Technical anyone using a stud girdle with Corvette valve covers?

The Summit 98437 has a max lift of .575 so it looks like the K-Motion K-800 would be the best one to run,
they are .023 larger in diameter. But Should still get socket in.

My question is do you think the spring pockets will have that room for .023 ?

I guess looking at the pic there should be no problem that I can think of

Thank You

Norb

 

I also suggested the Howards 98437, either one would work.
Heres the thing. I know you didn't ask my opinion, but I'm not convinced that a higher ratio rocker is the best choice for you. Please read all of this carefully, and give it some thought, I'm going to throw a lot at you.
I ***ume that what you are after is to make more torque across your existing rpm range, right? And with the glide, it spends a LONG time pulling off the shift point in high gear, so what you are really after is a big gain in torque between the shift point and 6300-6500 rpm, right?
Theres a big downside to the big rockers, you will need more spring pressure to control the valvetrain, which the K-800 will give you, but its going to stress the valvetrain a lot more, and I'll tell you right now, as you start to close in on .700 lift, you can FORGET any ideas about valve springs lasting ten years.
With a 220 cc head and a 6900 rpm shift point, I gotta guess the motor is fairly big, right? 383 or 400 based combo? I think you will get WAY more performance increase with a cam change. the 110 LSA is all wrong for a biggish small-block of this sort, it will be way down on mid-range torque as compared to a 104-106 LSA cam, and the glide makes it way worse, because the engine is slow (compared to a 3 speed based combo) to gain rpm off the shift point. Even if you already have the big rockers, the cam change is going to cost less in the long run, because valve train maintenance is going to up a lot with the big increase in lift.
If the current engine is 383 based, I would go to a cam similar to what you have, but on a 106 LSA, if its a 400 based combo, I would go to 104. You could go to something on a tighter lsa but with similar lift to what you have, and just replace your existing springs with new ones, you don't have to screw around trying to increase the installed height, and you wont need to increase over the nose pressure by close to 100 psi, like you do with the bigger rockers. It will gain a ****LOAD of mid-range torque (IMO, way more than the rocker ratio change), which is what your glide based combo REALLY needs. This is very clear by the fact that your rpm through the traps is 600 rpm lower than your shift point, its running out of track before it gets to peak power. And you wont have to raise your shift point or change your rear gear to see a big gain. I would REALLY focus my efforts on getting it to pull harder off the shift recovery point.

 

Don't forget to knock the oil deflectors off the inside of those valve covers, mine got removed the expensive way when I first went to roller rockers. I had a set of 461X heads, converted them to angle plug and ran 1.55(?) spring on them. They were ported to the max and I had a fortune tied up in them but they became obsolete the minute Dart sold their first cast iron head. Broke my heart, wish I still had them.

 

something like this...
http://www.compe***ionproducts.com/...5-106-LS/productinfo/111123-06S/#.WMLzC7QiyM8

or even a tad smaller...
http://www.compe***ionproducts.com/...0-106-LS/productinfo/111103-06S/#.WMLzV7QiyM8

EDIT: should clarify here, the numbers they publish in the catalogs as far as how much lift any given spring will support are pretty conservative, as a rule most racers will lean on that number. If you are really accurate with your installed hieghts and getting them all equal, you can run between .040 and .050 away from coil bind. His existing springs will JUST work with .645 lift and his 1.75 installed height, I'll show the math.
The Howards 98441's have a listed coil bind height of 1.05, so you add .040 to that, you get 1.09 as a safe limit with these springs. the installed height is 1.75, so you subtract your .645 gross lift from that, and you get 1.105, you are good by .015. Its actually a hair more than that because of lash, and there is always some valve train deflection.

EDIT #2: Cam choice on an existing combo. Norb, heres how I would choose between the two cams I listed above, this is a bit of a rough guess, but I would do it anyway. I would do a lash loop at the track. You need to go out to a test n tune day, and you need to use a weather station and correct back to a baseline for this to give meaningful results. First I would make two p***es with your existing combo, and correct for temp, density and humidity. Then I would tighten the lash by .005 and repeat. then loosen it by .010, and repeat again correcting the weather conditions back to your baseline. If it runs the best et with the lash @ .030, I would go with the smaller of the two cams suggested above, if it et's better @ .020, I would go with the bigger one.

 

I used B&B spacers with Vette covers to clear the shaft rockers with .700 lift cam.

 

Tall valve covers with thick gaskets to clear, I had to round off the corners of the bars to fit the contour of the covers....pict is before t*******....let me know if you want to see the trim job I can pull a cover and snap some photos.

 

Its all good BigDrag, I was already thinking the same thing about t******* the corners of the girdle if needed. Cool stuff. I have early 1 7/8 hilborns for mine. Should be fun getting all this to "work" on the street.

 

Thank You

Going #2 and install new 98441 springs and play with lash. and see the results.

Didn't mention that looking for more torque the cam was installed advanced at 106 lobe center, now advanced to 102 lobe center.

Then used Silly Putty to check piston clearance, and rechecked rod to cam clearance 1,2, - 5,6,
with a .060 feeler gauge p***ing.

 

for the record Norb, what is the motor size?

 

sent you a pm

 

knods as good as a wink to a blind horse!

 

I used spacers with my stud girdle and did not have trouble at .650 lift.

 

Because they look good
I run them on every old car in my fleet.
All both of them
Great thread