1995_maro_z

iTrader: (1)

I have been doing some research on which 1.6 rockers to get for my car. I have determined that I do not want aluminum ones because my car is a daily driver that will see occasional hard driving and infrequent track time. I have also determined that I would like self-alligning ones because I do not plan on camming the car anytime soon, and I probably won't get anything much more than a hotcam when I do. I know that I will upgrade to LT4 springs (pn: 12495494) and retainers (pn: 19171528) for cheap insurance, and because my car is at about 97,300 miles. My questions are:
1. Do I also need LT4 valve spring shims (pn: 10212809)?
2. Will I need to upgrade or change the pushrods?
3. Will roller-tip rockers be fine for my application? The only fulll rollers that I see are aluminum or extremely expensive.
4. These are the rockers I am considering: http://www.summitracing.com/parts/cc...make/chevrolet
does anyone have any thoughts, opinions, advice, reviews on these particular rockers?
5. Is there anything else that I am missing that I will need for the install? My main priority is to retain as much reliability as possible, as the car is my daily (at least for now).

96capricemgr

iTrader: (1)

Roller tip is not worth it. Notice when OEMs went to roller rockers they did roller fulcrum not tip, the fulcrum is where most of the gain is.

With a mild cam barely a possibility, aluminum can most definitely be on your list.

I haven't looked into options in awhile but a quality aluminum 1.6 full roller would be fine or more coin on Comp UltraPro Magnum steel.

IDriveChevy

iTrader: (5)

1. I would go with a more stout spring over the LT4 springs, but they would work with a stock cam.
2. Yes
3/4. Go with a quality rocker arm like Scorpion or Comp Ultras, skip the roller tip stuff.
5. Usually I would replace:

valve cover gaskets
Change rocker studs to ARP
Poly locks
Push rods (hardened or chromoly)
Guide plates (if rocker is NSA)
Springs/locks/retainers/seats
Replace your valve seals while its all apart

1995_maro_z

iTrader: (1)

I have read that aluminum rocker arms are not a good idea on daily driving applications. Does this only apply to applications which have a more-than-mild cam?

1995_maro_z

iTrader: (1)

With 1.6 rockers and LT4 springs will I need a different size push rod, or just a different material? Also, can all of this be done with the heads still on the engine and the enghine in the car?

96capricemgr

iTrader: (1)

The LT4 springs are perfect for a stock cam with 1.6s, springs aren't about "better or stronger" they are about appropriate. LT4s will do the trick without wasting work being too stiff.
The LT4 came stock with aluminum roller rockers made by Crane, read that twice to let it sink in. Now .600lift I might worry but stock or HOT cam, no concern.

Technically you should check pushrod length BUT I would bet the majority who do rockers and springs on a stock engine never check and never have a problem. With the stock cam and 1.6s I would just use the stock pushrods and not think twice.

Heads on in the car is fine, hardest part will be changing the springs back under the cowl.

If there is any chance you would go further(real heads/cam setup) later I would step up and do larger diameter ARP studs with guideplates and the Comp steel rockers right off the bat and save a buck doing it once.

96LT1Z

Get yourself a set of these, http://www.summitracing.com/parts/cc...make/chevrolet
some studs, guide plates, pushrods and you're good to go

1995_maro_z

iTrader: (1)

That makes me feel a lot better about the aluminum rockers lol. Thanks!

1995_maro_z

iTrader: (1)

Those have 7/16 studs. Are those better than the stock 3/8 stud size? On my pretty much stock application, would 3/8 studs be fine?

1995_maro_z

iTrader: (1)

Also, what factors should one consider when deciding between self alligning and non-self allingin rockers? Are there pros or cons to either? The main reason that I would like to go with self alligning ones is that they can be used with the stock pushrods, whereas I have read that NSA rockers require hardened pushrods.

96capricemgr

iTrader: (1)

Stock 95 and earlier pushrods are hardened.

cardo0

This has been discussed several times. Here we go again.

Did u do the math? To install higher ratio rockers u need to have enough room/lift before coil bind of you spring plus 0.060" safety margin. So find your spring installed height and subtract the coil bind height. This has to be greater than the cam lift plus 0.060" or your springs can go solid.

Im running the comp magnums with maybe 5k mi on them now and no problems. Yes on self aligning. Yes stock LT1 springs but not stock cam. Comp says to use new p-rods with the magnums but too late for me now - no problems yet. Roller tips should be good for <0.500" lift and <6000rpm. More than that go roller.

Not sure if u can even buy the LT4 springs anymore as GM seems to be promoting the LS6 beehives. If u crunch the numbers using the rated spring rate and installed height the LT1 has more open pressure than the LT4 spring though the LT4 starts with higher closed press.

My 2 cents if your gonna change springs and rockers then get some good springs as the LT4 are not an improvement on an LT1 with heavy solid stem vlvs.

Hope this helps.

BALLSS

OP

if your mod list is going to stop with just adding 1:6 RR and "maybe" the Hot cam then stock 3/8" SA RR like Crane Gold (narrow body) aluminum or Comp Ultra Pro Mag (steel) in SA will be fine using stock PR

But....if your mod list will later grow to head work and a bigger cam I would just get 7/16 ARP rocker studs, 7/16 Comp Ultras. TrickFlo Chromalloy hardened PR in 7.200" length with .080 thick walls and some ISKY adjustable guide plates now. Note cam and headwork later will likely require a different length PR (shorter) so you would have to measure PR length when you get to that stage

SA RR are OK for motors that won't spin much above 5700 RPM. Past that NSA with guide plates are recommended as SA RR can "come off" the valve stem at high RPM, especially with springs not up to the task.

The LT4 valve springs are "OK" with a stock cam...for a mild cam though you should consider something like the Alex spring kit for LT1 AL head.

Crane makes a valve spring compressor that allows you to do both intake & exhaust spring per cyl and is easier to get to cyl 7 & 8 also vs the typical screw type hand compressors when swapping springs on heads with motor in car.

You will need new valve stem seals. FelPro Viton are good.

Valve spring swap is not a basic job and you need to pay attention to what order and procedure you follow to do the swap. Get a pen magnet to help keep the locks from falling and stuff rags/something in the holes of head incase you drop one

96capricemgr

iTrader: (1)

Valve float that hurts power occurs when the valve bounced off the seat from closing too hard, so a spring with more seat pressure can definitely be beneficial even if it is weaker over the nose.

LT4 springs are great for a stock cam with 1.6s. I you really want to cheap out I believe Elgin makes SA stamped 1.6s if not spending the coin on full roller I would do those before roller tip.

GM went roller fulcrum on newer engines because that is where the bulk of the roller gain is.

bowtienut

iTrader: (1)

Don't believe that statement above about SA rockers not being suitable for over 5700 rpm. That's not true at all. Any moderate cam such as a CC503 will operate just fine to 6500 with good quality SA rockers such as the Cranes or GMPP's as long as you have sufficient valve springs to do the job. If you don't run a good enough spring, then you'll have more problems than just a rocker jumping off the valve tip!

96capricemgr

iTrader: (1)

Roger maybe you can get GM to issue a TSB, those dumbies used aluminum SA rockers on the LT4 with a 6400rpm rev limit............


For an aggressive build I prefer 7/16" stud guideplate steel rockers but SA and aluminum do work. I ran ProForm 1.5s on a ZZ4 crate motor cam in my LT1 for 40K miles or daily driving and weekend T&T. I did roller 1.5s because some guys had issues with that cam's .510 lift and stock LT1 rockers, though in hindsight it might have been a pushrod length issue, the problem was bottoming the rocker slot and breaking the pressed stud in the iron heads and with the lift limits of the iron heads 1.6 on the exhaust side would have mangled seals. So I am not saying do 1.5 rollers.

guppymech

iTrader: (7)

The Elgin stamped SA 1.6 rockers are junk. I tried them and found that the rocker body socket and pivot ball only met in a very narrow band on all 16 rockers.

1995_maro_z

iTrader: (1)

This cleaered a lot up! Thanks! What does "ISKY" mean or stand for?

1995_maro_z

iTrader: (1)

How well do less expensive full roller aluminum alternatives (scorpion, proform, summit brand) stack up to the crane golds? Particularly these scorpions:

http://www.summitracing.com/parts/sc...make/chevrolet

They seem nice and they are made in the U.S. and they are MUCH cheaper than the crane golds.

Also, I could not find the Comp Ultra Pro Mag's for the LT1. When I searched for them, I did find these:

http://www.summitracing.com/parts/cca-1618-16/overview/

They say that they are for a gen I small block. Will thse work on an LT1? If not, does anyone know the part number that will?

BALLSS

ISKY is a brand. iskendarian cams. They make adjustable guide plates that IMHO allow better rocker tip alignment if using NSA RR on LT1 ALL heads


I don't have any direct experience with Scorpion products other than the Cobra kit car guys I see with the Rousch 427 SBF motors all had them break. Of the dozen or so I see frequently at cruise nights, all had them break. I will add though those SBF 427's likely see higher RPM use & abuse than your motor will

My $02 is you often get what you pay for

The Crane Gold are "narrow body" RR and will fit under the stock valve covers of LT1 without any trimming. Other brands, including the Comps will require some trimming or massaging but it is a simple task to do. I have the Crane Golds 1:6 on a 355 LT1 carb motor I have with iron heads and a 227 Crane cam. I did have screw in studs put in the iron heads though

My $02 also is to use NSA RR on motors that will see high RPM and using aftermarket (or non stock valve springs & retainers), that's all. Do many run SA, yes. What you need to check carefully with SA RR and aftermarket springs is that the SA "tabs" or "washers" used on SA RR don't hit the retainers. Another reason many switch to NSA RR and aftermarket springs. There is no blanket answer on use or not use them. Several factors. On the LT4 that came with LT4 springs & retainers worked fine as the aligning washers on either side of the Crane (GMPP) RR did not hit the retainers. They did however hit retainers on Comp 987 springs for example. They did however work with Crane 10309 (iron head) springs I had and assume they would work with 10308 (Aluminum) heads. BTW the Crane 10308's would be a good spring for you to run with the hot cam

your goal with just a hot cam SA's will be fine...but get a good valve spring