Engine Swap

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Engine Swap

October 24, 2021, 01:07:56 am

Looking at an 87' GV, non-unihome with Detroit Diesel 6V92. It's pretty cheap! But I don't want that engine. Was thinking of an engine swap. Has anyone here done that? Are there pre-existing provisions in the structure of the chassis to install a variety of engines? Or am I thinking WAY outside the box? Thx!
Mikeado1

Re: Engine Swap

Reply #1 – October 24, 2021, 07:23:20 am

Curious as to why you do not want that engine? Is there an issue?

Re: Engine Swap

Reply #2 – October 24, 2021, 08:27:20 am

Any project is do-able if you throw sufficient money in the pot. I can't recall seeing any mention on this Forum of successful engine swaps.

Re: Engine Swap

Reply #3 – October 24, 2021, 08:28:46 am

IMO, a properly maintained DD 6V92 is an excellent engine.

Overheated, using wrong oil, etc can certainly kill them. So, their "care and feeding" is important.

Re: Engine Swap

Reply #4 – October 24, 2021, 10:09:09 am

LOL!!!! I AM thinking way outside the box!!! Thanks for the input ya'll !

Found it on the internet. It's about a 7 hour drive to get there. Don't wanna waste my time driving there only to find that the engine is completely toast. But if I could take possession of it and then do an engine swap, I might consider it. The coach appears to be in great shape.

It is a full-rail Oshkosh chassis, so I assumed that the chassis was delivered to Foretravel with pre-punched holes in the frame rails, to which Foretravel made accomodations to attach an engine. Am I wrong in that assumption? I've not had opportunity to actually view an Oshkosh chassis in a Grand Villa yet.

Was really attracted to the rig initially, until the current owner made reference to the engine overheating a couple times on his most recent trip. Rig has 180K miles on it. He "did a top overhaul" on it 7K miles ago with no records of the rebuild, which leads me to believe he did it himself. Which makes me wonder how long it would last. And what if there's a crack in the block and he missed it on the top rebuild? There are reports on the internet of that happening.

There's lots of mention on the internet about the DD's overheating and blowing head gaskets and needing heads replaced/rebuilt. I could overhaul the engine myself if I had to but haven't the desire to do so.

It's not that I have something against the 6V92! They have a lot of great attributes. They're actually quite simple. I really do like the fact that the engine can be rebuilt while still installed in the coach! That's handy!!!

It's just that, in reading a lot of internet posts, it seems that the DD owners are constantly anxious that their engine is gonna overheat. Kinda takes the fun out of it for me.

The coach appears to be in nice shape and as I said, it's CHEAP. So, I thought en engine swap might be an option.

I'm an open-minded guy. Maybe I should reconsider!

What's the highest mileage GV with DD 6V92 installed? Whats the cost of a rebuild?

Thanks again ya'll!

Mikeado1

Re: Engine Swap

Reply #5 – October 24, 2021, 10:18:14 am

Check again for exactly which Detroit Diesel engine it has.

With an Oshkosh chassis, more likely to be the 8.2 liter 4 stroke engine. A picture will tell you in a heartbeat!

As I recall, the 8.2 liter is 210 HP vs the 6V92 with 300-350.

Re: Engine Swap

Reply #6 – October 24, 2021, 11:02:24 am

When Foretravel buys the chassis the engine is installed. They are not in the business of building the Oshkosh chassis.

Re: Engine Swap

Reply #7 – October 24, 2021, 11:11:56 am

Quote from: Mikeado1 – October 24, 2021, 01:07:56 am

Looking at an 87' GV, non-unihome with Detroit Diesel 6V92. It's pretty cheap! But I don't want that engine. Was thinking of an engine swap. Has anyone here done that? Are there pre-existing provisions in the structure of the chassis to install a variety of engines? Or am I thinking WAY outside the box? Thx!
Mikeado1

The best engine then and the best engine now. Excellent economy, bulletproof, low EGTs so no dropped valves, super reliable ECU, excellent injector wiring, no stripped threads on the pan, modern exhaust manifolds that don't look like they were made in the 1800, no intercooler to crack and develop leaks (aftercooler under the blower). and if you are lucky, a Jake on the later Detroits. 3 million built and they are still making them.

If you recall, there are even a lot of 5.9s that can't be cooled. Some members have aux radiators installed in the nose on GVs. The side radiator was terribly done but the older models had the rear radiator and not prone to overheating. The EGTs are so cool that Detroits don't need to have an oil spray for the pistons. No CAPS injection pump to fail and cost thousands. Dead smooth at all RPMs and a smooth no shake 600 RPM idle whether just started or hot. Did I say no dropped valves???

Foretravel is responsible for the overheating with zero time aligning the pump and tensioner so many Detroits lose a belt and overheat. Many don't see the warning lights as the steering wheel rim is in the way. The DDEC shuts the engine down but some have used the override switch and fry the engine. Anyone with even the least DIY ability can align the pulleys like I did. It's not rocket science. I aligned ours after losing the belt on the way home from the East Coast and have the same belt today and even the OEM tensioner.

The 6-71 found in boats, Greyhounds is known to be the most reliable diesel ever made. Some of the famous Duce 2-71 generators have never even been overhauled since 1950. When I bought my 4107 ex Greyhound, it was advertised with a new engine. It had 117K but the bus company owner laughed and said that was the same as new.

I've driven two cycle Detroits since 1967 without any problems in the fire service, in my bus and now in our U300. That was the reason I wanted a Foretravel or would have gone with a Wanderlodge, Prevost, Eagle, Dina, etc, etc.

Anyone with a side radiator and the Rube Goldberg combination of belt, pump, motors has to be anxious. I'm anxious each time I think about it and how it can strand us in some remote destination. Still going to install electric fans for a backup so I can drive at lower speed.

You don't even have to be much of a mechanic to work on them. No fabled "rack to run" like the mechanical engine. As Jerry M posted, anyone can do an inframe in the barn.

There is a big reason that Mercedes now makes Detroits and supplies parts throughout the world. Best thing for anyone to do would be to dump the Allison and swap in a Detroit DT12 transmission to come out of the stone age.

So, adjust the tensioner/pump alignment if you have a side radiator, use the correct oil for the engine, take the heater out of the thermostat housing and install a real block heater where 99% of Detroits have them. In the block where they belong. Then you are home free.

Pierce

Re: Engine Swap

Reply #8 – October 24, 2021, 11:14:40 am

I kinda went through this when I rebuilt our kitty cat 3126.
Bruce Bean said they didn't build the coaches around the motor so other motors would work, which made me think.
But the more I researched it, the more I realized so many things would be different starting with adapting transmission. Converter stahl would probably be wrong. Wrong rear end gearing, making wiring work ( gauges etc.). Would be easier on a non electronic engine.
I have seen many FT's in the past, converted from the 460 Ford to a diesel.
It's not like throwing a Olds engine in a 55 Chevy!
In the end, I rebuilt the Cat, and at 17K miles, very happy we went that route.
Chris

Re: Engine Swap

Reply #9 – October 24, 2021, 11:38:57 am

Quote from: Pierce & Gaylie Stewart – October 24, 2021, 11:11:56 am

The best engine then and the best engine now.

Pierce

10 Best and Worst Diesel Engines in History - Capital Reman Exchange

Re: Engine Swap

Reply #10 – October 24, 2021, 12:16:12 pm

Quote from: Doug W. – October 24, 2021, 11:38:57 am

10 Best and Worst Diesel Engines in History - Capital Reman Exchange

So, while you quote one small shop, how about one of the largest and most successful companies in the world? They even invented the car back in the 1800's and are for the last decade, the F1 world champions. You have probably flown in an airliner with one of their Rolls Royce jet engines. Naturally, I'm speaking about Mercedes Benz (MTU) Here is their take on their Detroit 2 cycles: 2-Cycle Service Products

You probably know that Cummins is now making one of the most advanced 2 cycles today, CAT has controlling interest in EMD, the maker of 2 cycle locomotive engines and the biggest ships at sea are 2 cycle powered.
The 60 series while they were great, have been out of production for many years. Mercedes took many of their outstanding features and incorporated them into the DD13, 15 and 16 and is producing the DT-12, an automatic clutch, manual transmission with GPS controlled grade profiles and automated shifting.

Why do you think every bus company in the world has made the Detroit 2 cycle the mainstay of their fleet in the past? Smog killed them like CATs. But almost the same engine only larger (EMD ex General Motors) powers a big percentage of the railroad locomotives today with their 2 cycle. The 92 series is still being sold for on and off road vehicle applications, generators, boats most everywhere in the world today.

Pierce

Re: Engine Swap

Reply #11 – October 24, 2021, 12:33:21 pm

I wouldn't bother going to the problem of changing that engine. 2 cycle engines
are great engines.

Re: Engine Swap

Reply #12 – October 24, 2021, 03:05:02 pm

Quote from: Mikeado1 – October 24, 2021, 10:09:09 am

Whats the cost of a rebuild?

Last in frame kit I bought was ~$ 2500 for a 6v92.

Mike

Re: Engine Swap

Reply #13 – October 24, 2021, 04:47:26 pm

Several years ago we had an in-frame overhaul done on our 6V92TA. At that time someone commented that we could fit an 8V92 in there. I mentioned that to the lead mechanic on our job, and his response was, "Do you want to see a grown man cry?"

As was mentioned above, you can make almost anything fly if you throw enough money at it. Just ask Congress.

Re: Engine Swap

Reply #14 – October 24, 2021, 05:08:31 pm

Find a coach you like how it is made and buy it, not buy something you don't like...

Re: Engine Swap

Reply #15 – October 24, 2021, 05:27:33 pm

I would still like confirmation that the ORED he is looking at has a DD 6V92. If DD 8.2 much of the discussion is moot.

Re: Engine Swap

Reply #16 – October 24, 2021, 07:20:41 pm

87may have been built in 86 and could be either the 2 stroke or the Fuel pincher 4 stroke.
If its cheap and runs,drive it home and make an assessment.
At that age the engine will be the least of your worries. IMHO.

Re: Engine Swap

Reply #17 – October 24, 2021, 07:37:09 pm

So what engine do you want to swap in? Probably have to buy a donor coach. Just fix it, the donor. And in three months you can be using, says the man with too many projects. Lol save your sanity, if your looking keep looking a good one is out there. That's what I did and it still has been a full time career and was what I wanted
Scott

Re: Engine Swap

Reply #18 – October 26, 2021, 09:53:14 pm

I had a 6V92 in a 40' PT40 Wanderlodge, didn't use it at all as it needed redone and sold it for a loss. That being said. the engine ran awesome, plenty of power and sounded great in my opinion. Make sure you buy what you want, especially engine wise, seems like it'd be a pain in backside to swap engine. I now have what I believe my ideal coach, a 1988 31' Barth. Spartan Chassis, Cummins, Allison, and 22.5 tires. Just wait till you find your coach, you'll know. Foretravel Forum, and Barthmobile, Wanderlodge Owners Group are AWSOME to help with any problems or questions, which I will always stay with one of these brands. Blessings and good luck!!

Re: Engine Swap

Reply #19 – October 26, 2021, 10:02:31 pm

Quote from: 442john – October 26, 2021, 09:53:14 pm

I had a 6V92 in a 40' PT40 Wanderlodge, didn't use it at all as it needed redone and sold it for a loss. That being said. the engine ran awesome, plenty of power and sounded great in my opinion. Make sure you buy what you want, especially engine wise, seems like it'd be a pain in backside to swap engine. I now have what I believe my ideal coach, a 1988 31' Barth. Spartan Chassis, Cummins, Allison, and 22.5 tires. Just wait till you find your coach, you'll know. Foretravel Forum, and Barthmobile, Wanderlodge Owners Group are AWSOME to help with any problems or questions, which I will always stay with one of these brands. Blessings and good luck!!

Spot on info IMO
I spent a year looking and basically disqualifying everything I could till I narrowed it down to our current coach. I actually had basically given up on finding what I wanted. Do you plan to tow over 5k? If you do this will deleat most coaches including your engine swap regardless on what engine you put in. Can't change the GCWR. even if you have 600hp. This forum found it for me.
Scott

Re: Engine Swap

Reply #20 – October 26, 2021, 11:07:32 pm

Overhearing can easily be caused by oil and debris built up in the radiator fins which can be cleaned out using something like Simple Green.
You can check for oil and dirt build-up with a plastic straw.

Re: Engine Swap

Reply #21 – October 26, 2021, 11:24:23 pm

Okay guys, apparently I heard wrong.

It's a 1989, small basement, Oshkosh chassis. And has 8.2(Fuel Pincher?)! Information is coming from the current owner. I have not physically put eyes on the rig yet. Coach looks in great shape in the photos. Now, what do ya' think? Engine swap still sounds fun to me. But I'm a sucker for a good project also!

Sorry for the confusion!!!!!!!! Mike

Re: Engine Swap

Reply #22 – October 27, 2021, 08:35:11 am

I don't know the footprint of other engines compared with the 8.2 but you could certainly check.

The other critical factor that could limit your choices is the transmission's HP/torque limit-- unless, of course you are looking for a complete drivetrain transplant.

Also, be sure to consider the cooling capacity/heat rejection.

Re: Engine Swap

Reply #23 – October 27, 2021, 10:05:39 am

OK, here I am. I own a 1989 GV with the 8.2 DD turbo charged V8 engine and four speed Allison tranny.
A few things I would like to point out.
The chassis is a V-815-2 and the Allison four speed is an AT-545 NOT the V-917 chassis and the MT-643 tranny. The V-917 and the MT-943 were used with the Cat engines due to greater weight, more horsepower, and greater torque.
The chassis is a rear radiator model, and if anything like mine, has a louvered door on the driver's side near the back end of the coach that provides access for water and electrical hook
The brakes are most likely drum brakes. (less stopping power than disc brakes)
Any engine longer than the 8.2 means the foot of the bed will have to be shifted forward which means the loss of the small walkaround( walking around the foot of the bed and up both sides.)
Better check CCCP of the V-815-2. A bigger, heavier engine might put you over the top of spec. Not a big deal? Yes it is! Wheel bearing capacity, handling ability, axle rating, and leaf spring load limits.
OK, now about the overheating issue. I swapped the original steel fan for a newer nylon one. I also religiously check that I can see light thru the rear radiator. So we have not had an overheating issue in the almost ten years we have owned our coach.
TOWING: We tow a 2006 Saturn Vue AWD. It is at the upper limit of what is specified for towing, but it is what we have. So we know we are not driving a Greyhound bus.
If you go to a bigger, more powerful engine I recommend/suggest you change the brakes, the rear axle to a heavier unit, the leaf springs, and the tranny to a more robust one, and you had best take a really good look at what would be involved with converting from a rear radiator to a side radiator. This would involve losing the standing access to the driver's side of the bed.
Last two but not least-- try to contact James Holder in Tennessee. James has two GVs and is the Service Manager. I have his contact info if interested.
One more thing...Daimler now has ALL the info on the Oshkosh chassis's. I have that contact info also.

Re: Engine Swap

Reply #24 – October 27, 2021, 12:22:03 pm

We have looked at this for swapping prior . Do a search maybe
Issues are the trans mostly . Viable swaps are the smaller TD engines and trans , like maybe the Duramax , Ford 7.3 , Isuzu? ect.
Best bet is to run it carefully and fix the stuff that needs fixing. The engine may run perfect for a long while .

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