What wrong with this.. (pics)mustang

[mustangsally93]

Ok we put the engine back in and all stock parts. Well last weekend we got done and we started doing the timing but it wouldn't stay running. So after trying all types of things but nothing. So monday I took it to a mustang shop and after just taking the water pump and a few other things off the shop said I had a hole in the pistion. So we got the pony home and started ripping the heads back off and find nothing.


Now we are at a loss, so we need help. What of anything can you guys help? Also I took the engine all the way a part other then crankshaft and rods and pistions. So what do you guys think I could have done wrong or what can I do? If you need more pics of the car just ask..


Ripped the head and found nothing wrong

View attachment 478422

And nothing wrong with the head

View attachment 478424

Did a comp. test on the engine

View attachment 478426

Numbers

View attachment 478428

 

[tunedin302]

What is the history of this motor? When was the last time it ran? Was it rebuilt recently? If so, what was done (bored, pistons, rings, etc?) Whats the history on the heads - are they stock non-cobra? have they had the valve seals replaced?

 

[mustangsally93]

What is the history of this motor? When was the last time it ran? Was it rebuilt recently? If so, what was done (bored, pistons, rings, etc?) Whats the history on the heads - are they stock non-cobra? have they had the valve seals replaced?

Well the engine was out of my old 93 lx. It was bone stock with 30k on it. The car ran fine before I took it out in Nov of 05. It was never rebuid or anything. The heads are the ones that came with it.

 

[bluevenom867]

Boy thous comp. numbers are all over the place.

Are you sure the rockers were adjusted right?

Is there any signs of a comp. leak on the gasket?

 

[Mustang5L5]

Wow those numbers are all over the place.

Looks like you have 3 pistons in question....all on the end.


WHo put the heads on? Did they use a torque wrench on them? Did they reuse the head bolts?

 

[mustangsally93]

Boy thous comp. numbers are all over the place.

Are you sure the rockers were adjusted right?

Is there any signs of a comp. leak on the gasket?

I tourqed them down to the number I think like 18-25 psi. No leaks that we can hear or no water or oil in the pistions. This is going to hurt to say. But when I put all the rockers,pushrods, I just put them back in what every order I wanted too. Well that make anything. In the book it say they are all the same and the pushrods are the same size. No the rockers were not adjusted just put back on.I thought the rockers on a stock 5.0 HO are non adjustable.

 

[mustangsally93]

Wow those numbers are all over the place.

Looks like you have 3 pistons in question....all on the end.


WHo put the heads on? Did they use a torque wrench on them? Did they reuse the head bolts?

I used the same ones and I put all the stuff back on. But I had two good mech. there the last time. Also I had all the plugs out when I did the comp. test. Yes I retorque them in order. and used the same bolts.

 

[Mustang5L5]

I tourqed them down to the number I think like 18-25 psi. No leaks that we can hear or no water or oil in the pistions. This is going to hurt to say. But when I put all the rockers,pushrods, I just put them back in what every order I wanted too. Well that make anything. In the book it say they are all the same and the pushrods are the same size. No the rockers were not adjusted just put back on.I thought the rockers on a stock 5.0 HO are non adjustable.

I'm willing to bet this is your prob. Valves prob aren't sealing all the way.

I don't have enough expeirence with rockers so i'll let someone else explain it

 

[Bad92GT]

25 lbs seems realy low to torque them.. i was at 75 when i did mine.. check the head gasket as well.. and throw some marborol mystery oil all around the rings.. reseat them

 

[Mustang5L5]

25 lbs seems realy low to torque them.. i was at 75 when i did mine.. check the head gasket as well.. and throw some marborol mystery oil all around the rings.. reseat them

I think she meant 25 for the rockers...not the heads themselves

 

[mustangsally93]

I think she meant 25 for the rockers...not the heads themselves

the rockers was around 25 and the head bolts was like 75-95.

 

[94GT347]

Did you use a compression tester that screwed into the spark plug hole, or was it the type you have to force up against the head by hand?

No real problem on mixing roller valvetrain parts. Ideally you want to keep everything separated, but it's not a live or die thing. I've played mix and match many times myself and never had a failure. Even running high spring pressures.

If the motor was fine before, it's unlikely you dropped 3 cylinders. I'll take a stab here and say that outside of a mis-timed camshaft sproket, the only thing that was wrong with your motor was an external issue, i.e. vacuum leak, ignition issue, induction etc.
Sorry to hear if you tore the motor down for nothing!
I've been there myself.

Good luck getting it going!

 

[mustangsally93]

We used one that screwed in one(does it matter that the engine was cold and not hot). Also we had it all done before But it wouldn't stay running(never bent a vavle guide or no metal to metal). But again why wouldn't I have comp. The timing has to be right the marks are down on the camshaft and up on the crank. Is there anyway I put the cam in wrong???

 

[bluevenom867]

Push rods and rocker arms (at least stud mount,the pedistal might seat into it place after a while so try and place them where they came from) dont need to go on in order.The lifters must though.

75-95 is a big range for torque specs,and its probably not enough if it was with 30 wiegth oil.

Who torqued the heads?

I would just get a new gasket (after establishing the shortblock is ok) and re do the whole deal.

 

[mustangsally93]

We had the heads off twice and the comp. is the same both times. also can you put a cam in wrong.

 

[JRPony]

There is no real pattern to the compression #'s on your motor. I would bet that the valves are being held open . This could be caused by the rockers being adjusted too tightly.

 

[mustangsally93]

There is no real pattern to the compression #'s on your motor. I would bet that the valves are being held open . This could be caused by the rockers being adjusted too tightly.

I touqed them to 25psi. The book said that was the right thing.

 

[bluevenom867]

We had the heads off twice and the comp. is the same both times. also can you put a cam in wrong.

Not really,it usualy either works or it dont.

Unless the cam timing is so far off that it can somehow manage to fire up.

It really sounds like a valve staying open,adjust the rockers again.Maybe even get a adjustable push rod length checker,so you can know exactly what size rod/shim you need.

 

[mustangsally93]

Not really,it usualy either works or it dont.

Unless the cam timing is so far off that it can somehow manage to fire up.

It really sounds like a valve staying open,adjust the rockers again.Maybe even get a adjustable push rod length checker,so you can know exactly what size rod/shim you need.

How do I adjust the rockers??? We don't know how to..

 

[mustangsally93]

There is no real pattern to the compression #'s on your motor. I would bet that the valves are being held open . This could be caused by the rockers being adjusted too tightly.

How would I find out with a vavle staying open?