340 Cam Duration with High Compression

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ValiantRacing

ValiantRacing

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What is the most duration possible to run in a 340, that anybody has tried.
the engine will be over 13 to 1

I have an older/new hughes cam that is 282/287 at .50 on the duration.
 
racer brown cam from Don gould at 4secondsflat.com
ST-21
254
554
520
Mighty or Race
22-26
10.5-13.0
4.10-4.88
3500-4500
 
ValiantRacing said:
What is the most duration possible to run in a 340, that anybody has tried.
the engine will be over 13 to 1

I have an older/new hughes cam that is 282/287 at .50 on the duration.
Click to expand...

It's not just duration, it's intake center line and lobe separation that affects it also...
 
The best one is at the bottom of the page.

In all seriousness, most people run way too much cam for a given combo. That cam IMO will be a dog.
 
With stock 340 heads you loose the low end and do not flow enough air to gain any hp on the top end with a very narrow power (or lack thereof ) band
modified for Pro stock w2 or later etc you can go over 300 @.50 most of its miles will be on the trailer
 
Im sure you could go bigger than that,but i seriously doubt you have the rest of the package to make even that cam work.

For what its worth,the old way of going faster was to add more cam to overcome lack of cylinderheadflow and lack of cubes,its not rocketscience but very ineficient with the heads available today and if you try to do that with good heads you may just find yourself blowing up shortblocks over and over and over again,you will have enough problems keeping your shortblock togheter even with bad heads.
 
Wyrmrider said:
With stock 340 heads you loose the low end and do not flow enough air to gain any hp on the top end with a very narrow power (or lack thereof ) band
modified for Pro stock w2 or later etc you can go over 300 @.50 most of its miles will be on the trailer
Click to expand...

The point of running loooooooooong duration cams in engines with limited headflow is to turn more RPM ,it does not realy mather that you are not making any more power at the crank when you can make up for that with more gear and therefore make more power at the wheels.
Its the old way of doing things when there wasnt many good heads available.
Keeping the shortblock togheter is a different story.
 
skrews said:
The best one is at the bottom of the page.

In all seriousness, most people run way too much cam for a given combo. That cam IMO will be a dog.
Click to expand...
Yes, the one that comes in the modified box with lobe cut outs.
 
Great one rumblefish
Yep- old school - what we used to do
1fast nails it
if cam had to be stock- retard it and rev the snot out of it
springs were not capable of working with fast cams
Ran the Chet Herbert 400 degree cam- would rev forever
283 power pack heads
 
I got the cam in combo deal, just not sure what to do with, i am not going to run it in my 340. Duration does make power, but to much will hurt it.
 
I run this cam in my 340...if you are looking for some old school thinking. My compression ratio is around 9.6

Brand:Crane Cams

Manufacturer's Part Number:691191

Part Type:Camshafts

Product Line:Crane Mechanical Flat Tappet Camshafts

Summit Racing Part Number:CRN-691191


UPC:021174013634

Cam Style: Mechanical flat tappet

Basic Operating RPM Range: 3,000-6,500

Intake Duration at 050 inch Lift: 238

Exhaust Duration at 050 inch Lift: 248

Duration at 050 inch Lift: 238 int./248 exh.

Advertised Intake Duration: 300

Advertised Exhaust Duration: 310

Advertised Duration: 300 int./310 exh.

Intake Valve Lift with Factory Rocker Arm Ratio: 0.480 in.

Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.500 in.

Valve Lift with Factory Rocker Arm Ratio: 0.480 int./0.500 exh.

Lobe Separation (degrees): 114
 
I have a single pattern Crane like that on a 108.
IIRC, [email protected].
I gotta check again... dang! Gettin old.
(Parts, not me... LOL!)
 
ValiantRacing said:
What is the most duration possible to run in a 340, that anybody has tried.
the engine will be over 13 to 1

I have an older/new hughes cam that is 282/287 at .50 on the duration.
Click to expand...
That is pretty monsterous.
 
Seen Crower solid rollers on 108 l.c. 250's in duration @ .050 ,run sweetly on the street in a 340 (4.57 rear 4800 stall,tunnel ram actual 11.7 compression)...
Just something, to think about. ......
 
Abodybomber said:
Seen Crower solid rollers on 108 l.c. 250's in duration @ .050 ,run sweetly on the street in a 340 (4.57 rear 4800 stall,tunnel ram actual 11.7 compression)...
Just something, to think about. ......
Click to expand...

I'll second that. I'm running a 254/260 @.050 .638/656 on 108*, 12.4:1, 4.11's, 4000+ stall. Very happy.
 
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