340,to stroke or not to stroke

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SGBARRACUDA

SGBARRACUDA

ROY
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I havn't fooled with small blocks in many years, I bought a 69 dart with a mild built 360, but it just doesn't have the oysters that I would like. So my question being is. Do i build a 340 4"stroker? Maybe a 402 crate motor? My objective is to be able to drive it easily on the street to car shows and swap meets and the like but still have an eye opener when you firewall the gas pedal. I'm sure some of the members here have an opinion on which way to I should go. It will be an automatic with a 3.55 sg. Any help? Thanks---Roy
 
Even if I had a 340 block I would leave it be and stoke a 360 being they are everywere and there aren't as many 340's. I have 340 in my drag car but decided to leave it stock stroke and when I build a stroker I will use a 360.


Chuck
 
Go for it i stroked my 340 to 416 last year,best thing i ever did car runs 11.20's,and is very streetable,don't worry about it being a so-called rare motor theres plenty to be found out there,if you know where to look,just put a bigger cam in mine going 10's this season... :thumbup:
 
it took me forever to find a good 340..the only reason we went 340 instead of 360 id bc a 340 demon will end up bringin' in more $$$ if i hadto sell...i woulda done a 408 stroker...easy to put out 500hp with those beefed up 360's :)..and cuda..i love that dart..SCHWEET!!! You goin to the 10th anniversary car show in plant city april 21st..I'm plannin on bringin' the demon, bee, and daytona.....hopefully the demon is done..hope to c ya there
 
We are only talking about .040 difference in bore in the two blocks which is a very minimal difference in power that is why it makes more sense to run the 360 block. If something happens to it, Oh well, go get another one. But if you are trying to get every cubic inch possible out of it then you will need the 340 block.

Chuck
 
Wilnutt said:
it took me forever to find a good 340..the only reason we went 340 instead of 360 id bc a 340 demon will end up bringin' in more $$$ if i hadto sell...i woulda done a 408 stroker...easy to put out 500hp with those beefed up 360's :)..and cuda..i love that dart..SCHWEET!!! You goin to the 10th anniversary car show in plant city april 21st..I'm plannin on bringin' the demon, bee, and daytona.....hopefully the demon is done..hope to c ya there
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I was,but that is the weekend we're going turkey hunting. We went to the Dade City show this past sat, and there was a ton of cars there. I'll catch you in PC maybe in May. Thanks
 
340mopar said:
Even if I had a 340 block I would leave it be and stoke a 360 being they are everywere and there aren't as many 340's. I have 340 in my drag car but decided to leave it stock stroke and when I build a stroker I will use a 360.


Chuck
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Chuck, These forums are great, we get to see views from so many angles.
I truly respect your view on not stroking a 340, but for me, I wouldnt drag race a 340 for the same reason you wouldnt stroke one... they are getting rare. Since sgbarracuda just wants normal street duty with lots of oomph, the torque from a mild 416 would fit the bill. Am doing a 340 sunroof 73 Dart Sport resto right now, taking great pains to get it looking original. But Iam afraid with the weight of the car, 3.21 gears, and the rest of the original theme it will be disappointing in performance. Will go to a very mild 416 build of the original engine .
But then again, sgbarracuda didnt say this was an original 340 car and that he wants to keep it stock. If not... hell no, find a 360 and do the 408lol ,save a 340 for someones resto , please!
 
I have to say from a budget aspect the 360 stroker is a better deal-more off the shelf availability of pistons,cheaper more plentiful blocks and really no difference in power compared to starting with a 340.But thats just one perspective,if the 340 strokers what you have or want then thats all that matters!.
 
By the way if your just building a street engine with some power I think you could find all you want out of a 360,my brothers is nothing exotic and is running 107 mph in a challenger with 3.55s.Theres alot of examples out there of mean streetable 360s and the quality I feel is much better when you build your own or have a reputable local machine shop build it.
 
I think if you are going to build, you might as well stroke it...If you can't build a stroker, what makes you think the stocker is going to stay together...The stocker has more chance of coming apart than all aftermarket parts...well, good ones!..LOL...I would say build the 340...416 verses a 408...hmmm...Cubic inches...Actually, bore the 340 .060 over..4.100 bore and get that 422 cu. in...still streetable...or don't buy any of them off the shelf pieces, because they have a bad rod angle...Stroke the crank to 2.100 chevy journal, buy off the shelf chevy rod (longer), call ross get the piston you need,,,waaallaaa...you've got a stoker w/ better rod angle, less cyl. wall drag & will out run the off the shelf boys and way less likely to come apart when you start twisting it 6000 to 8000 rpm....Lee
 
I appreciate this thread because I have a 1970 340 on a stand that I'm wondering what to do with. I have the same questions as SGBarracuda, so I'm learning lots. Thanks.

Sometimes I think I should just sell the 340 to someone that really wants it for their date-coded correct car and build up a 360, but then I think "No, it's my motor, I want it in my car!" Tough decisions!
 
I two biggest plusses to building a 340 really have nothign to do with cost. The bigger bore supports bigger heads with less shrouding, which is a big deal. And the smaller jouranls are less drag when it's turning. The downsides are if you have a 360, and a 340 sitting waiting fro you, each std bore and complete, the 360 parts will cost about $300 less from start to finish. And, if this is a total street car or truck, a low rpm 408 can be uilt fro a total of about $600 less than a 416 because of piston choices and crank costs. As far as which will make more power? That depends ona lot. The 340 IMO will always have the ability to make more power, because of those first two things. But whether your builder can do things well enough to get that extra power, or the budget covers it..that's another matter entirely. Cheap strokers are made from 360s. They are all faster, and all torque monsters. And most parts do interchange. A std bore 340 block is not hard to find, but the prices are going up. I used to sell at $200 for a bare inspected ready to machine or sonic core. Now that price has doubled. I can get .030 over blocks easy. Any stroker build should include a sonic test by a qualified guy with a good tester. And none should go thinner than .150" on a major thrust side, regardless of .030, .040, or .060 over. Use that as a guide, and I gaurantee you will not find many blocks that will go .060 over. It gets hard to find ones for .040 over. Std ones cost more to buy. If you dont have the matching vin on that 340, bore it, stroke it, and dont worry. If it matches the car, you should find another core, or use a 360. At least that's my feelings about it.
 
Thanks for all the views and opinions. No my car is not a numbers matching. But I would still like to have the right year 69 340 block in the car. I plan on using original valve covers and I just bought a LD4B intake with the chrysler part number on it to use on this combo. I have the correct air cleaner for it and I'll probably switch from the current 600 edelbrock carb to a 750 or 800. I do have the 553 and 549 exhaust manifolds on the car now but I'll more than likely go with TTI headers so the motor can breath. And I'll go with a little more stall in the 727 with 3.55 sg. Basically I want a clean stock looking 340 with the 400+ cubes lerking inside. I have a 69,70 ,73 on hand now. Now with that said, who makes a GOOD QUALITY rotating assembly? I did check out the Speed O Motive long block ,but they use a solid cam which I do not want to run. By the way what is a good cam for this combo. Thanks for all your knowledge and view points.
 
Very Well Point Made...Lee :thumbup:
moper said:
I two biggest plusses to building a 340 really have nothign to do with cost. The bigger bore supports bigger heads with less shrouding, which is a big deal. And the smaller jouranls are less drag when it's turning. The downsides are if you have a 360, and a 340 sitting waiting fro you, each std bore and complete, the 360 parts will cost about $300 less from start to finish. And, if this is a total street car or truck, a low rpm 408 can be uilt fro a total of about $600 less than a 416 because of piston choices and crank costs. As far as which will make more power? That depends ona lot. The 340 IMO will always have the ability to make more power, because of those first two things. But whether your builder can do things well enough to get that extra power, or the budget covers it..that's another matter entirely. Cheap strokers are made from 360s. They are all faster, and all torque monsters. And most parts do interchange. A std bore 340 block is not hard to find, but the prices are going up. I used to sell at $200 for a bare inspected ready to machine or sonic core. Now that price has doubled. I can get .030 over blocks easy. Any stroker build should include a sonic test by a qualified guy with a good tester. And none should go thinner than .150" on a major thrust side, regardless of .030, .040, or .060 over. Use that as a guide, and I gaurantee you will not find many blocks that will go .060 over. It gets hard to find ones for .040 over. Std ones cost more to buy. If you dont have the matching vin on that 340, bore it, stroke it, and dont worry. If it matches the car, you should find another core, or use a 360. At least that's my feelings about it.
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408duster said:
Chuck, These forums are great, we get to see views from so many angles.
I truly respect your view on not stroking a 340, but for me, I wouldnt drag race a 340 for the same reason you wouldnt stroke one... they are getting rare.
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Your right, the difference is that I purchased the engine and put it together years ago when they were a lot easier to find. I purchased mine at a swap meet for $65. I'm already commited with all of the stuff I've done to it. When my area get the E85 fuel I am going to convert it to run on that and put it in my street car. I only shift the thing at 6500 because I don't want to hurt it.


Chuck
 
That LD4B intake isn't a really good choice for either a 340 or 360 engine, stroked or not. It's really going to hurt the breathing and fuel distribution in either engine. As far as your original question, "340, to stroke or not to stroke", I'm not going to offer any insight because I'm asking the same question about my 360, and I STILL haven't come to a final conclusion. It would be rather foolish to offer someone else advice on the matter when I'm still standing firmly on the fence myself. Good luck. :)
 
SGBARRACUDA said:
I havn't fooled with small blocks in many years, I bought a 69 dart with a mild built 360, but it just doesn't have the oysters that I would like. So my question being is. Do i build a 340 4"stroker? Maybe a 402 crate motor? My objective is to be able to drive it easily on the street to car shows and swap meets and the like but still have an eye opener when you firewall the gas pedal. I'm sure some of the members here have an opinion on which way to I should go. It will be an automatic with a 3.55 sg. Any help? Thanks---Roy
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Stroke the 340
 
SG, if it makes much difference, I'm building a 418 for my Swinger. Stock '71 Thermoquad intake, modified Tquad carb, factory correct exh manifolds, factory air cleaner. It will be a solid roller cam, iron heads, and should be close to 500hp at the crank, on pump fuel. I'm aiming at some FAST type racing, but with real tires. We'll call it FART racing ;). So I too and going for the stock look. Not sound or performance, but look. The best bang for the buck, if you are planning to properly rebuild a stock displacement engine, is to add stroke to it. There is a little more in parts costs, and a couple other machining details to do. But the result for a street or stret/strip car is pure magic. If you havent driven one. Do so before you order parts.
 
Well said Moper, most people over look it.

340s are rare, I have only found 1 in my area the past year and the guy wanted a life savings for it. But if I understand you correct, you have 3 340s? I know how you want the same date coded engine in your Dart and respect that so here is some insight to help you decide. The '69 340 was only avalible in Darts and Cudas. The 70 was avalible in Cudas, Darts, Challengers, and Dusters. The 73 was avalible in Challengers, Cudas, Dusters and Dart Sports.

With that said, I say number one, depending on pocket money, build the 69 340, since it was the first year in an A-body. Number two, dont over bore it, just enough to clean it up. Weakens the cylinder walls, so in turn it cant take much abusing, aka fun. Number three, I would piece together my rotating assembly like I have done for 1 engine and getting ready to piece another one together. If you are set on a whole package deal, you have Speed-o-motive, Hughes, Hensely, Mancini, Muscle Motors, Callies, Ohio Crank, and 440 source. Not sure if they all deal with 340s but they all make rotating assemblys. Number four, plain and simple, ITS YOUR ENGINE! O WITH IT WHAT YOU WANT, I have people telling me why are you going to restore the 70 Chrysler 300, its a boat anchor, gas hog, well I am doing it cause I love it and if you love the idea of having a 340 in that Dart, then by all means do it, just dont blow it up haha.
 
Where are the main conflict areas when putting a 4" crank in a 340? How much machine work needs to be done for the crank and rods to clear? "Bore and Stroked" What combo of parts do you buy for your stroker kit? Do you have the recepe on Hand? I really do thank everyone for your info on this. I'm not one to reinvent the wheel, if some of you here have a combo that works I will plagerize. He He
 
SGBARRACUDA said:
Where are the main conflict areas when putting a 4" crank in a 340? How much machine work needs to be done for the crank and rods to clear? "Bore and Stroked" What combo of parts do you buy for your stroker kit? Do you have the recepe on Hand? I really do thank everyone for your info on this. I'm not one to reinvent the wheel, if some of you here have a combo that works I will plagerize. He He
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I used Ross Pistons, dished 9.6 forged, eagle rods and eagle forged crank, single moly speed pro rings, and you need a cam to fit your applications, how you drive, car weight, gears, tranny, heads, intake,carb,exhaust etc.. Calis makes a high end crank too.. OH almost forgot, stay .030 over if you can and run the better head gaskets.

The 12 point bolts on the rods just barely hit the bottom of the block cylinder walls. You mark it and cut just enough to clear + about .060 for clearance insurance.

PS the Ross Piston are a little pricey, but lghter and I thnk overall a better unit when you balance. ALso the more expensive Eagle rods and forged crank are better to have toif inthe budget. Also dont forget the main caps, studs, etc if you go high end too and then do a line bore and a balance job. Lastly get the convertor you need to for the application if auto trans and add that to the balance job. ( go with the big flex plate and bolts too )

enjoy SGBARRACUDA :thumbup:
 
"Is a block stronger at std bore?" The most material you can have in any cylinder wall, will be the strongest. Period. Whether it's feasible or not...thats subjective. I'd rather have a perfect round, straight, correctly placed bore with the right wall finish, then a std bore size..lol. I also own a good sonic tester. So I can see the difference between them.

For my builds, I've used Ross dished (like DJ), Ross flat top, Diamond flat top, and have aset of Diamond dishes arriving today. I've used factory rods and Eagle H beams. I've used MP cast, Eagle cast, and Callies forged in various builds. What you need to decide on is intended use (be honest with yourself), intedned growth (again, be honest), and total amount of cash ON HAND (stuff "coming with the tax refund" or "when my other car sells" or something dont cut it) and again, you must be brutally honest there too. And consider all things. A fresh 416, with $6500 in it, sitting under a swap meet 750 DP in front of a stock 904 and one leg rear, with a 2 row 18" radiator, and in a car with no frame connectors is a time bomb waiting to be dropped. Engines need support systems to be utilized. You should account for this. I know MANY guys that will spend on engine, and skimp everywhere else. It never fails they are sitting home, or broken, instead of building a nice solid stock displacement engine and supporting it properly and achieving their goals. I'll post a typical build in another thread...I'll ge too wordy and I'm sure there will be debate on it...lol.
 
moper said:
"Is a block stronger at std bore?" The most material you can have in any cylinder wall, will be the strongest. Period. Whether it's feasible or not...thats subjective. I'd rather have a perfect round, straight, correctly placed bore with the right wall finish, then a std bore size..lol. I also own a good sonic tester. So I can see the difference between them.

For my builds, I've used Ross dished (like DJ), Ross flat top, Diamond flat top, and have aset of Diamond dishes arriving today. I've used factory rods and Eagle H beams. I've used MP cast, Eagle cast, and Callies forged in various builds. What you need to decide on is intended use (be honest with yourself), intedned growth (again, be honest), and total amount of cash ON HAND (stuff "coming with the tax refund" or "when my other car sells" or something dont cut it) and again, you must be brutally honest there too. And consider all things. A fresh 416, with $6500 in it, sitting under a swap meet 750 DP in front of a stock 904 and one leg rear, with a 2 row 18" radiator, and in a car with no frame connectors is a time bomb waiting to be dropped. Engines need support systems to be utilized. You should account for this. I know MANY guys that will spend on engine, and skimp everywhere else. It never fails they are sitting home, or broken, instead of building a nice solid stock displacement engine and supporting it properly and achieving their goals. I'll post a typical build in another thread...I'll ge too wordy and I'm sure there will be debate on it...lol.
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As you can tell by my screen name ,I've built and drive my own cars, I've been in the low 5's 1/8 so I do and intend to build the correct "support " system with this project. My intended use is just as stated, this is a go to car meets,drive on sunday, with and occasional stand on the pedal thrill to get the old adrenaline flowing thing. I'm looking for power but driveabillity and most of all dependabillity. Broken down on the side of the road is no fun. As in ALL aftermarket parts there is a vast spread in the Quality of stuff out there. This is why I'm asking you the board members what has been used and what works. I don't need to be a pioneer on different combos. I would like to do it right the first time and in the long run save time,money, and agrevation.
 
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