Greetings to all. I've been lurking around for a while and trying to learn, but I decided to jump in with both left feet and confess my sins right up front. You see, I have this '67 Toro which I think is about the coolest looking big car ever produced. But I want to do something unusual and have a driver that is economical to run, but still be fun to drive.
No, I'm not talking about swapping in an Ecotec, but rather a 6.5 diesel. It seems to me that the 6.5 is about the same weight as the 455 and it can be set up to get excellent fuel mileage.
I know this could seem sacreligious to some, so please don't flame me!
A part of this process is trying to come up with a decent final drive gear that will work well with the slow turing diesel. As much as I have been able to find out, the '70 transaxle had a final drive of 2.73, but are the gear sets used the same as in RWD cars?
Thanks. Great forums here!

 

can't help you but I think its a cool idea, I always waned to do a turbo diesel on a cutlass

 

Welcome to CO
GM made gear sets for motorhomes that used the toro setup. They are out there. Do an internet search for starting with GMC motorhomes. they look for sub-links

 

I'd shy away from the 6.5 if it were me. They had a bad habit of breaking the main webs out of the block and driving over the crank. They weren't the best on power either unless you spend alot to upgrade. I own a towing company and have a 95 Chevy 3500HD flatbed that was originally a 6.5/ 5spd truck. It weighs about 11,500 empty and could hardly get out of it's own way. I pulled the boat anchor and converted it to a 5.9 Cummins.. man what a difference! It gets around 16 mpg all the time and you can't slow it down. I'm not sure if you got enough room under the hood of that Toro for a 6 in a row diesel, but there's always the Duramax to think about....

 

Good luck, keep us posted and welcome!! Pic's are a good thing too!

 

i don't think you will ever get the transmission to bolt up right to the 6.5. if you would like a diesel i would go with the 5.7 Olds diesel. it will bolt up with much less work. you would also have to go to manual brakes or adapt a hydro boost brake setup. in the end, i don't think you will have that much better economy out of it. i would think the 455 could be made to get 14 or 15 MPG and the 5.7 diesel in that car would maybe get 20 tops. then the price of diesel is $.50 more per gallon.

 

The 6.5 uses the same bellhousing as any other Chevy, as far as I know, so any of the many available adapters will let you bolt it to the Toro transaxle. The bigger problem is the answer to the question, is this REALLY economical? The amount of money you'll spend to fabricate custom oil pan, mounts, exhaust manifolds, etc, etc, and to adapt the appropriate fuel system parts will likely far outweigh any long-term benefits from improved mileage, PARTICULARLY since diesel costs more than gasoline in most places. A far more practical solution would be to adapt a modern EFI system to the 455 and tune it for maximum economy.

The TH425 transaxle uses unique differential gears. As noted, the GMC motorhome community has developed parts for these transaxles. Expect sticker shock...

 

This has to be one of the most unusual ideas I have seen on here. As Joe P. mentioned, this will entail a tremendous amout of work and expense. You would probably have to drive it a million miles to ever get any kind of return.

 

Agreed. Check this badass 66 Nova Wagon Duramax twin turbo out.
It was on Power Tour this year.
http://www.youtube.com/watch?v=Gh63EZvSl2o

Here's his build thread.
http://ls1tech.com/forums/conversion...ax-diesel.html

 

i knew there were adapter kits but i never thought it would fit with the transaxle. it is a tight fit the way it is, not to mention the starter issue.

 

Thanks for all the thoughts on this subject. I researched the bellhousing adapters and found that to be doable. You guys have raised other issues that I hadn't thought out completely, but I don't think there are any huge hurdles.

I will have to do some measuring 'cause that starter issue could be a problem.

As for using the 6.5 vs the Duramax... I love the Duramax and have one in my GMC truck. It is a wonderful engine but comes with tons more electronic complexity. The 6.5 can make plenty of power and will work with a lot more bio than the Duramax. Not to step on too many toes, but a Cummins is out of the question. Besides the new castings for the 6.5 are way better than the original stuff.

As for that 'economy' thing, you are all more than correct. HaHa! I should have never said such a ridiculous thing! My '06 TDI Jetta is what I drive for the economy days and it's technology also likes bio. I guess I look at this as a unique project and think the 66-67 Toros were about the neatest looking muscle cars eveh!

So would a ring & pinion from the '70 tranaxle work in the '67 housing? Are the gear sets compatible with any other Olds RWD? As for the motorhome gear sets, they are all far too tall (numerically high).

 

Welcome to CO and good luck whichever route you choose to go with.

 

what about a 4bt cummins out of a delivery truck they carried the th400 bellhousing bolt pattern and in marine trim those 4bt cummins could produce some serious hp for a little 4 cylinder diesel

 

5.9 Cummins all the way. It is HANDS DOWN the best diesel engine in the auto / light truck market. If you could make it happen I'd love to see it...I live in Kingwood, hope to meet you some day!

 

@ ah64pilot the 5.9 cummins is a serious and reliable work horse i bought my 94 dodge 2500 with 180k it is now near 250k and all i have done is oil changes and fuel and oil filters along with regular brake maintnence no issues best truck i ever bought for 3k . also the 4bt is the same engine as the 5.9 just minus 2 cylinders i just see a 5.9 being a nightmare for fitment in there a well tuned 4bt cummins will blow the 6.5 L and the 350 olds out of the water performance and fuel economy wise

 

You aren't lying! 5.9 is a great engine...I was devastated when the 6.7L came out in '07.5...now we've got the 6.7L figured out and are getting about 20-22 mpg in a 4X4 Mega Cab. Turns out the DPF, EGR, and CAT choke it down to about 12-16 mpg. I'd say 20-22 isn't bad for a 9000 lbs truck.

If you could fit a 4BT in a Toro I believe you could tune it to get 20 mpg easy.

 

From above:

 

Thanks, Joe. A guy could only hope!... Now I'll be out looking for a '70 transaxle or gear set.

 

Not a fan of putting in anything other than an Olds in an Olds, but this has got my attention.

Good luck with your reseach and build. If it comes to life, keep us posted, with pics

Personally, I think Cummins is the way to go