DAMN IT!!!

[Guest 88rustang]

Anyone that knows anything about 5.0s... i need some help. I put a set of 351W heads (1.98-2.02)on my 302, and am having a bit of a prob. I got the Crane Cam rollers, with the ford racing push rods for a 302 w/ 351W production heads... it seems like the timing is so far off that it won't fire right at all. I put an Edelbroch Performer RPM intake on it with a Holley 650 double pumper. I had my neighbor come over and tune the carb perferctly. It will actually shoot some flames and exaust up the carb. I put the #1 cyl. on TDC and put the rotor on the #1 spark plug. It starts and will run, but wont stay going under 2K RPM's, when it isn't blowing it self up through the carb. No matter how slow you turn thr distributor... WHAT GIVES???. Any kind of advice would be helpful.

[Guest stevil]

Hmmm... you want to have a meeting about this... or uh... tongue.gif

 

-----------------

http://stevil.easy48.com/images/columbusracing/gt3_sig_small.jpg

5.2 @ 231 mph | 1967 rwhp | 1807 tq/lbs | 3535 lbs

"Sounds like a sinking ship... straight to the ocean floor."

[Dual Webers Suck]

If I remember correctly, I believe that if exhaust and flames are coming from your carb, the timing is waaaay too far advanced. I don't like to say I know these things for sure, but that sounds alot like what's going on to me. Firing before the intake valves close, thus going through the heads, into the intake manifold, and out though the carb. Maybe try retarding the timing and working from there?

[kenny]

Do you have EGR? Is there a massive leak under the EGR valve?

[Guest mad man mikey 0212]

well matt, i think the best thing you can do is put the efi unit back and sell the heads and upgrade yuo ecu. but i can't tell ya anything. the nmra is comming in this weekend and i want my sister car out.

[Clifford Automotive]

I had an idea that was you when I looked at the Topic. Like I said put all the fuel injection back on and Coggossi will come and tune it for you. I tell you, you mustang guys, (you and Ben) always need my chevy knowledge. Just givin you a hard time. Actually tell everyone that you see that I wont be out. Im gonna be in Michigan all week for Keystone.

 

Peace Kevin

[Hwilli1647545487]

Moving to tech

[Guest Ubilam]

You didnt mention what cam you are running, with the larger valve heads you may have piston to valve clearance problems, this needs to be checked very soon! also, this may sound stupid, but every one has done it, check and make sure the plug wires arent crossed up. exhaust coming back through the intake sounds like piston to valve clearance isnt what it should be, good luck and see you at the track.

[rl]

Double and triple check the firing order, I don't care if you are POSITIVE that its correct....CHECK IT AGAIN.

How did you set the lash on the rockers? could they be holding the valves open? (did you torque them to 20ft/lbs slowly on the base circle with less then a full turn of the wrench?)

Have you timed it with a timing light? try to.

What kind of vacuum is it pulling?

Did you have the cam out as well, or did you not touch the short block?

[20G TSi]

Originally posted by 5.OOOHHH:

Anyone that knows anything about 5.0s... i need some help. I put a set of 351W heads (1.98-2.02)on my 302, and am having a bit of a prob. I got the Crane Cam rollers, with the ford racing push rods for a 302 w/ 351W production heads... it seems like the timing is so far off that it won't fire right at all. I put an Edelbroch Performer RPM intake on it with a Holley 650 double pumper. I had my neighbor come over and tune the carb perferctly. It will actually shoot some flames and exaust up the carb. I put the #1 cyl. on TDC and put the rotor on the #1 spark plug. It starts and will run, but wont stay going under 2K RPM's, when it isn't blowing it self up through the carb. No matter how slow you turn thr distributor... WHAT GIVES???. Any kind of advice would be helpful.

check and recheck the valve lash. You may have a valve stuck open due to incorrect valve lash (they're not idiot proof like the bolt down rockers in the 5.0's). What rocker arms did you use? Those windsor heads have pressed in studs and are a bitch to adjust properly (with aftermarket rockers) so be careful.

 

Also, what size cam did you use, and do you still have stock (un-notched) pistons? Every 2.02" Int. valve application I've ever encountered needed the pistons notched for proper clearance. Its possible that a combination of incorrect (or correct for that matter) valve lash and not enough piston/valve clearance has bent a int. valve.

 

I'd try everything that has been mentioned in this thread, and if you still have the problem do a compression check.

[SupraGlue]

Definately go with what rl and blupastu said. Particularly in terms of valve lash. It really sounds like an intake valve or valves hanging open, presuming your ignition timing and firing order are correct.

 

The only other thing I can add is make absolutely sure that you've got the distributor on the right cam tooth and not off by a tooth or by 180 degrees (been there, done that).

 

Good luck.

[Vulcan900]

Check the firing order again.

 

We put a 302 w/351 heads into a ranger, and it took us forever to get the firing order right. It wasnt 302's order. I think it was a 351's but could be wrong.

 

We ended up switching wires around till it was running on all 8 cylinders.

[rl]

make sure you are using the 302 HO firing order, the NON ho's are different

[20G TSi]

he said a Crane Cam roller, so I assumed he meant it was for a 5.0HO (since they're factory roller).

 

Thats a good point though, make sure the cam was for a 302HO/351w (1-3-7...) and not for a regular 302 firing order (1-5-4....).

 

Most likely he has the ignition timing off, possibly 180deg out of phase.

[kenny]

Originally posted by blupastu TSi:

Most likely he has the ignition timing off, possibly 180deg out of phase.

Sounds more like a vacuum leak to me. I've had timing 180 off plenty of times, and I've never had it backfire through the exhaust.

 

I have had a nice vacuum leak on the EGR valve, which would do exactly what he said. The car would start, and run, but if you got it over 2k rpm it would backfire.

 

Piston/valve theory sounds extreme, I don't think it would be that.

 

On a side note: check to make sure you have the kit to prevent the power valve from being blown. If you don't have it, you need a new power valve.

 

Keep us posted. Would like to hear what it is/was. Good luck.

 

[ 29 April 2002, 03:07 PM: Message edited by: kenny ]

[Guest Grant]

you cannot put 2.02 valves on a 5.0 motor without haveing the pistons cut and the block bored out cause if you look at any 5.0 head the valves are never bigger than like a 1.94

[rl]

Originally posted by GMBMotorSports:

you cannot put 2.02 valves on a 5.0 motor without haveing the pistons cut and the block bored out cause if you look at any 5.0 head the valves are never bigger than like a 1.94

nice uneducated guess. *cough*AFR, EDELBROK, TFS, WORLD, FMS, HOLLEY*cough*

 

you can run 2.02 valve heads on stock 5.0 blocks, it is a common thing, SOMETIMES you have to flycut the pistons, but most of the time you don't have to (the 2.02 valves are accutlay going to hinder the flow of those heads however...you cant unshroud the valves enough in a d0oe head to utilize a 2.02 intake vavle)

It is ALWAYS a good idea to check the piston to valve clearence (clay)

however, I do not think that this is his problem...

 

[ 30 April 2002, 12:49 PM: Message edited by: rl ]

[20G TSi]

Originally posted by rl:

</font><blockquote>quote:</font><hr />Originally posted by GMBMotorSports:

you cannot put 2.02 valves on a 5.0 motor without haveing the pistons cut and the block bored out cause if you look at any 5.0 head the valves are never bigger than like a 1.94

nice uneducated guess. *cough*AFR, EDELBROK, TFS, WORLD, FMS, HOLLEY*cough*

 

you can run 2.02 valve heads on stock 5.0 blocks, it is a common thing, SOMETIMES you have to flycut the pistons, but most of the time you don't have to (the 2.02 valves are accutlay going to hinder the flow of those heads however...you cant unshroud the valves enough in a d0oe head to utilize a 2.02 intake vavle)

It is ALWAYS a good idea to check the piston to valve clearence (clay)

however, I do not think that this is his problem...</font>

Did he say what castings was used? I've seen 351w heads (C90E castings) flow greater than 250cfm at 0.600 with 2.02 valves.

 

Regardless, I doubt it is piston/valve interference.... most likely timing or plug wire in incorrect place.

[rl]

Originally posted by blupastu TSi:

did he say what castings was used? I've seen 351w heads (C90E castings) flow greater than 250cfm at 0.600 with 2.02 valves.

 

Regardless, I doubt it is piston/valve interference.... most likely timing or plug wire in incorrect place.

I assumed d0oe's, but you might be right.

[Clifford Automotive]

matt like these guys said, they have all told you thing that i have already told you, if you get fuel injection put back on it give me a call and i will get ahold of cogossi and he will come out and tune it , remember know one knows more about mustangs then him...