1968 Mustang w/289-questions

[Guest]

[289nate]

Assuming for the moment that the engine is a '68 like the car it should have the rail styple rockers.  Indeed I seem to think that they were like the ones in the picture below on the left.

 It should ,  trust ..but verify ..lol

 Any number of things could have happened in the last 43 years

Yup.  Someone could have re-done the heads and used the wrong shorter valves.  In that case there will be noise.  It's a shot in the dark, but worth checking before you go tearing into it further.

[gerg1962]

Well the rocker arms are the rail style.

Since we pulled the heads I went ahead and took them to the machine shop.

They did not find any major wear in a random inspection of a cylinder on each head.

Maybe a little sinking of a valve or two.

I decided to have them go ahead with a re-fresh as it should be only $150 for the pair.  If they encounter other issues they will let me know.

I have new lifters even though the old ones looked fine.

Hopefully I can get it all buttoned back up by this weekend and see what happens.

I was thinking last night...maybe one of the push rods could be bent or shorter than the rest?  I will check those too.

Most of the cylinders had a tan exhaust valve and a chocolate colored intake valve, two cylinders had both valves being the darker color.  I guess that means they are running a bit rich.  Valve issue?

Ironically, one of the cylinders was where the noise seemed to be coming from.

Craig

[289nate]

I have new lifters even though the old ones looked fine.

Putting new lifters on a cam that has already been broken in with another set would have me a little worried about wiping out lobe.  Also, when you remove the lifters you should always number them so you put them back on the same lobe they came off of.  I'd do a little research before putting those new lifters in there.

[gerg1962]

Well there seems to be a division on the subject of new lifters on an old cam.  Some say no worries others express the concern you have.

Too late to number the old lifters...

Maybe I should get a new camshaft as long as I am at it.

The machine shop is done with the heads so I will be re-assembling this weekend.  They were one who saw no problem with new lifters on an old cam.

Will report outcome!

Craig

[289nate]

Just as long as you're aware of it.  I'd be sure to go through the full break-in procedure with the new lifters and throw a zinc additive in the oil.  Might even pay to use an oil filter with no bypass valve in case things go south with a lobe or two.   

[turbo2256]

I believe you have a 302 the only 289s in a 68 might have been a very few 289 HiPos but might have been 67 for the last year. The 390 back then was a 175.00 option the 289 HiPo was a 700+ option.

[289nate]

I believe you have a 302 the only 289s in a 68 might have been a very few 289 HiPos but might have been 67 for the last year. The 390 back then was a 175.00 option the 289 HiPo was a 700+ option.

Who knows what happened since then.  My dad's one family owned '64 Falcon convertible has a 289 when it had a 260 from the factory.

[dennis112]

I believe you have a 302 the only 289s in a 68 might have been a very few 289 HiPos but might have been 67 for the last year.

Naw-it could very well be a 289. 

There were tons of base 289's used in 1968 by Ford and they are very common. This 200hp 2 bbl 289 was replaced later during that year with the 302 and it was a $105.53 option over the base 200 6 cylinder.  There are also numerous bone fide examples of factory 289's using the 302 block during the mid year changeover.  Apparently Ford had a stock pile of 289 rotating assemblies and needed to move them and so they used them up in the base V8.

The easiest way to verify is to check the crankshaft casting #.

[juiced coupe]

Just for reference, the 68 289 heads had much larger chambers than other models. Like 8cc larger.

Thats nearly a full point of compression. That will take the zip out of a engine.

[gerg1962]

Well the heads and valley have "289" cast into them so it would seem it is a 289.

The bad news, gopt the car all put back together, fired it up and adjusted the valves.

The noise is still there!!!!

So, we know what it isn't...it isn't anything head or valve related, it isn't lifters and it isn't pushrods.

Now the question becomes what is it?

We did determine that the engine had been re-built at some point as it has .030" over pistons in there.  I was still able to see some cross hatching on the cylinder liners too.

It certainly seems to be coming from the front of the right cylinder bank and it is not deep down or a heavy knock.  Perhaps a bad wrist pin?

We will set the timing today and remove a plug wire at a time while running to see if we can isolate the noise.

Any other ideas?

Time to buy a crate motor?


Craig

[68mustang405]

U suuuure u don't have an exhaust leak? it'll sound like a tick. What kind of manifolds on it? I wanna say the stock ones are prone to cracking.

[gerg1962]

Quite sure now.  One of the original manifolds was cracked so I replaced them with headers.  With the recent re-assembly we used some extra thick and squishy graphite gaskets and there are no exhaust leaks.

Someone offered that it might be a broken skirt on a piston.

Will have to pull the oil pan to see what is going on in there.

Craig

[hypostang]

I had a 289 short block done by a local machine shop way back in the 80's and they had messed up the wrist pin on number 3  , I had a hell of a time trying to find that noise because it was yanking # 7  piston sideways too , so my noise was actually 2 noises 

[gerg1962]

Well I got the oil pan off and there are no large chunks of anything in the bottom.  At first glance I do not see any damaged skirts but the oil is still dripping so I will have to look a little closer tomorrow.  Not sure where to go from here...

Perhaps a bad wrist pin as suggested?  Is there any way to test for this short of pulling the heads and pistons?

Craig

[gerg1962]

I don't know if this will help any noise experts out there but I had made and uploaded some videos to Youtube since I have been trying to sell the car (or trade it).

The following segment shows the engine running, maybe you can hear the noise over my narration enough to offer an opinion?

http://www.youtube.com/watch?v=k1w76zAb71Q

Craig