Stock 85 TPI 305, 50,000 mi. Cheap mods in sig: since the 85 is NOT the "peanut cam", would 1.6 roller tip Crane Rockers be worth it? Should they go on the intake valves only or intake AND exhaust? Can I keep stock springs? Would they bind, cause other headaches, etc. Thanks in advance.

 

I would say that installing a set roller rockers on anything is worth it. Not only do you get a little more lift with 1.6 ratio but the rollers cut down on ALOT of friction which results in cleaner oil, less heat,ect. I would look into a set of cat roller rockers. I bought mine off of ebay for $66 and they seem to be good quality. I wouldnt hesitate to get a set if I were you. Now all I have to do is install mine if I ever get time...

 

Unless you replace the valve seals at the same
time, expect greater oil consumptiion as your
now pushing a cruddy valve stem deeper into
the motor and using the valve seal and valve
guide as "crud scrapers"

mike

 

Mike,very true but I would think with his 50,000 mile engine he shouldnt have that to worry about. That is if the oil has been changed on a regular basis.

 

Actually, I do need valve seals, since I get the dreaded "smokey start-up". The car is low miles-I bought it from the orig owner, a friend. It sat alot every winter, I'm sure this helped dry out the seals, although I know small blocks from this era are famous for the poor seals anyway. I hear this is not all that hard of a mod to perform, I don't know. I have been using Mobil 1, hoping this might help... it did'nt.
I guess it stands to reason that the 1.6 ratio roller rockers would help both friction reduction and give abit more lift. However, I have read threads where people said they felt almost no diff on the "butt-dyno". Again, does anyone know if these go on both intake AND exhaust? It seems they should, but I've heard both yes and no.

 

I think you'd see better gains from a pair of headers.

If you are talking about Roller tip rockers. you won't see much in gains from reduced friction. If the rockers you are looking at are Full rollers then you will see more noticeable gains. There will be gains from the increased ratio but as I said above you would likely see more gains from headers.

Hodge

 

Stay away from CAT roller rockers!!!! I got the self-aligning ones, and had nothing but problems!!! They wouldn't hold adjustment at all! I was adjusting them every week, till finally one exploded on my way to work! It looked like someone shot a 12 gauge slug through the end of it! There service is bad also! I only had them a month, and they wouldn't warrenty them!! Just my 2 cents! Later!!!!

 

I have had mixed views on the 1.6 cross over. On my vett, i had no problems however miminal results. I did the same thing on my Z and my valve guides went bad on the passengers side. Yes, i did everything right, checked for the proper gometry and lash. I picked up 3/10ths in the 1/4 mile. For that amt. of gains....it's not worth it. Just my .02$

 

Dont look at a certain or single mod in the wrong perspective...

People do this all the time, and i have to laugh... not at them, but at the ones who have info readily available and choose not to listen or believe...

These individuals are well known in the world of performance... We call them Horsepower stackers... You know, the ones who flip through the summit catalogue and write down all the "SUPPOSIVE" HP they will get if they purchase certain performance parts...

LOL

You cant base your decision on a single mod, or on what that single mod should/ would produce...

Base your decision on that mod, based on what it will produce along with your current mods and mods too come..

an engine is a machine, with a vast amount of precision parts working in close conjunction with one another.

For example, people put headers and a cat back on their cars, and complain they feel very little difference..

But, they didnt modify the induction system to allow the extra air in that the high flowing exhaust is designed to breathe...

Kinda like installing a crazy cam, with stock exhaust and induction system... Who would do that right?

Food for thought...

Roller Rockers... A definate step in the modification process..

example: stock rocker arm ratio is 1.5 aftermarket normal upgrades are 1.6

divide 1.5 into the total lift of your cam

.540" / 1.5 = .36" X 1.6 = .576"

Worth it in my book..

here is a pic of my rockers

http://www.abrinoperformanceengineer...s/DCP01128.JPG

 

Awesome explanation 385

Couldn't agree more about the 'isolated horses gain'

I say hold off on the rockers. You should get those when you decide to get a new cam and heads. For now, why don't you concentrate on intake and exhaust maybe gears... stuff that needs to get done before you expect real gains from internals.

 

I agree with 385 to an extent.... I had the same thought of mind in my Z but it wore the valve guides with proper geometry. If youir heads are set up for it...good idea. When I purchased my AFR's They were set for the 1.5's and not for the 1.6 rr's so i opted for the 1.5 rr' since the change to 1.6's could possibly freak up the valve guides of my new heads per AFR.

 

Thats why you check your pushrod length....

Your not going to change the angle of the valve guide, youll change the length of the pushrod...

 

Well, on my Z i had the push rod length checker and it still STIlLL wore teh valve guides out! IT's better to have teh proper set up by having the heads set up right prior to just throwing on the 1.6 rr's or getting the right length pushrods. you can not just put these 1.6 rr's on with out either putting on the right length pushrods OR....... having the heads machined for the 1.6's PERIOD. Sorry if i was a bit unclear, however, most think you can just put on parts and away you go........ IT's gotta be right and even then, as I experienced, it can still be wrong! Better to have the engine set up perfect...machined and set up for teh right rr's e t c.........

 

sorry... my wife and i argue about this crap all of the time,.....i.... she is too specific and I am too general about our communication

 

I think you are confusing everyone..... since when do you have to machine heads for 1.6 rockers?

Valvetrain Geometry will not change if you have the head decked, you just go with a shorter pushrod, if it is necessary at all.... Hydraulic Roller lifters are known for being very forgiving in cases like this...

In fact I am still running stock length pushrods... and my heads are CNC'd.....

 

A pushrod length check will only help you if you have to alter the length of the pushrod to get the Roller Tip into the center most portion of the valve stem at the open and closed rocker positions...

 

here is a page you might want to check out from

Competition Cams


http://www.compcams.com/catalog/277.html

 

Im not trying to argue with you, im trying to find out how your valve guides wore out.....

Maybe they did just that.... wore out.....?

 

Sorry, just used to the wife ! They could have! I only had 70K on the engine when i put the 1.6 rr's on but i have heard mixed views on this entire issue. I did the same to my vett and had good results..same engine l98? who knows???

 

385LT1

(since when do you have to machine heads for 1.6 rockers)

When using most stock type iron heads the 1.6 rocker changes the angle of the pushrod and makes them rub on the pushrod slot of the head, Since this happens, you must slot the head further for pushrod clearance!