valve spring issues.

[ari666]

just noticed yet another snapped spring. this one is down by the base and wouldnt have had much effect on vac, so it may have been broekn for a while, i just dont know.

however, this makes the 3rd broken spring from these springs. they were brand new 'from the box' LT1 springs to suit my crane 286 cam (496 lift 230 duration, 112 seperation)

the problem is when i bought them i had stock rockers, i later put yella terra 1.65 adjustables which brings my lift to around .511. i asked dude-face-sales rep (when the first spring broke) why it wouldve snapped and if 511 was too much lift for it to handle.

his response was "well you probably shouldnt be revving it to valve bounce" which is weird cos' i hadnt finished running in the build and had not once ever reved it past 4k rpm...

so i loosened off all my rollers a touch and drove it for a month or so with no further problems, till' one day my vac guage started going off its face and the engine started missing, limp it home, sure enough, broken valve spring.

i rang dude-face-sales rep again and asked "are you SUUUURE 511 is ok with these springs" and his response was pretty much the same as the first time. the thing is i dont rev my engine that high, i have the limiter set on 5500rpm cos thats where my power peaked on the dyno. so saying its my fault is BS

ive been looking around for springs and come across these: CROW #4843 Crow Performance V8 Holden Valve Springs (4843) (eBay item 160569697288 end time 17-Apr-11 08:38:12 AEST) : Cars, Bikes, Boats

in the listing it states they are good for 550 lift with no machining and stock collets/retainers. does anyone know if 511 is too much for LT1's. could there be another reason for them snapping? my driving is not at fault, so forget about "try not revving it to valve bounce" too tight roller rockers? anti pump lifters the cause?

anyone used those crow springs? is it true about 550 lift, or is it just a tall story? i have heard the only way to get 550 without machining is to replace the collets/retainers with .050 recessed bases.

[ari666]

a pic for the visual guys:

[delcowizzid]

how much preload you running the rockers at

[immortality]

yeah, those springs will do the job. depending on which springs you have now you'll probably have to much lift for them.

did you check to see what the installed height of your current springs are?

[ari666]

install height is 1.7 and i got the head guys to do it when they redid the seats. preload is basically tighten till they stop ticking

im looking around and pretty much all LT1 springs i can find are max .500 lift.

[delcowizzid]

if they are antipump lifters they will rattle and should have none to minimal preload its how they dont pump up they have very small preload to not allow any movement to pump up

[VR38]

They are pretty cheap and nasty looking springs.

[ari666]

what makes you say that?

[Boonz]

hey ari, i had the same problem with the crow springs in my ute with the same cam and rockers, ended up being shit material used in the springs in the end according to the crow cams diagnosis.
ended up getting a set of isky springs for $175 with slightly more seat pressure at the same installed height and havent had a problem since

[ari666]

cant find those springs in stock anywhere, everywhere has to order them in, so i am looking for something else now. wanna get this resolved today.

just checked for coil bind and there is about 2.5mm clearance between each coil, both inner and outer. BUT just measured install height and its 1.75", rather than 1.7" that i asked the head reco'ers to check... still not sure if that would make things snap, but it does mean i can look for slightly taller springs, and not worry about recessed base collets.

does anyone know if the anti-pumps will lift to full without oil in the engine? its been dry for about 2 or 3 weeks now, and am guessing there is about 50 thou of travel from the hydraulic factor.

[VR38]

They look very poor quality, the surface looks rough, not smooth and uniform.

[soop]

They're coated in oil? wtf

[ari666]

^^^

anyways, after long talks with the sales-rep-dude, i picked up a set of heavy duty crane LT1's. they suit 600 lift, 330lbs seat pressure ( ) and suit 1.75 install height.

installed two just now and they dont even come close to binding, now all i gotta worry about is bending a pushrod or wiping off a lobe. the old springs showed 190lbs on the compression tested, new ones 330lbs. so its a huge step up.

[delcowizzid]

wow 330lb is that at 1.7" not gonna be nice on the cam lobes or on collets and retainers since they look stock LOL.you need to make a solid lifter by shimming an old one solid to measure coil bind the lifters will allow over 5mm of preload when theres no oil pressure to hold them out

[VR38]

anyways, after long talks with the sales-rep-dude, i picked up a set of heavy duty crane LT1's. they suit 600 lift, 330lbs seat pressure ( ) and suit 1.75 install height.

Do you have a brand and part number cause LT1 valve springs are the Chev HD option.

installed two just now and they dont even come close to binding, now all i gotta worry about is bending a pushrod or wiping off a lobe. the old springs showed 190lbs on the compression tested, new ones 330lbs. so its a huge step up.

Did you get heavy duty retainers too?

[immortality]

^^^

anyways, after long talks with the sales-rep-dude, i picked up a set of heavy duty crane LT1's. they suit 600 lift, 330lbs seat pressure ( ) and suit 1.75 install height.

installed two just now and they dont even come close to binding, now all i gotta worry about is bending a pushrod or wiping off a lobe. the old springs showed 190lbs on the compression tested, new ones 330lbs. so its a huge step up.

i think you mean 330lbs on the nose

330lbs on the nose, good for .600 lift sounds a bit like the old comp cams 26918 beehive springs but they run a 1.8" installed height. about 120lbs on the seat

with the increased spring pressures don't let it idle to low and make sure you have good oil pressure so your getting plenty of lube on the lobes

[ari666]

yeah my bad, 330lbs is at 1.2. not seat pressure.

[Blown V6 Hatch]

So not much of a step up at all then?

Crow LT1 springs are 120lb on the seat and 320lb @ 1.2

Not in a million years would LT1 springs take 600 thou lift, it's not possible.

I'd be shimming up a lifter so it's solid and checking, because it would be pretty close to coil bind IMO. Considering LT1 springs coil bind at 1.15" and the installed height is 1.7", that means 550 thou lift is coil bind.

As VR38 pointed out, LT1 springs are just a heavy duty Chev option spring, nothing special.

[ari666]

*sigh* ok.

1.260 OD
0.876 ID
107 lbs @ 1.800
348 @ 1.200
coil bind 1.110
395 lbs/in.
0.600 max net lift

i have 'hardened' locks, but not retainers, i have never heard of a retainer breaking. i dont think i need 10 degree locks cos' even though the springs are to suit 600 lift, then cam is still only opening at 511. and only 230 duration, so they are not going to be flapping around much.

but i am ready to be corrected

[Blown V6 Hatch]

So are you getting the heads machined or changing the retainers to suit the 1.8" installed height? If you don't, the installed height will still be what it was with the other springs at 1.7". You will be back in the same boat with these springs IMO.

Also, the seat pressure is pretty low at the installed height.

[delcowizzid]

didnt greenfoam post pics of his cracked stock retainers split the collet hole

[ari666]

what i calculate (assuming all the lobes are as new and lifters are lifting to full height)

1.110 coil bind
1.760 install height (meant to be 1.8 according to cranes website, but on the spec sheet that came in the box it says 1.750)
0.511 lift
1.249"@ toe

leaves .139 from bind. which is 3.5mm should be plenty. arent you supposed to have a min of 0.020?

and the seat pressure of these springs is HEAPS more than the old ones.

[DANNY8]

Here's some pics from of a cracked retainer on our old 253. Not sure wat springs they were but they were doubles, on yella terra heads. We'd put the heads on a diff motor with a bigger cam. Wasn't coil binding, but maybe something to do with more lift. We changed them for LT1 springs and put crow heavy duty retainers and collets on....still got the old springs, was just to scared to use them incase the same thing happened again haha. Heads are still goin strong with the LT1's and crow retainers and collets...altho got a smaller cam in it now tho.

[VR38]

Just confirming 0.511 is your valve lift and not your cam lift?

0.139 should be plenty.
I prefer 0.040 to 0.020 as a safety margin.

[ari666]

oh crap! that looks pretty cracked! ok maybe i should invest. damn, that means i gotta take all those damn retainers off again

um yeah 511 lift is AFTER you times the extra lift from the rollers. so .496 lift with 1.6's, .511 with 1.65 YT's, 310 lift at the lobe (its actually 510.5 after *1.65)

i forgot the add the 0.030 for the spring cups (the things under the retainer) mic'ed up 3 and they all measure 0.030 pretty much on the nose, so i am looking more at 0.109, which is getting close, but still should be ok.