Install Question on ported heads/1.7RR
Thread Starter
Drifting
Joined: Aug 2009
Posts: 1,971
Likes: 243
Install Question on ported heads/1.7RR
1994 LT1/ZF6
I bought a set of ported heads/intake, springs, 1.7 roller rockers, pushrods, guideplates, etc. The plan is that I will install on my stock cam/bottom end LT1. This setup will satisfy me for some time until I decide to do a full rebuild/cam.
I don’t think the 1.7RRs will clear the factory valve covers. So far, the only covers I can seem to find that are both tall and designed for the Vette with clearance for the alternator are the Canton aluminum set at around $200. Are there other options?
Is there a gasket set available that would essentially include all gaskets from the heads up?
Last question for now, the ported intake that I have has egr blockoff plates installed. I like the idea of a clean intake but the egr doesn’t seem to have negatively impacted anything either. The car needs to pass emissions. Thoughts on leaving EGR vs removing? If removed I would also want to disable in the pcm as well.
I bought a set of ported heads/intake, springs, 1.7 roller rockers, pushrods, guideplates, etc. The plan is that I will install on my stock cam/bottom end LT1. This setup will satisfy me for some time until I decide to do a full rebuild/cam.
I don’t think the 1.7RRs will clear the factory valve covers. So far, the only covers I can seem to find that are both tall and designed for the Vette with clearance for the alternator are the Canton aluminum set at around $200. Are there other options?
Is there a gasket set available that would essentially include all gaskets from the heads up?
Last question for now, the ported intake that I have has egr blockoff plates installed. I like the idea of a clean intake but the egr doesn’t seem to have negatively impacted anything either. The car needs to pass emissions. Thoughts on leaving EGR vs removing? If removed I would also want to disable in the pcm as well.
Thread Starter
Drifting
Joined: Aug 2009
Posts: 1,971
Likes: 243
I have 1.6RR on there now and I had to remove the drip tabs to clear them. So hopefullly, the 1.7s will clear as well. I did a google search before posting and it seems some reported they cleared and others that they did not.
Think I am going to keep the egr functional, I don't see a real reason not to. Sure the intake gets a bit dirty but I don't think that has any impact on performance or longevity.
Believe all I need to get is a gasket set and then I'll have everything I need to get the job done. But of course time is the issue.
Think I am going to keep the egr functional, I don't see a real reason not to. Sure the intake gets a bit dirty but I don't think that has any impact on performance or longevity.
Believe all I need to get is a gasket set and then I'll have everything I need to get the job done. But of course time is the issue.
Thread Starter
Drifting
Joined: Aug 2009
Posts: 1,971
Likes: 243
I took apart and cleaned the heads that will be going on the motor.
I'm going to be replacing the valve stem seals and I also have a set of 1.255 Hi-perform Lunati valve springs that will go on. This will be a 1.7rr/stock cam.
As I disassembled, I noticed that the springs on the intake valves had shims under the spring seats. There were no shims on the exhaust valves. Do I need to reuse these shims? I'm assuming that I do not and that the installer at the time put them in for a little more spring compression on the intake valves.
I have new guidplates and 7/16 rocker studs. The old studs had some kind of sealant on the threads (into the head). Why? Is it necessary?
Does anyone happen to know the torque spec for the rocker stud?
I'm going to be replacing the valve stem seals and I also have a set of 1.255 Hi-perform Lunati valve springs that will go on. This will be a 1.7rr/stock cam.
As I disassembled, I noticed that the springs on the intake valves had shims under the spring seats. There were no shims on the exhaust valves. Do I need to reuse these shims? I'm assuming that I do not and that the installer at the time put them in for a little more spring compression on the intake valves.
I have new guidplates and 7/16 rocker studs. The old studs had some kind of sealant on the threads (into the head). Why? Is it necessary?
Does anyone happen to know the torque spec for the rocker stud?
Race Director
Joined: Sep 2003
Posts: 16,837
Likes: 338
From: Database Error Indiana
Springs have a spec for installed hight. Thats why the shims were there. The new spring should have come with a spec sheet with that number. The shims are needed. If you are not going to be assembling heads a lot just have a machine shop install the valves. If you plan on doing it often you can buy the measuring tools and do it yourself. Its not real hard.
Advanced
Joined: Jul 2010
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From: Bolingbrook IL
I have 1.6RR on there now and I had to remove the drip tabs to clear them. So hopefullly, the 1.7s will clear as well.
Rick - '92 LT1
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Advanced
Joined: Jul 2010
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From: Bolingbrook IL
I noticed that the springs on the intake valves had shims under the spring seats. There were no shims on the exhaust valves. Do I need to reuse these shims?
I'm not sure if all factory heads do this but I'd make sure I took the preventive measure.
Rick - '92 LT1
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Joined: Jul 2010
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From: Bolingbrook IL
Be sure to reuse the cups. You'll have to do some measuring to determine if - and which - shims you'll need. Check back to JackDidley's post above about the installed height.
The installed height spec is there to set the valve seat pressure of the spring. To little and the valve "bounces" off the seat while closing. Too much shim and you could get into coil bind at max lift.
The best way to measure is with a spring pressure scale, but most guys don't have access to them. Checking installed height with good springs will get you really close.
Rick - '92 LT1
Do I need to reuse these shims? I'm assuming that I do not and that the installer at the time put them in for a little more spring compression on the intake valves.
The best way to measure is with a spring pressure scale, but most guys don't have access to them. Checking installed height with good springs will get you really close.
Rick - '92 LT1
