Helping a friend work on a 71 Mustang 351C. Trying to figure out if the cam is OG, there are no markings on the end of the cam behind the retainer plate. We were having timing issues, the motor kept back firing up throught the intake and out the exhaust. Any and all suggestions would be appreciated.
351C timing and cam question
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OG.. what's that ?
timing issues . mark walking all over the place ? thats a simple fix
OG... original...
He doesnt know if the cam has been replaced. No broken valve springs, he said compression was good, but a second look cant hurt. can also pull the cam and check for a flat lobe. I did drop a bolt into the front of the oil pan taking off the cam retainer and in fishing it out got a lot of silver mud on the magnet. thinking pulling the motor and starting from scratch might not be a bad idea if it's in his budget for all the parts and machineing.
Thanks for the info, keep ya'll posted
He doesnt know if the cam has been replaced. No broken valve springs, he said compression was good, but a second look cant hurt. can also pull the cam and check for a flat lobe. I did drop a bolt into the front of the oil pan taking off the cam retainer and in fishing it out got a lot of silver mud on the magnet. thinking pulling the motor and starting from scratch might not be a bad idea if it's in his budget for all the parts and machineing.
Thanks for the info, keep ya'll posted
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OE or OEM would be the correct term
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Well, at this point you may as well get a gasket set and tear it down to find any and all issues. Before you do, throw a degree wheel and dial indicator on there to spec the #1 set of cam lobes to compare with stock specs, or know what you have if it's not stock OE (Original Equipment in the trade). If you haven't done a cam spec'ing before, there are lots of good instructions on the 'net.
David
David
Easiest way out and you can check for chain stretch (nylon cam gear) also. Turn the engine over by hand and watch rocker arm movement or use a dial gauge to check for bad lobe(s).
Check curve(s) in distributor.
No use going in if the engine is healthy, IMO.
good to see no cut & paste
notice the op said had the cam plate off
plus to find cam specs , degree wheel is needed .
with a hyd. cam a dial gage can be used but not with the rocker arm on
Thanks all, here's what I've found so far. block is a 351c but the heads are 351 CJ open chamber heads. Also the cam is a Comp Cam 268H Hyd. flat tappet .494" lift and 368 duration. So he' picking up another cam and lifter set today, along with a new timing chain and gear set.. I play heck with three of the lifters on the left side head, they did not want to come out. All the others just slipped out with ease. So thats where we are at for now, thanks again for the advise and let me know if anything else ya'll think of.
G
G
Good to see no cut & paste? What does that mean?
Measuring lobe lift with any type of tappet is considered a known procedure. No degree wheel needed to simply measure lift for a possibly bad lobe.
Am I missing something here DanH
I would venture to guess the metal in the pan is related to the stuck lifters. You will probably find they are mushroomed on the end and that is why they won't come out. colkerr nailed it. Wiped cam.
hyd. cam with rocker installed and adjusted , lifter can bleed down.Good to see no cut & paste? What does that mean?
Measuring lobe lift with any type of tappet is considered a known procedure. No degree wheel needed to simply measure lift for a possibly bad lobe.
Am I missing something here DanH
removed rocker and getting lifter rise from the push rod , would be more accurate
Good to see no cut & paste? What does that mean?
Measuring lobe lift with any type of tappet is considered a known procedure. No degree wheel needed to simply measure lift for a possibly bad lobe.
Am I missing something here DanH
This procedure regarding hydraulic tappets is understood by most. Basic knowledge. A weak tappet would show false results even if the engine was just shutdown. I would measure lift from outer tappet edge, not the plunger (spring removed). Save some time. Maybe I take too much for granted when I post to some.
My main concern is your statement, "Good to see no cut & paste."
from a few years back .
remember when you said you are gone ?
your thumb
add , your words , not a cut/paste answer ,shows what you know and direct help to those that need it .
call it a custom answer
I apologize. My CRS is advancing rapidly and I have periods of confusion...
It also seems my reading comprehension is not quite up to par either... :frown:
Welcome back
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