Valve Springs

[cannondale27]

Keep in mind they were given a complete head,both styles of buckets,valves and a assortment of shot stock cams some with one good lobe others with none.They were told tell me what I need to do to fix this and run at up to 12,000 rpm.Nothing else.

Question:What have you found for problems and what is a solution to our issues?

Answer:Two problems.Cams and bucket to bore lack of clearance.

Question:What is causing them to wear like that?

Answer:Cams are not hard enough.Good lobes Rockwell tested 38.Will never survive.Must be above 55 with at least 60 being ideal.Also signs of valve float on cams and valve bounce on valves.Contacting Mega Cycle with serial numbers to see what they have to say if they made these cams.

Question:When a cam is hard welded how is Rockwell of 60 maintained?

Answer:They are hardwelded then heat treated and finally ground.

Question:What is causing the valve float and bounce?

Answer:The buckets are losing contact with cam lobe because they dont fit the bores properly.They should have .001 clearance minimum.None of the bores in this head meet that spec.With clean oil free bucket it should fall in and out of head.None of these do and one sticks very badly.

Question:Which one sticks really bad.

Answer : Dont like any but the exhaust one is worst

Question:What about the springs?

Answer:installed hieght =60lbs
.400 lift 166lbs
Nothing wrong with stock springs.More than
enough to control your valves.

Question:So what do we need to do to fix this.

Answer:Bores can be sized to buckets and properly
hardened Cams.

Opinion:This company makes springs but never tried to sell me a spring or anything.The day after delivery head was disassembled and cams Rockwell tested.They were very confident stock spring at lbs stated were more than adequet.All we need is to fit the buckets and keep an eye on them since we dont know if the clearances tightened over time from new and may continue to do so.We also need cams that we can count on being 60rockwell.R/d has gained my respect for sure.Showed enthusiasm and didnt try to sell anything we didnt need.Was also confidence there.Cant wait to meet them at Indy. :clap:

[cannondale27]

Talked to Chris Osborn.Very helpful guy gave me references to some more cam people to talk too since they only do springs and testing of springs.He recommended we get the cam solution first.

If we want to do valvetrain testing.He recommended the spintron with a complete motor to test since entire motor harmonics affect the valvesprings.$2500 a day+cost of jigs and fixtures.2day average for testing.

If new spring is to be designed,wound and tested $2500 in addition to testing costs above.

Opinion:A destroyed motor is cheaper than this testing.
R/D springs advice is way to go for testing.I am doing it others are also.We may be wrong and will have to pay for destruction if so but it would be cheaper than the cost of scientific testing.If I were rich this place would be doing the testing.Would love to see what they could come up with.Not reasonable for us though.

Check them out
http://www.racingsprings.com/capabilities.htm

[dalewannbe]

Sounds like some interesting analysis. At least we can focus on the cams now, and not have to worry about the spring as much.

27, did this information cost you a lot of money? I'm sure there are several of us that would be willing to donate to the cause.

Keep up the good work!
:clap:

[claas900]

..sounds good c27. Good work,cant wait to see what they say at the show. Iv always been a fan of ppl not trying to sell me stuff and just tell me like it is,then ill buy if need be.

[cannondale27]

I agree.Claas got the ball going with R/D springs by getting me contact info.Cost for this advice -0-,Nada nothing.Will be sure to take these folks out to eat or slip them a cash tip at Indy show.But never wanted a dime.I wish more people would do a Google search on subject.Look at the sites and make some phone calls.Takes time for sure but if more people do that more opinions will be had which is better.Since just dealing with two companies required about 15 calls.Not complaining but wishing more folks would get involved.More the better.

[fig]

I just found this post on dalers, "Unfortunately, a hole in the bucket indicates that there has been excessive Hertzian stress between the cam and bucket. This is most likely caused by the bucket bore being improperly sized or shaped. The bucket runs hard in the bore, and the cam eats the bucket while destroying itself. A valve sticking in the guide could also be the cause, but Cannondale had some bucket bore machining problems, especially the intake on the right side of the vehicle. The bore was distorted by a clamp on the machining center.

New intake buckets and a new cam should be installed. The bucket bore should be reamed if the bucket will not slide into the bore easily. If the bore cannot be repaired, another cylinder head should be used.

Caution: if the intake valve has hit the piston, the valve must be replaced, or you'll be tearing the engine down again after the valve head breaks off and smashes the head and piston, and probably some other valves."

It's dated 8/20/03.

http://forums.cannondaler.com/viewtopic.ph...ighlight=#10530

[Canniboomer]

I think that Timbo was the source for that right-rear bucket discovery, and before this past August.... but it's good to see it summarized again.

[cannondale27]

Wow missed that one.That was way back.Was a picture of one I remember.Now I have to look up Hertzian stress.Sounds like fancy name for destruction:D

[elkapower]

I have noticed that some buckets are hour-glass shaped. This causes them to be sticky at varying points of compression and will not release fully. Since they are hardened, grinding is the only solution.

Also talked with webcams, the lady a the booth at the show said she has them in their catalog, but her problem was fixing the de-compression release. Hotcams is considering suing my motor in the fall to develop sets of cams. I told them that the 6500 owners of Dales are coming to the point of needing replacememts, so they might (don't know if the owner will support this, sinc ehe was on break when I tried to find him, also talked with R/D spring, and what everyone said is true, nice people, seems that maybe the springs are ok in stock, should we be looking at ti valves instead?

[cannondale27]

We arent finding the buckets are hourglass shaped unless they were damaged.Are you?The bores in head are not straight though.Question is is this caused from heat cycling or are they misshaped new.Begining to think it is from heat cycling and will need to be something that is checked once in awhile.Ti valves would be nice but I would like to see other issues fixed first.R/D is going the route of fixing everything then attempting to run lighter springs which would reduce wear on everything.Ti valves would allow lighter springs.But there are definitly some draw backs and had problems running them in past.Sure would like to run them again though if they worked.