ill have it tomorrow may be a big advance for us

[6.9poweredscout]

I don't see why you couldn't have a machine shop make up some solid steel pushrods than have the ends teflon coated for less resistance....?

-Jon

 

[87crewdually]

I don't see why you couldn't have a machine shop make up some solid steel pushrods than have the ends teflon coated for less resistance....?

-Jon

"Solid steel" is weaker than hollow tube. Second, how do you expect to lube the upper valve train? Hollow is a must.

If you get an accurate measurement of the length, Jesel can make a set of chromolies.

 

[hesutton]

"Solid steel" is weaker than hollow tube. Second, how do you expect to lube the upper valve train? Hollow is a must.

If you get an accurate measurement of the length, Jesel can make a set of chromolies.

You beat me to it. The hollow push rod is what carries oil up the the rockers/valves. With out oil, things will get bad in a hurry.

Heath

 

[6.9poweredscout]

Well what about drilling a hole in the center for oiling than. Or at least use tubing that's thicker?

-Jon

 

[bike-maker]

Comp Cams sells universal chromoly pushrods in .050" increments. Companies such as Smith Bros Pushrods in Bend, Oregon will custom make you a set to whatever dimensions you want for about the same price.

 

[bike-maker]

Got the wheels turning now. Does anyone have a stock 460 pedestal mount rocker to compare side by side with a IDI rocker arm? On a 460, changing to studs and roller rocker arms is supposedly worth almost 25 horsepower. It would be less on an IDI due to better geometry between the valves and pushrods, but it would definitely free up a little horsepower. Even if the rockers for a 460 don't work, there's probably one out there that would. This also opens up the option of increasing the rocker arm's ratio which increases valve lift for more power (providing there's enough valve to piston clearance).

 

[sle2115]

I just wanted to mention that there is a lot more to springs than just pressure and one of the most important things will be standing height and bind height. Higher spring pressures often mean thicker material...which means less room for compression. Spring bind can cause all kinds of issues, from rapid wear to out and out trashing your valve train. Not saying this isn't a good idea, cause especially those wanting to spin these motors faster, I think more spring pressure may be needed. As Heath pointed out, the alternative may well be a double spring. It really doesn't matter what the application is, if you know the specs on a spring (IDI in this case) a good machine shop will be able to look up to see if a standard spring (meaning non-custom big money job) would work. The Brodix motors I built for the spring cars ran triple springs with over 380 psi at their standing height and would handle .700 + lift.

 

[bike-maker]

Very true. There's lots of valve springs out there. Lots of motors I delt with in the past we would just look up the specs of what we wanted in the book and order 'em. It depended on the installed height, diameter of the springs, and valve lift, then the cam specs would dictate the spring rate. If there is a clearance issue, solving that can be accomplished with machining, .050" offset valve locks, or longer valve stems.
The way to go would probably be a stiffer single spring. Machining is often required when going to a double spring. Not a difficult operation at all, just requires a cutter that none of us likely have laying in our garage. And it's not something you would want to do on an assembled engine.
Also remember that stifer valve springs take more horsepower to compress. Stiffer springs when you don't need them will cost you power.

 

[lotzagoodstuff]

Got the wheels turning now. Does anyone have a stock 460 pedestal mount rocker to compare side by side with a IDI rocker arm? On a 460, changing to studs and roller rocker arms is supposedly worth almost 25 horsepower. It would be less on an IDI due to better geometry between the valves and pushrods, but it would definitely free up a little horsepower. Even if the rockers for a 460 don't work, there's probably one out there that would. This also opens up the option of increasing the rocker arm's ratio which increases valve lift for more power (providing there's enough valve to piston clearance).

Roller rockers definitely kick butt. It means you actually get the lift from your camshaft at the valve. I probably wouldn't endorse changing the ratio from stock (anybody know what stock rocker ratio is?) due to clearance on these high compression motors, but the friction reduction and longevity are pretty undisputable. Anybody out there looked at what it would take to do screw in studs and roller rockers?

 

[88beast]

next time im up at the parts motor ill look
the psd springs are stiffer but about the same dia of spring so idk ill look farther too
also the better pushrods any ideas what that would run because 10 a rod is about what i figured

 

[IHDiesel445]

Did my homework for my IDI buildup. The specs for the stock spring are:

O.D. 1.400"
80# @ 1.83" seat pressure
200# @ 1.36" open pressure

I'm installing Lunati double springs part #73100 with Comp Cams 10 degree super keepers and machined retainers. They are a perfect fit. Spring specs:

O.D. 1.450"
125# @ 1.85" seat pressure
305# @ 1.25" open pressure
coil bind @ 1.10"

Will be using better pushrods, but haven't decided which route to take yet. With double springs, the top of the valve guide must be machined to accept a small diameter valve seal (umbrellas won't fit). Any good machine shop will have the cutters to do this job easily.

 

[Black dawg]

screw in studs would be easy, but the rockers wont be. The pushrod seat is offset in the rocker. some old chryslers are similar.

 

[88beast]

445 u got a quote on the machine work?

 

[Hyde]

Bringing up a dead thread, thats my specialty, hows the valve spring battle going?

 

[93f250idi]

im curious too....