What rockers are you guys using to clear 1.550 springs on your small blocks? I called Comp and they told me the 7/16" Pro Magnums would so I bought a set and guess what? They don't clear. Harland Sharp says theirs will clear but will they? I don't want to spend $320 on Crane Golds if I don't have to. Any ideas?

How about using different springs?

An 1.550 spring is not that big of a spring for a smallblock, isn't that close to stock size?, if so there should be no clearance issues, now with a 1.625 spring on a smallblock there usually is a clearance issue if not using the correct rockerarms.

im using harland sharps with beehive springs.
I have alot of clearance

Sounds like an Austin Powers thing - "Oh Beehive"...

Stock SBC springs are about 1.23"

I ran into the same problem with my Dart heads that are setup for roller cam with 1.550" springs. Comp said their's would fit and so on. They don't, kept hitting the retainer. Harland Sharp does fit and so does Scorpion without clearancing issues.

The 1.55" O.D. spring is the stock valve spring for a big block Chevy. I have Comp's ProMagnum rockers on my Edelbrock Victor Juniors and they clear (I am using ARP 7/16th rocker arm studs but that shouldn't be an issue). They have been running this diameter valve spring and larger on big blocks without issue for years. Are you sure you're geometry is correct? (push rod length, et. al.)


Larger Dave

The 1.55" O.D. spring is the stock valve spring for a big block Chevy. I have Comp's ProMagnum rockers on my Edelbrock Victor Juniors and they clear (I am using ARP 7/16th rocker arm studs but that shouldn't be an issue). They have been running this diameter valve spring and larger on big blocks without issue for years. Are you sure you're geometry is correct? (push rod length, et. al.)


Larger Dave


Larger Dave, I know mine was. I even brought my heads back to the engine/speed shop where I bought the heads and rockers from. They WOULD NOT clear and I had to go with Harland Shart with +.150" push rods. The main body on the rocker was hitting my retainer. I have 7/16 studs and +.100" valves with the stock springs from Dart set up with 1.550 springs for .700" lift roller cam.

Crane Gold should. The Comp Pro Magnums should also. If pushrod length is too short that can reduce clearance some and if you use +.050 locks that can reduce clearance as well.

I am using a Yella Terra shaft system on my SBC and they have LOTS of clearance. For $625 they are a pretty cost effective alternative to buying rockers, studs, poly locks, and guide plates IMO (if you are starting from scratch.)

I think stock, hi-po, BB springs are 1.487" and 1.531"... Depending on year and motor?

And the lo-po ones are 1.437"..

pdq67

Thanks for the help guys.

Camaro Fever - Thanks for validating my problem - I'm using Dart heads also. The roller tip on the Pro Magnums won't even touch the valve stem. I'll look into some Harland Sharps or Scorpions.

Chris,
Any of those rockers, including the ones you have, should work with that spring. I suspect that your pushrods are way too short. Try a longer pushrod and see what happens.

Bill,

Thanks for jumping in. I don't see any way the Pro Magnums can work. Even if I lift the back of rocker arm a full half inch above the end of the push rod the tip still can't contact the valve stem because of interference. For kicks I checked with Summit and they say the Pro Magnums will only clear a 1.50 spring. So I don't know what to think now. My old 3/8" stud Harland Sharps come closer to clearing than the Pro Magnum - and they aren't supposed to. I'm sure I'll need longer pushrods - going from a standard base circle flat tappet to a .900 base circle solid roller, but more than a 1/2" longer?

Chris

Chris,
I would call Comp and ask them. Thier catalog says nothing about spring size limitations. I have seen some "weird" retainers that are designed to give a lot more installed heights. They can cause problems the way they are designed.

I had a clearence problem with 1.55 springs, Dart pro 1's, and 1.6- 7/16" steel Pro Magnums too.
They only touched the top of the springs, when they where positioned with the flat area of the spiring, facing the rocker. The retainers cleared
I was told by two performance engine builders, to clearance the rocker with a die grinder the .020 to .030 needed to make them clear. This DIDN'T seem like a the best solution, but it did solve the problem.
The possibility of stress cracks is a concern, so I check them often (at lash time). It's been a total of 1,000 miles, and so far so good.

Chris; please post your final solution, I don't trust mine.

I am using 1.530 with longer stems and CC Magnums on my AFR 195. No clearance problems. AFR put the package together with their stuff.

Could take a mill tool and trim the under arm few thousands. Make a nice smooth radi, no sharp cuts.

hey fuji! i had the same problem with my pro toplines w/1.550" springs & comp pro magnum rockers. i had to shave a solid .060" off the inside corner (i cut them in my milling machine) & then still had to fit them with a air grinder to fit. i ended up buying jesel's & they fit. i have heard from a friend that norris rocker arms are the only ones that will fit 1.550's in a sbc from his experience. he tried crowers, cranes, & comps with no luck. good luck.

I use the Norris rockers on my 350, I have the Track 1 heads and .550 springs. The Norris are about the best you will find for clearance short of shaft type rockers, and they will last a long long time. Watch out for early Norris rockers, some of the older ones had less clearance.

I had the same problem in the past. Crane gold's barely worked. The problem was the +.100 valves in addition to the Comp titanium retainers. At the time, 15 years ago, the "standard" Comp Cams titanium retainer were at least +.050 compared to a regular retainer. Since the valve and stud are angled toward each other it takes up too much room. Putting a straight edge on my valve, it is only about .010 higher than the retainer.

Now I still have the same heads, Bowties, same .100 long valves and 1.55 springs but have a standard height retainer. I now have a ton of room.

I've got Comps Pro magnum rockers on my AFR 210's with 1.55" springs, and plenty of clearance between the trunion and spring.

Ah, sounds like the retainer might be the unknown variable here. I returned the Pro Magnums and ordered some Scorpions. They just arrived today so I'll check them out tonight when I get home from work. I'll post back with the results. Thanks again to everyone who posted. This has been very educational.

Chris

Scorpions don't fit either. :( I'm going to try some Harland Sharps next. My valve stems are only .025 above the outer edge of the retainer. Wonder if this could be part of the problem?

Like you said,, spring retainers can be a variable... many times it is. Can you stand a little more spring pressure?

Fuji, what heads are you running? I have Dart Iron Eagle 215cc set-up for solid roller cam. The valves are .100" longer and has 1.550 springs with an installed height of 1.9" I ran into the same problem with the Pro Magnums. I brought the rockers and heads back to the speed/engine shop and let the techs there play with them. We went through a bunch of rockers and the ones we found to fit without problems was Harland Sharp and Scorpions. The scorpions had the most clearance. This was with ARP 7/16 studs and I used Hi-Tech +.150" push rods. I hope the Harland Sharp work for you.

P.S. I had to clearance the push rod slots in a few places.

My comp pro's are fine on my 1.550 springs and protopline heads. comp rockers are usually the ticket if clearance is an issue, lots of those aluminum rockers are way too thick around the trunion, causing issues.
I think you will find its the reatainer causing an issue, probably in addition to incorect pushrod length. somebody maybe used a retainer that sits up on the stem higher, to correct installed height of the spring possibly.
On my topline heads they use a longer valve and there was more exposed above the retainer. this required me to use an 8.2 pushrod to get proper geometry. I bet a factory 7.8 pushrod would not work with mine either, besides the obvious geometry issue.
I think i would get a checking pushrod and light springs, determine exactly what pushrod you need, then try to find a rocker that will work. untill then one problem may be hiding the other. Get you geometry figured then go to the next step, rocker or possibly retainer. this may be a place where lash caps could help as well.
Good luck with it.

Got the Harland Sharps today and...drum roll...they clear! Not near as thick as the Scorpions in the throat area but hopefully they will hold up okay. I've got to add that I was totally unimpressed with the Scorpions. Many of the rollers would "catch" while rolling them under my thumb and some would completely hang up. Some of the trunion bearings were "growly" while spinning them in my hand. Others were inconsistent in the tightness of the trunion bearings. Found the Harland Sharps to all have smooth roller action and consistent trunion bearing tightness.

I had the same problem. My solution was to install lash caps ont hr valve heads. Cost $50, longer pushrods will work too, but cost more.


LDR

Got the Harland Sharps today and...drum roll...they clear! Not near as thick as the Scorpions in the throat area but hopefully they will hold up okay. I've got to add that I was totally unimpressed with the Scorpions. Many of the rollers would "catch" while rolling them under my thumb and some would completely hang up. Some of the trunion bearings were "growly" while spinning them in my hand. Others were inconsistent in the tightness of the trunion bearings. Found the Harland Sharps to all have smooth roller action and consistent trunion bearing tightness.

Sounds like you got a bad set. Mine are great.

They change management a while back and made BIG quality changes. Maybe you got an old set?

You might be right Matt. Anyway my problem is solved after wasting $25 in shipping charges. The Scorpions were very nicely machined and much beefier than the Harland Sharp's.

LBR - How much do lash caps extend the valve tip? With the

I had the same problem. My solution was to install lash caps ont hr valve heads. Cost $50, longer pushrods will work too, but cost more.


LDR

Not trying to nit-pick, but installing lash caps is not the same as installing longer pushrods. Lash caps would have the same effect as installing a longer valve or shorter pushrods.

I agree to above..on caps but to me its just another item to lose if something sticks,,, ever look for a lost lash cap in head oil gallies? I would consider running them if I was using 5/16 valves stems.. but thats preference.