Author Topic: Using Light Springs to Break In a New Cam  (Read 3092 times)

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Offline Nikkisixx

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Using Light Springs to Break In a New Cam
« on: June 01, 2016, 03:12:27 PM »
Has anyone broken in a new cam using just the outer springs, then installed the inners after the cam had a chance to run?

I'm talking about just for the first 15 to 20 minute run in of 1500-3000 rpm. 

The springs in question are the Kibblewhite racing springs Dynoman sells.  These springs have not been a problem in other motors BUT I toasted a brand new cam last week and want to eliminate ANY chance of that happening again.  My only concern is they would be too light and might float a valve, but at that rpm range it should be good? 

It is a proven fact that modifying a SOHC Honda in any way will bring on the apocalypse.

Offline gschuld

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Re: Using Light Springs to Break In a New Cam
« Reply #1 on: June 01, 2016, 03:27:12 PM »
Fair warning, I expect a conversation about hardweld cams, non hardweld billet
cams, used rockers, new hardweld on rockers to spring up around this.  It's a subject that I find interesting, so I'll start.

What kind of new cam got killed?  Billet? Hardweld?  And the rockers.  Low mileage used, run as is?  Had hardweld applied? I am assuming the cam lobes got ruined and the bearing journals were OK?  Oil type used on break in?  Any additives? 

The more specific info you share, the more those in the know (not talking about me BTW :)) can help you not repeat unfortunate mistakes.

George

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Using Light Springs to Break In a New Cam
« Reply #2 on: June 01, 2016, 03:54:16 PM »
Goof subject. Good questions.

Proceed......
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Offline Bill/BentON Racing

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Re: Using Light Springs to Break In a New Cam
« Reply #3 on: June 01, 2016, 04:38:56 PM »
Yes, we need more info to offer proper advice. But normal H/D spring pressure, not sure of your installed height,shims etc., but spring pressure didn't kill your cam, my .02. How about some pics and more info? G'luck, Bill
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Offline Don R

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Re: Using Light Springs to Break In a New Cam
« Reply #4 on: June 01, 2016, 04:45:00 PM »
  I feel your pain,  I just lost a cam and new roller lifters in a 567" V8 possibly because I put assembly lube on it. Go figure.
  Drag racers used to break them in on light springs.  I fail to see the harm if rpm's are kept to a minimum but it also needs to rev enough to splash oil on things in the engine too.
  I'm sure someone will inquire about oil flow and assembly lube and the time from when it was assembled until it was fired up so why not me? 
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Offline Bill/BentON Racing

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Re: Using Light Springs to Break In a New Cam
« Reply #5 on: June 01, 2016, 06:01:30 PM »
Yes, my next question,  did you check immediately for oil flow at number 1&4 tapped caps?  Was oil pump/ pressure good, pump primed, oil light off without ignition? Etc......Bill
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Offline MRieck

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Re: Using Light Springs to Break In a New Cam
« Reply #6 on: June 01, 2016, 08:28:06 PM »
Use break in oil with a good zinc additive. Megacycle recommended using just the outside spring on turbo cams because the noses are sharp
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Offline Big Jay

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Re: Using Light Springs to Break In a New Cam
« Reply #7 on: June 01, 2016, 09:55:29 PM »
I would advise using the correct springs for the application.  http://cbrzone.com/sohc.html

Offline PeWe

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Re: Using Light Springs to Break In a New Cam
« Reply #8 on: June 02, 2016, 02:53:47 AM »
Break in the cam?
Twist the throttle when engine is warm ;D
Proper lubrication as Mike wrote must be valid all the time, right?

5mm conv kit valves have lighter springs, less pressure than other racing springs, right?

New cam often with new pistons/rings and fresh hone...
If pistons/rings are new, first miles are very important to not rev too little and drive too careful. There is a homepage about it and I have also found a tech guy in Sweden that wrote his sience thesis based on that with own tests and verified that the rings must get rather high revs followed by heavy decelerations. Twists of 4000, 6000 rpms follwoved by no throttle at all.
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Offline MRieck

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Re: Using Light Springs to Break In a New Cam
« Reply #9 on: June 02, 2016, 04:43:03 AM »
Break in the cam?
Twist the throttle when engine is warm ;D
Proper lubrication as Mike wrote must be valid all the time, right?

5mm conv kit valves have lighter springs, less pressure than other racing springs, right?

New cam often with new pistons/rings and fresh hone...
If pistons/rings are new, first miles are very important to not rev too little and drive too careful. There is a homepage about it and I have also found a tech guy in Sweden that wrote his sience thesis based on that with own tests and verified that the rings must get rather high revs followed by heavy decelerations. Twists of 4000, 6000 rpms follwoved by no throttle at all.
Throttle chops are good as they introduce a high vacuum condition which pulls the rings into the walls of the cylinder.
 When you first start a new engine keep the revs ups and use a fan to keep temp under control. I have seen many videos of full starts with the owner letting the bike idle a very low RPM. You want oil pressure and you won't get it at low idle. People get  obsessed with having an idle set at 800 or 900 RPM. It isn't good as it kills oil pressure
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Offline Nikkisixx

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Re: Using Light Springs to Break In a New Cam
« Reply #10 on: June 02, 2016, 05:40:29 AM »
My question was about running light spring pressure during break in, and if anyone had done it. I thought about it as a bit of extra insurance.  No one has?  ok.

Yeah, what killed that poor little Webcam?  Seems to be a topic of interest so here is the deal: It was the OIL!  Grab your popcorn and move the thread...

Prior to assembly the cam got hit with some carb spray cleaner on the 3-4 end and this washed off some of the grey coating Webcam slathers on there.  Not all, just a few splatters but it was probably enough to speed up the murder and probably why 3-4 died first. 

Then I got educated in the ZDDP content in my favorite Rotella Diesel oil.  Seems the formula has changed significantly over the past few years (from a ZDDP content of 1200+ to who the f##k knows) while I wasn't looking.  My past experience told me the stuff was safe, and it is the only stuff readily available.  Yes I read the instruction sheet that came with the cam and says "Use a racing oil sae30 blah blah".  And so off I went to get some oil. 

The pimple faced kid at the parts stores (4 different chains I checked with) stared blankly at me when I asked for Kendall SAE30.  I searched the shelves and didn't find any brand I'd trust in a SAE30 - this weight is now apparently reserved for lawn equipment that runs recycled who knows what store brand. 

So while the cam was fat and happy during break-in with the high zinc assembly lube right there on the lobes, after the first oil change it lasted about an hour of run time and roughly 40 miles.  I have since mail ordered my oil (that is nucking futz in my paradigm) and changed the oil in EVERY old piece of junk I own to a "racing" oil with "high" zddp content.  Thus I got a $500 diploma from the school of petroleum chemistry and environmental protection.

Thanks EPA!  What is next?  Antifreeze that destroys radiators?!?!  Well HA!  My bikes don't have those!!! 

aw crap why is my old C10 leaking antifreeze?
It is a proven fact that modifying a SOHC Honda in any way will bring on the apocalypse.

Offline cbr954

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Re: Using Light Springs to Break In a New Cam
« Reply #11 on: June 02, 2016, 06:20:40 AM »
Did you use new or used rocker arms on that new cam? 
« Last Edit: June 02, 2016, 07:19:23 AM by cbr954 »
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Offline Bill/BentON Racing

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Re: Using Light Springs to Break In a New Cam
« Reply #12 on: June 02, 2016, 10:24:12 AM »
Used rockers with an established wear pattern......new should have been fine or hardweld ones.
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Offline turboguzzi

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Re: Using Light Springs to Break In a New Cam
« Reply #13 on: June 02, 2016, 11:28:12 AM »
not exactly cam related, never did light spring thing on my motors and never had any trouoble even with high lift racing cams and springs, just an anecdote that maybe applies. udo gietl, tuner of the AMA winning R90S beemers would build his motor DRY, put one drop of oil in the bores and start his engines like that, the idea was to use the still sharp machined surfaces to grind rings and everything else into full contact.

last fresh motor i did was put on dyno immediately (no idling) for 5-6 3/4 throttle pulls and then oil change. motor runs like a champ still after 30 something race weekends.

"Gietl examined the break-in process. He decided that the familiar cross-hatch hone pattern left by proper cylinder preparation is nothing but a one-time double-cut file to shave the rings into intimate contact with the wall. Once break-in was complete, the wide ring contact would be lubricated well enough to glide over the hone pattern, which would have worn down almost completely anyway. He reasoned that too good an oil film could stop the break-in prematurely. He therefore adopted a dry break-in procedure. The pistons, rings and cylinder bores are solvent- cleaned and assembled dry save for a drop of oil on each piston skirt. The engine is started and run at half red-line for nearly a minute. Upon teardown, the rings were seen to have seated very nicely."

Offline simon#42

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Re: Using Light Springs to Break In a New Cam
« Reply #14 on: June 02, 2016, 02:08:49 PM »
yes i read that a few years ago yossef , at the time i didn't believe it ..... and i still don't

Offline turboguzzi

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Re: Using Light Springs to Break In a New Cam
« Reply #15 on: June 02, 2016, 02:15:37 PM »
nice bit of dis-information then to "wreck" the opposition? :)

Offline MRieck

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Re: Using Light Springs to Break In a New Cam
« Reply #16 on: June 02, 2016, 02:33:33 PM »
 .....and Rob Muzzy would put their Superbike ZX-7 engines in street bikes and run them on the street for as long as they could. ;D
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Offline 01Thomas

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Re: Using Light Springs to Break In a New Cam
« Reply #17 on: June 02, 2016, 03:07:48 PM »
The only time I ever installed a new cam was in one of my Moto Guzzis, a Megactycle 620x-11 a.k.a. Norris SS (cam lift 0.36" ). I just dropped it in using regular valve springs (both inner and outer), well lubricated and ran the bike in at medium revs.

A. Graham Bell in his book "Performance Tuning in Theory & Practice - Four Strokes"  spends quite a bit of time on cam prep and running in.
He treats the cam lobes with a process called Parko-Lubriting. On installation he coats the cam liberally in SAE 90W-140 hypoid gear oil - the stuff for your diff, normally approved by the API to GL-5 standards.  (SAE 85W-140 is more common in this part of the world). He also adds a dose of Molybdenum Disulphide to this oil. He then runs his engines at about 2500rpm for up to 10 minutes and then at 4000 for a further 40 minutes. He does not mention valve springs in regard to running-in a cam at all.

I assume that he's run the pistons and bearings in already using a milder used cam? And of course he's talking water-cooled engines;  on air-cooled engines this procedure will have to be modified somewhat.

Being a technical person in the oil business myself, I can add that a GL-5 type oils (for hypoid applications like diffs) contain roughly twice the concentration of EP additives compared to API GL-4 oils (for most manual gearboxes). These additive packages will contain little amounts of zinc but most of it is sulphur-phosphorous (which gives new gear oils their characteristic smell).
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