[badbug1]

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.

 

[DanH]

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.

OG.. what's that ?

timing issues . mark walking all over the place ? thats a simple fix

 

[arnoldtx]

Lots of things can cause this issue. Wrong firing order, broken valve spring, etc. what has been checked? Compression check?

 

[colkerr]

Flattend lobe?

 

[badbug1]

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

 

[firehorse5_0]

OE or OEM would be the correct term

 

[PSIG]

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

 

[KULTULZ]

... 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

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.

 

[DanH]

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

 

[badbug1]

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

 

[KULTULZ]

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

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

 

[tkase]

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

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.

 

[DanH]

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

hyd. cam with rocker installed and adjusted , lifter can bleed down.
removed rocker and getting lifter rise from the push rod , would be more accurate

 

[KULTULZ]

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

hyd. cam with rocker installed and adjusted , lifter can bleed down.
removed rocker and getting lifter rise from the push rod , would be more accurate

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."

 

[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

 

[KULTULZ]

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:

 

[DanH]

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

 

[KULTULZ]

thank you dan! :d