Care to speculate my 340?

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Cam Type: Flat Tappet
.545 Intake .545 Exhaust
241 Intake / 247 Exhaust duration
@ .050 - 110 degree lobe separation is this a good cam
 
First is with small tube headers as only change to original. Second is with xe268 cam as only change to original.
 

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1970Duster said:
But at what rpm?

Oh yeah isn't there a stock stroke aluminum head hyd roller 340 from MRL that made 470 hp and 400+ torque, that a member has? I can think of the member name at the moment.
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398 TQ @ 4200 , 413 HP @ 5700 this is from memory , can dig out the papers later to be sure .
 
AlV said:
What a fantastic build! Geez!
Great job MRL!

That build is In a different league than mine.

I'm into mine for a lot less than 9K, that said wouldn't mind shelling out the dough for those results.

AlV
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Look at the cam specs
 
1970Duster said:
Look at the cam specs
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Duster,
MRL went with A "Custom hydraulic roller cam. 227/231 with .530" lift"

Mine is an out of the box hydraulic flat tappet cam. Valve Lift is .525 but the duration @ .050 lift is 231/237
 
Put a set of Dougs or tti headers on it, you won't be sorry... I prefer Dougs because they are about 200-300 less than tti for a ceramic coated set. Use the 20-25% off code at autozone.

That 340 with a 275hl will make 340-350hp and 400ish tq with a set of headers on it. The performer 318/360 is a decent intake, an RPM or Air Gap would make a bit more. If the 318/360 intake had the runners cleaned at exits, it's a real close deal. A 1" open spacer under the carb make a lot of difference on all of them.
 
interesting numbers for the XE268...maybe 20hp over stock but a bigger low end torque gain
 
crackedback said:
Put a set of Dougs or tti headers on it, you won't be sorry... I prefer Dougs because they are about 200-300 less than tti for a ceramic coated set. Use the 20-25% off code at autozone.
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Do the Doug's require a mini starter? I know it's probably posted somewhere, i just don't remember off the top of my head.
 
Dartfever,
If you're up to it.. Can you post the numbers for the setup with the stock 340 intake and performer rpm (or air gap)? Seems there is a lot of interest and opinion on this topic.

Thanks.

AlV
 
the 268 outperforms the 275 to about 4000rpm in hp and torque and they both look to be done at 5000 with the 275 having the edge at 5000
...this would be an interesting race
 
Both those cams (xe268, xe275hl) in a 340 with stock 2.02 heads will make power to 5500-5600+ range running headers.

As much as people like those 68-70hp exhaust manifolds, they are not good for making power on set ups like this.
 
A question for the experienced: What numbers are best from a compression check? I just checked my 340 and I have 123-126lbs overall. Manifold vac.@ idle is 9+, I use a 3.5 power valve. The cam is D.C. .488L, 108 separation, 288D. Purple S. I'm thinking this is too much, from the cylinder pressure. The .060+ pistons are -.010 down and the 1972 J heads milled/ matched, aprox .050, .020 shim gasket. This was a Chrysler dealer $800 replacement type with heads, we fitted w/2.02 intakes. It ran 12.40 @ the old Fremont strip in a 3300 Ebody Cuda with N50/14" Kellys w/ 4.30 gear @108mph.
Now in the 68, 12.97 @ 104 3.90gear, 275/60-15" in Sonoma. Same old Doug cheepys, 340LD, 780vac. Holley. I added 1.6 steel/bushed roller rockers. for aprox .530 lift. with no improvement in MPH. Now that I have adjustable rockers, IS THERE A BETTER SOLID FLAT TAPPET CAM I CAN USE INSTEAD??
 
crackedback said:
Both those cams (xe268, xe275hl) in a 340 with stock 2.02 heads will make power to 5500-5600+ range running headers.

As much as people like those 68-70hp exhaust manifolds, they are not good for making power on set ups like this.
Click to expand...

I totally agree... I'm am seriously considering headers since I have the front end out of the Car.

With the extra height DO you know if the RPM or Air gap intakes would clear the hood?
 
ir3333 said:
the 268 outperforms the 275 to about 4000rpm in hp and torque and they both look to be done at 5000 with the 275 having the edge at 5000
...this would be an interesting race
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indeed.
 
Air gap should clear no problem , at least it does on my car , using a Holley with the stock 340 air cleaner ,no spacer between carb and intake , that might be a problem with clearance , not sure
 
jerry6 said:
Air gap should clear no problem , at least it does on my car , using a Holley with the stock 340 air cleaner ,no spacer between carb and intake , that might be a problem with clearance , not sure
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X2

The air gap clears on both my 318, and my brothers 340 under stock hoods. I've used both Holley and AFB carbs with 3" drop base air cleaner. Trim the stud down to about 1/2" above the cleaner lid and you should be good
 
I ran what options DD gives me. Unfortunately they do't let me enter flow ratings for intakes. They have a low flow high torque flow, std flow and high flow. The original is with the standard flow. The first one here is with the high flow setting, second the high torque. Personally, from what I have read the 340 intake is closer to a standard flow result. I also believe the RPM airgap would not give up that much low end TQ as it shows either.
 

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jerry6 said:
Air gap should clear no problem , at least it does on my car , using a Holley with the stock 340 air cleaner ,no spacer between carb and intake , that might be a problem with clearance , not sure
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txstang84 said:
X2

The air gap clears on both my 318, and my brothers 340 under stock hoods. I've used both Holley and AFB carbs with 3" drop base air cleaner. Trim the stud down to about 1/2" above the cleaner lid and you should be good
Click to expand...


Thanks for the info.
AlV
 
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