Technical 340 in a 1937 Dodge truck

Do you mean a Small Block Chrysler?

 

Damn Tony! I hope your pooch heals up. Broken engines suck, but wounded dogs are worse. Good luck with getting her together in time for drag week.

 

Tony,
Finding Pistons and stuff like that is tough right now.
you might need to just find another engine that's ready to drop in. What about that Hemi? Is that ready?

 

Tony ,
Sorry about all that damage,,,,,hope it all turns out okay.
I know that’s a mean engine,,,,,,Mopar !

Tommy

 

LSA 112. Agree its a big cam for street.

 

There's definitely not a slippy slimy drippy sloppy stinky fluid coupling in Tony's truck!

 

I called Ross pistons up and they had 4 of them on the shelf. So far I have found all the parts I need, but would like to find another 340 block and crank. The head is the part I am stuck on right now.

No lifters, or crank, for the Hemi. Waiting to here from Brian on the lifters, that Hemi has been more of a problem than this motor, and I have never heard it run.

 

Its a little bigger now, with more compression, and more gear. I am trying to get into the 10's

 

So you drive it to the track? High 10's for normal looking vehicle with a N/A small block is impressive. Got a track photo?

 

This is a link to a video a guy made of my truck last year at Bryon. Since then, I got my gauges in and the interior done. On the first run I lost my posi, so it was a one-wheel wonder for the rest of the race, couldn't get out of the hole. I also have done Dragweek with the truck and it wasnt on the trailer then either. There are alot of people on here that have seen me drive the truck everywhere.VINTAGE DAILY DRIVER! RARE '37 DODGE BROTHERS PICKUP TRUCK! MOPAR 340 CI! GLORY DAYS! BYRON! - YouTube

 

Mcmopar, your luck with a 340 seems to mirror my own from the mid 80s. Back in those days, I thought they were "All That."
I had a bunch of tricky stuff in it. Arias 12-1 pistons, Cam Dynamics cam at 255° at .050", 560 lift, W2 heads, Manley valves, with a Victor W2 intake, 727 trans with an A1 8" converter...
It ran 11.30 at 118 in a 3400lb Challenger. I fought with low oil pressure and oil starvation issues it's entire life due to the long skinny pick-up tube. I finally cured that with a big rear sump pan and custom pick-up. And then of course, I had it a Winston World Championship divisional race at bakersfield in 1984, and it broke an exhaust valve as it passed thru the lights at the top end on the track. Destroyed just about everything related to that hole. Head, piston, con rod, block...It was a mess and that was the end of my diddling around with 340s.
I'll always have a place in my heart for 'em, but I'd never, ever run one again. Too difficult and expensive to get really good power from.
My son is looking at some early 70s Dusters right now. I told I'd rather see him go for a turbo'd slant six.
Best of luck. I really mean that.

 

Any thoughts on why the keeper turned loose ?

 

Been around 340's since 1969 when Dad bought a '69 340 4spd Swinger. I currently have 6 340's. We learned quickly on the circle track the 340 will pump itself out of oil and because of no factory baffling in the oil pan the pickup is sucking wind a large portion of the time. A simple pan baffle took care of that. Yours is nowhere near stock of course but stock ones should stop at 6000rpm to make them live. Then don't need to turn 10 million rpm like a chevy to make horse power as I'm sure you know.
BTW, I drive a '36 Dodge pickup, but it is mostly stock other than a '58 230 flathead 6.
Love those trucks and the 340's.

Dave

 

I agree with ya but I havent learned yet. If this next motor goes bad I am back to a 12 sec. 360 and I dont want that. I love the high reving motors, they seem to have a new sound above 6000 rpm.

 

The best answer we have so far is that the pushrod rubbed on the head and then it was done, other than that we have no clue. Every pushrod has marks on it from rubbing. Trick Flow heads are supposed to be good for a .650 lift, and I am at .600. My head guy is opening them up so there is no rubbing.

 

There is a old thread on a Mopar forum that a guy talks about the oiling mods needed to run his 340 at 8000 rpm for circle track laps. He picks on dragracers, by saying all we are doing is dyno pulls. I have been following them directions that he talked about and alot of positive comes from them. I believe his name is sanderson, but it is a old thread. My screaming little small block has put alot of bigblocks on the trailer. I enjoy doing it just not the part of emptying my wallet.

 

Sounds like you have had a tough go, hope the sun starts shinning soon for you.

 

Played with a lot small block Mopars back in my day. Please explain to me why you can't get the same power out of the cheaper 360 block you get from a 340 block. The bore is a pretty easy fix.

 

Do you think you could have hit valve float ?

 

Gene you can get the same power, I just like the 340.

Tony

 

I have it valve float before, but I don't think that is the problem here. This all happened around 3000rpm. I have a feeling that I will never know the true answer on what happened.

Tony

 

Wow , that does suck. I am a believer in small block Chryslers. I ran several combinations decades ago. But it was easy then , I could call McCandless up or go see him and he had what ever you needed to go faster. If you have had the valves float are the springs weak ? bad locks, heavy retainers , etc. Just a thought.

 

I had the float with the old motor at 7000 rpm. This winter I went to titanium retainers and 10-degree keepers. Head guy said i did have a few week springs but not on the cylinder that went bad.

Tony

 

Well that makes it worse when you when you are doing everything right.

 

Well then, I guess it would be pretty hard to complain about a specific motors cost, if you are doing it because "you like the 340."

I liked the 340 too, but not enough to spend 2x the cost for a bare block just to have the right number cast into the side of it.

 

360 has big diameter main bearings, make's for lots of bearing speed at high RPM.

 

The 340 That I have been running for 3 years cost me $200, I believe I paid close to that for the 360 I got from you. That 360 pushed my truck to 12.4 in the quarter. I believe the parts inside cost the same. The last 340 block cost me $400, it is a little harder to find but still reasonable price. I could have built a stroked 360 for the truck but I didn't want one, I want a high revving 340.

There are alot of things we do in this hobby just because. We all could be driving around in a KIA because they are cheap but we don't because we like old cars. There is no need to have a 600 hp motor in our cars but we do just because we want it. I build my truck with the parts I want BECAUSE that is the way I want it. I am pretty sure there are a few people that agree. Some people like to say I only have $1000 into my build, some say that they get good gas milage, I like to say I have a 340.

Sorry you dont like the reason I have my 340, but they are my reasons and I can sleep knowing that.

Tony

 

besides, we all know the 340 is a performance engine, the 360 is a truck motor

 

Running 10's - you shoulda opened with that - street manners be damned my kinda build. You may need more lift than what you have to get there

LSA is a calculation based on peak lobe lift, valve overlap has much more effect on vacuum.
https://www.cartechbooks.com/blogs/techtips/camshafts1

If youre not pulling enough vacuum, advancing the cam, at the cam, will generally increase vacuum, other valve events, piston to valve clearance should be taken into consideration.
Installing the cam straight up is the best option, see how it does......run it.