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CAM QUESTION

General engine tech -- Drag Racing to Circle Track

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perfconn
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CAM QUESTION

Post by perfconn » Sat Feb 09, 2019 10:42 am

New sb chevy build.I wanted to buy a circle track 258-266-107 cam because I know thats what works but I have a 258-262-106 on the shelf.My question is how will this cam act compared to what I know it needs ? Bore is 4.140 & stroke is 3.350 with RHS raised runner steelheads.

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CamKing
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Re: CAM QUESTION

Post by CamKing » Sun Feb 10, 2019 12:41 pm

perfconn wrote:
Sat Feb 09, 2019 10:42 am
New sb chevy build.I wanted to buy a circle track 258-266-107 cam because I know thats what works but I have a 258-262-106 on the shelf.My question is how will this cam act compared to what I know it needs ? Bore is 4.140 & stroke is 3.350 with RHS raised runner steelheads.
Need more info on the engine.
What RPM do you run it?
What size carb?
What compression?
What RPM do you come off the corner?

Are thew cams from the same manufacturer?
Are the lobes used, from the same lobe family?
What's recommended lash, on both cams ?
Mike Jones
Jones Cam Designs

Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com
Jones Cam Designs' HotPass Vendors Forum: viewforum.php?f=44
(704)489-2449

F-BIRD'88
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Re: CAM QUESTION

Post by F-BIRD'88 » Sun Feb 10, 2019 2:34 pm

What is the valve lash of each cam.? What is the cam lobe lift of each cam?
Whats the duration @ .200" (lobe) of each?

What rockers with cam A? What rockers do you have to use with cam B?

The point is to make cam B do what cam A is doing AT THE VALVE when running.

perfconn
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Re: CAM QUESTION

Post by perfconn » Sun Feb 10, 2019 6:42 pm

Mike,
Thanks for looking.Its a 361ci sb chevy.Normally 8100-8300 at end of straights w/1.400 venturi carburetor.Engine is 14.29 compression.Never had a driver that could tell me rpm off corner even when asked.Both cams are Comp rollers and both lobes are from same family.Lash is same on both cams.Rockers are same on both applications only difference in them is the one on shelf is 4* less on exhaust @ .050 and is on 106* lobe seperation.I am just trying to figure out if cam on shelf will be far off from what I know works.Nothing is different about this build other than wanting to know about how this cam would act compared to what I know works.Engines normally make 525-535# peak torque and 680-690 peak hp with averages from 5000 to 7500 at 510 torque & 614hp..

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CamKing
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Re: CAM QUESTION

Post by CamKing » Mon Feb 11, 2019 10:26 am

It will be fine.
Put the intake centerline at the same place you used on the first cam.
The shorter exhaust may hurt the power, beyond peak. Most likely, it'll nose over about 200rpm sooner.
Mike Jones
Jones Cam Designs

Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com
Jones Cam Designs' HotPass Vendors Forum: viewforum.php?f=44
(704)489-2449

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