35 MPG 1966 Chevelle

[jodydewey]

Originally Posted by RCB

Out of curiosity, is there a reason you skipped over the 6.5TD? It's not uncommon and many people get right around 30mpg without any aero mods in hot rod applications and it's relatively straight forward (as long as you're comfortable with the electronics).

I'm guessing cheap access to the v6 and 6 speed?

When choosing powerplants a diesel used to be a great choice - but now the economics of it just doesn't make sense:

1. Getting a used 6.5 diesel and computer package will cost a ton of money and will have a crapload of miles on it. Repairing a 6.5 costs almost triple what the equivalent gas motor would cost.

2. The V6 he chose has twice the power and torque of the 6.5

3. The gas cost for gas vs diesel here in Virginia is 1 dollar / gallon. So with both engines getting theoretically the same gas mileage, the gas version would cost less every fill up to drive.

4. The gas engine is 200 pounds lighter than the 6.5

5. The gas engine runs much cleaner than the 6.5

[67-ls1]

Actually, new "clean diesels" are cleaner than gas engines. Different emissions, but cleaner.
And the VW TDI gets WAY better MPG than the V6 gas engine I am using. And is lighter still.

[jodydewey]

It may get much better gas mileage....but at what cost?

Just a quick car-part.com search for a 2010 TDI here in my area....

2500 for an engine only with 94,000 miles on it. Thats a 190 hp and 238 lb/ft of torque.

The same year (2010) chevy 3.6 V6, 304 Hp / 273 lb/ft of torque. $1995 for that motor with 40k on it.

All the other costs would be roughly equal for the installation (transmission, electronics, mounts) since they are all custom work. So right off the bat I have the same power level for 500 less with the gas.

The fuel costs per year will be lower with the gas than the diesel, even if the diesel gets better gas mileage. Unless the diesel gets 10 mpg or better more than the equivalent gas motor, the cost per mile will be less with the gas.

[RCB]

1. Getting a used 6.5 diesel and computer package will cost a ton of money and will have a crapload of miles on it. Repairing a 6.5 costs almost triple what the equivalent gas motor would cost.

I can get a 6.5 with under 200k with computer for under 3k just about anytime. Around here they are fairly common. Just put one in my dad's truck, the motor had 108k and cost 600 dollars.

2. The V6 he chose has twice the power and torque of the 6.5

I do have to say I'm surprised that the chevy v6 makes over 700 foot pounds of torque. That's more than the new Z06 Corvette's torque. Very impressive for a v6... unless you are mistaken on your numbers.

3. The gas cost for gas vs diesel here in Virginia is 1 dollar / gallon. So with both engines getting theoretically the same gas mileage, the gas version would cost less every fill up to drive.

Very true, but there is a lot of flexibility in diesel sources.

I'm just saying it is cheaper and easier to do the swap and put him right near where he wanted to be. I was just curious what his reasoning was. It's his equipment, so if he wanted to put a 50cc moped motor, that's his thing. I like hearing the why's as I do a lot of conversions, tinkering and thrashing so I can add the considerations to my own. I don't believe anyone is "wrong" to put it together any way they want. As a gearhead I enjoy hearing the process.

Personally, I put a Cummins 4bt in my ramcharger, but the engine is so tall it doesn't work well at all for cars but it's built for work, not for commuting. Though I do know a guy that put one in a 49 merc and got high 30s, but the engine bay was tall enough.

True the 6.5 is heavier, but it will also likely outlast the v6 by quite a margin.

I just like getting to my goals in the most optimal fashion. The "burn cleaner" aspect isn't a concern of mine beyond making sure that I'm not wasting fuel.

VW ruined me on TDI's from the parts availability and costs. Cummins is cheaper... and that's saying something. When they are running right though, they are cool engines, but too small for my applications.

[67-ls1]

The gas engines are definetly less money. I bought my 2013 V6 with a 6 speed auto with only 525 miles on it for $3000 delivered. ECM, harness, everything was included.
But the Camaro with the V6 was rated for 30 MPG and the VW's are all in the 40 MPG range, so approx. 10 MPG improvement is not out of the question.
Plus I love diesels.
So if (when) I find someone who can get into the ECM, I will try the TDI motor in something classic.

[jodydewey]

I don't think the 6.5L duramax (700 lb ft of torque) was the engine used for the comparison. I think he was referring to the 6.5 TD IDI that used to be in older trucks (pre-duramax).

I am really warming up to the V6 option in the chevelle. The 66/67 chevelle is my favorite car of all time. After I finish the restoration on my 68 C10 truck my plan is to get a hold of a chevelle. I just may follow in his footsteps and go for the V6. 300 Hp / 273 ft/lb of torque is plenty for that car and there are turbo kits to move that very close to 500 hp. Having a classic car like that and be able to drive it every day would be AWESOME.

[jodydewey]

Originally Posted by 67-ls1

The gas engines are definetly less money. I bought my 2013 V6 with a 6 speed auto with only 525 miles on it for $3000 delivered. ECM, harness, everything was included.
But the Camaro with the V6 was rated for 30 MPG and the VW's are all in the 40 MPG range, so approx. 10 MPG improvement is not out of the question.
Plus I love diesels.
So if (when) I find someone who can get into the ECM, I will try the TDI motor in something classic.

One thing that I think would be an AWESOME swap for a TDI would be a 34 ford coupe....or a model A. Something very small that is lightweight where the diesel could really shine.

[67-ls1]

Cummins does have a new generation of smaller, lighter automotive diesel engine coming. You will see them in Nissan trucks shortly.
Once those start arriving in the bone yards, I'm all over one. Plus I know a bazzillion people at the Cummins factory that might be able/willing to help with their ECM.

[jodydewey]

I think with any ECM Bullydog in American Falls ID is the answer. Those guys probably already know everything there is to know about all production diesel ECMs. They are expanding into the big tractor trailer rigs now to improve their gas mileage. Think about it....those trucks EACH drive close to 1 million miles a year. Save just 1 mpg and save the owner/operator thousands of dollars in fuel costs.

I used to be a big supporter of diesel technologies. I have owned several versions, my last is my big pain in the ASS powerstroke (1999 F350). I really liked my old IDI motors. They ALWAYS ran. They just had no power and were very costly to repair.

Your 3000 engine package sounds extremely doable. Heck that is a great cost considering that the engine package will last for probably 150,000 miles without incident at all.

[RCB]

Originally Posted by jodydewey

I don't think the 6.5L duramax (700 lb ft of torque) was the engine used for the comparison. I think he was referring to the 6.5 TD IDI that used to be in older trucks (pre-duramax).

I am really warming up to the V6 option in the chevelle. The 66/67 chevelle is my favorite car of all time. After I finish the restoration on my 68 C10 truck my plan is to get a hold of a chevelle. I just may follow in his footsteps and go for the V6. 300 Hp / 273 ft/lb of torque is plenty for that car and there are turbo kits to move that very close to 500 hp. Having a classic car like that and be able to drive it every day would be AWESOME.

He said double the torque. the 6.5 gets 440ft lbs stock... so 880 would be double (I actually thought it was 360 but I was just told I was wrong). I was just having a bit of fun. In actuality the v6 doesn't put out as much torque as the 6.5TD as you noted.