1.7 Rr ?
Thread Starter
Burning Brakes
Joined: Nov 2002
Posts: 1,239
Likes: 1
From: Las Vegas NV
1.7 Rr ?
What is the verdict, good mod/bad mod. Did a search, came up with nothing. Considering using the 1.7 RR with stock cam and could use opinions. Winter time is here and it is time to mod! 
Last edited by crheinish; Nov 22, 2004 at 02:01 PM.
Drifting
Joined: May 2002
Posts: 1,581
Likes: 2
From: The Motor City
It's a good mod to make, but you will have to swap out your studs too. And you may have to modify your valve covers internally a bit too (to clear the larger rockers).
One shop I know used to run stock 1.7 rockers on showroom stock Camaros with 305s. They claimed a solid 20hp at the crank, and the where just they stock stamped steel units from big block Chevys. Good roller rockers should give a bit more.
One shop I know used to run stock 1.7 rockers on showroom stock Camaros with 305s. They claimed a solid 20hp at the crank, and the where just they stock stamped steel units from big block Chevys. Good roller rockers should give a bit more.
Last edited by TheCorvetteKid; Nov 22, 2004 at 02:56 PM.
Drifting
Joined: Feb 2004
Posts: 1,485
Likes: 2
From: Champaign, IL
St. Jude Donor '05
1.7 rr are a good mod on the LT1 with the LT4 Hot Cam kit but I don't know how they would do with the stock cam - make sure you upgrade your springs at the same time. Check out Nathon Plemons home page
http://www.wku.edu/~nathan.plemons
http://www.wku.edu/~nathan.plemons
Le Mans Master
Joined: Jan 2002
Posts: 5,556
Likes: 0
From: Jenison MI
Cruise-In VI Veteran
Cruise-In VII Veteran
St. Jude Donor '06
hmm, if 1.6 is good 1.7 is better, right? I would like some info on this too. Like part numbers for rockers, springs and what ever else I would need.
Thread Starter
Burning Brakes
Joined: Nov 2002
Posts: 1,239
Likes: 1
From: Las Vegas NV
Originally Posted by ToyC4
1.7 rr are a good mod on the LT1 with the LT4 Hot Cam kit but I don't know how they would do with the stock cam - make sure you upgrade your springs at the same time. Check out Nathon Plemons home page
http://www.wku.edu/~nathan.plemons
http://www.wku.edu/~nathan.plemons
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Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
You won't find much info on my web page about how much 1.7's affect a stock cam car because I've never tried it. Mathematically though you should still see a gain higher than with the 1.6's. I've calculated it many times before and determined that the net lift with 1.7's on a stock cam is still below the stall lift of stock LT1 heads. As such, you'll see a gain. As for my car I picked up 14 hp and 11 pounds of torque with the 1.7's and have been driving it that way for quite a while now.
1.8's on the other hand I tried and actually lost HP. Any power gained was offset by the increase in internal friction.
One thing that is for sure is that you will absolutely have to change your springs. I would recommend something a bit better than the LT4 springs too.
1.8's on the other hand I tried and actually lost HP. Any power gained was offset by the increase in internal friction.
One thing that is for sure is that you will absolutely have to change your springs. I would recommend something a bit better than the LT4 springs too.
Thread Starter
Burning Brakes
Joined: Nov 2002
Posts: 1,239
Likes: 1
From: Las Vegas NV
Originally Posted by Nathan Plemons
You won't find much info on my web page about how much 1.7's affect a stock cam car because I've never tried it. Mathematically though you should still see a gain higher than with the 1.6's. I've calculated it many times before and determined that the net lift with 1.7's on a stock cam is still below the stall lift of stock LT1 heads. As such, you'll see a gain. As for my car I picked up 14 hp and 11 pounds of torque with the 1.7's and have been driving it that way for quite a while now.
1.8's on the other hand I tried and actually lost HP. Any power gained was offset by the increase in internal friction.
One thing that is for sure is that you will absolutely have to change your springs. I would recommend something a bit better than the LT4 springs too.
1.8's on the other hand I tried and actually lost HP. Any power gained was offset by the increase in internal friction.
One thing that is for sure is that you will absolutely have to change your springs. I would recommend something a bit better than the LT4 springs too.
Burning Brakes
Joined: Nov 2001
Posts: 920
Likes: 0
From: Cherry Hill NJ
One of the top 3 valve covers in this link should work without mods, shouldn't it?
http://www.superchevyperformance.com...lvecovers.html
http://www.superchevyperformance.com...lvecovers.html
Instructor
Joined: Aug 2004
Posts: 151
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I just put in 1.7rr with a stock cam. I haven't dynoed or gone to the strip yet to verify, but it feels like it is pulling quicker 4500+, and it doesn't seem to die as much at 6000+ (i set my rev limit to 6300).
To get the valve covers to fit you have to remove the drip tabs. Everything else is straight forward.
I also highly recommend LT4 springs. They are good up to .525 lift, and 1.7rr only raise the intake to about .507 lift and exhaust to .520 lift with a stock cam. You can also reuse your LT1 retainers and keepers. For around $30 dollars, you would be set with new LT4 springs. The rest can be spent on Guideplates ($20), 7/16 rocker studs ($30-40), Scorpion 1.7rr ($230). As far as parts to upgrade that was all I paid.
If you really want more information on what you need, do a search at camaroz28.com for "Scorpion" roller rockers. You'll get a lot of information and even results from those with stock cams.
To get the valve covers to fit you have to remove the drip tabs. Everything else is straight forward.
I also highly recommend LT4 springs. They are good up to .525 lift, and 1.7rr only raise the intake to about .507 lift and exhaust to .520 lift with a stock cam. You can also reuse your LT1 retainers and keepers. For around $30 dollars, you would be set with new LT4 springs. The rest can be spent on Guideplates ($20), 7/16 rocker studs ($30-40), Scorpion 1.7rr ($230). As far as parts to upgrade that was all I paid.
If you really want more information on what you need, do a search at camaroz28.com for "Scorpion" roller rockers. You'll get a lot of information and even results from those with stock cams.
Le Mans Master
Joined: Jan 2002
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From: Jenison MI
Cruise-In VI Veteran
Cruise-In VII Veteran
St. Jude Donor '06
Ok so I will need.
LT4 springs.
Guideplates.
7/16 rocker studs
Scorpion 1.7rr
And I'm thinking hard pushrods.
Is this right?
Anyone know off the top of their head what pushrods I would need?
The other stuff I think I can figure out easy enough.
LT4 springs.
Guideplates.
7/16 rocker studs
Scorpion 1.7rr
And I'm thinking hard pushrods.
Is this right?
Anyone know off the top of their head what pushrods I would need?
The other stuff I think I can figure out easy enough.
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Originally Posted by fsr402
Ok so I will need.
LT4 springs.
Guideplates.
7/16 rocker studs
Scorpion 1.7rr
And I'm thinking hard pushrods.
Is this right?
Anyone know off the top of their head what pushrods I would need?
The other stuff I think I can figure out easy enough.
LT4 springs.
Guideplates.
7/16 rocker studs
Scorpion 1.7rr
And I'm thinking hard pushrods.
Is this right?
Anyone know off the top of their head what pushrods I would need?
The other stuff I think I can figure out easy enough.
As for pushrods, you can get by with stock length. If you really want it set up perfect you can get an adjustable rod and check the length and get exactly what you need. I would recommend that but being said I haven't had time to do it. Stock length will work just fine. I have a set of trick flow single piece chromemoly rods, I highly recommend them. They are costly but they are very nice.
Melting Slicks
Joined: Oct 2000
Posts: 3,010
Likes: 1
From: Sweden/Stockholm
Originally Posted by Nathan Plemons
Please do yourself a favor and get something other than LT4 springs. They are better than LT1 springs but they still have miserable seat pressures. You want a valve that will take the extra punishment and smile. Remember LT1 valves are heavier than LT4 valves, so that spring isn't as good on an LT1. You miss a shift and accidentally turn 7000k PRM's for an instant and you can likely kiss that engine goodbye. Spend a little more money on the springs and go with overkill and you'll have a much better "oh hell" buffer.
As for pushrods, you can get by with stock length. If you really want it set up perfect you can get an adjustable rod and check the length and get exactly what you need. I would recommend that but being said I haven't had time to do it. Stock length will work just fine. I have a set of trick flow single piece chromemoly rods, I highly recommend them. They are costly but they are very nice.
As for pushrods, you can get by with stock length. If you really want it set up perfect you can get an adjustable rod and check the length and get exactly what you need. I would recommend that but being said I haven't had time to do it. Stock length will work just fine. I have a set of trick flow single piece chromemoly rods, I highly recommend them. They are costly but they are very nice.
will this spring work with the hotcam and 1:7 rrs?
1.470" o.d. single with damper
120 lbs. @ 1.780" installed height
300 lbs. @ 1.280" open
360 lbs. per inch rate
.540" maximum valve lift
Cheers
Race Director
Joined: May 2001
Posts: 14,165
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That spring has better pressure characteristics than the LT4 spring, but unfortunately it won't take the lift of the 1.7 rockers. It would probaby be a fairly decent spring for 1.7 rockers on a stock cam.
The hot cam is rated at .525 lift with 1.6 rockers. Divide that out and you have .328 lobe lift. Multiply that by 1.7 and you have .557 lift with the Hot Cam and 1.7 rockers. You also need to consider what measurement they are giving you. Is that maximum recommended lift, or is that coil bind height? You want a minimum of .050 tolerance between your lift and coil bind. So if you have a cam of .557 lift you want a spring that will go to AT LEAST .607 before coil bind.
The hot cam is rated at .525 lift with 1.6 rockers. Divide that out and you have .328 lobe lift. Multiply that by 1.7 and you have .557 lift with the Hot Cam and 1.7 rockers. You also need to consider what measurement they are giving you. Is that maximum recommended lift, or is that coil bind height? You want a minimum of .050 tolerance between your lift and coil bind. So if you have a cam of .557 lift you want a spring that will go to AT LEAST .607 before coil bind.
Melting Slicks
Joined: Oct 2000
Posts: 3,010
Likes: 1
From: Sweden/Stockholm
Originally Posted by Nathan Plemons
That spring has better pressure characteristics than the LT4 spring, but unfortunately it won't take the lift of the 1.7 rockers. It would probaby be a fairly decent spring for 1.7 rockers on a stock cam.
The hot cam is rated at .525 lift with 1.6 rockers. Divide that out and you have .328 lobe lift. Multiply that by 1.7 and you have .557 lift with the Hot Cam and 1.7 rockers. You also need to consider what measurement they are giving you. Is that maximum recommended lift, or is that coil bind height? You want a minimum of .050 tolerance between your lift and coil bind. So if you have a cam of .557 lift you want a spring that will go to AT LEAST .607 before coil bind.
The hot cam is rated at .525 lift with 1.6 rockers. Divide that out and you have .328 lobe lift. Multiply that by 1.7 and you have .557 lift with the Hot Cam and 1.7 rockers. You also need to consider what measurement they are giving you. Is that maximum recommended lift, or is that coil bind height? You want a minimum of .050 tolerance between your lift and coil bind. So if you have a cam of .557 lift you want a spring that will go to AT LEAST .607 before coil bind.