Counterweight Offset

[Eric]

I have recently been given conflicting information, so I thought I would ask for input from the experts here. I have a late-model (1996) 351W from an E-350 van. I had been under the impression that all small block Fords pre 1982 use a 28 oz offset weight on the flywheel/harmonic balancer and 1982+ use a 50 oz offset weight. I have now been told by a respectable source that the 351W did not change offset weight in 1982, rather continued to use the 28 oz offset, and that only the 5.0L moved to the heavier offset. Can anyone verify if this is true or not? I need to know what is what before getting a flywheel. Thanks.

Eric

 

[Andy Green]

Hi Eric
the information I have is that the 351 stayed with the 28oz external balance weight throughout its production run and the 302 changed to 50oz in 1981

Regards
Andy

 

[Eric]

Thanks, Andy.

That concurs with what I was recently told...and makes my life much easier, at least cheaper. I thought I was going to need the rotating assembly rebalanced.

Eric

 

[Wayne M.]

I am under the same impression as Andy but I cant find it in writing.
wm

 

[Jac Mac]

Using a bit of historical logic here, the reason the 50oz factor was concieved/put into production was to enable the initial fitment of the small 255ci (79/82>) motors which still used the 3.00" stroke to use a shallow pan to fit the mustang/capri etc of that era. Since the physical size of the rods/journals of the 351w would never allow this to happen to it ( The 351w) then I dont think it ever happened. I know Ive never seen a 351w/50oz combo or reference to such & I have probably played with at least one of every model/year manufactured since 1965 in the pushrod stuff.
I have however seen some clever types ( cryptic adjective for dumb ) who have bolted 50oz dampers/flywheels on 351's & wonder why their teeth & other bits & pieces start to fall out!

 

[John P]

As a point of clarification, the 255 CI was a development of the 302 as an economy engine, and came after the 302. It was basically worthless. Heads had very small ports and valves, and larger heads couldn't be fitted because of the small bore size. It wasn't one of their "better ideas." The 250 I-6 developed more power.