Detriot 2-strokes?

[84 Convert]

I was just wondering if anybody out there knows if a 6V71 Detroit would fit in an '81-'87 truck without too much modification ( a little bit is okay). Also, I'm wondering if such a swap would be a good idea reliability-wise. I understand that an inline motor is inherently the best-balanced of engine designs, so an inline may be better. I've also heard a few not-so-wonderful things about the Detroits from truck drivers I know... most prefer a Cummins or Cat.

Just curious.

Gregg

[NH2112]

Well if it's too big for the engine bay you can always make a rear-engine truck, right? :D I do know that a 6V53 looks too big to swap into a Chevy/GMC (I've never measured) and I'm pretty sure a 6V71 is physically larger than a 6V53. One thing about Detroits in particular is they work best when they're running at the same (high) RPM all the time - they don't like the up and down, up and down they'd see during automotive use. Still, under the light load they'd see in a pickup they might just be all right. A friend was actually entertaining the idea of swapping a 3-53 or 4-53 into his '84, but went with a built 6.5 instead.

Another thing about Detroits is there are fewer and fewer people who will/can work on them. They're VERY different from any other diesel engine - but seeing as you live in WA I'm sure there are a lot of diesel mechs who are very familiar with working on them in skidders and other logging equipment.

[84 Convert]

I found a marine web page that had a table of the dimensions and weights of the Detroits...the 6V71 weighs about 2800 lbs!! Also it is over 5 feet long...fergit it! However, I have seen a couple of old GM trucks for sale that had 4-53's in them, so that is doable.
I just think that the Volvo you are using and the Isuzu turbokid used are better alternatives. The 6V71 was interesting because I've seen a couple complete trucks for sale with that engine for under $2000.

Gregg

[NH2112]

Are you sure that the specs you saw were for a 6V71 and not a 16V71?? I'm not sure if Detroit actually made a 16V71, but 2800lbs and 5+ feet sounds WAY too big for a 426CID V6! I know the 8V92s in the 10-ton trucks I used in the army didn't weigh near that much, and I'm pretty sure the VT903 Cummins used in our tracks only came in at around a ton.

The friend with the '84 K2500 I mentioned before lives way out in the sticks and has neighbor who has a beat-up old skidder powered by a Detroit. I don't think I've EVER heard a diesel that sounds as cool as that thing does, with its deep throaty growl, when he roars along knocking the snowbanks back into the woods to make the road wide enough for a vehicle to pass (they plow the dirt roads with their own vehicles out there.) BTW, you wouldn't BELIEVE just how much snow that 6.2L-powered K2500 w/4.10s could push around with skinny Remingtons and no chains!

[SoMnDMAX]

NH2112, 16v-71's are dang close to 12 feet long, IIRC. Been a while since I've seen one. 16v series engines are two 8v series engines bolted together... Detroit also made 12v series engines, both as a 71 cube, and a 92 cube. These were a true V-12, and used a common block and crank. The last time I saw a 12v-71 was when I was about 10-12 years old!! :eek:

A 6v-71's length should be close to 5 feet, from fan to bellhousing. Weight is real close to 2800 pounds, as there's a LOT of iron in the blocks, as well as the heads. They aren't a light engine....

[84 Convert]

NH2112, it is possible that the ones you saw in the military were all aluminum like the 6V53 used in the drag truck mentioned elsewhere on this forum ( "how 'bout this for a diesel ?") I think... 'Course I'm no expert. I do agree about the sound those engines make. That was one of the reasons for my interest. Oh well...

Gregg

[ 12-01-2002: Message edited by: 84 Convert ]</p>

[Jelisfc]

Check this site http://www.depco.net/resources/images/standard_engine_spec.pdf It lists specs for all Detroit 2 strokers. The 6V71 shows to be only 41" long and 2010 lbs but at 48" high I don't think it will fit.

[Wheat Whacker]

Don't know if I would consider an old "Screamin' Demon" for pickup use. #1 You better like the noise they don't call'em "Screamin' Demons" for nothing #2 They tend to leak oil #3 The ones I have been around DO NOT start good in the cold weather without being plugged in #4 They like the high RPM's which may or may not affect a pickup as much being they are lighter and this causes the noise factor.(This DOES NOT apply to the new 60 Series Detroits as they are an excellent engine)

On a positive note though you could see some very good fuel mileage. Might make an interesting project. A 60 Series Detroit in a pickup might be a neat idea as fuel efficiency should be excellent(we got 10.83 mpg with our T-600 Kenworth this spring bobtailing it as a 12.7L
60 Series in it) don't know if they make one that would fit this application.

Just my 2 pennies.

[Jelisfc]

Wheat Whacker, "They tend to leak oil" That's an understatement!!! I haven't driven one that hasn't leaked oil.

[NickLeinonen]

i'd love to get my hands on a 4-53T and stick that in a little jeep. tweek the governor for 3k rpm and put a co2 fogger in the intake [works better than the kill flap doesn't damage engine - no damaged blower seals]

[Wheat Whacker]

You are right Jelisfc "they tend to leak oil" is a little soft. How about they tend to "leave an oil slick on the scale with the Exxon Valdez". That might be a little more accurate.

[stretch]

Check into the specs of a 3208 Cat. A few years ago, there was a F350 with a 3208 and an Allison for sale. I have to assume its feasable.
As for the Detroit, Generous doses of silicone in the right places will keep MOST of the oil leaks in check, Engine height has a lot to do with the application it was designed for. MCI buses used a top mounted turbo which made the engine quite tall versus the same motor in an Eagle bus had a front mounted turbo that reduced the height significantly. This only applies to the 6V71T and the 6V92. Not sure if there's any different configurations for the non turbo versions.
IMHO.... Steer clear of the Detroits. They do sound sweet but there are alot of drawbacks. :cool:

[84 Convert]

A 3208!!! Holy cow!! That's a 10L motor! Weighs in at 1450 lbs. It sure makes some impressive numbers, though. I think the 3116 sounds like my kinda motor...same size as the D-Max but inline. Weight is 1250lbs. Ratings are up to 330 hp and 850 lb/ft :) Sounds like fun. Unlike the Isuzu and Volvo, I doubt I can find one of these cheap (not even a detuned one). The 3126 is 7.2L and makes slightly more power (duh) I'll have to check the dimensions on it. I think the weight numbers for the marine motors must include the outdrive because for a marine 3208, I see numbers around 2000 lbs. Marine 3126 is shown as 1560 Lbs.

Gregg

[ 12-08-2002: Message edited by: 84 Convert ]</p>

[arveetek]

In case you're interested, my dad is installing a 671 (inline version, not the v-6) in his truck, replacing the 6.2L. It's backed by an Allison automatic. He has a custom cab made from a Dodge van....the doghouse had to be extended quite a bit to make room for the motor.

We haven't got it running yet, but it looks to be pretty cool.

Casey

[84 Convert]

A little slow on the uptake here, but that ought to be interesting. A friend of mine who has been a jippo logger all his life and is in his 60's now, gave me a little info on the Detroit 2-strokes. He said that the inlines had a much stronger bottom end. The V-6 for instance used the crank from an I-3 with half as much rod bearing area per cylinder. In his opinion the 6-71 inline was one of the best of the Detroits. However, (and you probably already know this) he did mention that getting the injectors in sync is the hardest part of getting the most out of a Detroit. (each injector acts as its own injection pump) Tuning those motors tends to be kinda like tuning a 6-carb setup in this case.

Good luck and let us know how she runs!!

Gregg

[arveetek]

Yeah, we've had the top end open already. It's been a slow project, so it had been about a year since it was run last, so we decided to start it up and let it run for a while. That's when we discovered that when the 671 is shut down, the injectors shut down at full throttle. So, if the injectors get stuck in that positition, and you go to start it up.....

Well, luckily we just had the fuel line drawing out of a bucket, and I simply pulled the line out to shut it down. Hearing that 671 run away was kind of scary.

There is a long rod that connects to each injector, and this rod moves a lever on each injector, increasing or decreasing fuel flow. It's actually very similar to most any other direct injected diesel of this style. I know that a Cat 3116 with mechanical injection uses a similar setup. I had to adjust one as part of my training at the local diesel school. The injectors run off the camshaft, just like the valves do.

Casey