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1725 cam damage

alpine_64

alpine_64

Donation Time
A local member is in the process of rebuilding a 1725 motor.. while trying to get the best cam he can for the regrind he has come accross what appears to be a pattern of damage on the cams that indicates a comon problem of not enough oil on the #3 exhaust lobe... now he has sourced 4 cams.. all have similar damage at the same spot.. including a motor with a verified 60K miles..

Now this is the first i have heard of this as an issue.. anyone else have a similar issue? As a side note.. we are tlaking a full 1mm off the end of the lobe when measureed around...

click for larger pics:


 
alpine_64

alpine_64

Donation Time
I didnt get to see the rest of it, though was told the lifter had damage as well .. the other cams shared similar damage, though i am not certain the coniditon of the lifters (but would assume the same) It seems all these engines seem to have suffered an oiling problem at that point..

I dont recall having heard of that as a specific problem with the rootes motors.. but seems odd that all the cams the guy has found seem to be suffering this issue.
 
puff4

puff4

Platinum Level Sponsor
I don't know about others, but I recently rebuilt my 1725 (with well over 100,000 miles on it) and when I sent my cam back to Delta to look at it they said it didn't need anything and was still within spec. They just parkerized it, reground and parkerized the lifters and resurfaced the rockers and then sent the lot back to me. No damage whatsoever.
 
alpine_64

alpine_64

Donation Time
Jarrid,

Not seeing the engine i dont know.. but i will ask. What prompted me to post this thread was its a problem i have not heard of.. but seemed odd that he had found 4 cams with the same damage on the same location (all from different engines)

Over the years we have identified rootes specific issues with the motors.. so i was surprised to see this previously unidentified problem.. had it not been across 4 different cams i would have just put it down to a single motor.. anyway, i'll get back to the owner and see what i can find out about the rest of the engine he pulled it from.. and see what he knows/can find out about the others.
 
R

RootesRacer

Donation Time
The reason I mention the thrust plate is that the ugly sections of the cam lobe shouldn't even have contact with the lifter if the lobe is centered to the follower.

The lobe nose should have slope of a few thou across the ramp section so as to rotate the follower and the convex shape of the follower should cause gentle spin as it rides the ramp.

That damage looks to show the followers high point well offset from the center of the lobe so I wonder if the cam was not positioned properly to the followers, a job that is performed by the cam sprocket, the cam itself and the thrust plate between the two.

Just out of curiosity, does the far end of the cam have wear marks from riding the cam plug disk?
 
alpine_64

alpine_64

Donation Time
RootesRacer said:
The reason I mention the thrust plate is that the ugly sections of the cam lobe shouldn't even have contact with the lifter if the lobe is centered to the follower.

The lobe nose should have slope of a few thou across the ramp section so as to rotate the follower and the convex shape of the follower should cause gentle spin as it rides the ramp.

That damage looks to show the followers high point well offset from the center of the lobe so I wonder if the cam was not positioned properly to the followers, a job that is performed by the cam sprocket, the cam itself and the thrust plate between the two.

Just out of curiosity, does the far end of the cam have wear marks from riding the cam plug disk?
Click to expand...

Jarrid,

I dont remember seeing any other prominent damage on the cam (and didnt take overall pics).. i guess the other thing is that this is one of 4 cams sharing the same problem.. like i said.. not something i have heard of before.. just seems odd that the 4 he has all suffer the same issue. I will be speakign to him later this week, will ask some questions.. unfortunately he does not use computers.
 
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