Okay, I've noticed that racenet.net now sell 1.8 ratio rockers for the LT1. I was gonna do the 1.7 rockers since ppl seem to have been running these without too much problem, but I was wondering if anyone try the 1.8 rockers before.

I don't really want to go to deep into the engine to swap the cam for more lift, I'm lazy. The LSA on the stock cam isn't the best for power but the 1.7 or the 1.8 should give me pretty good lift numbers.

Assuming I changed the valvespring, retainer, guideplates, and went with a longer set of pushrods, as well as anything else needed to beef up the valvetrain. Is there a reason I couldn't run this? Will it even fit?

 

way too much stress on the valvetrain and you will need to get higher valve covers, prolly shave your alternator

1.7 is pretty much the max

 

Putting a couple of dents on the alternator is piece of cake. Same goes for hammering out the valve covers. I have no need for them to be pretty. However, replacing most of the valvetrain parts to handle the stress, should it be okay?

 

you def. would wanna get springs with a high lift rating, ARP 3/8" studs, harder pushrods (93-95 are hardened stock), and perhaps lifting

 

I'm very tempted to try it out just to see if it will work. The problem is that no one has tried this, which makes sense, since most people who want that much lift just get it in the form of a cam. Part of me want reasons that if everything is beefed up and aligned sufficiently (the pushrods have to been longer and at least hardened), it should be okay from a logical standpoint. The other part says stick with the 1.7s that other ppl have proven to work.

 

I posted about the 1.8rrs awhile ago. Every1 said it was not a good idea because of the stress, even if u get the right match compents your heads will not flow @ the level they should be because of the lift, so unless u want to get ur heads ported also i wouldnt go no higher then the 1.7

 

That is true that the stock head don't really flow well. But I wouldn't go as far as to say that there wouldn't be any gains from it. The gains over 1.7 rockers would be slight. But it seems that there have been alot of people who throuw huge cams onto stock heads and still come away with something. The biggest concern is really the stress.

 

I've have tried this. it can be done. The car seemed to have some more top end but lost some midrange torque. I have since decided to go with a custom grind. I went back to the 1.6 promags I had. I have some comp 1.8s for sale for 275 shipped.
Kory

 

if i was going to do it i'd probably go up to 7/16" studs and rockers. and i'd probably use comp hi-tech pushrods in a 3/8" diameter as opposed to stock 5/16's and you'll probably want to check the geometry before you decide what length you need from hearsay. the highest quality components you can get and the stiffest setup you can get will be key here.

 

yeah
I have 7/16" studs and trickflow pushrods as well as really good springs and titanium retainers. I also had to have my guide plates elongated to work with the 1.8 rockers.
Kory

 

Did you try it on your hotcam, cause that would produce lift numbers that are way too high imho. I think it might actally work pretty well on the stock cam. Did you have to hammer out the valve covers. Was there anything else you had to beef up compared to 1.7rr.

 

yeah I tried it on the hot cam. it produced just over .590 lift. which was ok because my heads don't stall till over .650. it would probably work great on the stock cam. I don't know tho I never had a stock cam in this engine. I was and am using stock valve covers with the upper(toward the intake) reliefs removed.
Kory

 

Which brand of rockers were you using? And just to make sure, this was on a LT1 right? I 'm tempted to actually try it. I think the lift on the stock cam would be around .550. With this big a jump, I'd probably buy that pushrod length check thingie to get the fit right, but just for point of reference, what length and diameter did you end up with. The LSA would still kinda suck though. Which guidplates were you using and how did you elongate them, did you just cut into them?

Sorry for so many questions, but I have a thing about getting a good plan together before I tackle a project. Thanks in advance.

 

Just have a cam custom ground with more valve lift. It only costs a couple of bucks more than a off the shelf cam.

Hell, it will probably be cheaper than going with those rocker arms, and be a much more elegant solution.

 

I have comp cams high tech stainless 1.8 rockers. comp cams guide plates that I had elongated at a tool and die shop for 20 dollars (they are hardened steel not easy to do with a file) I used a length checker and got my trickflow pushrods from summit. I dont remember the exact length I think they were 7.2" but I don't remember for sure. If you are interested in used parts I'll cut you a deal on the rockers and the guide plates. it would cost alot to buy them new. THe rockers go for around 525 new. I got a deal on them. I'd let the rockers and guide plates go for 300 shipped.
Kory