is floppy, i wouldnt expect it to be super tight, but this one im sure is definitely not right. Its not play in the locating pin the chain is actually to what i can tell, stretched.
we actually devised a possible reason to what happened, when the previous owner had to fit peter jackson timing gears and screwed the cam timing causing the valves to stack onto the pistons, it would have put load on the chain which has stretched it we think. Will check repco or like tomorrow for a new double row chain.
we actually devised a possible reason to what happened, when the previous owner had to fit peter jackson timing gears and screwed the cam timing causing the valves to stack onto the pistons, it would have put load on the chain which has stretched it we think. Will check repco or like tomorrow for a new double row chain.
#6
Struggler
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Posted 17 January 2010 - 08:58 AM
The chains do stretch and usually in the first 20 min of running the engine.
I have pulled some 253/308's apart that have had extremely sloppy timing chains and have still run. The real problem is what this does to the cam timing (ie the looser the chain the more retarded the cam timing). I have reused timing sets on budget builds as long as they are not too sloppy and advance the cam timing to compensate. If you need to advance the cam more than 3 or 4 degrees you need to buy a new chain.
Hope this helps.
I have pulled some 253/308's apart that have had extremely sloppy timing chains and have still run. The real problem is what this does to the cam timing (ie the looser the chain the more retarded the cam timing). I have reused timing sets on budget builds as long as they are not too sloppy and advance the cam timing to compensate. If you need to advance the cam more than 3 or 4 degrees you need to buy a new chain.
Hope this helps.
#7
Heath
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Posted 17 January 2010 - 09:45 AM
Is it definitely the chain stretching? Not the teeth being worn? Just a stab in the dark Brad I've never dealt with one
#8
_outer control_
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Posted 17 January 2010 - 09:53 AM
The chains do stretch and usually in the first 20 min of running the engine.
I have pulled some 253/308's apart that have had extremely sloppy timing chains and have still run. The real problem is what this does to the cam timing (ie the looser the chain the more retarded the cam timing). I have reused timing sets on budget builds as long as they are not too sloppy and advance the cam timing to compensate. If you need to advance the cam more than 3 or 4 degrees you need to buy a new chain.
Hope this helps.
Also use an Iwis chain for sure thats what i,ve always used [i think thats how its spelt,but good suppliers will know]
Edited by outer control, 17 January 2010 - 09:53 AM.
#9
micklx
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Posted 17 January 2010 - 09:54 AM
Like other 308 components (rod bolts valve springs etc) if you are doing a standard rebuild you can get away with reusing parts.
But if its a performance build and your going to rev it reguarly then you should be using new components.
But if its a performance build and your going to rev it reguarly then you should be using new components.
#10
_Brad1979UC_
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Posted 17 January 2010 - 06:05 PM
done...bought a new double row timing chain from east coast, will fit it up tomoro.
Heath the teeth look fine, if you actually rattle the links in the chain you can feel its stretched im v sure its the chain
Heath the teeth look fine, if you actually rattle the links in the chain you can feel its stretched im v sure its the chain
#11
Heath
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Posted 18 January 2010 - 12:01 PM
Okay, just thought I'd throw it out there because I'm pretty used to pushbikes. With pushies you will normally go through 3 chains with one set of gears (the chains' links stretch and the roller wear out), but yeah the teeth definitely wear out with time as well. Don't know if it's anywhere near as much of an issue with a cam drive system.
#12
rodomo
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Posted 18 January 2010 - 01:16 PM
if you actually rattle the links in the chain you can feel its stretched im v sure its the chain
This rings a bell?????
Isn't there a method of measuring wear by the amount of curve in the chain?
#13
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Posted 18 January 2010 - 07:02 PM
^ Yes rodomo, it is the same method as for a fan belt, use one of those spring scales, just couldn't think of the kg's to answer, will have to dig it up sometime.
#14
GML-31
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Posted 18 January 2010 - 08:03 PM
for the cost of a chain its not worth stuffing around
#15
Heath
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Posted 18 January 2010 - 11:02 PM
Yeah I just saw the motor tonight, new chain in place & sits nice and snug, not particularly expensive either.
#16
rodomo
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Posted 18 January 2010 - 11:19 PM
^ Yes rodomo, it is the same method as for a fan belt, use one of those spring scales, just couldn't think of the kg's to answer, will have to dig it up sometime.
I agree, I would just replace it as well for the price.
But the wear method I was refering to was not as described with spring scales.
Hard to explain but it was laying the chain flat on it's back and then bending it in an arc.
The amount of deflection from parallel gives the wear limit as it measures pin wear and plate wear if that makes sense?
I think I saw this in an old workshop manual?
#17
_oldjohnno_
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Posted 19 January 2010 - 06:03 AM
As everyone else has mentioned the chains are so cheap you wouldn't waste time trying to measure the wear. Just as a matter of interest tho the usual method of quantifying chain wear is as a percentage of stretch. So if you had a chain that was 1" pitch and 100 links long, and the wear limit was 0.5% (a common figure), then you'd replace it if it measured over 100.5" in length. But for the tiny (and cheap) chains in car engines you wouldn't bother..
#18
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Posted 17 July 2010 - 12:41 AM
I was talking to someone about this the other day and he said, for a chev, he winds the crank forward then backwards while watching the rotor for movement, it it takes more than 10 deg (on the crank) of movement then the chain is loose.
The holden block is similar so I might try this method with the next motor I do soon and see what results I get.
The chain would need a bit of play otherwise the cam and crank would ride on the bearings as it was dragged around by the chain.
Another one that comes to mind is with the chain installed, push down on a roller with something while you try and lift the link.
The holden block is similar so I might try this method with the next motor I do soon and see what results I get.
The chain would need a bit of play otherwise the cam and crank would ride on the bearings as it was dragged around by the chain.
Another one that comes to mind is with the chain installed, push down on a roller with something while you try and lift the link.
#19
_Gunmetal LH_
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Posted 17 July 2010 - 04:11 AM
My VN timing chain is 'loose as a goose' so much so, that I get a little more top end out of it!
$800 car, not looking at replacing it yet...
$800 car, not looking at replacing it yet...
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