What can you tell me about a Ford 6.6L?

[Train-train]

I am considering a bus amoung several. Two of them have the 6.6L diesel. I have read a few things about them but what should I know before I decide on a particular bus? Thanks for your replies.

 

[the_experience03]

Well I own a 6.6 and Jason (Lapeer20m) also owned one so hopefully we can be of some help.

First the basics...

6.6 liter (401 ci) displacement diesel
Inline-6 configuration
16.7:1 compression ratio
4.4 x 4.4 square bore to stroke ratio
Turbocharged and Aftercooled
Power ratings came in 4 configurations:
165 hp/400 ft lbs 49 states
165 hp/410 ft lbs California
170 hp/412 ft lbs 50 states
185hp/474 ft lbs 50 states


Ok...enough of that. I can get you most of the technical specs if you're curious. The motor is not overly powerful. It will get you from A--->B jsut fine, but you need to remember it is a big school bus with an engine with less horsepower than the average compact pickup today. Sure it has the torque, but it's still no hotrod. What it is is a stupidly simple and reliable engine. The parts on it are common for the most part (like the injection pump). Other odds and ends like fuel filters and oil filters might not be AS easy to find, but any bigger parts house should have them. The engine was also used extensively in New Holland farm equipment so you have more places you can look for parts.

The engine is easily modified for more power given its injector pump. The limiting factor as to how much power you want to get is really in the transmission. The high output version (the one I have and suspect you will have) actually exceeds the specs of what the AT545 can handle, but rest assured you aren't going to be breaking one anytime soon. I guess the other factor in determining how much power you can get would be lifespan. These engines are notorious for lasting a really long time. This is good because they are sleeveless and as such are not easy or cheap to rebuild. They are not along in their sleeveless construction either so don't let that turn you off.

They are a somewhat loud engine, but not in a bad way. They sound an awful lot like an older Dodge pickup. I think this has an awful lot to do with the fact that the 6.6 Ford is mighty similar to the 6BT Cummins in both layout and injection system. The turbochargers on these buses sound SWEET. So do the Ford air brakes for whatever reason. It's a Bendix system, but rest assured...they are louder than most in a most fantastic way. You will also get the cool Ford column shifter, something no other bus has that I'm aware of.

I'd be happy to help you out if you had any other questions. I guess the long and the short of it is that I wouldn't turn my nose up at the 6.6/7.8 engines. There are others out there that might get better mileage....or might have more power....or blah blah blah but those engines really are trustworthy and easy to work on and do just fine for what they are.

 

[Train-train]

Thanks for your reply the_experience 83. A couple offollow up question I have, does this engine and transmision have what I need if I want to tow a car by dolly, or a small horse trailer? Do engines styles have starting chartacteristics and if so, how does the 6.6L rate for starting reliblity? On average, What mileage is probable and what is its happy speed and associated mileage?

 

[lapeer20m]

i drove mine tens of thousand of miles. had the at545 trans which didn't help at all. she was underpowered, but at about 300,000 without a rebuild when i sold her she was still going strong.

it's a great starting diesel. my block heater stopped working, but she'd still fire up even when it was down to 10 degrees. She might have to crank for 30 seconds or so, but she'd always start even on the coldest days.

in the summer she'd fire up in half a second. One thing i wish i had done is turned up the hp and the govenor, but i didn't know how back then.

i think i got 8 or 8.5 mpg most of the time. Flat out she would only run about 60 mph....but i drove her with the throttle all the way to the floor pretty much all th etime. Even had a special "stick" that i put between the dash and the pedal to hold her to the floor when my foot got tired...dont' do that, it's dangerous.

it's a long lasting motor...not too much power, decent fuel economy

 

[Train-train]

Will it pull a small horse trailer or a car and dolly decently?

 

[the_experience03]

The limiting factor on towing is going to be the tranny more than the engine. You can always bump up the horsepower on the engine a little. Look for a bus with the MT643 or a manual tranny if you're going to be towing a lot.

As for starting...as Jason said, they thing is AMAZING. One compression and it is running during the summer. I've never used my block heater in the winter and it has started well down to about 10 degrees without any help. The longest I've cranked is probably 15 seconds. It will be cranky for the first minute (run rough), but it will start and stay running. Below 10 degrees and I give it about 2 seconds of ether and it starts right up. Those engines start amazingly well considering the lack an intake grid heater or glowplugs like a lot of other diesels have.