Scott

Yes it was spring pressure!!! I measured mine at 180+lbs

No rust just broken parts

This is fact from my own motors and also many others!!

One more thing I do have the new risers and had no signs of reversion. I now run a different cam and springs

Back to the EFI motors, none of the above has anything to do with them other than the advise given to change them at 200 hours.

rpm

I give up.

Rod

Guys, I'll post spring info tomorrow.

frankie

Scott, sounds like an unnesessary amount of pressure for a hydraulic roller, but still not an excessive amount to break springs, unless mismatched pressure vs. coil diameter size. Most likely a defect in Crane's manufacturing process. These cams are not that big compared to what is available. What type of new cam did you install and what do the specs read on the card ? what kind of spring pressure is recomended ( on the seat)? Frank.

Scott

Here is a link to the HP500 carb cam spec.Cam Card

The OLD style springs had too much pressure per MERC + CRANE. This was harmful to the whole valve trane including but not always the springs. Crane made a announcement a couple of years back about there new anti Harmonic spring that they still suggest and use in the card above. Harmonics were tearing up the valve tranes and it didn't have to be at WOT it could be 3000rpm it just depended on the springs. Yes there could of been a inner coil VS outer mismatch or it could of been the two different metals (don't know don't care) all I know for sure was the Harmonics created by these springs do to there HIGH seat pressures and bad engineering made the recipe for a lot of broken valve tranes.

Merc no longer uses the new crane they have changed to Comp (I think) when I ordered the Crane replacement springs (number is on cam card) we tried them in my heads and still had pressures around 168 to 170 lbs sorry but TOO MUCH for my roller valve trane. Sent them back and used the Comp's.

Here is the Spec for my new cams. Notice the RPM range, the #5 module is set for around 5350rpm's so this makes a nice change without going to the 741 which in my opinion would not work well with this ignition setup and also the headwork I had done.
New cam card

mcollinstn

Scott -

I've got a set of Crane 896 springs that I checked myself on the test stand. Measured +/- just a few from spec.

If your installed pressure is as high as you say, are you sure you have the height set correctly?

It is always better to use LONGER springs than SHORTER springs when you have a choice. Do you have a shim or can you use +.050 retainers to allow the 896s at a longet installed height?

The pressures on the 896 spring look good to me on paper.

In fact, in looking at the Comp chart, the 92 9spring appears to come out of the same batch, except that the CRANE goes tighter before coilbind...

Scott

mcollinstn,

I do not have a answer I saw the readings from the old springs and got a phone call from a trusted Head guy about the 896's.
Sorry but I was already ticked about the Crane spring issues so I changed over to the Comps that were running a lot closer to the specs on the cam card. BTW I purchased these from another source. Not the head builder so there was no financial gain involved. I will only state what my experience has been I am far from an expert but had a lot of hours tied up in trying to get the facts straight.

frankie

If you can't get the correct seat pressure at the specified installed hight then you have to either cut the spring pockets a little deeper or go to a longer valve stem , like+.100 longer, or a combo of both. Frank.

Scott

So what your saying is that I have to modify the product that the manufacture says will work without modification. We are talking about a proven set up that should not require any changes or machining other than shims. I am talking about one specific motor setup and that’s the 500 carb. With that I am done with this I have no desire to debate my findings or talk about rust breaking a spring What about all the other components that should break from rusting out or are they immune to the rust! I am talking from logical research and first hand experience not from wives tales.

Sorry I just stopped smoking today and my sarcasm is showing

I think we can all agree from this thread that it would be wise for all of us to keep a eye on our springs and valve trains and consider a spring change on our setups at the prescribed intervals.

One quick note I have talked to Merc, Crane + HPproffesionals about this numerous times (too many) and Harmonics is always the common answer. Including many articles by Teague and other respected names. With that I throw in the towel. Time to go buy some more Patches

mcollinstn

Not to beat a dead horse, but what did your installed height measure?

And - the agitation and fits are STILL better than continuing to smoke aren't they? I'm not and never been a smoker so I can only offer to be a cheerleader for you. Rah Rah ree - throw em in the trash!

h2owarrior

OK......OK.....I think I've got it now......I need to replace my valve springs when I get close to 200 hours on my 500 HP EFI's.......right.....someone tell me is this right

I can do the work myself but am not interested in taking a motor apart that does not need to be.

It is a little unsettling that Merc. would actually recommend valve spring changes at 200 hours on a motor that only produces 1 hp per cubic inch. I built a 289 the produces 310 hp at the flywheel and it has 400 + hours on it (actually more but 24,000 miles at 60 mph is 400 hours). I have had the car for almost 25 years....man am I getting old.

I wonder what GM is saying about their new motor (HP3) with respect to replacing valve springs