Max lift?

[torq455]

I'm trying to find out what the max lift is on a stock Gen II head, and haven't found anything. Anyone know?

[Superdave]

I can measure it for you tomorrow.. it's probably going to be in the .7 range though... You'll be limited by springs before anything. With stock springs.. maybe .450

[torq455]

Cool! I figured you'd know! I remember when I installed my 1.6 roller tips that the valve moved quite a bit with just the spring on. I'm not looking for what the stock spring can handle. Here is what I'm looking into for a big cam: http://www.cranecams.com/index.php?s...&lvl=3&prt=122

That seem a bit much for a 272? I'm also considering a bigger roller cam, ie schneider solid roller. 224/228, .520/.520”, lsa 108.

With the new gearing, I could use a higher powerband now!

[torq455]

DAVE!!!! You ever measure that lift???

[Superdave]

I'll make a point to check tomorrow night after work... the heads are on the bench allready..

IMO you need more top end flow to take advantage of a 272 or larger cam. a hybrid would really wake that thing up. mix that with a solid roller cam (have fun finding lifters) and it would pull to 7K easy.

[torq455]

oh i do know. there's a really cheap option, reasonable option, and wait a couple of years option. tossing 272 in will still wake her up for now and have that lovely idle. then later on i can do some other kind of swap to roller cam or 3400/hybrid. mmmmmm 7K they do sound sweet about there don't they?

[Bones]

Don't know if gen 2 is the same but on gen 3s I've measured coil bind at around 1.10-1.15 (need better tools) which would make the max lift about .550

as always, your milage may vary.

[Superdave]

(Not counting the springs of course) here ya go...

Gen2 head with Gen3 retainers and locks.. .700' between the seal and lock

Gen2 head with Gen2 retainer and gen3 locks.. .600"

I couldn't find any gen2 locks but i'd suspect that they'd be around .700

So safe lift.. maybe .650 or so... with all gen3 hardware or all gen2... there is no way the heads will flow very well at that much lift.. and you might run into piston to valve clearance issues.

[torq455]

is that with any particular valve spring? that's wayy mucho extra! i'm looking for a .520 or maybe a .550 tops lift. Ben was telling me max was pretty much .500. i still have trouble believing that!

wow Dave! in that new picture your car looks as white as mine!!

[Superdave]

is that with any particular valve spring? that's wayy mucho extra! i'm looking for a .520 or maybe a .550 tops lift. Ben was telling me max was pretty much .500. i still have trouble believing that!

wow Dave! in that new picture your car looks as white as mine!!

you'll have to find a spring that will allow that much lift before coil bind. the Comp 26915's should work. In the end you'll have to measure the installed height of the spring, subtract your desired valve lift and see if that's still under the coil bind height.


lol, thanks. the pic was taken in 2005

[torq455]

sounds like from what you are saying, i can use the following spring with a safe lift of .520. correct?
Outer Diameter Top 1.255
Inner Diameter Top .870
Damper NO
Seat Pressure @ Installed Height 114 lbs. @ 1.700
Open Pressure and Height 340lbs. @ 1.200
Coil Bind 1.153
Average Spring Rate 432 lbs./in.
Maximum Net Lift 0.487

[Superdave]

damn, those are some hardcore springs... your lifters would hate those and you'd need hardened pushrods.

nope. those bind at .547 lift so i wouldn't go more than .490


here are mine:

1.055/1.290 single Beehive Ovate

I.D. .660/.885

Seat load 105@1.800

Open load 293@1.200

Coil bind 1.085

Rate in (lbs/in)313

@ 1.7 installed height they allow for about .570 safe lift

[torq455]

yellow LS6's?

[Superdave]

the Yellow LS6's are good for about .510 lift @ 1.7 installed height

[merlot566jka]

those springs are crane springs....i had them on my 3.4. i went with even stronger ones after those. deff too much spring! you could hear the engine rev down faster cause they were so stiff. had lifter failure as well.