351w not starting
Thread Starter
|
New User
Joined: Jan 2017
Posts: 24
Likes: 0
351w not starting
Hey guys I know this has been covered before but I've read and reread and for some reason the truck still won't start. It's a 1970 f100 originally had a 302 but swapped it out for a 351w. The 351 has a comp cam not sure of the specs was in there when purchased. 1.6 roller rockers. Heads are off a 302. Edelbrock rpm air gap. And a quick fuel 670 carb. Summit billet distributor and a msd 6al box. So it tries to start but backfires a lot. So I thought 180 out right? Nope still backfires a lot. I tried to set it on the compression store the intake stroke. 180 out every witch way and still nothing. Can anyone think of something else it could be or point me to another thread? Thanks.
Lead Driver
Joined: Aug 2003
Posts: 7,592
Likes: 10
From: **** hole San Jose ca.
Has this motor every been running with all the upgrades ??
So we know it timing off since it's back firing.
Not sure if your timing it correctly as it may be just a few degree off instead of 180.
Don't over think the timing is 180 off.
Pull spark plug place finger over hole crank unit compression blow off finger. use a wrench to move till it line ups on TDC.
Line up #1 at TDC set rotor pointing at #1 plug wire on the cap.
Orich
So we know it timing off since it's back firing.
Not sure if your timing it correctly as it may be just a few degree off instead of 180.
Don't over think the timing is 180 off.
Pull spark plug place finger over hole crank unit compression blow off finger. use a wrench to move till it line ups on TDC.
Line up #1 at TDC set rotor pointing at #1 plug wire on the cap.
Orich
Thread Starter
|
New User
Joined: Jan 2017
Posts: 24
Likes: 0
That's exactly what I did and I was adjusting the distributor and still was just back firing. The previous owner said it was running. I don't know if it was running before the cam was put in or after. For all I know he put a bunch of upgrades in it and couldn't get it to run and that's why he sold it. And to be honest I've never really worked on a Ford motor. I've always done chevy stuff so it seems like it's completely different.
Lead Driver
Joined: Apr 2011
Posts: 6,399
Likes: 40
From: El Dorado, Arkansas
I'm not clear how long ago the 351W was swapped in (?) --recently or, a good while ago? and if it's been a while ago, did the 351W ever run normally up until recently?
It takes air, fuel and spark, in the right amount and in the right timing sequence, for the combustion process to happen. If this engine ever ran normally, go back to the last event that was done to the engine before it no longer ran normally.
If it's never run normally, you'll just have to go through the three requirements for combustion and determine through a process of elimination what is or isn't happening, that's keeping the engine from running correctly --is it getting spark and at the correct timming event? (yes or no). Is it getting fuel and in the correct amount? (carburetor adjustment, yes or no). Are there any air restrictions to the induction into the engine or any vacuum leaks? (yes or no).
It takes air, fuel and spark, in the right amount and in the right timing sequence, for the combustion process to happen. If this engine ever ran normally, go back to the last event that was done to the engine before it no longer ran normally.
If it's never run normally, you'll just have to go through the three requirements for combustion and determine through a process of elimination what is or isn't happening, that's keeping the engine from running correctly --is it getting spark and at the correct timming event? (yes or no). Is it getting fuel and in the correct amount? (carburetor adjustment, yes or no). Are there any air restrictions to the induction into the engine or any vacuum leaks? (yes or no).
Lead Driver
Joined: Aug 2003
Posts: 7,592
Likes: 10
From: **** hole San Jose ca.
That's exactly what I did and I was adjusting the distributor and still was just back firing. The previous owner said it was running. I don't know if it was running before the cam was put in or after. For all I know he put a bunch of upgrades in it and couldn't get it to run and that's why he sold it. And to be honest I've never really worked on a Ford motor. I've always done chevy stuff so it seems like it's completely different.
Rotor turns the other way and the #1cyl. is on the passenger side not drivers side. firing order not same.
Yup it's all back *** words
EDIT MAYBE CAM IS OFF
Orich
Thread Starter
|
New User
Joined: Jan 2017
Posts: 24
Likes: 0
Tell me about it... but I have never seen this motor run. We did this swap a couple months ago and have been fighting with it since then. Carb is good I know for sure. We are getting spark. And I timed it on the #1 compression stroke. So the only other thing I can think of is something with the cam/valvetrain like the timing chain being off? I'm gonna pull the timing cover and look just be be cautious
Lead Driver
Joined: Apr 2011
Posts: 6,399
Likes: 40
From: El Dorado, Arkansas
Firing order on a 351W is 1-3-7-2-6-5-4-8. CCW rotation on the distributor rotor, looking down on top of the rotor.
Trending Topics
Cargo Master
Joined: Oct 2011
Posts: 2,241
Likes: 299
From: Kenner,La.
302? 351? Cam
In addition to this problem you could have a 1-5-4-2-6-3-7-8 cam firing order cam for a 302. When I had my marine repair shop a customer had his engine rebuilt and the rebuilder installed a 302 standard cam in place of the 351. By the time I figured out the problem the boat owner was dismayed to find out that he now has a 170 hp instead of the 190 hp .
So now you have to observe the valve action as the engine is turned to be sure which cam firing order you have.
So now you have to observe the valve action as the engine is turned to be sure which cam firing order you have.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Thread Starter
|
New User
Joined: Jan 2017
Posts: 24
Likes: 0
In addition to this problem you could have a 1-5-4-2-6-3-7-8 cam firing order cam for a 302. When I had my marine repair shop a customer had his engine rebuilt and the rebuilder installed a 302 standard cam in place of the 351. By the time I figured out the problem the boat owner was dismayed to find out that he now has a 170 hp instead of the 190 hp .
So now you have to observe the valve action as the engine is turned to be sure which cam firing order you have.
So now you have to observe the valve action as the engine is turned to be sure which cam firing order you have.
Lead Driver
Joined: Apr 2011
Posts: 6,399
Likes: 40
From: El Dorado, Arkansas
Older 302s and non-H.O. 5.0L engines have the older firing order of 1-5-4-2-6-3-7-8. H.O. 302/5.0L engines have the same firing order as the 351W/5.8L engines; 1-3-7-2-6-5-4-8.
Thread Starter
|
New User
Joined: Jan 2017
Posts: 24
Likes: 0
Alright so I did some digging. Pulled the timing cover the marks seen here that align with each other are on the number 6 cylinder TDC I belive. I set the distributor on the compression stroke. How i was told to. It's hard for me to explain cause I'm not really a sbf guy. But I'm sure you guys understand. Is the cam upside down? Or is it just me being crazy? 
Cargo Master
Joined: Oct 2011
Posts: 2,241
Likes: 299
From: Kenner,La.
Timing marks
The marks look correct. Turn the engine to the #1 compression stroke @ Tdc.
Then start turning it by hand and then you wil be able to find out which firing order this cam is. As said before 1234 right bank 5678 left bank, ccw on the distributor. Also check that the marks on the harmonic balancer line up with the marks on the timing cover @ #1. You could have either the wrong or a slipped outer wheel on the balancer.
Keep going, you will find the problem.
Then start turning it by hand and then you wil be able to find out which firing order this cam is. As said before 1234 right bank 5678 left bank, ccw on the distributor. Also check that the marks on the harmonic balancer line up with the marks on the timing cover @ #1. You could have either the wrong or a slipped outer wheel on the balancer.
Keep going, you will find the problem.
Thread Starter
|
New User
Joined: Jan 2017
Posts: 24
Likes: 0
I was 100% sure but now im beginning to question my entire existance. So I'm gonna go back and check another 12 times. Is it at all possible that the cam shaft is upside down though?