Re: 1.6 VS 1.7 ROCKERS
[Re: MIKES_DUSTER]
#1477113
07/31/13 04:25 PM
07/31/13 04:25 PM
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Joined: Jan 2003
Posts: 10,020 Frostbitefalls MN (Rocky&Bullw...
gregsdart
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 10,020
Frostbitefalls MN (Rocky&Bullw...
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There are many variables to whether they would help or not. I would go with the 1.7 IF the valve to piston clearance is enough, the cam and spring combo is compatible, and you have the room for lift change for retainer to guide.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: 1.6 VS 1.7 ROCKERS
[Re: MIKES_DUSTER]
#1477114
07/31/13 04:38 PM
07/31/13 04:38 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
Would you see any gains from switching from 1.6 to 1.7 rockers???
One of my adjusters broke and need to get another, should I stick with Cranes or another brand??
Should i change them all???
Rocker shaft hold downs...Whos should I buy????
Thanks!!!!
I have NEVER seen any gains on the exhaust side... unless its WAY off... as said its hard to say if a 1.7 will help on the intake... you might have to change springs or make piston clearance
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Re: 1.6 VS 1.7 ROCKERS
[Re: MIKES_DUSTER]
#1477115
07/31/13 04:40 PM
07/31/13 04:40 PM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
Taking time off to work on my car
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Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
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Quote:
Would you see any gains from switching from 1.6 to 1.7 rockers???
Not likely.
Quote:
One of my adjusters broke and need to get another, should I stick with Cranes or another brand??
Smith Bros.
Quote:
Should i change them all???
Yes.
Quote:
Rocker shaft hold downs...Whos should I buy????
Hughes has decent stuff.
Quote:
Thanks!!!!
You're welcome.
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Re: 1.6 VS 1.7 ROCKERS
[Re: AndyF]
#1477117
07/31/13 06:17 PM
07/31/13 06:17 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
1.7 intakes could be worth 10 to 15 hp but it all depends on a bunch of variables. I've done some rocker arm ratio testing on the dyno over the years and usually bigger is better, but you can quickly get yourself wrapped around the wagon wheel. Especially on a Mopar engine which has fairly poor valvetrain geometry to start with.
I ended up with 1.85 intake and 1.70 exhaust rocker arm ratio on my 514 after multiple dyno tests. That setup makes pretty good power but it cost a bunch of money to get there.
Andy.. what was the cam ground for on rocker ratio
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Re: 1.6 VS 1.7 ROCKERS
[Re: MIKES_DUSTER]
#1477120
08/01/13 12:30 AM
08/01/13 12:30 AM
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Joined: Oct 2007
Posts: 4,213 New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,213
New York
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Depends on how good your cam choice was. If it's too small 1.7 intakes will help. If it's already too big, it will run worse.
Boffin Emeritus
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Re: 1.6 VS 1.7 ROCKERS
[Re: MR_P_BODY]
#1477123
08/01/13 10:05 AM
08/01/13 10:05 AM
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Joined: Jan 2003
Posts: 31,078 Oregon
AndyF
I Win
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I Win
Joined: Jan 2003
Posts: 31,078
Oregon
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Quote:
Quote:
1.7 intakes could be worth 10 to 15 hp but it all depends on a bunch of variables. I've done some rocker arm ratio testing on the dyno over the years and usually bigger is better, but you can quickly get yourself wrapped around the wagon wheel. Especially on a Mopar engine which has fairly poor valvetrain geometry to start with.
I ended up with 1.85 intake and 1.70 exhaust rocker arm ratio on my 514 after multiple dyno tests. That setup makes pretty good power but it cost a bunch of money to get there.
Andy.. what was the cam ground for on rocker ratio
The cam I have now is a Crane R-280 with 452 lobe. You do need to make sure that the cam lobe is happy with a higher rocker ratio. But most high performance cam lobes are designed to work with Chevy big block rocker arms so a person is usually safe.
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