Cascade Crew

chevymad · Posted: Sun May 08, 2011 6:41 pm Post subject: Not lovin the valve springs

After breaking 7 or 8 springs on the truck, all of them lunati, some of them replacements even. Then floating my valves on the dyno with the 74 formula, and having to replace those year old springs with some $$ crowers.. Now i'm replacing the valve springs in the 87. Rolling Eyes

These springs are alot older then the other 2 rigs, about 10 years. I have no idea what they really are either. Last few times on the dyno its been losing some rpm and starting to make wavy graphs lol. So figured it was time to change em. I did half of them today. 3d spring I took out the damper was broken and there was no valve seal at all. Evidently the seals been chewed and spit out. All of these springs are almost 1/4" shorter then the new trick flows when uncompressed! Shocked

Trick flows are supposed to be similar to the plain old z28s.

On a positive note, synthetic oil sure is keeping the inside of the motor clean! It's spotless in there. Very Happy

The cylinders seem to hold air pressure real nice too, so looks like the old 327 is in pretty good shape.

I'm getting the idea that maybe we should be changing valve springs alot more often then we do. I mean this 327 only has a comp xe256 cam and stock rockers. So its nothing radical.

QwkTrip · Posted: Sun May 08, 2011 6:56 pm Post subject:

So is there some big problem with a lot of valve springs on the market? All from China?

chevymad · Posted: Sun May 08, 2011 7:08 pm Post subject:

Can't even say that. The ones that floated on the 74 are NOS ones that came with a motor I bought, uninstalled. The motor had been in storage 15 years I was told. I had Paul test pressures and they looked like they'd work. Well they did.. for awhile.

The ones i'm changing on the 87 came with a set of heads I ordered complete. The heads are 305 heads that have larger valves installed and cnc work done to the chambers to make them 64cc. Instead of installing valve guides they reamed all the guides to 3/8s and installed 3/8s stem valves. I have no idea at all what they used for springs. But they're about 10 years old now.

Reading some performance forums. The machinists there are saying anything over about 550 lift you should change the springs every 150-200 passes! Shocked

Only my truck is even close to that lift
.. but still.

camarokid · Posted: Sun May 08, 2011 9:59 pm Post subject:

guess ill be doin springs not long after i get my stroker done...... kinda sad that the springs cant hold up. any idea if there is a really good manufacturer of springs?

chevymad · Posted: Sun May 08, 2011 10:12 pm Post subject:

So far, my summit springs are working in the truck much better then the Lunati's.. whodathunkit.

Anyway, what cam you running? That will be the biggest thing. Then i'd google it and see what people are using, and how they're lasting. If you have a good machinist ask him too.

And really I can't complain too much about the ones in the 87. No idea what they were and its been 10 years and lots of miles. Main reason for my rant is that i've now had to change valve springs in 3 vehicles in the last 6 months for obvious faults. Think its all mostly a bad coincidence.

BigDaddyVu · Posted: Mon May 09, 2011 8:23 am Post subject:

solid lifter?

camarokid · Posted: Mon May 09, 2011 5:07 pm Post subject:

286HR

560/560 230/230 @0.50
106 CL
110 LOBE SEP

with patriot freedoms and crane energizer 1.5 rockers

IROCDave · Posted: Mon May 09, 2011 5:56 pm Post subject:

Seems to be a common problem now. Wonder if it has anything to do with the current state of motot oil? I heard that breaking in a flat tappet hydraulic cam was an adventure now days.

My brothers GTO had sever problems with this same issue as did my old Trick Flow heads.

camarokid · Posted: Mon May 09, 2011 6:00 pm Post subject:

i dont think its the oils, sounds like poor metals used in production.

QwkTrip · Posted: Mon May 09, 2011 6:15 pm Post subject:

Fatigue fractures are subpar design and/or materials. Best thing to do is use product from a better company. You can't fix a bad company.

blue89 · Posted: Mon May 09, 2011 8:02 pm Post subject:

So... modern engine manufacturers all use roller lifters to avoid break in issues, amongst other reasons. But how is it that you are breaking cam springs when plenty of engines still use springs? Okay, all of them. The materials they use are used in modern after market so why do the after market springs suck so much??? I just can't see GMC Honda Ford or anyone getting access to materials not available to after market.

Twilightoptics · Posted: Mon May 09, 2011 8:13 pm Post subject:

You ever check to see if you're coil binding? Only time I've ever seen dampers break.

chevymad · Posted: Mon May 09, 2011 8:18 pm Post subject:

Only one spring so far with a broken damper. Bout 3/4" off one end of it. Must have happened long ago, because no trace of the seal at all. Cam is only 0.490/0.495 lift. I remember pulling one spring when I first got the heads. What I checked I dont remember now.

There's lots of room on the coils(visibly), but no idea bout the damper.

chevymad · Posted: Mon May 09, 2011 8:38 pm Post subject:

Got me curious now. I'll try to compress one in the vice and measure it tomorrow. I did recheck the installed height and its right on the money.

Twilightoptics · Posted: Mon May 09, 2011 8:47 pm Post subject:

Compare also to the advertised coil bind of the springs. You need atleast .060 clearance from coil bind. If you're that close it's possible those springs just don't like it.

chevymad · Posted: Mon May 09, 2011 9:03 pm Post subject:

Have no idea what these springs are, or what their specs are, other then what I can measure. At this point just know that I can turn the motor over and look at max lift.. and still have a huge area between coils left.

Doesnt matter too much, as long as the new trick flows will handle things from now on. I figured regular z28s should have handled this cam since its so mild.

QwkTrip · Posted: Tue May 10, 2011 4:18 am Post subject:

Twilightoptics · Posted: Tue May 10, 2011 10:38 am Post subject:

The old "z28" spring is good for a stock smogger cam. That's about it in my experiances. They are super weak.

chevymad · Posted: Tue May 10, 2011 6:56 pm Post subject:

These springs had lots of clearance. Coil bind is at 1.125, install height is 1.8. so 0.675 clearance when my cam's only 0.454 max lift. . Wasnt a binding issue.

I know when I had this motor in the truck with the old camel humps on it, I used a eldelbrocks version of the z28 spring. Had no troubles then. Really.. 10 years and I dont know how many miles out of this set probably isnt bad either.

Ah.. this cam is even smaller then I said. Had the wrong version when I looked it up.. specs are

Camshaft, Hydraulic Flat Tappet, Advertised Duration 256/268, Lift .447/.454, Chevy, Small Block

The comp spring recommended has 105# seat pressure and aprrox 270# open pressure.

The trick flows i'm installing are 110# seat, approx 250# open.

I have no idea what these are I'm taking out.

Like I said.. it seems to be a maintenance issue, and the only reason I'm whining is because it hit me with 3 rigs at once! Evil or Very Mad

chevymad · Posted: Sat May 14, 2011 1:59 pm Post subject:

Hoping this isnt a mistake. I know it needed springs.. and I've been out installing them on the 2nd bank.. when I realized that these heads still have the stock press-in rocker studs! Shocked

I hope the pressure of the new springs doesnt pull the studs during Cows.. maybe I'll be the one on the trailer this year. Embarassed