Timing chain, same for 70 and 89, 302's??

[OX1]

Just curious??

 

[broncnaz]

Yes more or less the main differance is the fuel pump eccentric depending on the timing set used you may have to swap the eccentric there is a one piece and a two piece if not running a fuel pump its no big deal but you also ahve to watch the lenght of the dowel in the end of the camshaft. The last cam I bought came with 3-4 different lenght dowels dependent upon which eccentric you used. I know very early 289/302s had a one piece eccentric where later models have the two piece.

 

[OX1]

Yes more or less the main differance is the fuel pump eccentric depending on the timing set used you may have to swap the eccentric there is a one piece and a two piece if not running a fuel pump its no big deal but you also ahve to watch the lenght of the dowel in the end of the camshaft. The last cam I bought came with 3-4 different lenght dowels dependent upon which eccentric you used. I know very early 289/302s had a one piece eccentric where later models have the two piece.

Thanks!!. My 70 has been backfiring out the exh since I bought it. Tried 2 different carbs. The other day I put in Duraspark, new plugs, and wires. Still backfiring While I was putting the dist back in, I was rotating crank a bit and distr was not moving until a whole bunch of play was taken up. Seems my timing chain is shot. Will replace, but if this engine does not work out, may just drop on the 89 5.0 Ho I have. Would like to use that new chian on that if needed.

 

[Broncobowsher]

I will also throw out that it is a chain and sprocket set interchangable as a whole. The early engines had a flat link chain often on a nylon coated sprocket. the '89 HO engine will have a double row roller chain. So chain and sprockets, not chain alone.

 

[Skiddy]

The early engines had a flat link chain often on a nylon coated sprocket.

didn't ford put the nylon coating on to make it a little more quiet so my dad says. and well after a while the coating came loose and then the chain would get slop in it.

 

[Broncobowsher]

Yea, the nylon was suppose to make them run quieter. that is until it gets brittle and starts coming off in chunks and the cam timing goes to crap.

 

[OX1]

I will also throw out that it is a chain and sprocket set interchangable as a whole. The early engines had a flat link chain often on a nylon coated sprocket. the '89 HO engine will have a double row roller chain. So chain and sprockets, not chain alone.

of course, does anyone just replace a chain???

 

[Mikey]

of course, does anyone just replace a chain???

I've heard that Bubba Buttcrack does! ;D

 

[fordtrucks4ever]

I dont think the later model double roller works with essentric. There are also differences in the steps that space top gear out to line up. I had to machine a gear to match the old one it replaced. Dont just blindly replace it and expect to work.

 

[Broncobowsher]

I believe the '89 timing chain is the same as the '85 double roller timing chain. that was available with a mechanical fuel pump. But there are differences in the fuel pump ecentric between early and late engines. Get it wrong and the timing cover won't fit.

 

[Bronco73]

This has been a common question as of late. I know ford still installed the eccentric on some of the early EFI set ups but I am not sure when ford stopped using the eccentrics all together. What I do know is that the 94 302 I have has a thicker cam gear. I had to surface grind .080 from the eccentric for it to clear the back side of the timing cover. I ground .100 to give me a little extra clearence for the cam end play.

Then you have the cam dowel length to worry about if you have the early one piece eccentric because the dowel locates the eccentric and the later two piece eccentric has a bent tab that locates it.

There could be a difference in the timing covers themselves and not the cam gears. That was something I never thought to check but I could see the cam gear was clearly different in thickness.

Some one asked if you could just change the chain. If you had a steel cam and crank gear you could get away with it but the old style with the nylon cam gear, no way would it work. The cam gear is what fails and when it does as mentioned it looses teeth. A new chain does not replace teeth on the cam gear. These old pot metal nylon cam gears can almost be broken by hand, cheap.

 

[OX1]

The chain I was eyeing up was the Cloyes billet true roller, Summit PN CLO-9-3535X9. It does not list what years it will fit. Edelbrock does have one that claims it fits 62-84 (including Boss) and another that fits 62-65 and 73-95???

 

[Bronco73]

The timing chain will fit all of them. The problem occurs when you're trying to use the eccentric or it was in my case with the factory ford timing chain. It could very well be that the after market timing sets are not an issue when using the eccentric.

 

[broncnaz]

It seems that 62-64 engines had a spacer and different thrust plate. 65-72 1 piece eccentric 72up 2 piece eccentrics. Basically you have to change the eccentric to a one piece type if you have anything other. I believe there is a differance in thickness of late model timing covers because most dont use a mechanical fuel pump once EFI was standard. You dont have to run a eccentric if unless you want to run a mechanical fuel pump.

 

[Bronco73]

You can run either the one piece or two piece eccentric. You just need the matching dowel pin for the one being used. It's been a while but I don't think the two eccentrics were different in height. I'm pretty sure they are the same. The two piece is the later of two. The one piece eccentric was used on early motors and is what I used on my 94 engine with stock timing set. I had a two piece but felt the one piece was stronger with the dowel holding it inplace over the bent metal tab on the two piece. I don't think the one piece can be bought any more. I may be wrong but I think only the two piece is offered.

I have an explorer timing cover I can measure but I have nothing else. I got rid of everything else I had when I moved to FL.