I was wondering if putting a RR 1.6" rocker setup on my stock 350 TPI would make a difference. I want to have the effects of a bigger cam with out having to pull the engine. Will the higher ratio help me since I have the stock cam.

AND will I have to Change valve covers?

Also will this help or hurt gas mileage and performance.



Car
89 GTA 350
110,000 miles
corvetto servo
gutted MAF
AIRFOIL
no smog stuff
3" hooker catback

 

you'll still have to open up the pushrod holes in the heads... and yes, you can run 1.6's in there with the stock valve covers BUT it depends on what type. i'm running steel 1.6 rollers with an LT4 hotcam with no problems, other than still having to tune everything...

 

thunderstick

What mods did you do to your heads to handle the lift. I want run a similar set up.

 

only thing i had to do was to open the holes, as mentioned, and also the spring pockets (slightly) to accomodate the larger springs that came with the cam set. also had a 3-angle valve job done, but has nothing to do with the lift...

KAM

 

did you use the stock valve locks and retainers?
I have read that there is some clearance issues between the retainer and the valve guide.

 

sorry, no. had to get those, too. i just ordered everything i needed to do the cam/spring install together...

KAM

 

I could be wrong here, but I doubt you'll have to elongate the pushrod holes in the heads to run 1.6 rockers with the stock cam lift specs. They're pretty low. Like around .420 or something like that. To run roller rockers with the stock centerbolt valve covers, you'll have to go with the narrow body roller rockers like Crane's narrow body gold series. I think I also seen sets from GMPP that'll work with centerbolt covers, but they're just roller tipped, and not a full roller rocker (i.e. roller style fulcrum). If you just want roller tipped style rockers, you probably have a lot more choices at cheaper prices. I think the comp cams roller tipped ones will work too. The full roller narrow Cranes are around $300 or better for a set.

 

I have 1.6 Roller rockers on stock heads/cam with no modifications to either. I however did not use the stock valve covers. I didn't even try, I picked up a set of tall polished covers. here's a few pics, needs to be cleaned but still looks good.

 

http://www.techcessive.com/tech/rockers/rockers.php

Kat

 

Hey man thanks for all the info on this.

Did you notice any increases in performance after the install?

I was wondering if i got new pushrods it would matter how i put them in as long as they are the right size all i need to do is drop them in. Right?


Thanks
Jason

 

Well, for me, I did the rockers and had a custom chip burned then ran 3.5 tenths better the next time out. So I couldn't say how much of that was the rockers and how much was the chip, but it definetly ran better.

 

As long as you have the correct length of pushrod for your application, yeah, you just drop them in. They don't have to be in a certain order. I usually try to keep the tips on the same ends as they were originally though. This is usually easy to tell because you usually see a shiny area on all of them where they pass through the guides in the heads. Just remember that the pushrods for a factory roller cam engine are a different length than flat tappet cam motors. I think the roller ones are like .100 longer if I recall right. So make sure if you order new ones that you specify you need the ones for the factory roller engine. Also remember that if you ever decide to run guideplates, you need hardened pushrods. If you're going to buy a new set, I'd just go ahead and get the hardened ones. That way you'll already have the right ones if you ever decide to install guideplates in your heads.

 

ATOR, did your 92 formula come with a maf sensor. if so how are you able to run with the snub nose air filter. i wanted to do that to my 87 gta but cant cause the maf sensor.

 

Did not come with MAF, it's speed density, I believe all 91-92's are speed density.

 

i had to enlarge the pushrod holes on mine cuz of the cam pushing .525 lift... with stock cam, you're probably all right.

KAM