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MELLING MTF5 Firing order

sineden06

New Member
Joined
Jul 28, 2025
Messages
12
Is anyone using the MELLING MTF5 camshaft? Is it the original firing order or the high output firing order? I've tried the original firing order with no success and I am waiting for melling to get back to me?
 
OP
OP
S

sineden06

New Member
Joined
Jul 28, 2025
Messages
12
Thank you for the responses. I received an email from Mellings and he concurs with what you all suggested, I'm almost at the end of my rope with this. Ive tried both firing orders (original 302 and and the 13726548) with nothing but a backfire or two. Ive been to TDC on number one so many times i cant count. It just wont fire. New build, everything is new minus the block and crank. Obviously I'm missing something, I just cant figure it out. I have spark to the plugs, plug wires are all good. Even had a old engine guy over to look at it, He couldn't figure it out either. Tried two different caps and rotors. I can post more info on what procedures Ive used to get to this point if anyone has questions. If anyone has ANY suggestions thatwould be appreciated.
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
37,066
The basics...
You are going counter-clockwise on the cap for the firing order?
You know that Ford numbers cylinders different than most any other auto maker? Passenger side is 1-4, driver side is 5-8. Not an odd bank and an even bank like other number it.
#1 TDC, You know there are two different TDCs. One at the top of compression, the other at the top of exhaust.

Deeper than the basics. What do you have for cam and heads? There is a chance you have adjustable valve train but tightened the rockers as positive stop. Holding the valves open and not building compression. This can also happen with machined heads or even mix and matched heads and pushrods. There are a couple different length of stock pushrods that go with different heads and rockers. If you have the lifters bottomed out and the valve is head slightly open you can't build enough compression at cranking speed to start the engine. Do you have a compression tester? Check a couple holes. IF you are getting strong compression in more than 3, you can quit. If they are weak in more than 3, you have build issues.

What are you running for ignition system? Was it running with this before or any parts new?
Is the fuel actually fuel? Did you get some rain into the gas tank while the engine was being rebuilt? Drain the carb completely, fill with some 2-stroke premix (as much as you are cranking on this a little 2-stroke in the fuel will be friendly to the new cylinder walls).
 
OP
OP
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sineden06

New Member
Joined
Jul 28, 2025
Messages
12
The basics...
You are going counter-clockwise on the cap for the firing order? Correct counter clockwise.

You know that Ford numbers cylinders different than most any other auto maker? Passenger side is 1-4, driver side is 5-8. Not an odd bank and an even bank like other number it. Understood 1-4 passenger side 5-8 drivers side.

#1 TDC, You know there are two different TDCs. One at the top of compression, the other at the top of exhaust. Understood.

Deeper than the basics. What do you have for cam and heads? Melling MTF5 and AFR renegade heads.

There is a chance you have adjustable valve train but tightened the rockers as positive stop. Understood and they are adjustable.

Holding the valves open and not building compression. This can also happen with machined heads or even mix and matched heads and push rods. There are a couple different length of stock push rods that go with different heads and rockers. If you have the lifters bottomed out and the valve is head slightly open you can't build enough compression at cranking speed to start the engine. Do you have a compression tester? Check a couple holes. IF you are getting strong compression in more than 3, you can quit. If they are weak in more than 3, you have build issues. All cylinders are within 10% of each other (around 140 psi).

What are you running for ignition system? Was it running with this before or any parts new? MSD blaster coil MSD wires all new replacement distributor new unknown manufacture.
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
37,066
140 PSI cranking compression should be fine. Chance of over adjusted valves with the adjustable valve train. I've been guilty of missing the zero lash and going until the lifter is bottomed out and thinking that is zero lash and cranking down too much. Don't think that is the deal

Unknown new distributor sets off an alarm bell. I've had a lot of issues with new parts. Few years back I figured it was time to do a tune up on my boat. First set of points were so badly built that the contacts would not open and the pivot was lifting instead. Got that sorted and still didn't run, condenser was a dead short to ground. New parts are not always a good thing.
 
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