Badrs2810

I'm bout to spend some pennies on a nice set of aluminum heads in a month or so. In the description it states, .550 (flat tappet) springs. (this is what they come with)

Would these work with h.r. cams? What would these springs equate to on a h.r. cam, if they could work? Or would I definitely need h.r. cam specific springs?

These heads have 180/190/205/ and 210 intake runners
- they are all 64cc
- they are 2.02/1.60 valves

My biggest question is;

When I finally get my camshaft, it's going to be a 276/276 adv duration, .510/.510 114 lsa. The intake I have and am running is an edelbrock performer rpm. Which intake runner size would best suit my intake and cam combo? My stock compression ratio is 9.6:1, don't know if you needed that. I'm running Hedman elite headers, 600cfm tbi, 350 injectors with an 18psi fuel reg. spring, and an upgraded fuel pump. Will burn a new chip when my combo is finished. This is the last piece to my puzzle so, any help would be greatly appreciated, thank you!!

sofakingdom

iTrader: (1)

Probably not. Springs advertised that way are referring to hyd flat-tappet cams, not roller-tappet ones. You need more spring for rollers because of their more aggressive ramps.

But it's not at all impossible that for a minor upcharge they would make the necessary change.

I'd suggest the 180cc version for the rest of your setup.

Badrs2810

Ok, 180cc would be enough? Would 190cc hurt it?

Could I use ls1/6/7 springs? Reason I ask, there is a brand new set on craigslist for 75$

305sbc

iTrader: (3)

My vote is also for 180cc ports.

From my experience the different descriptions of flat-tappet springs and roller springs, is basically the difference between a street type cam and a race type cam.

Solid roller cams used for racing need incredibly high spring pressures, - much higher than what is typically ran on a hot street setup.

A hydraulic roller cam, as those used in both hot street setups, and those used from the GM factory do not need the crazy spring pressures.
Thus, the springs on your heads (as advertised) will probably be fine for your streetable hydraulic roller cam. If in doubt call the cam manufacturer or refer to the cam-card for required spring pressures.

FYI, I see the flat-tappet type springs run with hydraulic roller cams on the street very often with great results. Some of the other cylinder head guys like to go a little over-kill on the spring pressures because customers tend to abuse them with over-revs, missed gears, and such. Most of the time they overshoot because of heavy valvetrain parts being used, added to the customers desire to over-rev the engine.

IRT the LS6 springs, yes you can use them but you will need the correct spring pocket/locators to go under them, and you'll need the correct retainers and locks which Comp can provide.
It might not be a lot of money savings in the end, but it will significantly reduce your valvetrain weight.

ref - the info at the links in my signature, if you can get 8mm valves in your heads, 0.500" guide bosses, and a 1.3" I.D. spring cup, then you can likely use stock LS6 springs, stock LS1 retainers, locks, and locators.
I'm talking about the older style LS1 locators that don't have the seal built on to them, - as you may want to run your own type of seals.

Damon

Agreed with above. MILD HR cams you can use performance flat tappet springs. Unfortunately, the lobe designs on many performance-oriented HR cams (Like Comp XFI or XE roller cams) are beyond what a modest flat tappet spring can handle. It's nothing you can tell from the published specs (lift and duration). It's way down in the ramp design and engineering of the lobes. Rollers can impart some VICIOUS acceleration rates on a valve, even if the lift and duration look modest in the catalog.

Look at the manufacturer's specs for recommended springs. Compare that with what the head comes with. If they're not pretty close you should change them out.

In general, flat tappet cams and HR cams are similar in their seat pressure needs, give or take 20#. But the RATE of the spring is usually quite a bit higher on an HR spring. That could be different by 100#/in. or more, depending on how aggressive the cam lobes are. Flat tappets generally don't have a big problem "tossing" the valvetrain off the top of the cam lobe- 300# over the nose is usually more than sufficient. HR cams that might not be near enough.