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1.6 VS 1.7 ROCKERS #1477112
07/31/13 04:09 PM
07/31/13 04:09 PM
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Now - Port Orange,Fla. Former...
MIKES_DUSTER Offline OP
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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!!!!

Re: 1.6 VS 1.7 ROCKERS [Re: MIKES_DUSTER] #1477113
07/31/13 04:25 PM
07/31/13 04:25 PM
Joined: Jan 2003
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Frostbitefalls MN (Rocky&Bullw...
gregsdart Online content
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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
Re: 1.6 VS 1.7 ROCKERS [Re: MIKES_DUSTER] #1477114
07/31/13 04:38 PM
07/31/13 04:38 PM
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY Offline
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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

Re: 1.6 VS 1.7 ROCKERS [Re: MIKES_DUSTER] #1477115
07/31/13 04:40 PM
07/31/13 04:40 PM
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
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BradH Offline
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Val-haul-ass... eventually
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.

Re: 1.6 VS 1.7 ROCKERS [Re: MIKES_DUSTER] #1477116
07/31/13 05:22 PM
07/31/13 05:22 PM
Joined: Jan 2003
Posts: 31,078
Oregon
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AndyF Offline
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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.

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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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

Re: 1.6 VS 1.7 ROCKERS [Re: MR_P_BODY] #1477118
07/31/13 07:47 PM
07/31/13 07:47 PM
Joined: Jan 2003
Posts: 9,146
Now - Port Orange,Fla. Former...
MIKES_DUSTER Offline OP
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Thanks guys!!!!! These Crane rockers are BRAND NEW and the stupid adjuster broke.... NOT HAPPY!!!!!!

Re: 1.6 VS 1.7 ROCKERS [Re: MIKES_DUSTER] #1477119
07/31/13 07:50 PM
07/31/13 07:50 PM
Joined: Jan 2003
Posts: 9,146
Now - Port Orange,Fla. Former...
MIKES_DUSTER Offline OP
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Just so everyone knows, I'm running Crane 1.6 rockers now and was thinking about going 1.7 but will probably not do it.
Anyone out there wanna trade my(spare set) 1.5 HS's for 1.6's??????

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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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
Re: 1.6 VS 1.7 ROCKERS [Re: polyspheric] #1477121
08/01/13 12:58 AM
08/01/13 12:58 AM
Joined: Jan 2003
Posts: 9,146
Now - Port Orange,Fla. Former...
MIKES_DUSTER Offline OP
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Quote:

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.




Ultradyne solid roller. .556/.556 .285/.295 .249/.259@.050 It was measured in around .575 with 1.6 rockers.

Re: 1.6 VS 1.7 ROCKERS [Re: MIKES_DUSTER] #1477122
08/01/13 08:29 AM
08/01/13 08:29 AM
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Southington Ct.
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Quote:



Ultradyne solid roller. .556/.556 .285/.295 .249/.259@.050 It was measured in around .575 with 1.6 rockers.




Going to a higher rocker ration will not only add lift but also intensify the opening and closing events on the cam and add a little more duration at the higher lifts. You ramp profiles are very non-aggressive and would probably help some.
Allan G.


1970 Challenger w/572 Hemi street car and my pride and joy. 1986 T-Type with 272 Stage 2 Buick V6 engine - True 8 second street car. Just updated the engine and put down 928 HP @ 35# boost to the ground on chasis dyno. 1976 Cee Bee Avenger Jet Boat - 460 Ford powered.
Re: 1.6 VS 1.7 ROCKERS [Re: MR_P_BODY] #1477123
08/01/13 10:05 AM
08/01/13 10:05 AM
Joined: Jan 2003
Posts: 31,078
Oregon
A
AndyF Offline
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Oregon
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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