1973 340 issues.

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trigger_andy said:
Ok cool. Might be best doing this. I guess it will tell me if the Head Gasket it ok too?

By the way, what did you mean by this '' If you think you're halfway happy with it now, you ain't seen nuthin yet.''

Many thanks
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I mean that if you say it runs better than the 318 now, wait till you get it repaired and running right.
 
nm9stheham said:
Not specifically that; it will just say that it is not likely rings. RRR's note is good if you have access to compressed air. If you are gonna do that, do it BEFORE you pull the heads.

The black residue could be an exhaust gasket leak too.
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Good point. :) I'll check that too. Think its ok to re-use the intake gaskets after less than 100 miles?
 
RustyRatRod said:
I mean that if you say it runs better than the 318 now, wait till you get it repaired and running right.
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Ah ok, haha. True. But if its only #2 thats really causing issues and I get that sorted will I really see a big difference?
 
Hi Andy, I doubt it, on that motor your looking roughly at around 25hp per pot for the good'uns, that "2 pot is somewhere in the region of around 8hp, you probably got around 175hp in total there, thats a long way off of 240.
 
Hot Metal said:
Hi Andy, I doubt it, on that motor your looking roughly at around 25hp per pot for the good'uns, that "2 pot is somewhere in the region of around 8hp, you probably got around 175hp in total there, thats a long way off of 240.
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Thanks. :) I think I follow what you're saying but I dont see where you get the last 240 figure from? 8 x 25 = 200.
 
Fuzzy math.

I wouldn't try to repair just one part of that engine. Do a complete teardown, inventory what you can and can't use, what machine work needs to be done, what parts you need and go from there.
 
RustyRatRod said:
Fuzzy math.

I wouldn't try to repair just one part of that engine. Do a complete teardown, inventory what you can and can't use, what machine work needs to be done, what parts you need and go from there.
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I have a '72 340 that needs a full rebuild/bore etc and I was planning on running this one till that was ready, about a year or so I guess?

So really I do want to repair this one part of the engine and run it as long as I can till the other one is ready. Do you think thats feasible at all?

Thanks. :)
 
trigger_andy said:
I have a '72 340 that needs a full rebuild/bore etc and I was planning on running this one till that was ready, about a year or so I guess?

So really I do want to repair this one part of the engine and run it as long as I can till the other one is ready. Do you think thats feasible at all?

Thanks. :)
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Not the way I do things. IMO, a head is going to have to come off at the very least. You're over half way there at that point.
 
RustyRatRod said:
Not the way I do things. IMO, a head is going to have to come off at the very least. You're over half way there at that point.
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I appreciate its not the way you'd do things and I appreciate your informed replies. :)

Ive spend over $10,000 on the 340 and 4 Speed, shipping the parts and all the costs of installing and getting parts shipped over from Australia and the US to Scotland. So Im completely out of budget and if I can finally have a little fun in the Charger I'm gonna take it. :D

The Head will have to come off to potentially lap in the valves at a minimum? With the Heads off in what way would I be half way there?

Thanks again. :)
 
trigger_andy said:
I appreciate its not the way you'd do things and I appreciate your informed replies. :)

Ive spend over $10,000 on the 340 and 4 Speed, shipping the parts and all the costs of installing and getting parts shipped over from Australia and the US to Scotland. So Im completely out of budget and if I can finally have a little fun in the Charger I'm gonna take it. :D

The Head will have to come off to potentially lap in the valves at a minimum? With the Heads off in what way would I be half way there?

Thanks again. :)
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You'd have the engine more than half way apart. What if it's a burned valve? I wonder how close all of the rest of the valves are to being burned? Get where I'm going? I get that you want to have fun, but do you want to be doing this again soon?
 
trigger_andy said:
I see, thats for the clarification. :) So the 25hp per pot is a guestimate for a good used 73 340?
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No, I am making guesstimates on your motor from your test, you have 6 pots at around 25hp, 1 at around 15 and 1 at around 8 = 173hp+/-...a good used '73 340 could still be up around 220+
 
RustyRatRod said:
You'd have the engine more than half way apart. What if it's a burned valve? I wonder how close all of the rest of the valves are to being burned? Get where I'm going? I get that you want to have fun, but do you want to be doing this again soon?
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I hear ya. :)

But taking the heads off can be done insitu and fairly quickly/easily. If I get lucky and it’s not that that bad the can be back on within a day or two. If it’s anything to do with the bottom end I’m assuming the bores will need to be bored out and then it’s new pistons etc. It would just add arms and legs. :(
 
Hot Metal said:
No, I am making guesstimates on your motor from your test, you have 6 pots at around 25hp, 1 at around 15 and 1 at around 8 = 173hp+/-...a good used '73 340 could still be up around 220+
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Ah I see, thanks again. :)
 
I bought a '71 340 Cuda here, was supposed to be a '71 which is 10.5:1CR, it wasn't, the seller bought me a set of 10.5:1 pistons which we fitted and boy that changed things, if you have the money its a worthwhile thing to do on the rebuild of your other motor which is prob also 8.5:1..(8.1) reality. Then you can add a more radical street cam etc. and 300hp is on the cards.

Les
 
Looks like for now, all you can do is run it and patch it as well as you can. Understood on the situation. IMHO, keep diagnosing and pecking away at it, and I am sure you'll figure out what makes the best sense for you. If #2 is ring or piston/bore wear, there is nothing you can do with it..... unless you can find a lot of those old JCWhiney compression pills!
 
RustyRatRod said:
Why?
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because a leakdown test can tell you more accurately where the leak is coming from. if you detect air coming from the oil pan it points to rings. if from the exhaust ports from a bad exhaust valve, from intake port it points to a bad or bent intake valve, if from between the head and block a blown gasket or cracked head
 
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Hot Metal said:
I bought a '71 340 Cuda here, was supposed to be a '71 which is 10.5:1CR, it wasn't, the seller bought me a set of 10.5:1 pistons which we fitted and boy that changed things, if you have the money its a worthwhile thing to do on the rebuild of your other motor which is prob also 8.5:1..(8.1) reality. Then you can add a more radical street cam etc. and 300hp is on the cards.

Les
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Hey Les,

my '72 340 will be getting rebuilt with 10.5:1 Pistons and a wilder cam as you mention and I simply cannot wait to see what that feels like. :)
 
nm9stheham said:
Looks like for now, all you can do is run it and patch it as well as you can. Understood on the situation. IMHO, keep diagnosing and pecking away at it, and I am sure you'll figure out what makes the best sense for you. If #2 is ring or piston/bore wear, there is nothing you can do with it..... unless you can find a lot of those old JCWhiney compression pills!
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Yes, thats the situation Im facing and Im truly grateful to you guys for all the advice and pointers even though its not what you'd do or advice. Means I can have a little fun spending serious cash again.

Very curious about those Compression Pills. :D
 
trigger_andy said:
Not really on the cards just now as I have no way of doing this. Thanks though.
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if you have an adapter from an air compressor to a fitting that would fit a spark plug you can get close to the same results. Just make sure the vavles are closed on the cylinder you are testing
 
Oh, one other point of interest was when I was filling the Bores with the ATF and Acetone mix the Bores #1 and #8 where bubbling/boiling the mix for a few minutes. The other Bores did not do this. What would cause this? Heat Build up caused by blocked coolant passages?
 
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