dustdevil
Well-Known Member
hi guys what cam would yall suggest for a 340 bored 30 over with trw pistons? and should i use my stock x heads and intake?
what cam for 340 bored 0.30 over?
- Thread starter dustdevil
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dustdevil
Well-Known Member
i guess i should add that i would like street/strip cam but could also ride and highway. any suggestion?
GoodysGotaCuda
Mr. Goody
What about gear ratio in the rear? 4speed or automatic? Stall converter?
tomt966
Well-Known Member
I'm running a comp XE278H-10.
longarm
Car sold back to original owners
I'm with Goody,
What is your complete build?
new rebuild?
expected compression ratio
induction
exhaust
stall/ clutch
gear ratio
and lastly, what type of use will the car see most
What is your complete build?
new rebuild?
expected compression ratio
induction
exhaust
stall/ clutch
gear ratio
and lastly, what type of use will the car see most
bobs340dartsport
Well-Known Member
I have the same basic set up :
340 .030 oversized with TRW forged replacement pistons (flat top 10.5:1 compression)
Steel crank
stock rods with new bolts , reworked, new bushings, etc
stock "X" heads
Mopar Performance .509 lift hydraulic "purple shaft" cam and lifters
Cloyes double roller timing set
Edelbrock TM5 single plane intake (what I had laying around!)
Holley Double Pumper carb
MP electronic ignition
I use it as a race car, but it would work fine as a street/strip package. Just might burn a lot of fuel. Car runs 12.86 @ 105 mph when it is cool outside and low to mid 13's when it is hot and sticky.
If you do more street driving and not much racing you might want something with less duraction and lift to make car more street friendly.
Bob
340 .030 oversized with TRW forged replacement pistons (flat top 10.5:1 compression)
Steel crank
stock rods with new bolts , reworked, new bushings, etc
stock "X" heads
Mopar Performance .509 lift hydraulic "purple shaft" cam and lifters
Cloyes double roller timing set
Edelbrock TM5 single plane intake (what I had laying around!)
Holley Double Pumper carb
MP electronic ignition
I use it as a race car, but it would work fine as a street/strip package. Just might burn a lot of fuel. Car runs 12.86 @ 105 mph when it is cool outside and low to mid 13's when it is hot and sticky.
If you do more street driving and not much racing you might want something with less duraction and lift to make car more street friendly.
Bob
dustdevil
Well-Known Member
well im using a rebuilt automatic 727 tranny, stall im not to sure of..im imagine a 2800-3000 stall would do? i was planning on using the stock gear ratio for now. i just want an all around car with a good street/strip cam that will allow me to drive on the freeway from time to time.
dustdevil
Well-Known Member
Engine Has 9.5 To 1 Compression If That Helps..
I hate to say this, but you have not helped yet. This above post of yours is scarry.
In order to actually give you good help and ideas on what would be a good idea and help, you have to help us and not provided criptic answers or posts completely blank of facts.
Lets start at the top.
YES! The know ratio helps alot. We are of to a start!
We will need to know what the specs are and what you have to start with and where you want to go with it. So far we only know you have a .030 over 340 with TRW 9.5-1 pistons & a 727 trans.
Lets look at the rest of your car;
Year, make , model, (weight is helpful)
rear end size is helpful, but gear is more important. Also tire size is helpful. But to say stock gear ratio actually means nothing since the wide veriaty of ratios that could be had in the car. From 2.76 to 4.10's are very possible. This is a huge spread.
Is this a street. street strip, or are we going racing?
Getting on the Hwy. once in a while is a general description that can also have a wide verity of answers. Can you included possible travel times or distances you may be covering and what Hwy. speed is and what is a good Hwy. speed you can travel at on a min. level?
The stall converter choice, if not a stock unit to be used, will be dictated to a large degree on the answers above.
A stock intake and heads can perform very well in the right arena and do not actually need to be changed. Alot also depends on what you want it to look like when the hood opens up or not.
AKA, look flashy or look stock, but ethier way, you can run like stink.
Now, lets get crackin on this and get some answers here so we can get ya going and get'er done!
dustdevil
Well-Known Member
thanks rumblefish for being patient. ok here we go. street and strip 73 ply duster w/ 1969 340 block bored 0.30 over trw pistons..everything else internally is to stock specs. rebuilt stock x heads, stock intake, rebuilt 727 with a shift kit, i do have the drive shaft for it. not to sure of what stall to get tho, maybe 2800 to 3000? rear end is not a 8 3/4 sure grip but plan on switching as soon as i can find one or have one built.
front rims are 14x7 rears are 15x10 with 28x10.50x15lt mickey t's sportmans. hwy i would say at least 10 miles to get around town. 20 to 30 mins from home to work. 65 to 70 hwy speed. so not sure what gear ratio would be best for that kind of traveling.
im not to concerned about the engine looking stock at all. doesnt need to be flashy. i already have mopar performance valve covers and air cleaner, msd wires and elec distributor. header i do not have at this time. trying to find stock exhaust manifolds for that block.
front rims are 14x7 rears are 15x10 with 28x10.50x15lt mickey t's sportmans. hwy i would say at least 10 miles to get around town. 20 to 30 mins from home to work. 65 to 70 hwy speed. so not sure what gear ratio would be best for that kind of traveling.
im not to concerned about the engine looking stock at all. doesnt need to be flashy. i already have mopar performance valve covers and air cleaner, msd wires and elec distributor. header i do not have at this time. trying to find stock exhaust manifolds for that block.
AdamR
Big Member
With a mostly stock 340 I would use a Comp Cams XE262 or XE268. Stay small for the street,
DD, I have nothin but time to burn, I turn into a pumpkin before midnight though...work...patient, yea, nothin to get upset about
On the rear gear, for a street strip car, IN my head at least means 3.91's but your huge tires could use a bit more ratio (Numericaly high.)
The big catch hear is Hwy. speed. Something that will not have the engine rev so high at 65. And still work with the cams cruise rpm range. That also goes for the converter as well.
Exhaust manifolds are not street strip material or exactly a go-fast part.
Would you consider an OD tranny instead by chance?
Adam suggest a XE268 from Comp Cams. In the right set up, that cam should propel you into the high 12's. (I'm used to a 4spd manual car and would use a stouter cam for the street strip effort myself.) With the 28 inch tire, I believe a 4.30 gear would be about what your looking for. 60 -65 mph shouldn't be to bad.
(I'd rather 3.91's and a 26 inch tire. If I had an OD trans, I'd go and do the 28 inch tires and 4.56 gears. The OD ratio will feel like 3.14's, plenty low for the Hwy speeds and then some. 4.88 = 3.36. Max ratio I'd look at.)
I would finish up the rest of the build with a RPM or equal intake and bowl port my heads with headers bolted on. A bodies are hard with good fitment and I'd rather not use typical headers for this job. As in avoid the 3 tubes under the linkage problem. They'll do the job, though I would opt. for the next larger tube size myself for a little more top end punch with a 750 carb.
Take your time tuning the carb.
On the rear gear, for a street strip car, IN my head at least means 3.91's but your huge tires could use a bit more ratio (Numericaly high.)
The big catch hear is Hwy. speed. Something that will not have the engine rev so high at 65. And still work with the cams cruise rpm range. That also goes for the converter as well.
Exhaust manifolds are not street strip material or exactly a go-fast part.
Would you consider an OD tranny instead by chance?
Adam suggest a XE268 from Comp Cams. In the right set up, that cam should propel you into the high 12's. (I'm used to a 4spd manual car and would use a stouter cam for the street strip effort myself.) With the 28 inch tire, I believe a 4.30 gear would be about what your looking for. 60 -65 mph shouldn't be to bad.
(I'd rather 3.91's and a 26 inch tire. If I had an OD trans, I'd go and do the 28 inch tires and 4.56 gears. The OD ratio will feel like 3.14's, plenty low for the Hwy speeds and then some. 4.88 = 3.36. Max ratio I'd look at.)
I would finish up the rest of the build with a RPM or equal intake and bowl port my heads with headers bolted on. A bodies are hard with good fitment and I'd rather not use typical headers for this job. As in avoid the 3 tubes under the linkage problem. They'll do the job, though I would opt. for the next larger tube size myself for a little more top end punch with a 750 carb.
Take your time tuning the carb.
dustdevil
Well-Known Member
im not planning at this time on getting an overdrive..so would it be wise to switch to a 26 in instead of a 28 in tire?
My vote goes for the .484/ 284 Part#4120231 mopar performance cam with a auto shift, but also with a 2800-3200 stall converter behind it. I really like the 509 cam but for use with a stick, really got to get a lot of converter to make those perform well in an automatic and that can be a little unfriendly on the street.
If you stay with the 28's, then a higher gear ratio is a prefurred way to go. Just the reverse on a numeriacly lower gear ratio. Like 3.55's, would like a 26 inch tire better. The taller tire would be harder to spin or actually, run 50ft burnouts.
On the Hwy, they will be close in RPM's.
On the Hwy, they will be close in RPM's.
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340srule
Guest
I say at least a 3.91 gears,3000 stall converter,and i'm sold on the Lunati voodoo series of cams for you part# lun-60402 .475/.494...
dustdevil
Well-Known Member
what if i just went 4:10 gears in the rear. to much on the freeway?
RPM's will be close to 3000 - 3200 with 28 inch tires with the 4.10's. The amount of stall or how good the converter is hads a factor in RPM.
If you do 4.10's and a 26 inch tire, it's going to jump up a few hundred.
340'srule, do you have the specs to the cam handy? Thanks.
If you do 4.10's and a 26 inch tire, it's going to jump up a few hundred.
340'srule, do you have the specs to the cam handy? Thanks.
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340srule
Guest
Sure..rpm range 1,400-5,700
dura @.50...220-.226
duration...262/.268...
lift...474 int/.495 ex...
Oooooooooo, I like that. Thanks
SGlez10
68 Barracuda
I have a question of my own. So I’m bringing this back to life. Just doing some research before I make any decisions on the engine. I want the car mostly for cruising and street use, if I jump on the highway I want it to have some power just in case I wanna push it a little. No racing in mind. But wouldn’t mind stepping on it from time to time. Ya know? Ok... so...
Im in the process of rebuilding my 340 (1972) for my 1968 Notchback Barracuda. Im having the 360 heads rebuilt and they’re being bored over .30
I have a Carter Thermo Quad Carb that is being rebuilt.
8 3/4 rear end, 727 automatic tranny -which will be changed to manual in the future.
What cam should I look into to achieve some of what I’ve shared with you guys?
if you guys need more info from me to help please let me know. I’m sorta new to all this so I’m doing my best not to miss anything.
SGlez10
68 Barracuda
Typo, meant to say block will be .30 over
Yea, oh yea!
What number TQ?
What are the valve sizes of the 360 heads being rebuilt?
What is your gear ratio and tire size?
Have you owned and driven a 340 car before?
Do you have power brakes?
Is a upgraded torque converter OK to spend on? They are pricey and you mentioned a 4spd swap.
How soon until you swap to a manual trans?
SGlez10
68 Barracuda
2500 stall TQ
Stock valve size. The 1.88 1.66 heads
Do you recommend milling of the heads to give me more compression?
Gear ratio: I don't know yet. Assuming it's in the 2.96s
Never owned or driven a 340 this is my first.
Future tire size will be 2457014
No power brakes
The manual trans swap won’t happen anytime soon. Maybe in a year or so. When that time comes I’ll look at where they engine stands and I’ll probably be back for more advice.
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