Can I use the lt4 hot cam springs for the lpe 219 cam? Its with 1,5 rr so the lift is .525?

And why? Because I got the springs free from a friend. And I am right now installing a lpe219 cam in my 1991 tpi vette...

 

The HOT cam lifts 0.525" w/ 1.6 rockers, so OK there.

It depends on the valve hardware you're running...LT4 valves are hollow sodium-filled and weigh ~70grams on the intake side, much lighter than any solid valves available without upgrading to Titanium. Heavier valves will want more spring pressure than the LT4 springs can deliver.

So...if you have LT4 valves to go w/ the springs, no problem. If you're running solid valves, you'll float somewhere above 5000 rpm.

 

i will use manley stock vavles.

 

Those are much heavier than LT4 valves, so the LT4 springs won't control them as well.

Might work if you keep the revs below 6000rpm, or might float at 5000rpm, hard to guess.

I'd go with stiffer aftermarket springs and be sure, but springs can be changed on the car so testing the LT4 pieces is possible.

 

test? Cant I brake annything?

 

LT4 springs are designed for lighter valves then you're running. If you're feeling lucky, pop 'em on and test for valve float after you've measured for coil bind clearance...the LT4 springs don't leave much room for error @ 0.525" lift, and if you go crazy w/ shims you can chew up clearance and put things in a bind.

If the springs can't control valve motion, because the valves are too heavy in this case, you can damage the cam and/or lifters and/or valve stems and/or rockers. Might bend pushrods too. During valve float parts of the valvetrain are occasionally travelling in opposite directions, resulting in impact at places not designed for it.

Valve float is easy to catch, sounds and acts like a really bad misfire at high revs. The engine runs fine up to a certain RPM, then develops the "misfire" symptoms. Cause is valves being open when they're supposed to be closed.

Again, I'd go with whatever springs the cam manufacturer recommends. In my case I also went with Manley Race-Flo valves and Titanium retainers to cut dynamic mass as much as possible without dropping major $$ for Ti valves. The Race-Flo valves didn't cost much more than the street version, like $30 or so, and they shaved ~20 grams off the valve weight. Street-Flo version has nearly identical weight and costs less.

'Nuf said.

 

well im going to use 1,5rr npt 16,rr.

And i am going to use springs,shims,retainers etc from the hot cam kit.
If i use Manley Race-Flo valves , shoul I be ok not oign abow 6000rpm?

REgards

 

Not sure. The Race-Flo valves are light, but still heavier than LT4 valves.