I know this has probably been asked before but I hear a lot of people talking about doing 1.7 roller rockers on the stock cam . I'm wondering if anyone on here has done this and whether it would be worth it . I'm considering rr's and am wondering which would be better to go with on the stock cam . Also on either what all would be necessary for the swap ? Any valve cover modifications on our cars needed ?
Sorry for all the questions I just need a little better advice on the subject than what I am finding . My car is a 94 LT1 by the way .
Thanks

 

It's really just some added stress and sets the geometry off. For a stock cam I would stay with stock ratio. Rollers are a good thing though

 

Added spring stress may cause issues on a high milage set up as well....the LT4 already breaths pretty good. I have no experience with the 1.7s though...maybe they are a good thing.

 

He has a LT1. The LT4 has 1.6's stock. I don't see why he couldn't run 1.6's. 1.7's would add side-loading on the valve stem. Causing wear on the guides.

 

Oh yeah he could run them. Really it's a matter of opinion I guess. I just have a hard time justifying the added stresses for the gain of rockers alone. If he was going springs, lifters, and cam I guess it would make sense.
I look at over ratio rockers as kind of a gimmick for most applications. If you want that added duration or lift then just get the cam that gives it to you. For just rockers alone they benefit too little to bother. IMHO

 

Never been crazy about 1.7s on the sbc.

 

While we're on the subject, has anyone ever installed these? Have been contemplating these for a couple of years. FYI, L98 speed density, stock covers.

http://www.ecklers.com/product.asp?p...4&dept_id=1771

 

Nathan found a very nice gain with the 1.7 rockers, his page:

http://www.wku.edu/~nathan.plemons/h...ockerarms.html

 

Get them from Summit Racing instead.

You can get Crane or Comp Cams roller rockers for less than that.

 

I'm not sure where to find them anymore but I have used the "scorpion" rollers several times and they are great quality. I was getting them from a local guy in El Paso, but the set was only running me a little over $200

 

I like these Stronger & lighter then aluminum. I've run them before with a high lift cam, big springs. These Enduro's accept the largest diameter retainers without interference I know of. Huge fulcrum, light but strong body. Just the ticket

http://store.summitracing.com/partde...6&autoview=sku

 

To run 1.7 ratio rockers on an otherwise stock LT1 your going to need new valve springs, retainers, 7/16 studs, guide plates, an adjustable pushrod and 5/16 .080 wall C/M hardened pushrods.

The stock LT1 has a .300 lobe. So its .450 lift using the stock 1.5 ratio rockers, .480 using 1.6 ratio rockers and .510 using 1.7 ratio rockers. Since its only .510 lift at the valve, retainer to guide clearance SHOULDN"T be an issue, but DO check it anyway.

The stock ovate wire LT1 springs are only good to .480 lift from their stock 1.700 set up height.

Scorpion is the only company I know of that still makes a 1.7 ratio stud mounted rocker for the SBC. They are 7/16 stud, non-self aligning only. Hence the need for studs, guide plates and pushrods.

You will HAVE to plot your valve train/rocker geometry to buy the correct length pushrods. Hence the need for an adjustable pushrod.

I tried to get it all from one place but your PROBALLY going to have to call and special order the rockers. Links to the parts I think you should use, now this is all good stuff, not the cheapest stuff but it is the cheapest I would try and do it.

Howards 1.250 valve springs, C/M retainers and locks. $73.00

http://www.competitionproducts.com/p...sp?number=VSA4

ARP 7/16 studs. $34.00

http://www.competitionproducts.com/p...umber=100-7101

Manley Guide Plates. $20.00

http://www.competitionproducts.com/p...number=42151-8

Scorpion 1.7 rockers. (pn SCP1026) $200-250.00

http://www.scorpionperformance.com/n...category_id=74

FLATLANDER RACING ALSO MAY HAVE THEM IN STOCK-

http://www.flatlanderracing.com/scor...s.html#chevySB

Comp 6.8-7.8 adjustable pushrod checker tool. $19.00

http://www.competitionproducts.com/p...?number=7702-1

Manley C/M 5/16 .080 wall pushrods. (Your going to have to buy the correct lenght after you plot the rocker gemoetry). $130.00

http://www.competitionproducts.com/p...s.asp?dept=691

I'd be interested to see the difference on a dyno. Good luck
Will

 

Just by adding 1.6 rockers to a stock engine will give you increased torque and horsepower. The engine will also rev quicker and higher. The question is whether another step up to 1.7 will benefit a stock engine.

 

well right Jimi but benefit at what cost is my point. The added stress and loss of geometry TO ME is just not worth the nominal increase in power. Like I say just MHO.

 

Just added my 1:6's on my 95' yesterday. Really runs great..Very noticable SOTP increase.

CAJUN

 

Thanks to everyone so far . I'm still debating on the mod though .... It just seems to me that going with the 1.7's would be similar to having a mild cam . That is if I were to get everything right and everything worked . It would be interesting to try just unsure because so few have done it so far . As for the 1.6's that everyone has installed what did yall include in the swap and what kind of total price ?

 

They cost $458.95.

 

There was a long discussion about the 1.6 vs 1.7's on the z forum a while back. I believe those that went from the 1.6's to the scorpions said there was a slight gain but the trouble was not worth it. I'm going with the comp pro mag 1.6's.

 

And they are a copy (ALBET A HALF A$$ED ONE) of Jim Millers mid lift rocker desgin.

Nearly $460 for stud mounted rockers that the pushrod cup to trunion geometry is still all screwed up on. What is the world comming to.
Will