Full RRs question
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Joined: Nov 2006
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From: Plano TX
Full RRs question
My car will most likely never make it to a drag strip or auto cross.
That said, to go to full RRs in an 85, stock, should I just stick with 1.5 or upgrade to 1.6?
1.52 would be a bolt on fit w/ no need to mod the valve covers (I know it's not a hard mod) but I'd still get the benefit of full RRs.
If I go 1.52, are the LT4 springs too much for those rockers or is it still a good upgraded spring even for that size?
That said, to go to full RRs in an 85, stock, should I just stick with 1.5 or upgrade to 1.6?
1.52 would be a bolt on fit w/ no need to mod the valve covers (I know it's not a hard mod) but I'd still get the benefit of full RRs.
If I go 1.52, are the LT4 springs too much for those rockers or is it still a good upgraded spring even for that size?
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Joined: Feb 1999
Posts: 12,772
Likes: 17
From: Indianapolis IN
My car will most likely never make it to a drag strip or auto cross.
That said, to go to full RRs in an 85, stock, should I just stick with 1.5 or upgrade to 1.6?
1.52 would be a bolt on fit w/ no need to mod the valve covers (I know it's not a hard mod) but I'd still get the benefit of full RRs.
If I go 1.52, are the LT4 springs too much for those rockers or is it still a good upgraded spring even for that size?
That said, to go to full RRs in an 85, stock, should I just stick with 1.5 or upgrade to 1.6?
1.52 would be a bolt on fit w/ no need to mod the valve covers (I know it's not a hard mod) but I'd still get the benefit of full RRs.
If I go 1.52, are the LT4 springs too much for those rockers or is it still a good upgraded spring even for that size?
http://www.vetteweb.com/tech/0204vet...er_arms_ratio/
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Joined: Nov 2000
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From: stop the fun suckers
things to note on that article..
We know from experience that a higher-ratio rocker makes more power in engines that would normally need a bigger (higher lift/more duration) cam. But we weren't able to prove it this time. After installing the 1.6s we were shocked when the engine dropped more than 40 hp! As we explained earlier, rocker arms increase the ratio by moving the pushrod cup closer to the rocker fulcrum pivot point. That's where our problem was. The pushrod was contacting the top of the clearance hole in the cylinder heads with the 1.6 rockers. So, you can see that swapping rocker arms involves more than just deciding what ratio to run. In fact, this problem is very hard to spot because it's typically hidden beneath the pushrod guideplate, which is why it took us a while to find it.
Westech came to our rescue, however, and dug up some old dyno tests comparing 1.5s to 1.6s on other small-blocks. Those results found the 1.6 rockers making more than 20 hp over the stock 1.5 rockers. But that engine was equipped with a smaller cam than this one, and it seemed to really need the additional lift and duration afforded by the higher ratio.
Westech came to our rescue, however, and dug up some old dyno tests comparing 1.5s to 1.6s on other small-blocks. Those results found the 1.6 rockers making more than 20 hp over the stock 1.5 rockers. But that engine was equipped with a smaller cam than this one, and it seemed to really need the additional lift and duration afforded by the higher ratio.
Last edited by Z06_BluByU; May 7, 2007 at 09:00 PM.
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Joined: Nov 2006
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From: Plano TX
That was interesting... I like doing all the research I can before buying my upgrades. 
I like to upgrade once 
As far as additional power... I'm really not too worried about it, but it's never a bad thing to gain either. So going 1.52 or 1.6 is not a huge concern to me since I'm just cruising most of the time.
I like to upgrade once As far as additional power... I'm really not too worried about it, but it's never a bad thing to gain either. So going 1.52 or 1.6 is not a huge concern to me since I'm just cruising most of the time.
