SketchyZed

Okay so i find everything i think i need for mu plans, then something pops up and i always get stuck on camshafts. For example i got everything sorted out a few days ago on what i wanted to do but i wanted to check again to make sure i ask on here and someone says i would be better of with sticking with a roller which im fine with i just cant fine one that will work with these and if i do its really close to the max lift and i look up what people say how much lift you can run then i see them saying i would have to have machine work done but i dont want to do that so i go back and look at more cams i have stayed up to 3am some night just looking.

I'm gonna tell you my plans im gonna use
https://www.summitracing.com/parts/nal-12558060
the original cam i was gonna use but i dont know if it will even work anymorehttps://www.summitracing.com/parts/cca-cl12-262-4/overview/
and thats all im gonna do till i have the money for a procharger

I just need to know safe lift for these heads, should i just go to flat tappet cam
or should i just find a cam thats smaller like smalest one i can find is this https://www.summitracing.com/parts/c...make/chevrolet

I could really use help...

SketchyZed

Right in front of my face im such an idiot for not looking here too http://sdparts.com/i-23901396-sdpc-s...g-upgrade.html

NoEmissions84TA

iTrader: (1)

Check out what Ja85z28 did: https://www.thirdgen.org/forums/tech...-aerohead.html

Read his other posts also.

sofakingdom

iTrader: (1)

There's more to selecting a cam than just looking up its "max lift".

Those heads, like any other factory part, are designed to 100% work with their STOCK associated parts so that cars can just go down the assembly line trouble-free, but DO NOT take into account any possibility of working with anything else. And like any factory part, they have tolerance, LOTS of it; some of them have individual valves that clear the retainers by enough to allow .480" of lift without destruction, some only .460". Which, if you think about it, the difference between those is just a little more than the thickness of a business card.

Therefore it is meaningless to split hairs over the "max lift" they will accept. You may find that each valve on each head has a different limit., and that 14 out of 16 or the like, will accommodate some random cam, but 2 will self-destruct.

Furthermore, the springs they use are only JUST BARELY adequate for the stock truck cam they put under them. They are TOTALLY inadequate for ANY aftermarket one and therefore MUST be replaced if you expect any kind of longevity out of it.

But, that gives you the opportunity to choose a spring package that gives more room between the retainer and guides, since you need to replace the springs ANYWAY. Just buy ones that open up the clearance. The easiest ways to do that are with beehive springs (their retainers are MUCH thinner), or offset keepers.

People talk about the Alex's setup. I've never seen it and cannot comment on it. I also can't recommend it.

For a super basic engine with a street cam, a great choice is LS6 springs, Comp 787 retainers, and the keepers that go with them. That combo opens up the guide clearance by about .050" or so (again, no hard numbers, there's too much variation between individuals) which will safely accommodate an AFTERMARKET cam with .500" of lift or maybe a bit more. http://www.texas-speed.com/p-1383-ls...od-to-550.aspx Note that they say the springs will go to .550" before their own limits are exceeded; that DOES NOT take into account the size of the guides on Vortec heads, which is what limits the lift they can accept.

You can then use a cam such as https://www.summitracing.com/parts/cca-08-502-8

sofakingdom

iTrader: (1)

Those are only barely enough spring for the mildest of aftermarket cams. Not an Xtreme Energy, Voodoo, or other modern "high intensity" lobe design. And also IMO not worth a cost delta of $100 per head, for sure.

SketchyZed

I know i found a cam but people have told me i would have just been better off with a roller https://www.summitracing.com/parts/c...make/chevrolet but i feel like i would be pushing the heads limits with cams like these i've seen people do flat tappet swaps but a friend of mine told be i might have problems down the road

sofakingdom

iTrader: (1)

That cam is a very poor choice for Vortec heads.

THIMK... what makes those heads so good, is their relocated intake port. This allows MASSIVELY increased intake flow as compared to legacy SBC heads. However, they have the same sucky exhaust ports as any other SBC head. Now: how are you going to take advantage of the improved int ports' ability to allow material to move INTO the cyl, if the exh port doesn't allow it to move BACK OUT??? For this reason, Vortec heads literally REQUIRE a longer duration exh lobe than int.

The problem with flat-tappet cams is two-fold: first, their limitation on ramp rates, compared to a roller, which limits performance potential, which means that a roller with any given level of "big cam" compromises (gas mileage, vacuum, cold start behavior, poor low-end, etc.) will outperform a flat with the same level of those; and then, the matter of risk. While they were fine back in the day, in fact they were all any of us had for decades, this is now 2017, not 1970. Things have changed and they are no longer a good choice. If your block supports the factory roller system, just go to the junkyard and strip all that out of a blown-up motor that has it.

SketchyZed

Thank you so something like this https://www.summitracing.com/search/...1%2B4294845874
or https://www.summitracing.com/parts/c...make/chevrolet

Tuned Performance

iTrader: (92)

Sticking with efi com xfi series or lunati 20080721
Would be a great cam. Or comp 502
The lunati turned out great for this guys 355 efi
https://www.thirdgen.org/forums/tech...ld-thread.html

SketchyZed

thank you

Tuned Performance

iTrader: (92)

https://www.thirdgen.org/forums/engi...-cam-sale.html
Here’s a good cam, just cut down or tap in the front timing chain dowel.
Iirc the specs are for a xfi276hr
http://www.compperformancegroupstore..._Code=LTCAMSXE