Vintage Mustang Forums banner
1 - 20 of 25 Posts

·
Registered
Joined
·
13 Posts
Discussion Starter · #1 ·
Guys, Over the last year I've finally decided to get my 65 Mustang back on the road. My foundation, 5.0 HO from 94 GT Mustang into my 65 mustang. The mustang was an inline 6 with 5 lug conversion and 8 inch rear end pre done years back.

The 5.0 motor was converted to carb, edelbrock 289 intake, Holley 600 carb, rebuilt - c4 from a late 70s ford van. New brackets, new mounts, vbelt setup, electronic fan. New spark plugs .54 gapped new wire set, pertronix ignition with coil. Pertronix set to go positive and negative from dissy to coil as per manufacturer. Hooker long tubes headers. Exhaust just got buttoned up using X pipe. Kept the 164 flex plate from the 5.0 HO motor since the c4 I used has the bigger bell housing. Purchased 50oz damper to go with the flex plate. Kept the 5.0 starter. Timing was set to 10 degrees BTDC. Using mechanical fuel pump, eccentric installed, new timing cover for pump. Switched the oil pan to front sump. I am using the 1, 3, 5.0 ho firing order.

Now that I've listed alll I can think of done to it here is my issue. Upon turning the car on.. it vibrates. In park it vibrates, in drive, or at any gear, it vibrates. Car idles at 800, 1000 and it vibrates. If I increase rpm, it vibrates. Upon first installing the c4 I sheered a bolt from the converter. When I fired it up it vibrated and my initial thought was I need to replace the torque converter. I did, I brought it down and purchased a rebuilt, installed.. buttoned everything back up. Same deal. This weekend, I took it to get the exhaust done. On a 1 to 10 scale the vibration was at about a 4 so It was drivable. Upon picking up the car and driving home.. that vibration was at a 7 to 8 all the way home, on the street. The reason I mention this is because it almost seems as the vibration can slightly improve at times but it is still present at all times.

Things I've checked. Timing, vacuum leaks. using intake vacuum for trans, and power brakes. pcv goes to carb, vacuum timing to carb. all other available ports have been plugged. Checked for intake and carb vacuum leaks. Any advice is good advice.. hope you guys can shed some light. Pics for reference..

Motor vehicle Vehicle Car Auto part Automotive super charger part
Light Motor vehicle Hood Automotive tire Automotive exterior
Light Hood Motor vehicle Wood Automotive tire
Car Wheel Tire Vehicle Sky
Motor vehicle Car Automotive design Gas Auto part
 

·
Premium Member
Joined
·
7,812 Posts
Gorgeous and very clean car! My OCD would make me re-route your plug wires and some wiring under the hood, but that is a nice car!!!
Sounds like (pardon the pun) it's the exhaust. Check the spacing of your headers to the shock towers, power steering bracket and ram etc, bellhousing and trans, and man...those tailpipes look like they are sitting right on top of the rear axle. Maybe you need some different hangers or insulators if you have the exhaust hard mounted. Have another Mustang nut like us drive it without giving them too much background or theory and get their opinion. Good luck!
 

·
Registered
67 Fastback T5 331 TCI Frt End, Canted 4 link rear susp
Joined
·
1,159 Posts
Exhaust mounting wouldn't have anything to do with what's described. Sounds like one of two things, either firing order or wrong imbalance. Was the motor rebuilt? If so, a cam change could have changed you firing order.

786908
 

·
Premium Member
Joined
·
1,200 Posts
if you are using the 289 harmonic balancer -that can be a problem as the 5.0 is internally balanced. you need a neutral flywheel/flexplate and a neutral dampner.
later 302's were internally balanced - so using a late 302 accessory setup could be the way to go.
I did this conversion in 1988, so I found this empirically. :)
 

·
Premium Member
Joined
·
1,200 Posts
also - in the interest of completeness - I have seen bad torque converters cause vibration. (just noticed car is auto).
 

·
Registered
Joined
·
5,679 Posts
if you are using the 289 harmonic balancer -that can be a problem as the 5.0 is internally balanced. you need a neutral flywheel/flexplate and a neutral dampner.
later 302's were internally balanced - so using a late 302 accessory setup could be the way to go.
I did this conversion in 1988, so I found this empirically. :)
??? Factory 302/5.0 after 1981 were 50 oz imbalance to the best of my knowledge.
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #8 ·
Gorgeous and very clean car! My OCD would make me re-route your plug wires and some wiring under the hood, but that is a nice car!!!
Sounds like (pardon the pun) it's the exhaust. Check the spacing of your headers to the shock towers, power steering bracket and ram etc, bellhousing and trans, and man...those tailpipes look like they are sitting right on top of the rear axle. Maybe you need some different hangers or insulators if you have the exhaust hard mounted. Have another Mustang nut like us drive it without giving them too much background or theory and get their opinion. Good luck!
thx for all the feedback so far.. The car was turned on with open headers and it made the vibration then.
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #9 ·
Exhaust mounting wouldn't have anything to do with what's described. Sounds like one of two things, either firing order or wrong imbalance. Was the motor rebuilt? If so, a cam change could have changed you firing order.

View attachment 786908
The motor was not rebuilt. Same cam same bottom end, nothing changed. Only thing i did was swap out the top end intake and carb setup. I was told 5.0 HO roller motors are 50oz balanced. Based on the pic you have provided i am using the 1,3,7... order.
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #10 ·
??? Factory 302/5.0 after 1981 were 50 oz imbalance to the best of my knowledge.
That was my thought from the start. The Damper i purchased was Pro Products 8007 which is 50oz. Kept the 5.0 HO flex plate which is 164 tooth.
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #11 ·
Overnight thoughts..While installing the damper. I recall i had started the install by using a piece of wood and with a mallet getting into the shaft about 1/2 to 3/4 in before using the ratchet or impact to get it to bottom out. What are the chances i ruined thrust bearings. It was mild taps to get it started. I removed the pulleys and turned the car on and i can see the HB rotate without any variances.
 

·
Premium Member
Joined
·
7,812 Posts
Since you said it vibrated with just the headers maybe the headers are what are rubbing on something. But is it a vibration like something is rubbing or is it a rhythmic vibration that fades in and out? I once had a rhythmic vibration that occurred in park, neutral, or drive at certain RPM in my car and it was cured when I replaced the torque converter.
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #13 ·
Since you said it vibrated with just the headers maybe the headers are what are rubbing on something. But is it a vibration like something is rubbing or is it a rhythmic vibration that fades in and out? I once had a rhythmic vibration that occurred in park, neutral, or drive at certain RPM in my car and it was cured when I replaced the torque converter.
Vibration i would say rhythmic like as the rpms increase the vibration can really be prone. Note that the vibration does no make its way to the steering, or inside the cabin. It is only present in the engine bay. It does make the front end shake without a doubt. The headers are cm away from rubbing on the shock towers.. but they clear. thx
 

·
Registered
Joined
·
5,679 Posts
2 unrelated things:

1.) the rear end is not an 8" as it has a rear inspection cover and not a removable carrier. It's been too long since I have had my 6 cyl. rear end to know if it's that with some conversion 5 bolt axles.
2.) Are those air shocks? If so, get rid of them. The attachment point on the bottom of the car is not made to support an air shock or helper spring mounted to the the shock.

Oh, and the car looks great. I wish mine were that straight.
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #17 ·
2 unrelated things:

1.) the rear end is not an 8" as it has a rear inspection cover and not a removable carrier. It's been too long since I have had my 6 cyl. rear end to know if it's that with some conversion 5 bolt axles.
2.) Are those air shocks? If so, get rid of them. The attachment point on the bottom of the car is not made to support an air shock or helper spring mounted to the the shock.

Oh, and the car looks great. I wish mine were that straight.
Point taken on the shocks. I've owned the car about 12 years now, always with air shocks. No issues.. but i do plan on upgrading tires at some point to some bf's. May have to go gas shocks at that point. thx for your comments. Always thought it was an 8inch rear.
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #18 ·
I may have to pull the damper out and inspect it. it may have gone bad as mentioned in the thread. Otherwise.. can't get my head wrapped on what it may be. Bad carb? I did buy it used. I bad carb should not be causing the car to vibrate like that. Thing is, engine feels strong besides the vibration. Stumped!
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #19 ·
So, after taking a closer look at the damper, i happened to come across the timing cover. Dorman cover.. brand new upon install. Mind you the car has no leaks. Could a crack in the timing cover cause vacuum issues?
Automotive tire Hood Motor vehicle Automotive design Bumper
Motor vehicle Automotive tire Hood Bumper Automotive exterior
Hood Automotive tire Motor vehicle Automotive lighting Automotive design
Automotive tire Wood Bumper Motor vehicle Automotive exterior
Automotive tire Motor vehicle Bumper Automotive exterior Automotive design
 
1 - 20 of 25 Posts
Top