Diesel Changeover?

[Joshpow]

I got a real good offer on an 86 or so 1 ton Ford with a 6.9l diesel and a 4 speed. I wondered what you guys thought about a swap into one of the ol bumps. My options are replace a good 352 in the ol 67 one ton or a good 302 in the ol orange swb. I kinda wonder how you guys think power comparisons may be between tose swapped engines. Also, does an old non turbo diesel seem cool in a swb truck to you guys. I am just thinking this through right now, so I want opinions of others. Thanks

[Ranchero50]

Doing it, should be on page two or three of the projects subforum.

The 6.9 is a decent performer for what it is. Nothing like a 6BT for torque, but more like a decent big block with much better fuel economy. Mine isn't finished yet (on hold for a bit to get some stuff done).

You need to do a good bit to make them fint in a 2wd truck. I lifted the body 1.5" and trimmed the oil pan an inch or so. The drivers exhaust manifold rests on the steering box even offsetting the centerline like the original motors plus you get to make you own motor mounts.

Jamie

[70_F100]

I worked for Navistar for several years, and worked on MANY of the 6.9's.

When they ran right, they were good engines. They were used in everything from an F-250 through school buses built on the Navistar chassis.

When they gave trouble, they became a POS. We had LOTS of trouble with them.

When I retired from that line of work in 1990, the 7.3's had just come along to replace them.

I understand from talking with some of the guys I worked with, that the 7.3 was a much better choice, built with the same basic block.

[OldRedFord]

My 84 F250 had a 6.9. Was real good to me. None of the issues posted above. I say if its a good engine, go for it.

[ToughOldFord]

The 6.9 wasn't/isn't really known to have problems unless you put a turbo on them, then they blow head gaskets.

The 7.3, while still a good engine, is more problematic. If you don't keep on top of your SCAs then they are prone to cavitation. And IHC felt there was a problem with the 6.9s burning a little oil though the valves so they tightened up the tolerances in the 7.3s, but that led to some valve breakage.

I think a IDI in a bump would be a great idea, I wonder what the weight differences between one and an FE are...

[70_F100]

Those engines may have been good performers in Fords, but honestly, guys, we had TONS of trouble with them in IH/Navistar vehicles. May be that we saw a lot more of them in heavier applications, but we DREADED them!!!

[Ranchero50]

The body lift was probably the simplest mod and only needed bacause I couldn't lower the motor anymore because of the steering. Only trick was using manual steering column bracket with the power steering. You may not need to if the 4 speed bell housing and hump are shorter vs the ZF 5 speed.

Jamie

[Joshpow]

I may have to check into that ranchero. Thanks a bunch.

[gregamorton]

I dont think you will be able to make a slave cylinder fit on the firewall because the engine takes up so much room. I will take pics of mine to show you.

[Joshpow]

I'd appreciate those pics. Thanks

[gregamorton]

with looking at pic now maybe you can fit but it looks like it would be tight.

[Joshpow]

Thanks for the pics.