I realize it is tough to make generalizations here, BUT....

I have some fresh LT4 Hot Cam springs installed on some 300hp/350 crate motor heads. Can I run these with a small solid flat tappet? Something in the 225 @ 0.050 / ~.470 lift range? If I recall, seat pressure is like 105#, and rate is 330 lb/in.

Do your homework and see what springs are recommended for the solid cam you are talking about and then compare the numbers!

That's about as good as it gets unless somebody pop's in here with more real world experience..

Sorry..

pdq67

Back again..

I just pulled this site up

http://www.sallee-chevrolet.com/Cam_Specs/lt4hotcamkit.html

to check your information more and to me they should do fine even though they are a little light on the seat AND at the nose at 101 and 264 or so pounds AT THEIR INTENDED INSTALLATION HEIGHT!! You are still using the lightweight retainers aren't you? B/c they will help high rpm spring loads...

If you install them at 1.75" or even 1.70", they will be correspondingly "stouter" on the seat and over the nose....

Remember that these springs have been designed to work with a 5500 rpm hy-roller cam so if you really want to rpm the new solid cam, I would go with a different set of springs unless you install them shorter, BUT then watch for any coil and guide binding to stay out of trouble!!!!!

I figure a set of good old Z-28, (-142) springs or the newer LT-1, (ZZ3, 350HO "orange") springs should do better. Unless the little cam is more aggressive then what I think it is..

Z-28 springs are about 400 #/" and the LT-1 springs about 444#/" per Competition Products cat.

Anybody else, please chime right in and PLEASE put me straight if I have screwed up..

pdq67

I think CJLandry is running LT4 hot springs on his crane 278 solid. The light retainers really seem to make up for the lower pressure. And I think the Hot cam goes to 6k or more too.
I'm sure CJ will tell you if you e-mail him.
Also, I ran 105/300 on a 280 hyd and it was good to about 6k with vortec heads.
Make sure to check for retainer to seal clearance if going to higher lift.

I ran the complete Hot Cam kit (including springs) on a ZZ4 short block with Vortec heads.
No problem spinning it to 6K.
I did, however, had to have the Vortec guide bosses modified for the .525 lift obtained with the 1.6 rockers included with the kit.
Stout little street motor. graemlins/thumbsup.gif

Anyone have CJLandry's e-mail?

Here is the deal on the heads / springs:

The heads are 300hp/350 crate motor heads (the crate motor that preceded the 330hp vortec equipped engine). I bought them off of a guy that installed the HOT cam kit in his crate engine. When he had the guide bosses cut for the .525" lift, he also had the heads machined for 2.02/1.60 valves, and used stainless parts with undercut, swirl-polished stems. Springs and retainers are the ones that came with the cam kit. He removed the heads after 2000 miles to go with a bigger head / cam package.

I am planning a mega-low-$$$ 327 build-up, and I want to use the heads as-is, since they are fresh. Just wondering how much cam I can use with these springs. I am looking at something like a solid w/ 225 @ 0.050 and .470" lift. Not a BIG cam, but I understand that solids have high accelerations, and you need to choose springs accordingly. The HOT cam looks kind of lazy for a hydraulic roller (high lift comes from 1.6s), so I do not know how aggressive it is compared to a solid FT cam.

Measure a spring or two. Kinda chasing your tail until you know EXACTLY the spring pressures on that set of springs. You'll want 115-130 on the heel and no more than 340 on the nose. Those spec's with steel retainers/SS valves are good for around 7000+.

Too little pressure, especially on the nose, and you' might float it and ruin parts.

If what you give is accurate, 105 seat and that rate, is only 260 over the nose. Kripes, you overrev the thing and it'll float on you OR it just won't rev right. Bet those specs DO NOT match the cams you are looking at.

Yeah... the springs are a little light compared to the specs for most of the small solids I have seen. I intend to measure a few springs so that I know exactly what I have (height and pressure), but I am assuming published values are correct.

Looks like I'll need to back off from the solid idea if I want to run these things. The springs do seem like a great match for many 215-220 deg hyd FT cams, so maybe I will just go that way. Seems the tamer accelerations of a hyd cam do not require as much spring.

By the same token, it doesnt take much spring for a 7500 rpm solid ft cam.

I just got a "kit" of springs, retainers and keepers from Midwest Motorsport this week for $60 or so plus S&H for my 283.

Their second up Elgin springs, PN RV1943X springs!!

That to me is a good deal and I won't have to worry about mix-matching my old stuff in my coffee-cans..

I also picked up a set of 1.6 ratio stock type rockers and hardened stock type p/r's..

All decent prices..

Gonna run all this with the Cheap PAW 264 solid cam..

pdq67