Harmonic Balancer and Timing cover

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Losi

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trying to finish my rebuild of 340 and running into a complication. During rebuild i found that the water ports on the timing cover corroded 2 holes which caused the head gasket type symptom of fluid switching. I purchased from summit a Dorman replacement 635-400. When trying to reinstall my old harmonic balancer it makes contact with the cast timing marks. Has anyone ran into this problem? it would look as though i would need a less than 7 inch dampner
 
This is what the summit site says about your new timing cover,
"Made from quality materials for durability—and thicker than typical timing covers"
So the question is, how much thicker? How much more room do you need to fully install your balancer? Assuming the balancer is the stock unit you removed.
Is it possible to compare the profile with your old cover and find the difference?
Once you know that it may be easier to find a solution. The easiest and least costly would be to gently grind a small amount from the timing mark boss if it's possible without grinding through it. Good luck.
 
Christ. Why would they make it any different than OEM? IT has to have the correct thickness / dimensions so the water pump works and the pulleys line up............................
 
I don’t have the old but I believe the extra thickness is in the water ports that corrode. Google searches show some people running into this issue.

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Also while those pics are posted that should be a internally balanced balancer right?
 
If I remember correctly the only 340's that were externally balanced were the late 1972 and the 1973's. Depends on crank design...forged or cast. What year's your engine?
That looks like an internally balanced type but.....from what I've found that's from an internally balanced engine.
I've never owned a 340 though.
 
The old timing cover is '70 or newer, timing marks are on the driver's side.
 
That is not a cast 340 crank balancer. The cast 340 ones say so as cast in to the counter weight.

Is it just me or does it look like the outer ring has slipped back towards the block?
 
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With that age, the rubber is starting to stress, I would just replace it.
 
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I ran into that problem using a new cover and summit balancer. I did a little grinding on it to get this clearance, not the best pics but that’s all I have..
While installing the balancer the rubber flex’s some so when it’s all the way on the balancer touches the cover but once you back off the installer there is some clearance there. Verify by torquing the crankshaft bolt.

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View attachment 1715894569 I ran into that problem using a new cover and summit balancer. I did a little grinding on it to get this clearance, not the best pics but that’s all I have..
While installing the balancer the rubber flex’s some so when it’s all the way on the balancer touches the cover but once you back off the installer there is some clearance there. Verify by torquing the crankshaft bolt.

View attachment 1715894572
I actually bought that same summit one thinking maybe there would be a difference
 
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