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roy
roy, import/domestic specialest
Category: Ford
Satisfied Customers: 5425
Experience:  ASE master tech for 40 years
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I have a 1996 f250 with A 460 brand new rebuild 60 over rv

Customer Question

I have a 1996 f250 with A 460 brand new rebuild 60 over rv cam and I'm getting pinging with 93 octane gas I do not have smog or egr valve or cat anything I can do to help this without putting emissions back on
Submitted: 1 year ago.
Category: Ford
Expert:  roy replied 1 year ago.

good afternoon my name is ***** ***** I will assist

what did you set the base timing at???

Roy

Customer: replied 1 year ago.
It's at 10 degrees right now
Expert:  roy replied 1 year ago.

ok, what about the vacuum advance?? is it hooked to ported vacuum or manifold vacuum?? what is the total timing at 1800 RPM??

Customer: replied 1 year ago.
It's electronically advanced by the computer
Expert:  roy replied 1 year ago.

ok, then check the total advance at 1800 RPM

it sounds like the timing is too far advanced.

did you do anything else to the motor?? timing chain?? compression change????

Roy

Customer: replied 1 year ago.
New timing chain and higher compression motor it's new from the ground up
Customer: replied 1 year ago.
It adds 10 degrees to base timing at idle and I'll have to recheck but I think it was 15degrees at 1500
Expert:  roy replied 1 year ago.

ok, thanks.

if you moved the timing back to 0 and it still pings, I am worried that the timing chain may be advance 1 tooth.

did you build it or a shop???

Roy

Customer: replied 1 year ago.
total is 20 at idle and 25 at 1500
Customer: replied 1 year ago.
Shop did
Expert:  roy replied 1 year ago.

with your timing light at 1500 you should be seeing around 30 degrees of total advance. if you have pinging at that low timing, there is a definite issue with the timing.

Roy

Customer: replied 1 year ago.
I'll have to recheck it but that should be 10 at base timing correct
Expert:  roy replied 1 year ago.

8 is where I believe with the cam you have. all the power curve comes in by 2200 rpm

Roy

Customer: replied 1 year ago.
I was thinking it had to do with deleting my egr or the higher compression
Expert:  roy replied 1 year ago.

the higher compression yes, but it must be very high to be like this. do you have any idea what the compression ratio is??

Customer: replied 1 year ago.
Not sure talked to the engine builder he told me he got the wrong cam he got a carb rv cam on accident instead of the fuel injection rv cam does that make sense to you ?
Expert:  roy replied 1 year ago.

yes because a trailering cam is completely different. did he tell you what the timing should be???

is he going to do the change for you???

Roy

Customer: replied 1 year ago.
if I take the motor back to him
Expert:  roy replied 1 year ago.

that sounds like you have to remove the motor to do this???

Roy

Customer: replied 1 year ago.
Yea
Expert:  roy replied 1 year ago.

I hope he compensates you fort the labor time for this.

Roy

Customer: replied 1 year ago.
Only have a couple hours in pulling it out
Expert:  roy replied 1 year ago.

ok, as long as you are ok with that.

Roy