LA vibration damper assistance request.

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Ron_M

Ron_M

1970 Plymouth Duster 318
FABO Gold Member
Joined
Jan 23, 2021
Messages
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Location
Connecticut
Hello. I'm piecing together a mongrel 340 budget build as a spare engine. Primary parts:

1971 340 block
1968 340 MT crank and rods
1970s timing chain cover
My question is if I can use a vibration damper from a 1973 318? I don't see cast numbers on the backside, I figure taking a wire brush on Dremel tool to see if one exists.
I've attached pictures I f the damper.
Thoughts? ( I did see optimum option is to buy new.) Thank you in advance.
PXL_20211004_142655307.jpg
PXL_20211004_142558502.jpg
 
I believe neutral.
I have used this damper before on a different 68 340 (which is why it's red) but that was in the 90s until I bought a different damper. Never had a issue. That was pre internet.
 
It looks like it may be "balanced" with the three drill spots where metal has been removed although it does look like an early damper, the late ones are marked "340 cast crank only" or something like that...Id say you could use it on your early crank.
 
My thought process is the balancer needs to match the crank. But in 68 it's a different t/c cover and balancer and timing tab.
I want to use early 70s set up.
 
That balancer is for sure neutral. But when you are using non-factory rods and pistons, if they are different weights than factory, then the thing is no longer balanced.
 
this is true, one difference that I am aware of is the early balancer timing mark will line up on the passenger side of the engine while the later balancer the timing mark lines up on the drivers side.
 
Ron_M said:
Hello. I'm piecing together a mongrel 340 budget build as a spare engine. Primary parts:

1971 340 block
1968 340 MT crank and rods
1970s timing chain cover
My question is if I can use a vibration damper from a 1973 318? I don't see cast numbers on the backside, I figure taking a wire brush on Dremel tool to see if one exists.
I've attached pictures I f the damper.
Thoughts? ( I did see optimum option is to buy new.) Thank you in advance.View attachment 1715800786 View attachment 1715800788
Click to expand...
Go ahead and use it. No 318s were ever externally balanced.
 
Pistons are TBD dependant on what the bores require. Not that far yet. Taking inventory of what i have laying around. Going to use early j heads, repro 340 MT cam from Oregon and an LD340 that needs a home.
Damn phone spell check!
 
Dartswinger70 said:
this is true, one difference that I am aware of is the early balancer timing mark will line up on the passenger side of the engine while the later balancer the timing mark lines up on the drivers side.
Click to expand...
That is easy to deal with.........Piston stop, remark the balancer
 
Ron_M said:
Pistons are TBD dependant on what the bores require. Not that far yet. Taking inventory of what i have laying around. Going to use early j heads, repro 340 MT cam from Oregon and an LD340 that needs a home.
Damn phone spell check!
Click to expand...
This is coincidental but i am engaged in a similar project, I had a 340 std bore block sitting around for years, I also had the crank but one of the journals was scored, I finally sent that out January of this year, and started "scrounging" up parts..I have a set of J heads with 1.88s Ill either run them or have them worked and 2.02s installed.... Im trying to get the short block together, here hopefully before the holidays. I have an engine in the car so no rush, but i want the "parts" I have lying around assembled and ready to go.
 
This project started when I lost out on buying back a 70 short block I sold 10 years ago. Then, I lucked out and was offered a rotating assembly which I promptly scored. The assembly was lonely and I found a block and large valve heads. Most of the rest I already had from other projects.

I don't want another car project but a SB motor project is pretty harmless, right?

Good luck with yours!
 
Yah man, you too. I guess we shall see how this "balance" situation works, mine is internally balanced early 340, and I scored stock part number rods and pistons, i figure they cant be that far off weight wise but we shall see...key thing is using correct damper and flywheel etc.
 
That balancer will work. Just get it balanced with the rest of the reciprocating assembly. Just for your information, that balancer will have an even bolt pattern for the crank pulley. Depending on which pulley you use, it might have to have one hole slotted to get all 6 bolt installed. '71 and earlier had one bolt offset a bit.
 
Thank you all for the replies, it is much appreciated.
New question... How do I get the oil slinger off? I have another damper that is shot and I want to keep the slinger and add the bad damper to the scrap weight pile.
 
The external one is, but, it's more of a seal protector than a slinger. The stock balancers all have one, but, some aftermarket ones don't.
 
cudamark said:
The external one is, but, it's more of a seal protector than a slinger. The stock balancers all have one, but, some aftermarket ones don't.
Click to expand...
All stock dampeners do not have the seal protector. That’s why every so often ppl will ask where this foam type circle piece goes. Kim
 
I'd like to see a factory V8 balancer that didn't come with a seal protector. I've seen a few where that part was removed, but, none without it from day one.
 
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