TheMysticWizard

iTrader: (1)

I was wondering if I could put a set of 1.6 Ratio Rocker Arms on my stock '87 305 TPI (LB9), and what it would do for performance... Would I notice any gains with the extra lift? Or would I just suceed in running my valves into a piston or something?

Also, would I need self aligning rockers? Or should/could I add guide places and get regular rockers? What size studs do we have on our stock 305's?

Would These work?

Any other suggestions on this?

Thanks!

D Stroy H8

Skip em' - get some headers

gen3z

use self aligning 1.6 rockers,you may notice a small gain the lift on a small cam will not cause piston to valve interference at all go for it...

TheMysticWizard

iTrader: (1)

How about if I put a ls1 or lt4 hot cam? will there be problems with valve to piston interference then?

Headers will be coming shortly.

Would it be worth the extra money to get roller tip rockers? or are regular rockers fine?

Would these be good?

What size studs do our stock heads have?

DANIELEK

MysticWizard,

I have a set of the same roller rockers that you have included with your first post. They are 1.6 ratio. I am going with a high lift cam so i don't need them.

Let me know if you are interested and i will send you more info.

dddanielek@yahoo.com

PS. The higher the valves lift the more air gets into the chamber. It will help a little 305 alot if you have taken care of your exhaust shortcoming.

gixxer9

MYSTIC, I HAVE A SET OF COMP CAMS ROLLER TIP 1.6 ROCKERS FOR 3/8 ROCKER STUDS (WHAT YOU HAVE) WITH 10,000 MILES ON THEM. PM ME IF YOU ARE INTERESTED IN THEM.
MIKE

gixxer9

BTW, IF YOU KNOW YOUR VALVE LIFT, YOU CAN DIVIDE THAT NUMBER BY 1.5 AND THEN MULTIPLY THAT NEW NUMBER BY 1.6. THIS WILL GIVE YOU THE NEW VALVE LIFT.

.400 / 1.5 = .266(LOBE LIFT)

.266 * 1.6 = .426(VALVE LIFT)

80smetalfan

kind of adding on to Mystic's question regarding whether 1.6s will work with an Ls1/Lt4 cam. i'm considering getting 1.6 crane rockers for my 305 TPI w/zz4 heads & cam setup. will i have any problems using 1.6s with a zz4 cam?

TheMysticWizard

iTrader: (1)

Okay I'm getting the idea on this... let me recap on what I've learned:

I can use 1.6 Rockers with my engine if:
a. They are self aligning
b. I install guide plates
-or-
c. My heads have pushrod holes that are .015" larger than the pushrods

They will give me a little extra lift, I believe my stock cam is 202/207 duration, .404/.415 lift, so with 1.6 rockers, I would have
.431/.443.

My new questions are:
-Do we have heads with small pushrod holes on our LB9 engines?
-How much lift can stock sprigs handle?
-How much lift can stock heads handle?
-How easy would it be to pull my stock rocker studs and tap threads for new ones?

Thanks for the help guys, but I am beginning to think it would be a much bigger project than I originally though, I might as well keep saving for my 383.

gixxer9

YOU CAN USE 1.6 ROCKERS ON YOUR MOTOR IF YOU BUY SELF-ALIGNING ROCKERS (A LITTLE PRICIER)

OR

YOU CAN INSTALL GUIDPLATES AND USE NON- SELF ALIGNING ROCKERS (SUCH AS THE ONES I TOLD YOU ABOUT).

THE PROBLEM IS THAT YOU HAVE PRESSED IN STUDS, AND WOULD NEED SCREW-IN STUDS TO INSTALL GUIDEPLATES. IN ORDER TO INSTALL STUDS, YOU WOULD NEED A STUD REMOVER, AND A 7/16" TAP.

IF THE 383 IS IN THE NEAR FUTURE, YOU'D PROBABLY BE BETTER OFF SAVING YOUR MONEY FOR THAT PROJECT. YOU COULD PURCHASE SELF-ALIGNING ROCKERS, AND TRANSFER THEM TO THE 383, BUT THEN YOU COULD NOT USE GUIDEPLATES ON THAT MOTOR. JUST KEEP THIS IN MIND.

MIKE

shaggy56

They sell in summit a really inexpensive combination stud remover and tap guide. All you would need is a decent tap set. I dont know how well you work with tools, but if you think you are up for the task might be worth it.

8Mike9

I see some problems with doing studs this way, especially if running guideplates that need a fastener or "nutted" stud.


#1 is that the adjacent bosses may not be at the same height, nor be flat and when bolts down, could distort the guideplates and give uneven torque on the fastener.

#2 Is that there's a chance the rocker would hit the fastener before the rockers were adjusted properly...seems you may get away with it using stamped rockers, but not too sure about fullroller rockers.

I think I'd only feel good about installaing a screwin stud for a repair, unless i had the bosses machined down and at the same heighth.

Has anyone actually run guideplates without machining the bosses? Ever checked the clearance between the bottom of your rockers and the top of the stud boss?

Reason I ask is I figure a 3/8th nut is about 3/8th of an inch thick the guideplate maybe about .10th of an inch?

So that means a nut and guideplate would reduce the clearance under the rocker by about .475in..roughly a 1/2inch.

There maybe more clearance if a "nutted" stud was used, since I'm sure they're thinner (nut part) than a regular 3/8th nut would be..infact I think the rule of thumb is to machine about .4inches off the boss.

Anyway, just some things to consider.

I think I'd stick with pinning the studs if I was concerned they would pull out, or send the head in for machinework....then again, it's a good reason to buy a Mill

anesthes

iTrader: (12)

I'm sure someone tried it.. But theres fools everywhere.

Guideplates are surly the way to go. Take the heads off, drop 'em off at the machine shop. Then run guideplates and screw in studs.. Your machinest will machine 'em down, tap them, and open up the pushrod holes a little for you.

-- Joe

shaggy56

I think i get spoiled sometimes because i have access to lots of machine tools. Stud Boss Mill Cutter with 3/8" arbor 99023-1 .
Would work great with a Drill Press.