I just had a cam swap in my 103 cu in twin cam motor. I had them install 255 cams from stock cams. Now when I hit a hill and roll on the throttle I'm hearing a lot of valve clatter (noise). Has anyone else had this problem and how did you go about getting it fixed?

 

Yep, its a Harley!

Could be a lot of things, some people hear clatter, same bike other people hear nothing.

But, could be bad lifters (did they replace them when they did the cams?), pushrod adjustment, or just a noisy valve train very common to Harleys.

I'll also add that if you had it tuned at the Harley dealer thats a big mistake. If you did, take it to someone who knows how to tune a bike and then see if your noise persists.

Yes, there are exceptions, but there's a lot of turnover at HD dealerships, often the guy doing the tunes is the yutz that replaced the last guy that left and has very little skill or experience.

 

Yes it has new lifters, and yes it was tuned at a Harley dealer. I was definitely thinking about the yutz factor too. My thing is I'm still under warranty, but for only a few more months.

 

Talk to the ones that did the work for you, and discuss options.
Do it soon!
Mine does not clatter in such a situation, it just roars, snarls and scoots!

 

The "valve noise" only under load sounds more like pinging from too much spark advance. Did thy change your map at all when changing cams?

If it's truly from the top end have a look around my website, you might find it interesting

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255's have a lot of cranking pressure; they can be ping monsters... Sounds like preignition to me.

 

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" Now when I hit a hill and roll on the throttle I'm hearing a lot of valve clatter (noise). "

Thats not valve clatter when you only get the noise rolling on the power/throttle under load going up a hill or when acell hard,thats normally detonation/pinging.

Valve/lifter issues will generally make nose all the time at certain rpm no matter if your cruising @ steady speed on lvl ground or going up hill under load.

Whats likely happening in your case is when you put the 255's in your bike that have fairly short duration/short cam timing increased cyl pressure due to fairly early valve closure causing detonation under load.

1st thing to consider/try is if there is still winter blend fuel in your area that can cause detonation issues esp when inc cyl pressure with shorter duration cam timing the 255's have.

Another thing to consider is if the bikes got 6month old fuel in it that fresh prem 93 octane fuel may stop the detonation too.

That used to cause issues with a diff 1700cc v-twin bike i had that would ping on winter blend fuel and not on same octane summer blend fuel so try a tank of fuel thats known to be summer blend fuel.

But if that doesnt help if your not running premium 93 fuel try running the fuel tank low and then filling up up with fresh 93 fuel and see how that does.

If that doesnt get it just to ensure its higher cyl pressure issue requiring more octane try mixing some race fuel on 1 tank fuel to see if it stops the detonation.

If that works then you either have to find/run higher octane fuel or get a tuner to reduce timing to see if that helps.

Motor likely also runs hotter with shorter cam timing so if you add an oil cooler with elec cooling fans that can reduce oil temp up to 50deg f while also significantly reducing engine/combustion chamber temp @ same time can also help reduce or stop detonation like it did for my bike.

Fattening up fuel mix can also help reudce detonation too so if you dont have a tuner night rider XIEDS / adjustable resistors can also help reduce detonation too ,but they didnt seem to reduce engine temp much if any on my HD.

Good luck & happy motoring.

Scott

 

I agree with the others on checking the pre-detonation possibility. Pinging sounds like rocks hitting your front fender. Valve train noise is different. It will be RPM dependent. Valve train noise is normal in twin cams and it varies. Lifters and how your adjustable push rods are set can have an effect on it. Rocker box noise is another source of annoyance. That usually comes on from 22-2700rpm and sounds different but again is RPM dependent. This noise happens when the rocker shafts move about.

 

Don't let anybody blame it on the 255's, that just aint right!
Make them get it right.
Two up, going uphill, twist the throttle, man that's where that cam thrives.
"Back to the dyno", and you should NOT have to foot that bill, if they make it right.

 

I didn't see it mentioned by anyone else so I'll throw this out there as well, it's very possible what your hearing is cam reversion through the throttle body. If you've never had a cammed bike before this will definitely be a sound you haven't experienced before. It's a very distinct clucking sound. Not saying this is your issue because the 255's are known to ping but just throwing this on the table as a possibility of what your hearing.