Mopar 340 on the Dyno

I was surprised to see what numbers this 340 put out at 406 HP and 430 TQ

[@andy347495]

you can't use numbers from 7 years ago to determine the difference of different carburetors.

[@ryanbarsness]

I know the difference because same Engine and same dyno and I have sheets on the fuel consumption

[@ronnieboucherthecrystalcraftsm]

1 inch spacer under the carby - 725 cfm - good headders ! love me a 340 mopar thank you ! - top quality distributor is an investment !

[@BigfootsnMopars]

Man that’s a stout little 340!! Dynos are fun. Great video Ryan!

[@melaniecotterell8263]

dynos are fun but how do you know how accurate they are? With modern GPS technology acceleration runs should be just as informative, Mass, Time, and Distance are direct measurements. power = W/g x v^2/2t . 1 hp = 550 ft-lb/sec so to get a 4000 lb car to 120 mph in 12. sec you need 292 HP in a frictionless perfect traction infinite torque instant shift no rotational inertia constant power output world. 547 hp would get you to 150 in 10 sec. Wind resistance could be guessed pretty accurately and integrated into the calculation. Assume that 200 mph requires 700 hp. HP used to fight the wind isn't accelerating you. Add 10% to the car weight for the rotational inertia ,

[@BadTreeProductions]

Big block killer. Love 340s Congratulations on 500 bud

[@ryanbarsness]

Thanks BTP I hit 504 last night and now I'm at 497 for some reason. Lol

[@melaniecotterell8263]

340 in3 ~ 0.2 ft3 at 6000 rpm you need a 0.2 x 6000/2= 600 cfm carb. Divide by 2 because cylinder only fills with air/fuel every 2nd revolution 1 cu ft = 1728 in3

[@kenc.2448]

Can anyone recommend a Cam/converter combo? Specially for street/strip duties. Have the 71’ 340 and looking to refresh heads along with cam and converter but I hear so many options. Was hoping to hear this setup if you could.

[@ultimatejay]

seems a little on the lean side for WOT

[@dwb4462]

Agree,12.3-12.6 would pull a few more ponies

[@360escapades]

Is this 340 from a 70? 71? 72? Dodge or plymouth?

[@ryanbarsness]

Late 1970

[@360escapades]

@@ryanbarsness would you happen to know the real HP on a 73 cuda 340 all stock no mods?

[@ryanbarsness]

@@360escapades not much power in 1972-73 340s and I dont like small blocks in general.

[@rexmasters1541]

Needs a lot of work and a bigger cam and a nice set of after market heads.

[@ryanbarsness]

Its a nice healthy iron head 340. The goal wasn't to make major power. Id wager if it had a little tuning and some minor carb changes it would hit near 450hp

[@22doger]

mine came out a 375 hp and 424 torque

[@rafaeltorres2886]

Did they try to tune it, the AFRs where a bit high 13.6 to 13.8 seems in the lean side . what was the final timing set at?

[@ryanbarsness]

I didn't get into the tuning of it much. The long story short is that I sold this engine to a guy and he wanted to see it dyno tested before he purchased it. The new owner was responsible for all the tuning decisions

[@rafaeltorres2886]

@@ryanbarsness Oh ok 👍.

[@stephenwest798]

The 340's that came with TQ's were 800CFM, I have a 73 340 w/ 71 J- heads w/a comp cam 270H, low compression seal power forged pistons and Wieand intake and have turned it 8200 rpm under load as we all know you don't rev them for any length of time with no load. Been running for 33 years in two trucks and two Ram Chargers now in a jeep and still runs great. That rpm is with the factory stock valve springs.

[@schlemmer1960]

8200 with that cam, you are dreaming or your tach is set wrong

[@stephenwest798]

@@schlemmer1960 No I am not dreaming, and my pro-comp tach w/memory is wired correctly or was at the time as I am not running it in my jeep. Eat your heart out. Not sure what it will turn with the restrictive shorty headers thru mufflers and with a 650-cfm carb in my jeep, but that does make a difference, I know because just downsizing the carb reduced the rpms it would turn with the open long tube headers, the smaller carb lets it run at lower rpms when off-roading, which is why I am running the 650-cfm carb now. Sorry your 340 doesn't run like mine, strange you think you know how my engine runs, are you like a god or something.

[@schlemmer1960]

@@stephenwest798 you must have a magic engine that does the impossible, you are full of it or did you mean 5200

[@stephenwest798]

@@schlemmer1960 Number one, there is guy here on KZbin who claims he turned his 340 in an oval track modified 8200 rpm three seasons in a row with stock rod, no tear down, so we know the rods will take it, I have ARP rod bolts in my 340, I also have forged pistons so we know they will take it. I am running comp cams HighTech hydraulic lifters which have a very high bleed rate, so they don't float the valves and crane nodular iron rocker arms. Stock valve springs but a small cam so they can take it. Now I was surprised it wound that high myself, but it did and I've only done it a couple of times and that was in my 78 Ram Charger, first gear 6.69:1 3.21 gears and I only took it up there for a couple of seconds because we all know if you going to turn your LA engine high rpms for extend periods you have to modify your oil passages, which I did not do with this engine. And something else for you to chew on, with high tech lifters which are collapsed under 3500 rpm and crane CD multi spark ignition and a 500-cfm carb it will run at very low rpms and keep on pulling, so yea I guess you could call it a magic engine. Now go lock yourself in aa closet and have a fit, fool.

[@hockmedcamelfucker7470]

Your cam makes power to 5800, your heads to maybe 6000 and your stock springs are good for maybe 6200, you are such a farking liar

[@karlsracing8422]

I'm confused? Where does it say 500hp? All I see is 406hp

[@ryanbarsness]

I must have said something wrong or maybe you heard something wrong. 406hp and 430 tq

[@edsmachine93]

Very Nice Ryan. Great dyno session. Thanks for sharing. Take care, Ed.

[@rong4189]

Nice 340. I’ll admit I was a little bummed to hear you say that you sold it lol! Anyway, good luck congrats on 500! Subscribed!

[@MostlyOldPartsAndRust]

Excellent video, Ryan do you have any specs on the engine? Cam, compression, head info possibly?

[@ryanbarsness]

Had a comp XE274H I believe. Its a 230 236 .488 .491 on a 110 LSA... Heads are ported J heads. Not sure on compression, I believe it was 10:1 or better.

[@MostlyOldPartsAndRust]

@@ryanbarsness Thank you, I have heard good results from the XE274H cam, just seeing what works out there. Do you know if the engine was stock bore size or was it overbored?

[@ryanbarsness]

.030 over i believe

[@MostlyOldPartsAndRust]

@@ryanbarsness Thank you!

[@dannychiguina3962]

Awesome MOPAR Build guys 🤙

[@ryanbarsness]

Thanks

[@approachingtarget.4503]

Here it is. A good dyno test provider will be able to show you precisely what cfm the engine is pulling. And all dyno guys like to sell carb services. I love watching the guys jawdrop when we run 8000 rpm with a 500 cfm carb.

[@moparnut6286]

Great video thanks for posting it Ryan.

[@NSBCustomCars]

Congrats on the 500!! See you at No Name

[@trackandtravelwithrick8933]

Congrats on getting over 500 Nice 340

[@lm45acp]

What was the 750 carb?

[@ryanbarsness]

Holley quick fuel. Vacuum secondary

[@outfitsgarage88]

Man I love watching a good dyno pull.

[@mariojackson6096]

Stock rotating assembly?

[@ryanbarsness]

Yes

[@mariojackson6096]

@@ryanbarsness Looks like J-heads! Nice build and nice numbers good stuff 👍🏽

[@ryanbarsness]

@@mariojackson6096 ported J heads

[@mariojackson6096]

Did you have them milled?

[@chiraqvlogs]

Blessings to your channel 🙏

[@ryanbarsness]

Thank you

[@chiraqvlogs]

@@ryanbarsness ✊

[@drainpluggarage]

👍