Cam shaft and rocker arm wear?

[K2-K6]

Shifting the cam timing like that shifts the torque peak to different rpm (usually upwards) with BHP a calculated number using rpm as multiplier, it appears to have higher BHP from the same engine.

It's an odd thing,  as torque is what pulls it along but BHP is often used as the big headline number that people are interested in.

It will go faster as in rpm the minute component brings a time basis to performance in that you'd gear it down to rev higher and produce more power pulses over the same distance you travelled (that's effectively what BHP means, workrate in time stated) but probably with exactly the same torque as you had before.

What it means;- you'll have to run higher rpm to match or exceed the std one.

Look at torque for a current 600 and compare it to these 550, then look at BHP and the rpm difference to illustrate the above. At 14000rpm a modern motor is packing far more power pulses into each mile and so it's faster.

[alexdecker]

Wow, that price was better than I expected. I have written Newcams as well now 

[murdock]

supongo que newcams trabajara en unos cuantos hondas esta temporada

I guess newcams will be working on a few hondas this season.

[Oddjob]

Phil, just say you want 5 degrees more overlap and 10 degrees more duration and let them worry about it. It's the way the lobes are profiled, overlap is the time both valves are open at the same time, duration is the time the camshaft holds the valve open.

According to Mark it really wakes up the 500/550 engine, there are other little things you can do like making a pocket above the inlet valve, they always say "Don't lower the floor, raise the roof", and raise the exhaust ports about 2-3mm and smooth the port out. That's to aid the flow of exhaust gases as they exit the engine.

[Sesman]

Thanks, Ken. That’s exactly what I was looking for.

I’ve already ported the head…nothing drastic, just smoothing matching and a slight raising of the roof. Basic fluid dynamics stuff. I was going to fit a 650 cam, but the opportunity didn’t present itself, so your 5/10 comment piqued my interest.

Not looking for remarkable gains, but I used the rebuild to optimise what I have. I’m pretty sure it won’t be worth the time invested, but it kept me off the drink and donuts for a while😊

[alexdecker]

For reference, I got a quote for alle rocker arms + cam shaft for £420 all in all. That is quite a bit cheaper than buying new. Now I just gotta figure out how to ship into the country. Don't know what changed since Britain left in regards to shipping into the country, but it would seem that I could still save a lot by going this route.

Unless someone has a cam shaft and rocker arms they wanna sell me?

[Oddjob]

New cam and rocker arms?

Quote from Newmans by any chance?

Wonder what the cost of a ferry trip is? Pop over and pick it up yourself 

[Bryanj]

Check your customs i think into UK repair parts are zero

[murdock]

For reference, I got a quote for alle rocker arms + cam shaft for £420 all in all. That is quite a bit cheaper than buying new. Now I just gotta figure out how to ship into the country. Don't know what changed since Britain left in regards to shipping into the country, but it would seem that I could still save a lot by going this route.

Unless someone has a cam shaft and rocker arms they wanna sell me?

los balancines no se ven mal

the rockers don't look bad

[K2-K6]

The rockers look knackered, and it's their surface that's been taking the cam apart. 

It may be  the pictures,  but they're not good. I wouldn't put them near a new or refinished camshaft.

[murdock]

Ok , lo miraré de nuevo cuando encuentre mis gafas

Ok, I will look again when I find my glasses, where are they when they are not on my head? 

[K2-K6]

It's the "strakes" ( the lines going in direction of cam travel)marking the rocker faces I'd be most concerned about, which is what they look like in the photos. 

Ordinarily to wear the cam lobes you get pickup (lubrication failure under pressure) that cold welds one surface to another, this then acts as abrasive (on the rocker face) to wear the cam lobe as it goes round. It can also leave no tappet clearance at that point, which further destroys the oil film right the way round the cycle in that line. This is why it starts to leave that characteristic strake.

Ultimate cause is oil condition/quality, usually through fuel dilution as it's been run too long between changes.

[K2-K6]

Phil, just say you want 5 degrees more overlap and 10 degrees more duration and let them worry about it. It's the way the lobes are profiled, overlap is the time both valves are open at the same time, duration is the time the camshaft holds the valve open.

According to Mark it really wakes up the 500/550 engine, there are other little things you can do like making a pocket above the inlet valve, they always say "Don't lower the floor, raise the roof", and raise the exhaust ports about 2-3mm and smooth the port out. That's to aid the flow of exhaust gases as they exit the engine.

Thinking about this and follower geometry. It looks as though you could do this with a rocker geometry change, in that if you have the rocker pads refaced (Newman cams) and ground to a larger radius, then it would achieve the above overlap and duration with the std camshaft. You could swap them out to see what you preferred then.