vibrating gyrating ford 302-- just annoying

Well I guess a flex plate is cheaper than an entire engine, so I would start there!

 

lol.. true. guess Its time to get the lift out. while I was out I hoped under the truck.. I took a peak at the flexplate... It has a large weight on it... not sure if that even means anything ...but thats all I could really see.. can you have a warped flex plate.. or off balance?

 

I was hoping someone would say .. aw man you just have a vacuum leak. or .. the hei coil is not firing correctly or advancing in the curve... errr even circuits in the carb. lol.

 

so something like this may be what I need?
http://www.summitracing.com/parts/bmm-50238/overview/make/ford

 

I've seen weights barely welded on from the factory. When I was a kid I worked the counter at a parts store. I would check parts before I handed them to customers, and one time both flex plates on the shelf, brand new in the box, had really porous piss poor tacks. I wouldn't want crap like that on my truck, so I wouldn't pass it off to someone else. The guy actually got pissed at me because I wouldn't sell them to him! Flexplates can bend, but it takes a bit for that to happen. You can check that with a mag base and dial indicator.

 

Have you double checked your firing order? there are two for a 302, standard 302 and H.O. 302 which is the same for a 351w. Depends on if you have are running a H.O. cam or not. I've got in a hurry and had a few wires mixed between the two firing orders before and it idled fine but shook like hell off idle. Just something to double check.
1-5-4-2-6-3-7-8 for standard and 1-3-7-2-6-5-4-8 for 351w and H.O. 5liter/302

 

So if its external balance and it was balanced why the hell are the flex plate and balancer replaced I dont under stand it whould be an assembely seem like thats the problem or am I just stupid.

 

well thats what I thought... unfortunately I had the motor on the stand almost a year before I ran it.. and it was out of the warranty period.. the guy was helpful but not overly...he offered to rebalance it for 200 but said I would have to tear it down and bring the bits to him.. and reassemble... which im not overly comfortable doing. not that I couldnt.. just never have. if that were the case I would of just bought a block and top and bottom kits and proceeded from there...

 

im pretty sure its a standard 302 firing order.. its not a roller 5.0 cam.

 

Then I would go back to # 23 post trick and work it out that way sounds eazy enuff you could use some tape a waits till you found the sweet spot and then make somthing more permanant.

 

See if this helps, if you have a production external balance assembly and you balance with the correct counterweighted damper and F/W or F/P, you should be able to swap another set of correct counterweighted parts and it still be well within spec.

Now this holds true for stock rebuilds but not necassarily for a Race Engine build. In my over 30 years of balancing, I have many times come across or had to external balance a assembly and the damper and F/W or F/P had to stay with that crankshaft for life. Tungsten had to be added to the crankshaft as well as the flywheel and smaller weights added to the damper or front pulley and they became a permanant part of that particular rotating assembly. When you spun this crank on the machine it had to have said special counterweighted parts on the crank. The flywheel torqued and the damper installed and spaced out with a timing gear just how the engine will be final aseembled and run on the dyno.

 

You can verify the correct firing order by just pulling off the 5-6-7-8 valve cover. Take out all the spark plugs and be sure to rotate the engine in correct direction of rotation. Watch #7 intake open and close and then come to TDC. At the same time if the #8 intake is just closing and it should come up on TDC with a another 90* turn of the crank- then you have the 1-5-4-2-6-3-7-8 firing order cam, TR

 

I under stand that TR but I think I remember he said it was a new rotating assmbly mybe I am wrong.

 

My bad most things are short in my life. I guess I am use to taking my crank with the balancer and flywheel or flex plate when I have somthing balanced.

 

Yes saltflats, but he said, " a new rotating assembly ", and then he said a " like new crank ", so I have the feeling something is confusing here. I question the builder, or any builder who is supposed to be good, and then uses the high flow or high volume oil pump, sorry but I hate how those things are used 99% of the time when they are not or should not be needed. Abused is more like it.

 

Yes nothing like spending H/P turning an oil pump.
Maybe he should have got it from an engine guy not a ford guy.

 

You dont need to verify the firing order, it wont even come close to running if you have the wrone one. It will backfire and blow fire out the intake. Also it makes a funny alien mating call niose. You will understand if you have done it.

Because you say it only happens at a certain rpm, maybe try jacking the rear axle and "drive" the car in first or second.... see if your wheels start vibrating, then move to the driveline... then pull the trans and verify the flex plate.

 

For those following, here is how you identify a true Mexican block. This block BTW is a great find because of the high nickel content and additional material in the highly stressed areas. The Mexican block even has a higher nickel content than the mid 67 through early 1970 blocks. Yes it really is better than the USA block.

You have to remove the timing cover and look at the front of the block. If it is a Mexican block it will have to humps directly in line with the front main cap bolts that are cast into the block. The humps are vertical, one on each side of the main bore. TR

 

o boy.. well theres that. I never really meant to imply he was a ford guy.. just that he was known for building good ford engines.. most of the builders around here are chevy builders and don't venture out of that too much. This guy is the NAPA engine rebuilder. yes I assumed since he was the engine builder for a large company that would make him good.. the motor runs perfect starts every time.. wouldnt leak if I didn't warp the pan when I pulled the pan to check the casting.. I really would believe that the more than likely its either the flex plate or the Torq converter... The Crankshaft was one that he had that was a low mileage 5.0 he had.. he did all the appropriate milling or whatever to bring it to spec. This was all because the engine I had was pretty bad... it was just a motor I picked up off craigslist for a core. as far as the high volume pump...I asked for it... figured it wouldnt hurt to have it. also have high volume alum. water pump.

 

I re-read some of this and scratch the wheel thing... check your plugs for color and make sure that flex plate is right...

 

Well "high volume" just puts stress on the cam/dist. unless you have bigger bearing tolerances or additional oiling holes. "loose is fast" is a term used in racing so you need more oil and racing oil is usually thicker, ergo high volume high pressure pumps.

Anyway if the parts are indeed 5.0, they should be 50 oz. It cant hurt to take it apart and make sure.

 

Thanks.. I'll give it a check..I have been tempted to replace the HEI coil and wires..I haven't checked the plugs in awhile.. I may give that a go too.. couldn't hurt. kind wondering about those wires anyway.. they were new performance cut to fit wires.. never really been happy with them.

 

he did drill more oiling holes and I do run VR1 racing oil.

 

Good luck to you sir.

 

Yeah, it's imbalance, the flex plate on most of the late 302s and this balance change was started in 81 and up 302s, besides having a larger weight on the one side also has cut-outs on the opposite side to add more weight, does your flex plate have those cut-outs??

 

I appreciate all help.. im just a poor broke guy trying to figure this out.. I had the motor built for about 2300 .. its by no means a fancy motor.. I only know what the guy told me.. ( other than basic mechanics of the engine im pretty dumb to the drilled down details of engine building ) and compared to some of the other builders he carried a good rep.. maybe I made a mistake by taking it to him .. but I figured it would have to be better than going to autozone and getting a longblock. I didn't really intend this to be a bash the builder thread. more just how do I fix it. and it looks like signs point to the flex plate.. I'll get one on order and swap it out.. see if thats it.. if not.. I can either sell it and move on.. or pull it all back out and have it all balanced. I wish I 28000 to spend! I haven't even put side glass in because it cost 175 bucks for the window kit and when I had windows I was always rolling them down. my wife and I just had a kid a year ago and I've been recouping all those expenses.. just now being able to get back in the game. Thanks for you help.

 

Did it do this from day 1 of its rebuilt life ?
Start eliminating stuff -
Solid motor mounts ?
Pull the belts & run it
Disconnect torque converter & run it.
Double check your fly wheel while your looking at it.

Now you are down to internals and the accuracy of the builders balancing job
Was Mallory used ? Maybe it came loose

 

I can go check.. right now on the engine side I see a weight thats about 3 inches or so long and maybe an inch or so wide. I can go spin it over to see whats on the opposite.

 

I might be able to help you get rid of the vibration without tearing it down, let me know. Mike.

 

yes always done it.. just never really noticed it as much as I never was in that RPM range other than warming it up.. I had several guys look at it all of which were kinda ify on what it could be.. I have stock motor mounts with rubber. I disconnected the crank pullley earlier and pulled it out.. still vibrated.. can I disconnect the tc with out removing the trans? seems like I remember you could and slide it back? am I remember right? if so I can do that as well.