[Zimmo]

I'm finally gonna start up on my '59 pickup project in a few months. The truck has been sitting in storage for about 15 years now. It pretty much needs a total overhaul, everything except for the Dana 60 that in it. So, I'm faced with the decision on the motor: Rebuild the Olds W-30 455 that's currently in it, or install a SBC for about 1/2 the price. As for the trans, I want to go with a TKO-600 w/.64 OD. The engine speed at 75 mph will be about 2000 RPM, which will save gas.

What will give me better gas mileage, a mild 455, or a hot 327?

The 455 will be 9:1 with a 216* at .050" cam, & the 327 will be 10:1, with a 230* cam.

All opinions welcome...

[Henry Highrise]

I would go with the mild 455.

[F&J]

The engine speed at 75 mph will be about 2000 RPM, which will save gas

If you figured all the data and if that is correct, then using that setup on secondary CT roads at 55ish...a "hot 327" would likely need to stay out of OD for "most" of your driving??

If you are concerned about mileage, the above setup looks real wrong to me.



Cubes cost mileage, despite what is said about "BIG doesn't have to work as hard".

So, neither will be good MPG IMO ... especially in old iron, heavy, non-aerodynamic..

[Zimmo]

Originally Posted by F&J

If you figured all the data and if that is correct, then using that setup on secondary CT roads at 55ish...a "hot 327" would likely need to stay out of OD for "most" of your driving??

If you are concerned about mileage, the above setup looks real wrong to me.



Cubes cost mileage, despite what is said about "BIG doesn't have to work as hard".

So, neither will be good MPG IMO ... especially in old iron, heavy, non-aerodynamic..

Good point. It's about un-aerodynamic as a vehicle can get - LOL. So, what would you recommend for a motor / cam? Also, it won't just be confined to the backroads. I want to build it to drive on the freeways, too.

[F&J]

The rpm at 75 is what bothers me the most. I am from Ct, and I am used to the roads....as well as how little "most" of us guys use the real highways with a collector type vechicle.

I just don't think it is a great idea to build it for max mpg at 75.

I'm just going by my last 35 years with older GM trucks & suburbans. I have tried all sorts of motors "except" the big block, trying to find some mileage. These are all pretty bad around town with the hills & traffic. Gears don't seem to matter much for some reason. Cubic inches really does matter around town in my experiences.

I was thinking about your 2 motor's cubic inches. I did not calculate it, but is the 455 something over 35% bigger? If so, and if using the same driveline & tires, you now are using up 35% more CFM per mile at a somewhat similar air/fuel ratio?? (that's what they mean about big inches not working as hard...using slightly leaner A/F ratio at a certain speed/load)

The hot cam would not like a super low rpm at 55 with your calculations of rpm at 75. IMO

Sad to say a cloned mild 300hp factory 327 with it's very mild cam will be better suited with that OD, but I still think MPG will be a shock if you never had one of these older trucks.

Someone has posted in the last day or 2 about a late driveline with computer FI, OD, etc, going into an old truck. I'd love (hope) to see if he can find big gains. The weight and aero is still a huge obstacle. Drive an underpowered tiny car and add 1 adult...you can really feel it on hills! ...or take a modern 4 cyl average sedan and stick something big in the trunk so the lid is up; you can't believe how the car looses so much "power" due to ruining the aerodynamics.

Sorry I can't help...except saying a big cam is not good with that much OD.

[Zimmo]

I guess I can re-think my cam selection. The truck previously had a 283 & 3 speed manual in it. It sounded good, but it was pretty weak. The 455 install was a pretty big jump, pwr wise, but it really went thru the gas. I think primarily due to the gearing & the stall on the torque conv. If I remember right, the RPM at 70 was like 3500 (27" tire, TH400 w/perf TQ conv & 3.54 diff). That's why I want to go with an OD trans.

I'm hoping if I can slow down the motor enough for MPG, I can keep the 455.

[F&J]

When I said "gearing did not seem to help", I was referring to rear end gears with stick trans. With a modern OD plus lockup convertor, maybe it would help with a stock big block engine.... more likely on highway, and less on in town driving.

[Zimmo]

I knew what you meant. There's really no getting around feeding a big block. I want to return it back to a manual trans, too, & get rid of the auto. Not just for mileage, it was also more fun to shift gears manually.

[AntnyL]

Originally Posted by Zimmo

I'm finally gonna start up on my '59 pickup project in a few months. The truck has been sitting in storage for about 15 years now. It pretty much needs a total overhaul, everything except for the Dana 60 that in it. So, I'm faced with the decision on the motor: Rebuild the Olds W-30 455 that's currently in it, or install a SBC for about 1/2 the price. As for the trans, I want to go with a TKO-600 w/.64 OD. The engine speed at 75 mph will be about 2000 RPM, which will save gas.

What will give me better gas mileage, a mild 455, or a hot 327?

The 455 will be 9:1 with a 216* at .050" cam, & the 327 will be 10:1, with a 230* cam.

All opinions welcome...

If it were me, I'd stick with the Olds.....for the "different is cool" factor. But if $ is the issue, a SBC is a safe choice. I chose a SBC for mine, more due to availability of parts (if I need a water pump in Oshkosh while on the road at an event, I want to know that the local NAPA will have it in stock.). I would think that the SBC would be better on gas, but by how much? A couple of mpg?

Antny

[joe_padavano]

If the engine is a real Olds W-30, sell it to an Olds restorer and put the money into the Chevy motor.

[Zimmo]

Thanks for your input guys. I think I'm gonna keep the 455. I'm sure I'll like it a lot more with a 5-speed manual bolted up to it

I'll keep you updated on this project.

[joe_padavano]

Originally Posted by Zimmo

Thanks for your input guys. I think I'm gonna keep the 455. I'm sure I'll like it a lot more with a 5-speed manual bolted up to it

I'll keep you updated on this project.

Unless the Olds motor originally came with a manual trans, the crank is most likely not drilled for a pilot bearing. If so, you can either have your crank machined or get a conversion bearing from the Olds specialty houses that fits in the current recess for the torque converter nose. Unfortunately in this situation you need to trim 1/2" - 3/4" from the tip of the input shaft.

[Zimmo]

Funny you mentioned that. I was just looking for details on getting the crank drilled for the MT. There's a couple of Olds builders here in the North East that I'm gonna get estimates from on a short block rebuild.

[techinspector1]

Originally Posted by Zimmo

I'm finally gonna start up on my '59 pickup project in a few months. The truck has been sitting in storage for about 15 years now. It pretty much needs a total overhaul, everything except for the Dana 60 that in it. So, I'm faced with the decision on the motor: Rebuild the Olds W-30 455 that's currently in it, or install a SBC for about 1/2 the price. As for the trans, I want to go with a TKO-600 w/.64 OD. The engine speed at 75 mph will be about 2000 RPM, which will save gas.

What will give me better gas mileage, a mild 455, or a hot 327?

The 455 will be 9:1 with a 216* at .050" cam, & the 327 will be 10:1, with a 230* cam.

All opinions welcome...

You may find that the sweet spot for that 216 cam is well above your desired 2000 rpm cruising speed and that a little shorter cam might work better for what you want to do. I could be wrong though.