What's Wrong With The 340 From My 1971 Dodge Demon 340?

Well, it could be much worse.

[@rcberry]

I had a 340 in my 1970 Cuda. All my paychecks went into that engine and it would run high 11's. What an engine!

[@BrandonLeeBrown]

A lot of early 1968 340's had the thicker rocker arms contacting the edges of the larger diameter valve spring retainers. The service bulletin called for the dealer to grind a clearance in the existing rocking arms.

[@DeadDodgeGarage]

Oh, that’s interesting. I haven’t read that. I have had pretty bad interference problems like that with aftermarket rockers on 360 heads a couple times so it makes sense.

[@MrTheHillfolk]

😂😂😂 Reminds me of the GM service bulletin during the 68 strikes that stated: missing parts cause no service issues. Same but different 😂😂

[@matthewb8229]

"It's not all loose and floppy". Unlike my belly from a career of drinking beer.

[@DeadDodgeGarage]

🤣

[@Anthony12valve440RB]

You need a poly 318 aka “Semi hemi” thats a engine that not many people know or talk about. Another thing i love about Chrysler is when they came out with the 340 TA From the factory it is ready for you to put a 4 bolt main if you wanted to. I’m a die hard 440 guy but after building my first 416 (340) i was even more impressed.

[@DeadDodgeGarage]

I’ve got two Poly 318s here! I will be doing video on one in the near future, incidentally. They just don’t count as an LA engine. Haha. I am planning to do a video comparing /all/ of the 318s at some point.

[@1575murray]

@@DeadDodgeGarage The Poly 318 was a good engine but it won't fit in an A body car. That's why the LA 273 was introduced in 1964 to compete with GM and Ford which both introduced V8 engines into their compact cars at the same time.

[@DeadDodgeGarage]

@@1575murray I am *extremely* well versed in the history of the A/LA series engines. I didn't say that I was going to put one in an A-body. That has never been in my plan. However - I myself have explained to people that the Poly engine doesn't fit in A bodies because I read that on the internet, only to then see pictures of Poly engines in A bodies... as well as early Hemi engines. Do with that information what you will.

[@Roosters_Restos]

Regarding the tick. You said some of the lifters you can't push down. I had some that became stuck and took on apart to find bearing material. So do have a look at the bearings for groves. Now things you can't live without. A deep pan for the 340. A edelbrock straight ram intake for the 273. And not to harp on this but the 2x4s intake for the charger and its wakey wakey for that motor.😂

[@DeadDodgeGarage]

The Charger smokes both of them 295s down the block as it is 😁 but I like where your head’s at. Yes I’m thinking now that I will gut all of the lifters and look for debris. Glad it didn’t seem to be wiping the cam. I will also check bearings at some point.

[@m1a1hm]

Your right the 340 is AWESOME!! I like to think the 340 is a small block that thinks it's a big block.

[@AverageJoeBuilds]

That's the exact same way my 318 keeps leaking in the swinger, somehow, just somehow, I keep missing a microscopic spot in the rear corner and it leaks enough to make me cry in similar fashion

[@DeadDodgeGarage]

🥲

[@phonebackup8132]

Someone has already mentioned the poly 318. Not many aftermarket parts but it's very possible to make a beast of an engine out of it and they sound amazing!

[@DeadDodgeGarage]

Oh hell yeah! This is in the plan. A friend and I are considering a *very* healthy Poly build…

[@bigwrenchtech]

CHICKENS 🐔 Epic video as always jamie.

[@majorpayne5289]

👍Good stuff! That 360 looks great & is dressed perfectly!

[@TimothyRussell-uv7uv]

340 is no joke my older brother has a 69 dodge charger with a 340 not factory of course, and I have 70 roadrunner with a 383 mild cam and the 340 will walk all over it. The RPMs are ridiculous on a 340.

[@dartdude4084]

I had a 340 In my 67 b body it was ok. Needed to be in a a body

[@Ross046]

Ya know a vid on smallblock heads would be cool. Large valve "J",small valve "J" and "X" heads make my head ache.

[@DeadDodgeGarage]

I’m far from an expert and don’t have any Xs, but I do have many others to look at. There are so many casting numbers… enough to make my head ache too.

[@HowardJrFord]

340's were known for taking down the " legendary " L79 327 on many occasions .

[@leehouston5436]

They were known for taking down big blocks

[@vincemajestyk9497]

I would always take a 340 over a 383 like when it was offered in the later RR's. Actually, the stock performance was about the same but the car with a 340 was more well balanced, nimble and better handling. With the short stroke the 383 is more like a 'big' small block and won't rev as quick or high as a 340. The small block head design (OE) is better too.

[@DeadDodgeGarage]

Exactly! Both are great for their own reasons. But given the choice of the one or the other in a relatively light car, I’m going 340 all the way.

[@sandozman6085]

Years ago i had a light weight rotating assembly, 13 to 1 440 with indy heads and dominator. That would rev like a worked 340, Turned over 7k through the lights. After hurting a rod bearing i learned about big block oil system mods. 😊

[@DeadDodgeGarage]

Oh wow. That’s awesome. Yes I’ve heard a bit about that. In stock land where I usually live (you know, under 5500 RPM, haha) they seem to be quite good.

[@mikesr3407]

Great Video 👍 can't wait for more on the cuda ! I'm told the j heads are the ones I Should Want ! Mine has the X , and of course it leaves a huge oil mess everywhere 😂

[@michaelnault5905]

I keep hearing a ticking as well. Mine goes away when I start the engine :-) Maybe the Demon just needs it's heart back.

[@dantupper1784]

I agree with a careful examination of the lifters. Also could one slightly shorter/longer pushrod be present in that set ?

[@DeadDodgeGarage]

Absolutely something I considered - just also had noise before I installed them. So I’m thinking it’s probably not related.

[@carebear2272]

I remember taking my 383 out of my charger when I decided to restore the car. My friend and I decided it needed rebuilding because it had a ticking. It sound like it was coming from the back left of the engine. When we took the engine out we found out it was the flywheel sprocket hitting the dust cover underneath. It sounded so much like it was coming from the top lol 😝 duh!

[@DeadDodgeGarage]

Yep… I’ve seen that a couple times over the years. I actually mentioned it in a video not too long ago. Good one.

[@plumSRT]

If a 340 is built right and not overheated too badly or over revved too many times, it'll last a long time. I built mine in 96, drive it at least monthly, I don't baby it and she's still going good. I drove it across the country in 99 just for good measure. 26 in 2 core Radiator, 11 to comp. Solid cam. My friends think it's a freak of nature.

[@michaelstrafello7346]

Check the valve guides for wear

[@gasser66]

No whimsical comments out of me this episode, but I will be saying "consternated" from now on. I'm surprised I didn't know that term, being that anxious is my middle name.

[@DeadDodgeGarage]

No one could’ve predicted this show would turn into an English class, but I think I dropped a similarly verbose word or two in today’s video too

[@gasser66]

@@DeadDodgeGarage Now I have to look up verbose 😃

[@rodg2708]

I found big end of some of the rods hitting the windge tray....on my 360 powered 69 barracuda. Check there

[@DeadDodgeGarage]

Will definitely be looking for witness marks there. I’ve had scraping on the windage tray before, but that one definitely didn’t sound like a tick.

[@nakedshorts6784]

I wonder if that ticking sound could be more related to that intake leak into to crankcase in the lifter valley. Every time an intake valve closes the af mixture has to stop . Might sound kinda like a header gasket leak, only internally. Just a thought.

[@DeadDodgeGarage]

Interesting thought. But I think that would be more like vacuum, then loss of vacuum. So a whistle or sound of air moving might be more likely than a tick. Someone else said a valve rocking in its guide could also do that. Whatever it was, it was inconsistent. Just sounded exactly like ticky lifter to me. Even with the new engine, there is a very slight exhaust leak… somewhere… but it’s giving me a different sound than the tick.

[@nakedshorts6784]

@@DeadDodgeGarage Is there any sign that the deposits in the intake runner were burnt? Or do you think they just accumulated over time as sludge? No doubt it wouldn't be running right, and making less power. My idea was just a shot in the dark. There probably would have been some oil carbon build up in that cylinder though. Maybe that was a pre-ignition knock in that one cylinder during higher temperatures. Was it mostly after a full warm up? I can usually locate odd sounds with a piece of hose and use it like a stethoscope and plug the other ear. A valve train issue would be my first thought also, bad rocker, stem, geometry etc.

[@plumSRT]

22 inch radiator, my bad.

[@plumSRT]

Oh, and knock on wood...

[@DeadDodgeGarage]

Definitely knock on something 🤣 sounds awesome!

[@brentforte5950]

It's not like you didn't have good reason to get her out and open her up and check for damage. She's been ran hard racing probably without a proper brake in.

[@DeadDodgeGarage]

I think he did a proper break in. Hey, they cam is in one piece, good enough for me. But yeah… lots of reasons to pull it and evaluate.

[@acardiac5983]

What was the compression ratio with the j heads?

[@mopartron3030]

I have a similar problem with my 360 blowing oil out the front "China" wall like your 340. I'm also running the open-chamber Edelbrock heads, hmmm. I've tried resealing it once but it didn't accomplish anything.

[@DeadDodgeGarage]

Interesting. As I showed on mine, the main issue was actually the shape of the intake - it didn’t have material toward the back at that corner where the silicone was put down. But it did seem to sort of seep from all corners…

[@kevinroy8611]

Does your 340k member have a washer welded to the front face of the k member?

[@DeadDodgeGarage]

Yes, it does! I thought it did but I didn’t want to say that with confidence before taking a look again.

[@kevinroy8611]

@@DeadDodgeGarage it should have, I was told that the factory welded these washers on to let the assembly line know that it was a 340 car

[@kevinroy8611]

So when ya buy a advertised 340 k member look for the washer

[@DeadDodgeGarage]

@@kevinroy8611 I knew they were used in high performance engine lines in other cars. Hadn’t thought about it for the 340. Essentially a 318 K member is a 340 K member - but no washer, and someone looking for correct details should know that.

[@kevinroy8611]

@@DeadDodgeGarage yes, i had a guy try to sell me a "340 k member for 300$, and it didn't have the washer. I guess you know what i told him..... hey anyway, great channel! keep it up

[@wbarney59]

All the 340,s I saw back in the day were blown up. Hand grenades. Junk garbage blown up crap.

[@DeadDodgeGarage]

Interesting. One has to wonder if that’s an engine problem, or an operator problem… I have definitely seen at least two with sleeves in them. Seems to have been a common enough problem with 426 Hemis too.

[@wbarney59]

Operator problem

[@trojan440]

273 was and is a great little motor,race that 360 and save 340 till you don't wanna race any more. No. Matching. Won't be another one. Just saying. 340 is bad ass,383 is also an asskicker.

[@justincampese3446]

Spivey!

[@Roosters_Restos]

First to comment or run my mouth Jamie 😂 discounting a 383 and insinuating that a 340 could beat one. Nope never happen. In fact 383s would woop a 440 with just a cam change. You had to spend cubic $ to make a 440 hot. 383 with the shorter stroke would ramp rpms fast and used the same heads as a 440. Thus bb torque with rpms of a small block. Knarly little 383s. Won lots of races with them. Then spent the money on a 440 to go faster. Cuz we always want that 😅

[@DeadDodgeGarage]

You know I love a short deck. Haha. They’re great. But the 340 has weight advantage and it sure loves to spin. There are good points for both sides there. I know people do it, but to me the 340 is the choice for an A body instead of the 383. If for no other reason than actually being able to work on the damn thing.

[@Roosters_Restos]

@Dead Dodge Garage I will never dis a 340 they are special. There cool. The weight difference is less than couple hundred lbs which is nothing really. What's even crazier is a 4"bore 318 that blows the doors off a 340. The little engine that could lol. Thomas the tank engine lol. It's all good and fun.

[@Roosters_Restos]

@Dead Dodge Garage as for a big block in a A body. Let's just call that 10 gallons in a 5 gallon pail. Changing plugs is optional lol

[@jumpinjojo]

@@Roosters_Restos I had a 440 in my 72 Dart. It was a bitch to work on!!

[@trojan440]

Race that 360,save 340 till you are done playing. 273 awesome motors. Everybody forgets the 400,biggest bore of them all. Short stroke.

[@javimacias1215]

If the 273 has 920 closed chambered heads wouldnt you add bigger intake valves like 1.95, rather than using the 302's which I hear have some restrictive flow?

[@DeadDodgeGarage]

I have heard that too. I think the 302s are pretty decent - but maybe not for my goals here. I was more thinking for compression. I realized later that it should have closed chamber heads already. I could just use them. Either would get a mild porting and cleanup job but I wouldn’t go crazy with it. We were also considering Magnum heads for this.

[@stannelson2582]

What headers are on that 340? Tti?

[@DeadDodgeGarage]

Yep! They’re awesome. Just a little cramped on clutch linkage and starter.

[@stannelson2582]

@@DeadDodgeGarage could your lifter tick be a header leak? Is it on the side with the two piece design? Lol maybe ticks squeaks and rattles are sort of like leprechauns lol. Poof and gone then back then gone lol.

[@brianandglendaharkin9457]

👍🏻🇦🇺💯⛽️

[@musclecarmitch908]

Great episode! I can't say that I particularly like that timing chain set up in the 340, I'm sort of a purist and something tells me even though the Mark's lined up something may be off with that setup. I'd put a good old factory style double roller timing chain back in it.👍

[@DeadDodgeGarage]

It’s definitely… interesting. They’re pretty popular though. Supposed to help keep timing rock solid.