Fuel pump cam lobe excessive wear???
 

Last season while tearing down one of my motors I noticed an excessive amount of wear on the cam lobe that runs the mechanical fuel pump. The lobe was worn off close to a third of its original size. I am in the process of having the other motor freshened up and this cam is incredibly worn on the fuel pump lobe as well.

I know many well known engine builders use the 130 gph pumps on their blower motors but is this the result of the heavy spring pressure from the large volume 130 gph pump?

I hate the thought of ruining a motor because of the cam material shedding from running a mechanical fuel pump!

These motors had less than 150 hrs

What do you think?

Kurt

...also, is there a special fuel pump pushrod for these big mechanical fuel pumps?

I have run a bronze tip ligtweight fuel rod and haven't had any abnormal wear issues on a solid roller cam. I haven't run it 150 hrs so I can't say what you are seeing is normal or not.

Billet cams need rod w/ bronze tip.

Who makes the bronze tip pushrod?

Kurt,

The lobe wear is not uncommon. Happens to everything from vanilla 330's and up. Some wear much faster than others.

Is one of the first things I look at when somebody tells me that their BBC just started getting really hard to start when it has been sitting a couple of weeks.

Crane and Comp Cams make good ones.

This just blows me away! I've been playing with performance boats for over 20 yrs and seem to learn someting new everyday :eek:

Wouldn't you think you would have a low fuel pressure problem with the lobe wearing as much as I have just experienced but that was not the case. Fuel pressure was 8.5 lbs idle and 5.5 under boost :confused: the lobe was missing two thirds!

Can the lobe wear be eliminated by going to a better pushrod?

Kurt

I have used the comp cams one.. I had learned a long time ago, if using a billet cam you need to use a bronze tipped pushrod..

Thanks for the info guys!

The Comp Cams website mentions the need to run a bronze tip pushrod when running a steel roller cam or damage will result!

Comp Cams #4607 bronze tip pushrod.

Kurt