200 Long Rod or Not

[StarDiero75]

Howdy Guys,

So I'm having my 84 250xflow built and my builder is keen on sticking with using 200 long rods instead of going aftermarket, and custom forged pistons. We're turbocharging, and looking for about 500hp, so I assume probably 625-650lbft at that number. Are the 200 long rods up to this after peening and all? I know they help rod ratio, but are they that strong?

Thanks

 

[aussie7mains]

Long rods are of limited value in a 250, the rod ratio only changes a small amount, 1.5:1 to 1.6 which isnt enough to affect anything. If your talking of 500bhp you will need around 35psi manifold pressure for that, so some tough internals will be needed. The aftermarket rods for the Barra are probably a better proposition, custom pistons will be needed. Stock barra rods can take the power levels your seeking. You would have to work out pin height to get a suitable piston, not difficult. The 200 long rods 6.27 inches, are not that easy to find, and are no stronger than 250 rods. Peining only helps fatigue strength. BTW all Australian rods are forged. You could go the way some high end racers go and destroke to a 200 crank and used the 200 length rods, you loose ci, but when boosted this doesnt matter a lot, manifold pressure makes up for that. I have a blown 200ci crossflow, with all stock bottom end, I have about 200kw, no problems so far in a street driver. You cant give the car much grief as a road going thing, the law and safety see to that. Tell us more about the engine!

 

[pmuller9]

The 6.21" long Molnar rods are exactly what you need. The are designed especially for power adder applications.

Ford 300 Inline 6 Rods | Molnar Ford 300 Power Adder Rods

300 Inline 6 connecting rods for high performance and racing Ford 300 engines. Molnar billet H beam Ford 300 Power Adder rods for press fit and floating pin

molnarrods.com

 

[aussie7mains]

The 6.21" long Molnar rods are exactly what you need. The are designed especially for power adder applications.

Ford 300 Inline 6 Rods | Molnar Ford 300 Power Adder Rods

300 Inline 6 connecting rods for high performance and racing Ford 300 engines. Molnar billet H beam Ford 300 Power Adder rods for press fit and floating pin

molnarrods.com

Pin is 0.975, too big for small six. look here:-https://www.spoolimports.com/pistons/ford

 

[StarDiero75]

Long rods are of limited value in a 250, the rod ratio only changes a small amount, 1.5:1 to 1.6 which isnt enough to affect anything. If your talking of 500bhp you will need around 35psi manifold pressure for that, so some tough internals will be needed. The aftermarket rods for the Barra are probably a better proposition, custom pistons will be needed. Stock barra rods can take the power levels your seeking. You would have to work out pin height to get a suitable piston, not difficult. The 200 long rods 6.27 inches, are not that easy to find, and are no stronger than 250 rods. Peining only helps fatigue strength. BTW all Australian rods are forged. You could go the way some high end racers go and destroke to a 200 crank and used the 200 length rods, you loose ci, but when boosted this doesnt matter a lot, manifold pressure makes up for that. I have a blown 200ci crossflow, with all stock bottom end, I have about 200kw, no problems so far in a street driver. You cant give the car much grief as a road going thing, the law and safety see to that. Tell us more about the engine!

I probably should have clarified, 500 crank horsepower. I think that puts me around 370-400whp.

Yeah I have 200 long rods which is why he wants to use them, but I’ve been very clear with Jeff that he can use whatever he wants. I sent him the spool imports link and will push for that. Thanks for the input man.

 

[mustang6]

Hey Star, any updates on your build and projects in general?

 

[427John]

When buying custom pistons pin size can usually be whatever you want it to be.