Highest LIft cam with 68 340 with stock intake and carb

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johnnycuda

johnnycuda

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With stock intake and carb, What is the highest LIFT cam you can get away with?
My motor has a 585 lift. Just wondering if this engine is being held back by the stock intake and carb.
It does have an MSD ignition.
Thanks all for your input
Johnny
 
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johnnycuda said:
With stock intake and carb What is the highest LYFT camp you can get away with my motor has a 585 lift, just wondering if this engine is being held back by the stock intake and carb it does have an MSD ignition thanks all for your input
Johnny
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What rockers do you have? Have you verified lift at the retainer? What is the intake and carb?
 
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The stock cam is being held back by the stock intake and carburetor.
 
johnnycuda said:
It's a 585 lift I have all the specs on it I believe the rockers are adjustable not sure which ones .I have the factory 68 340 intake and AVS carburetor.
It's also solid lifter and cam set
here is the cam
Voodoo Solid Roller Cam - Chrysler 273-360 273/279 - Lunati Power
Click to expand...

It is your lack of punctuation that is holding the motor back.... :lol:...j/k

It is your heads that are holding the motor back...and if you don't have adjustable rockers with that cam your motor will probably break very soon...:popcorn:
 
johnnycuda said:
just wondering if this engine is being held back by the stock intake and carb.
Click to expand...

Um. Yes.
If you want to provide more info as to the engine, the car, and what you do with it we could give you some ideas.
 
flyfish said:
It is your lack of punctuation that is holding the motor back.... :lol:...j/k

It is your heads that are holding the motor back...and if you don't have adjustable rockers with that cam your motor will probably break very soon...:popcorn:
Click to expand...


He has to have some sort of adjustable rockers because it's a solid roller cam.

Unless he has a loose converter and some gear, he needs a different cam.
 
Stock intake, heads and carb? I'd go straight opposite. .455 lift with a ton of duration, and it'll need a converter and gears.
 
first of all, the spring heights are too short for that cam, you will have coil bind big time!!!! secondly, piston to valve will probably hit. there is not much room with stock pistons for big cams. also, to install a roller, the oil passage on right side has to have tube installed for oiling, about most lift with stock springs is .500 lift, need to go different route. BTW, the stock intake and carb will not hold it back. a 71 340 duster, in D/SA, ran 9.92 @ 130 mph. has stock intake and carb. imagine that !!!
 
perfacar said:
first of all, the spring heights are too short for that cam, you will have coil bind big time!!!! secondly, piston to valve will probably hit. there is not much room with stock pistons for big cams. also, to install a roller, the oil passage on right side has to have tube installed for oiling, about most lift with stock springs is .500 lift, need to go different route. BTW, the stock intake and carb will not hold it back. a 71 340 duster, in D/SA, ran 9.92 @ 130 mph. has stock intake and carb. imagine that !!!
Click to expand...

Has LD340 intake and Eddy heads on it...
 
perfacar said:
first of all, the spring heights are too short for that cam, you will have coil bind big time!!!! secondly, piston to valve will probably hit. there is not much room with stock pistons for big cams. also, to install a roller, the oil passage on right side has to have tube installed for oiling, about most lift with stock springs is .500 lift, need to go different route. BTW, the stock intake and carb will not hold it back. a 71 340 duster, in D/SA, ran 9.92 @ 130 mph. has stock intake and carb. imagine that !!!
Click to expand...
I believe he is currently running THAT cam. And as been for a while. SO the problems must have been worked out already.
 
perfacar said:
first of all, the spring heights are too short for that cam, you will have coil bind big time!!!! secondly, piston to valve will probably hit. there is not much room with stock pistons for big cams. also, to install a roller, the oil passage on right side has to have tube installed for oiling, about most lift with stock springs is .500 lift, need to go different route. BTW, the stock intake and carb will not hold it back. a 71 340 duster, in D/SA, ran 9.92 @ 130 mph. has stock intake and carb. imagine that !!!
Click to expand...


I agree with all of this.
If you are very careful you can get a spring to take .600 net lift with SFT lifters. I'd have to go and look to see if I can find a spring that would take a roller lobe at that short installed height.
 
The car is a 68 Barracuda fastback Formula S 340 4-speed...

He just bought it a few weeks back...
 

I think he has the spec sheet from the PO...

Maybe he can post it in this thread for us...
 
You can get a bunch of power out of the stock 340 intake. I run a 800 cfm thunder series on my 410 ci stroker through the stock intake and exhaust manifolds. Other than the stock carb being small from the get go gor the 340. The exhaust manifolds are the bottle neck. My lift is .558 on a cast iron x head. Its tough to go big lift on sbm heads that aren't w's
 
yellow rose said:
You'd be hard pressed to get a batter intake and carb for what you are doing, unless you have 1.75 headers, a loose converter and 4.10 gears.

What is the rest of the combo?
Click to expand...
391 rear gear with the stock 4 speed 833 trani no headers just 2-1/2 TTI X pipe Exhaust with an MSD ignition.
I posted the cam specs link above
 
flyfish said:
It is your lack of punctuation that is holding the motor back.... :lol:...j/k

It is your heads that are holding the motor back...and if you don't have adjustable rockers with that cam your motor will probably break very soon...:popcorn:
Click to expand...
Sorry I missed a few periods!!!
202 valve heads are holding it back?
 
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johnnycuda said:
With stock intake and carb What is the highest LYFT camp you can get away with my motor has a 585 lift, just wondering if this engine is being held back by the stock intake and carb it does have an MSD ignition thanks all for your input
Johnny
Click to expand...
For a streeter no, First gear is good to over 50 mph and will be spinning all the way. Second is good to over 70.
If you can make it hook zero to 60 will be in the low 5s. A bigger intake and bigger carb, may shave some time off that, but only the stopwatch will know it.
Spend your money on getting it to hook.
Then headers, those logs are costing you a lot of power by as good as killing the overlap cycle. I realize it's only 56*, compared to the stocker at 44*but this cycle occurs at or near TDC where the piston is dwelling for a time. These 56* are 48% of the intake stroke(117.5). If you think about it, this is a lot of time. With no headers to put the yank on the intake charge, this is lost time; time you will never get back. You might as well put a cam in there 2 or 3 sizes smaller, and get some decent bottom-end torque back.
more comming
 
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I guess my question is if I throw that
Victor 340 on it with that 800 CFM Holly.
it won't make a difference?
 
johnnycuda said:
I guess my question is if I throw that
Victor 340 on it with that 800 CFM Holly.
it won't make a difference?
Click to expand...

It will give you more top end, but sacrifice a little low end, but that's not as important with a manual trans...
 
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