Got a free motor, don't recognize the manifold on it.

TheIronSausage

TheIronSausage

Two brain cells left.. rubbing together for warmth
A buddy of mine called up and asked me if I wanted the motor he promised me ages ago. I didn't remember anything about any motor promised to me, so I naturally said "sure, I guess.." We ride out to his farm and under a lean to by the barn is a small block V8. He said "I know you've been looking for a 340 for a while, and I finally dug this one out." A 340? Shit! We load it into my truck and get it home. It's got an old Edelbrock manifold with what looks like a Chrysler part number, and "ld4b" under it. Preliminary research says it might be a small port manifold for 318s, but this motor has 360 J heads on it (no, I don't know why). At any rate, the 340 has a date code of 2/70, and came out of a white 70 Cuda that used to street race around here about a decade ago. More checking showed me that the crank is drilled for a pilot bushing. Win win. The same buddy is offering me a pair of "X" heads for what I assume will be a very reasonable price. I'm honestly thinking of dropping it in my truck after a rebuild. The valves are rusted in the heads at the moment, haven't torn it down to check the bottom end yet.
Back to the manifold, anybody have experience with it? Does it belong on a 340? Is it for bottom end torque or high rpm noise?

On a semi related note, same guy has a '73 Challenger factory 340 4 speed car. It's been sitting for six years. He's thinking of selling it
 

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All '70-'72 340s had J heads (some have an O or a U cast in place of the J but they're all 915 castings); in '70 and '71 they have 2.02" intake valves but in '72 they went to the 1.88". That's right, the 340 had them before the 360 did (the 360 didn't appear until '71). The '70 Six Pack cars had specially-machined versions with different pushrod holes that require special rockers, the "T/A" heads that allow porting the hump out of the intake port. Technically, those T/A heads were the W1. Regardless, if you go with the X heads, you're downgrading. The J heads flow a scosche better on the intake and much better on the exhaust. More than likely, if you pop those heads off you'll find 2.02" intakes. It could be either a '70 or '71 engine based on the casting date; if you look at the number stamped in the side of the block at the pan rail, the first digit will be the year of the engine. Either way, those are probably the original heads.
All 340s that I've seen have a pilot bushing, regardless of cast/forged crank or whether they were installed in an automatic or stick car. I have the original crank from my '73 340 Charger automatic, and it's got the never-used pilot bushing still in it.
The intake is a good unit for the smaller 273/318 heads; the "correct" one for a 340 would be the large-port LD340. However, if you're going to waste this engine on a truck, I'd suggest keeping the LD4B. It'll improve the nearly nonexistent low-end torque of the 340.
If your buddy decides to sell his 340 Challenger, let me know. My first Mopar was a double-black 340 4-speed '73. Yes, I have my '74 but I'd buy another Challenger if the price was reasonable and it were a '73 340 4-speed. Bonus points if it's NOT a Rallye model.
 
Guess I didn't realize that 340s didn't have any low end grunt. Maybe I'll throw it in the valiant instead. The heads actually have "360" and "AAWJ" stamped into one of the intake runners, so unless they've been reworked with bigger valves, my guess is they're stock mid seventies 360 units. I knew that "J" heads were originally made for the 340, but I thought the "X" heads had the bigger valves in them.. If they don't, they why does everybody think they're so great?
 
it would be a fun one in the valiant..and in all honest i would leave that intake in place PERIOD..if only to help the torque...if it was a 360 i "might" swap it out but i doubt it
as for the x heads..fuck em..youve got j's..just if they are the 202.s check from cracking between the valves...the smalled valve versions dont seem to be as prone to this

doc wasnt this the "improved" intake based off the sp2p for low end torque?>...yeah i know you hate that bastard that i love..but i think this was its mor e agressive sister
 
340s like to be spun, and spun high. No other Chrysler engine compares in that department by a long shot. It was the only small-block that had its own specific high-performance head casting (the X heads, and the J/O/U in '70).

All "J" heads have the 360 casting marks, even the 1970 castings. The 360 was already well on its way to production and with its larger displacement it needed larger ports than the crappy 273/318 heads. Since it was a newer casting, it got a different number and the "360" cast into it. They're not mid-'70s anything since the J casting disappeared at the end of the '72 model year (July '72), replaced by the miserable 587 casting (which was still far better than any 273/318 head) Take 'em off the engine and I'll bet you $100 they've got the 2.02" valves.

Why does "everyone" love the X heads so much? Probably because X is a sexier letter than J and they're much harder to find. They're not worth the effort, since the Js are better, period. Every competent Mopar specialty engine builder knows this. If they're 1.88" valves, all that needs to be done to make them superior to the X heads is cutting the intake seats and installing the 2.02" intake valves. I've never had a set of Js with cracked valve seats, but I've only had six sets of factory 2.02" heads and a dozen or better sets of 1.88" (I still have five sets of those).

There is no "improved" version of the SP2P (dual-plane) or the Streetmaster (single plane) intakes. Those are total pieces of shit designed solely for fuel economy, and they didn't even do that well. Why you would think either has any redeeming qualities whatsoever is beyond me unless you're hell-bent on going slow. They make less power than a 360-2V intake, for fuck's sake. Those piles of scrap aluminum came long after the LD4B. The LD4B was an NHRA-approved 4-barrel intake for 273/318 engines, which is why it has a late-60s style Mopar casting number on it as well as the Edelbrock part number. It's an old DC intake, and because of that guys not truly interested in making power or stuck in the '60s seek them out and often pay idiotic money for them (the same guys stuck on X heads, maybe?). On the dyno, it's about the equal of the factory '71-up spread-bore (ThermoQuad) intake but it's a bunch lighter. It's not as awful as the Performer 2176 and nothing is as bad as either the SP2P or Streetmaster. The LD4B is simply a small-port version of the legendary LD340--which guys will still club each other over the head to get for some reason. The LD340 was the best dual-plane intake for the LA engine for probably 25 years, but time and technology left it behind. If you want to run a dual-plane, the only game in town is really the Edelbrock Performer RPM, with or without the Air Gap (preferably with). It's actually much better than even some single planes, such as the Torker/Torker II and Holley Street (not Strip) Dominator.

If you don't want to spend much money on it, keep the LD4B. It's a decent intake and you've already got it. You could also sell it on eBay and potentially make good money on it if it was bead-blasted and new-looking. Use the money to pick up a swap-meet/eBay/Craigslist Performer RPM, Victor Jr., or Strip Dominator. The Performer RPM will still maintain what torque is there, but with either of the single-plane designs don't plan on shifting below 6,500RPM.

Here's a good illustration, by the way, of what makes the SP2P such a pile of shit. Note that the same idiotic port sizes, with an extremely-small, choked-out plenum was used on the even-worse Streetmaster.

sp2pPORT.jpg
 
So, if I like Thermoquads.. And I love a thermoquad. What manifold do I want? Obviously, you're going to say the stock 340 manifold. I'm running a '72 340 Thermoquad on my mildly built 318 in my truck. It's sitting on an Edelbrock Performer. The motor came with a performer rpm, but it was a square bore, so I pulled one of the performers in my stash and sold the rpm. If the stock cast iron job is hard to find, what T-quad manifold do I run? You may or may not like the carb, but I love those secondaries.. They're addictive, and the noise is intoxicating
 
While I've got you here, are your recommendations for a 440 similar? Performer RPM? I do prefer a spread bore based on my butt dyno and the fender shaking noise. Also, the performer in my truck is sitting on a pair of J heads. Before reassembly, I hogged out all of the ports on the manifold to match the head and used a flap wheel to smooth everything out as far up into the manifold as I could get. Have I fixed the Performer? Or are you laughing as you write your reply?
 
You improved the Performer. There's no fixing it. Another improvement, if you didn't do it already, is the Vanke modification. Essentially, cut a notch in the center of the plenum divider about 3/4" deep and 1-1/4" long, from the carb flange level down. Exact size isn't terribly critical but you don't want to overdo it by much. It gives more top-end pull without sacrificing any bottom-end torque. It's a fluid-dynamics thing. At high vacuum, the intake doesn't "see" the notch and pulls right past it, maintaining high port velocity. At higher engine speeds though, the pressure waves can equalize across both sides of the plenum allowing better cylinder filling.
As far as whether to leave it on the truck? Personally I would, especially if you have factory AC. That's the only aftermarket intake with the rear mounting boss for it, and since it's a 4WD you want to maintain low-end power. Or, I guess I should say I would want to maintain it, unless the truck's got like 4.56 gears in it.
 
Ooh! That'd be cool, let me know if you find it, and are willing to part with it/how much you'd want for it.

Thanks!
 
i just tripped over the fucker...so yes..i still have it......my intention(as it sitting next to the blast cab) was to blast and ebay..so send me a pm with a number...and we will figure out shipping so its out of here....ill grab pics later
 
69, thought I sent you a PM.. My compooter has no trace of it, maybe I'm high? Wish somebody'd tell me I was having fun.
 
image.jpg
Well, I found this in the number 7 hole.. My measurements say the block was bored at least thirty over, and I know it was used primarily for street racing. On the plus side, I've got a bunch of good parts for free. Oh well, better luck next time
 
I was wondering about that. I didn't know how bad or thin the original walls could be before a sleeve couldn't be installed.. then I saw an article from hotrod where they totally gutted a hemi block and installed sleeves into the water jacket like an Alfa's wet liners.. So, that question's been answered. I guess I can go back to scouring the internet for something either incredibly appropriate or offensive to put the 340 in.. Part of me wants a first or second gen cuda, part of me wants a shitty four door dart or aspen sedan or wagon with half the vinyl roof missing along with half it's original sheet metal, part of me wants to cram it into my Volvo wagon, and the darker side of me wants to do something ridiculous like a pre 81 Mazda GLC hatch (rwd), although I doubt the engine bay is large enough.. Not even sure it'll fit in the Volvo
 
Wanna buy a '69 Valiant? :D

Seriously, here's the one I had repaired. You don't want to wet-sleeve it, though. Just have it magged and if there are any cracks anywhere else in the bore, have them drill-stopped prior to sleeving. Bore it out far enough to press in the sleeve, but there's no need to remove the whole original cylinder. My machinist left a step in the bottom on which the sleeve sits, and machined the excess protruding from the block. That way the sleeve can't move--the head's holding it down against the step.

Jen340_017.JPG
 
I saw your post on that Valiant earlier.. a little jealous, I'm not gonna lie. The three "D" thing rings true, though. I'd have to sell off my two older Volvos and parts first. Of all the inventory i have, they'd be the least sleep I'd lose.
 
It was a lucky score, that's for sure. It was an awesome hookup through a mutual friend; I managed to get to the right place at the right time with cash. Thing is, I bought that whole menagerie simply to get my mitts on that 340, not just because it's a 340 but because I have history with it. Everything else is getting sold off to cover the outlay and further finance my other junk. I have no plans to sit on any of this stuff for any length of time in an attempt to maximize profit. Even if I merely broke even, I still got a free 340 out of the deal. That's a big win in my book.

The point of that whole post is that great deals are still out there even this late in the game. It literally pays to keep a network of similarly-minded friends with their ears to the ground. Why didn't my friend jump on it? He worked his own score on an extremely-solid manual-trans V8 '66 Coronet 500 three days ago. :dance:
 
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