LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

1.7 rockers and 224/236 questions

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Old Jan 20, 2004 | 09:13 PM
  #1  
94irocz's Avatar
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1.7 rockers and 224/236 questions

I know this topic has kinda been blown up as of late. I did a search and haven't seen anything really pertaining to this cam. So I have a couple questions about my set up and if it'd work with these rockers.

My set up consists of the stuff in the sig. 224/236xe cam, stock heads, cm custom single springs that are supose to be good up to .600, 1.6 rockers, hardend pushrods etc.. Car gets rev'd to 6400rpms. Peak power is at 6200.

What would the new lift be with 1.7 rockers? Do you think I'd have piston to valve clearance probs? And do you think I'd pick up anything by switching to these?

Thanks for any help ya can give me

Joe
Old Jan 20, 2004 | 09:27 PM
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Your lift with 1.7 rockers would be .570/.578

You would need springs good upto .600 lift.

Piston to valve clearance shouldn't be a problem unless you milled a lot of your heads.

With this high lift you should check to make sure you don't have coil bind (spring becomes completely compressed) or you will bend pushrods and break rockers.

You might have to go with a slightly shorter pushrod. But you'll have to check the rocker geometry for that.

Might not be a bad idea to go with non-self aligning rockers with guideplates for a more stable setup at that lift.
Old Jan 20, 2004 | 09:39 PM
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Originally posted by Gripenfelter
Your lift with 1.7 rockers would be .570/.578

You would need springs good upto .600 lift.

With this high lift you should check to make sure you don't have coil bind (spring becomes completely compressed) or you will bend pushrods and break rockers.

You might have to go with a slightly shorter pushrod. But you'll have to check the rocker geometry for that.

Might not be a bad idea to go with non-self aligning rockers with guideplates for a more stable setup at that lift.
I'm supose to have springs that are rated for up to .600 lift. How does one check for coil bind? As far as I know the only 1.7 rockers for an lt1 are only non self aligning.

Joe
Old Jan 20, 2004 | 10:18 PM
  #4  
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Scorpion makes a set of self-aligning as wll.

When you ighten down the rocker, turn the crank over manually and watch the spring to see if the coils bind (compress all the way)
Old Jan 21, 2004 | 12:23 AM
  #5  
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Well if you are willing to spend the money, sounds like it would be worth it. Combination Motorsports told me the higher lift won't really do much since the stock heads poop out at around 550 lift. It can't hurt to try if your are willing to spend the money, or get the heads ported someday in the future. Will you need different valve covers? Also is your cam the 114 LSA supercharger cam, or is it ground for NA. I have the supercharger grind, and just trying to get an idea where I'm at with power, yours has some very high numbers, I didn't think these cams and stock heads could give so much-makes me excited to see some good power.
Old Jan 21, 2004 | 01:07 AM
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I've been away for a while... who makes 1.7 RRs for the LT1?
Old Jan 21, 2004 | 07:54 PM
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94irocz's Avatar
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Originally posted by D James
Well if you are willing to spend the money, sounds like it would be worth it. Combination Motorsports told me the higher lift won't really do much since the stock heads poop out at around 550 lift. It can't hurt to try if your are willing to spend the money, or get the heads ported someday in the future. Will you need different valve covers? Also is your cam the 114 LSA supercharger cam, or is it ground for NA. I have the supercharger grind, and just trying to get an idea where I'm at with power, yours has some very high numbers, I didn't think these cams and stock heads could give so much-makes me excited to see some good power.
It won't be a mod soon. Trying to get some nitrous first. But it will most likely be a future thing. And the heads will be done also. Yes mine is ground on the 114lsa and that was through the stock stall and stock heads.

Joe
Old Jan 22, 2004 | 08:11 PM
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I've got comp cam 1.8 rockers on my hot cammed lt1. They are non self alligning, and I am using stock valve covers.
Kory
Old Jan 22, 2004 | 08:48 PM
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I thought 1.7s and 1.8s were for big blocks. What modifications did you do? What about your pushrod length?
Old Jan 22, 2004 | 08:55 PM
  #10  
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I used trickflow pushrods that I bought through summit. they are one size longer than stock. I used kmotion k800 springs and titanium retainers with 10 degree locks. I ran the lash on the tight side. The car pulls much harder above 3000 rpms. definately noticable.
kory
Old Jan 22, 2004 | 10:05 PM
  #11  
94irocz's Avatar
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So do some people need new pushrods and others don't or what? Anyone think I'll pick up anything power wise?

Joe
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