wa4ky

Ok guys, have spent hours looking at threads on this but can not get a real answer.

I am going to pull valve covers, replace springs and valve seals and am considering replacing stock rockers with 1.5 roller type. I have STOCK , center bolt valve covers, stock heads, etc. .

Will the rockers fit ok under my stock valve covers?

I know someone must know for sure, but the answers always seem to drift into what kind of rocker ratio to use and the word possibly gets used a lot.

Anyone know for SURE?

Thanks!

Scandalous

Yes, roller rockers will fit, but you will have to remove the oil drip tabs from inside the valve covers. I used a dremel tool with a little cutoff wheel and that worked well. It was actually the rocker studs that had clearance issues with the covers, and not the rockers themselves.

And just FYI, I have the Comp Cams Pro Magnum 1.6 rockers and they are very nice units. My car is a '95.

PAINTER MAN

I did the same thing tomy 86.

CAJUN C4

I'm doing my 95' soon.

Was Geometry an issue ? My friend told me we have to check the Geometry with 1:6's and might need custom push rods?
I never heard of this before with so little extra lift increase?

PAINTER MAN

I didn't have any problem installing 1.6 rockers in my 86. I did not have to use a longer push rod.

65Z01

You should have no problem with the drip tabs though you may need to narrow the bolt towers a little, depending on how wide are the new rockers.

Scandalous

Well... every application is different, so the only way to know for sure is to fit all the parts together and check for clearance. But it's safe to say that if you plan to install roller rockers with the stock covers, you should be prepared to do some minor trimming/cutting/grinding if needed. It's really not a big deal.

mavidatt

what kind of performance increase are you looking at if you install the 1.6 roller rockers. Ive been considering it but i dont know to much about it?

65Z01

I've read that 1.5s will bring up to 10chp gain while 1.6s can bring up to 1.5chp gain.

mavidatt

Has anybody had any problems after installing 1.6 roller rockers, dont have no negative affect on your car does it? I dont know much about roller rockers, but was looking for some other upgrades for my 89 vette besides the intake and exhaust.

CAJUN C4

Nothing Negative...Just about 15 HP.

Chatman

Just wanted to add that oil flow through full roller rockers is different, more directed. The drip tabs are probably of no use or are not necessary with rollers.

wa4ky

Thanks, thats some good clean info right there! I think I'm gonna do it.

http://images.ibsrv.net/ibsrv/res/sr...es/cheers2.gif

JAKE

Apparently it does vary because when I went with 1.7s on the 388 I built I couldn't grind enough clearance in the covers to keep them from hitting the underside.

I ground on the covers so much, trying to get the clearance I needed, that I actually ground a small hole in one of the covers. I had to buy a set of GM polished steel covers that were 1/4" taller to get the clearance I needed. SummitRacing.

Remember, the difference between Scorpion 1.6s and 1.7s WASN'T in the size or shape of the rocker arms themselves, the difference is where the pushrod cup is mounted. So I would have had the same problem with their 1.6s.

Also, I was running a .60x" cam, longer pushrods and Crane dual springs. So those things could have contributed too.

Bottom line: Some do and some don't; so you'll have to do a trial-fit to see where you're at.

Jake

Yorcci

I put 1.6 Scorpion rr's in...



...and just to be sure I cut the drib tabs off from the valve covers:



They fit well, but everything else is bone stock. Some guys said, that those 1.6 roller rockers would be louder than originals, but I could hardly tell the difference. In practise, it's meaningless, barely noticeable.

JAKE

Scorpion advertises that their rockers are quieter than others and I believe it because mine weren't noticable.

I did have to go with a taller installed height for the valve springs on the AFR heads using the Crane dual spring setup. I opted for those springs because I wanted to be sure I could carry the RPMs up top. So since my heads, springs, pushrods and reduced base circle cam were all different from stock, my covers didn't clear.

Now that I recall it, I even had to grind on the rear most corners of the #7 and #8 exhaust rockers too, even with the taller covers.

Anyway, like I always "preach", too few pay close attention to valve train geometry. I tried to follow my own advice, and when you change "one" thing, it oftens calls for changing something else.

Jake

JOSH13

When putting in RR's what else needs to be swapped just springs ? How difficult is the swap ?

JAKE

Some guys go with their existing springs but it's not the way I'd go.

First, chances are the springs on the engine have probably had a long life and are nearing the end of their performance usefulness and are tired, which'll show up particularly at higher rpms.

Second, moving up one ratio in rocker arms, like going from 1.5s to 1.6s, increases valve lift and, hence spring compression, about .030", give or take. That puts the springs a lot closer to coil bind. The existing springs will be working harder too.

So Yes, I'd definitely change the springs. Now whether the pushrods will need changing depends on how close to stock the installed height of the new springs will be. If the new springs will have close to the same installed height as the tired ones, you'll be able to rer-use the pushrods you have.

Many spring sets advertised as being specifically for your engine will drop right on and you can re-use your existing pushrods. Moving to something like a dual spring setup will usually call for a taller installed height (to keep seat pressure in check), so a pushrod change will be needed.

Rods are inexpensive and usually come in .050" length increments. Many times you can use a different retainer to adjust the valve spring installed height.

Rule of thumb: A pushrod that's a little too long is always better than one that's a little too short. Without going with custom made pushrods, if I'm caught in-between, I'd always go with rods that's .030" too long than ones that are .020" too short.

So, I'd go with new springs, retainers and locks and, if needed, rods. Other than that, a pair of valve cover gaskets, a valve spring compressor tool and a way to keep the valves up will be needed. Oh, a the tools to pull the spark plugs.

To change the springs, you'll need a way to keep the valve(s) closed as you remove the spring. You'd need a fitting for the spark plug hole and an air compressor to keep the valves "up", or you can use the nylon rope trick. You'll also need a valve spring compressor, which you can probably borrow from AutoZone or O'Reilly's for free (just leave a fully refundable deposit).

It would be a good idea to change the valve stem seals at the same time, since the springs will be off.

If you haven't done it before, the first one will be the hardest. After that they become easier as you become use to doing it. It'll take several hours but it would be best to figure on a whole day.

Jake

JOSH13

Thanks for all of the info . I'm planning on buying a set of rr's so that helped alot . Probably going with some 1.6s . Never done it before so this should be good haha .

sub006

Tall covers can have clearance problems with things like alternator brackets. Stay with stock outside height if you can.