Has anyone got any 400 con rods handy ?
Could some one measure the vital stats for me?
I need to know the WIDTHS at each end.
The diameters I can look up but if you measure them that would be appreciated.

I'm looking to use them to stroke an FE but need the dimensions before buying.

thanx

 

[font size="1" color="#FF0000"]LAST EDITED ON 25-Jul-01 AT 12:03 PM (EST)[/font][p]FEina52F1,

The M-block (351M/400) connecting rods are 6.580" long (centerline-to-centerline), almost 0.1" longer than the FE390/427/428 connecting rods (6.490"). I'm not sure how long the 352 rods are, but I understand they are longer than the 390/427/428 rods.

Changing connecting rods on the same crankshaft will change only the piston pin height (i.e., distance from the piston pin to the crankshaft rod bearing), not the stroke (i.e., distance of the piston travel up/down in the cylinder). The only way to change stroke is to change the distance from the crank main journal centerline to the rod journal centerline, as the length of the crankshaft throw is what determines the stroke. You probably know that.

I assume you are thinking of offset grinding the FE crank rod journals?

M-block connecting rods have 2.4356" bore diameter at the crank end (2.311" crank journal size) and 0.9738" bore diameter at the piston end (0.9752" piston pin, non-floating). Even though the M-block and FE use the same diameter piston pin, the M-block rods would have to be reamed or bored to allow for a floating pin like FEs use.

I think the FE crankshaft rod journal size is about 2.44" (correct me if I'm wrong), so you could possibly offset grind the FE rod journal down to the M-block 2.311" journal size and gain about 0.258" of stroke. I understand most guys that stroke an FE use the BBC HP rods with a rod journal size of 2.20", which would yield 0.48" stroke increase (almost double the stroke increase over M-block rods) from offset grinding. OTOH, using all Ford parts would be admirable.

If you still want the M-block rod width info, give me a few days and I'll measure some for you.

BubbaF250

1980 F250 4x4 Custom, 351M/NP435/NP208/D44HD-TTB/D60-FF/3.55s 6750 GVW, Rust & White.

 

BubbaF250


thanx for the feed back

Please send me the width measurements.
This is the vital stat for me because if the 400 rods are to narrow for the fe crank pin then oil control is a challenge.

Why 400 rods well they are 10% the price of custom BBC, and in Australia also adds ($) challenges.

I think you doubled up on the stroke increase calculations
ie a 0.2 inch smaller crank pin can only move the "inside" 0.2 inch ,thus the centre only moves 0.1 inch.

Or 0.2 inch offset gives 0.2 extra stroke

 

FEina52F1,

I got confused about the stroke calculation. You're right.

Give ma a few days to dig out a rod and measure it.

BubbaF250

1980 F250 4x4 Custom, 351M/NP435/NP208/D44HD-TTB/D60-FF/3.55s 6750 GVW, Rust & White.

 

400 rods are 0.884 as apposed to FE rods at 0.874
ie perfect size for setting up for an FE

 

Guys, aren't those rods 6.680 long, not 6.580 ? Correct my memory if I am wrong. DF

 

Nope, 6.580 is correct.