Posts: 49
Threads: 11
Joined: Oct 2014
Hi gurus,
Just finished 3226 miles in our classic 1972 and she ran beautifully! Sadly it looks like I have a leaky head gasket in my Detroit 8.2 since I'm getting tiny bubbles in my coolant. My brother in law is a diesel mechanic and suggests that if I want piece of mind I swap engines. He suggests a Cummins 6bt 5.9L engine. This seems a little small to me since I have an 8.2L in there right now but space is a problem too. Originally it had a Ford 391 gasser.
Anyone with any thoughts for engine/transmission combos. Our 1972 is 32 feet long and weighs about 20,000 lbs. and we tow a 1981 Honda Accord which weighs maybe 3500 with the dolly.
It's either this or new head gaskets.
Thanks!
Bob Kopicki
1972 Newell Chauffeur
1964 Land Rover 88 Series IIa TOAD
Posts: 5,092
Threads: 248
Joined: Jul 2012
Bob,
Check oil for coolant, either with an oil test kit, or by draining a quart into a glass jar and letting it settle over night. If any coolant in oil, do not run engine! I don't know why but coolant in oil will make main bearings sieze.
Richard and Rhonda Entrekin
99 Newell, 512
Maverick Hybrid Toad
Inverness, FL (when we're home
)
Posts: 1,616
Threads: 120
Joined: Aug 2012
Bob,
The first thing I would do is measure to see if the 6BT will fit. Then determine if your final drive ratio will keep the 6BT in it's "Sweet spot" for fuel economy at cruising speed. A V8 might fit better. In that case I would be looking at a Duramax or a Ford (International Harvester) 7.3. The modern turbo-charged diesels should provide adequate power. It's not hard to get 300+ horsepower.
1993 Newell (316) 45' 8V92,towing an Imperial open trailer or RnR custom built enclosed trailer. FMCA#232958 '67 Airstream Overlander 27' '67GTO,'76TransAm,'52Chevy panel, 2000 Corvette "Lingenfelter"modified, '23 Grand Cherokee.
Posts: 49
Threads: 11
Joined: Oct 2014
Yep, checked the oil.....all ok there and she's still running great. Honestly, if I hadn't installed a coolant reservoir I wouldn't even suspect anything.
My brother in law LOVES the 6bt, but I'm afraid it might be a dog compared to the 8.2. It does produce the same torque but short on hp. It should fit and I was planning on changing the final gear ratio in the diff anyway.
I'm just trying to put out feelers, to be honest I'd rather just fix the engine I have. It would be a lot cheaper and I wouldn't have to re-engineer the whole drivetrain.
Bob
Bob Kopicki
1972 Newell Chauffeur
1964 Land Rover 88 Series IIa TOAD
Posts: 1,616
Threads: 120
Joined: Aug 2012
I too like the 6BT...I've got 150,000 miles on one in my 2005 Dodge 3500 that puts out 325 hp/600# torque before I put the Banks system on it. The 8.2 is known to have head gasket issues. Is yours turbocharged? I was thinking about it today....Some of the newer gas engines in the 1 ton trucks are producing lots of power and better fuel economy than in the past they are smoother and quieter that any diesel. ...Something to consider in a front engine motorhome...Another thing to consider is whether you want to get into the electronics that the newer engines require.
1993 Newell (316) 45' 8V92,towing an Imperial open trailer or RnR custom built enclosed trailer. FMCA#232958 '67 Airstream Overlander 27' '67GTO,'76TransAm,'52Chevy panel, 2000 Corvette "Lingenfelter"modified, '23 Grand Cherokee.
Posts: 703
Threads: 47
Joined: Apr 2014
Bob,
I think that your brother-in-law is giving you sound advice. The Cummins 5.9 and a Allison 3000 series 6 speed transmission is a combination found a lot in motorhomes.
This is also a combination used in a lot of front engine school busses which can be picked up rather inexpensively. If you have the space, getting a donor bus will save you a lot of time and money. The donor bus will have almost all the necessary parts and wiring for your conversion and save you the frustration of having to figure out what you need and how to get it.
Jon & Chris Everton
1986 40' Dog House #86
450 hp ISM 5 spd ZF Ecomat 2
2004 Range Rover L322 Toad
Posts: 294
Threads: 20
Joined: Mar 2014
Jon is right about the donor bus, If you decide to go with a 5.9 find a mid 90's with the mechanical injector pump. It will save alot of wiring issues. Allison 3000 series trans. Theres LOTS out there for sale cheap and they're a great engine.
Love old school
1976 Newell 8.3 cummins allison 6spd
1977 Newell 8.3 cummins allison 6spd
Posts: 1,616
Threads: 120
Joined: Aug 2012
Ditto Jon and Retro!!!
1993 Newell (316) 45' 8V92,towing an Imperial open trailer or RnR custom built enclosed trailer. FMCA#232958 '67 Airstream Overlander 27' '67GTO,'76TransAm,'52Chevy panel, 2000 Corvette "Lingenfelter"modified, '23 Grand Cherokee.
Posts: 49
Threads: 11
Joined: Oct 2014
I'm amazed how many Cummins 5.9 chassis there are out there with 400-500k miles! Don't see that with the Detroit 8.2. I'm not sure I want to do all the engineering work that goes along with a re-power but there seems to consensus here that the Cummins is the way to go so I'm leaning toward pulling the trigger. I think I've even found a rolling donor chassis. I'm guessing if I ever want to sell her she'd sell better with a Cummins of any mileage over the Detroit even reman-ed.
Thanks for your input everyone!
Bob Kopicki
1972 Newell Chauffeur
1964 Land Rover 88 Series IIa TOAD
Posts: 123
Threads: 28
Joined: Nov 2013
I've never driven the Detroit, but I know that I really like the difference between my original 1983 vintage Cummins and the '96 version in it now.
I suspect the modernization of your power train would make your coach much more enjoyable as well.
Scott
1983 38' Classic #007
8.3 Cummins, Allison 6 spd.
"Any other Way"
