Detroit Diesels 8V71TT

[Art]

Ad Says: "1976 Detroit diesels 8V71TT twin turbos 305 hp"

While awaiting return call from owner/seller:

I seek comments on diesel engine listed atop this page.

Thanks in advance for anything you may share on these diesel beasts!

Happy Boat Daze! - Art

 

[utclmjmper]

Beast is the right word,, they are very heavy.. few mechanics these days around that have any real knowledge..>>>Dan

 

[Art]

Beast is the right word,, they are very heavy.. few mechanics these days around that have any real knowledge..>>>Dan

Thanks, Dan. Yup, weigh over a ton each. I did some google on em. Sounds like those stout baby's if cared for and not tooooo many hours use will virtually last and last. Your comment re lack of mechanics availability makes me realize my and those engine's age! LOL

 

[Ken E.]

Art. I had 871N's and they weigh 3100 lbs each, bobtail. Mine were marninized by Covington and were rated at about 300 hp. I thought this was optimistic and have seen 250 as the rated hp which I think is more accurate. The only other version of this engine in the mid '70's that i know of was the TA rated at 450 hp. These went into the 46 Hatt convertible and other models. Summary comment....Big, heavy, noisy, many leak oil profusely. But thousands are still in service thoughout the world and with reasonable service the aspirated versions will about run forever. Parts are available but the mechanics who really know these engines are scarce, at least in the PNW. My shop won't work on them anymore.

 

[Art]

Thanks, Ken... I understand what you say.

Are at least some parts for these beasts still available now and for how long do you believe the parts may still be available? Don't imagine many of the parts are being new-manufactured... old-stock supply must be on decline.

 

[tiltrider1]

8v71’s are all over the place. The TT means Tailored torque which means it is designed to maximize fuel use at a constant rpm rating. I don’t see anything to be afraid of.

 

[Art]

8v71’s are all over the place. The TT means Tailored torque which means it is designed to maximize fuel use at a constant rpm rating. I don’t see anything to be afraid of.

OK! - Thanks!

 

[Ken E.]

Thanks, Ken... I understand what you say.

Are at least some parts for these beasts still available now and for how long do you believe the parts may still be available? Don't imagine many of the parts are being new-manufactured... old-stock supply must be on decline.

I believe most all 2-cycle DD parts are available from aftermarket suppliers. When I had mine, the parts' cost was reasonable. Lepke on this site knows a lot about these engines...maybe he will join in.

 

[utclmjmper]

Two stroke DD parts are now obscenely priced and the after market Chinese stuff is pure junk,<<<Dan

 

[Art]

Two stroke DD parts are now obscenely priced and the after market Chinese stuff is pure junk,<<<Dan

Does not sound inviting...

 

[C lectric]

There is a fellow on B.D. , Ronald Sparks, who is a D.D. expert and he has said a number of times that parts , good ones, are still available for the DD engines from the Federal Mogul.

He will answer questions about them. THere is a recommended shop for injector rebuilds he suggests out of FLorida. Yes, a ways away but he says they are good.

Are you anywhere near San Diego? Sorry, S. F. Another knowledgeable person operates a shop called Marine Diesel Service there and he frequents B.D.
He answers on B.D. to MDS.



Look them both up. Ask their opinions.


Yes , the DD mechanics are getting scarce as they will both agree but they are not impossible to find to get work done.

 

[Art]

There is a fellow on B.D. , Ronald Sparks, who is a D.D. expert and he has said a number of times that parts , good ones, are still available for the DD engines from the Federal Mogul.

He will answer questions about them. THere is a recommended shop for injector rebuilds he suggests out of FLorida. Yes, a ways away but he says they are good.

Are you anywhere near San Diego? Sorry, S. F. Another knowledgeable person operates a shop called Marine Diesel Service there and he frequents B.D.
He answers on B.D. to MDS.



Look them both up. Ask their opinions.


Yes , the DD mechanics are getting scarce as they will both agree but they are not impossible to find to get work done.

Thanks! Boat owner said on phone today that strongly potential purchaser is to review boat tomorrow. I'll let this thread know if I still get a shot at review and purchase.

 

[Sailor of Fortune]

Thanks! Boat owner said on phone today that strongly potential purchaser is to review boat tomorrow. I'll let this thread know if I still get a shot at review and purchase.

is this an ex military boat by any chance? Maybe a 36' LCVP?

 

[Art]

is this an ex military boat by any chance? Maybe a 36' LCVP?

Nope! 1976, 67' fiberglass hull sport fisher, low transom, sedan-style with fly bridge and three location pilot controls.

Photos look real good. Description sounds OK. Owner talks OK. Won't know till deep survey and good sea test are preformed if it's OK as far as I'm concerned. Owner says serious buyer flying in tomorrow. We shall see!

I just don't have background with its old Detroit D's... thus this thread!!

 

[Lepke]

I've been running Detroits, especially 71s since 1961. I like the reliability. In a yacht, starting from a proper tune up and proper maintenance, they sometimes go a decade without much more than oil changes and an occasional checking of the clearances.
It's true there are fewer real Detroit mechanics and many that think they can do a Detroit. I do my own, it's not that hard to learn the settings. I have no problem getting quality parts. Lots of used parts and accessories on ebay for spares.

My current mains are 1947 engines, overhauled once in 2011 by me. Before covid they did 500+ hours a year. Since 2011 I've kept the oil clean, fuel clean with a 2 micron filter, and haven't changed an injector. Every couple years I check the valves. The governor hasn't needed adjustment. And so on...

 

[Comodave]

We had Detroits in a previous boat and never had a problem finding parts or a mecto work on them.

 

[Art]

I've been running Detroits, especially 71s since 1961. I like the reliability. In a yacht, starting from a proper tune up and proper maintenance, they sometimes go a decade without much more than oil changes and an occasional checking of the clearances.
It's true there are fewer real Detroit mechanics and many that think they can do a Detroit. I do my own, it's not that hard to learn the settings. I have no problem getting quality parts. Lots of used parts and accessories on ebay for spares.

My current mains are 1947 engines, overhauled once in 2011 by me. Before covid they did 500+ hours a year. Since 2011 I've kept the oil clean, fuel clean with a 2 micron filter, and haven't changed an injector. Every couple years I check the valves. The governor hasn't needed adjustment. And so on...

L

Thanks for personal stuff from 61 yr. affair with DD 71's. Just for S&G... how many hrs. on the 1947 reman's when you OH'd in 2011?

 

[Art]

Guess that 67' LOA boat sold. Ad has been removed. Twaz a BIG fish that got away! - LOL

Thanks to you all re info/input/outlook on old DD 71's. Now I know better and can react quicker toward potential purchase if another attractive DD 71 boat-fish comes cruising along!

 

[RonR]

This about sums it up.

 

[bowball]

I always recognize a DD powered boat from sound. Like the rumble of a Harley or a p&w r985 engine in a DeHavilland Beaver!

 

[Lepke]

L

Thanks for personal stuff from 61 yr. affair with DD 71's. Just for S&G... how many hrs. on the 1947 reman's when you OH'd in 2011?

I could confirm 30,000+ hours, but there were owners I couldn't contact. Detroits or Gray Marine engines often outlive their owners. The engines were installed used about 1972. Sleeves had Gray Marine numbers, so I figured they were original. They were originally painted white, most likely yacht engines. It's wouldn't be normal for a yacht DD to have been rebuilt in that time. From 1973 to 1991 the boat made yearly trips from Canada to Mexico. The owner of that time ran the engines several hundred rpm over the max rating, making 12 knots. I run at 10 knots @ 1800, the max rating.

GM designed and built the engines in the 1930s and Gray assembled and marinized them until around 1960 when Detroit took over the diesels.

 

[Slowmo]

The 8V71 was a very common engine. While not the most efficient the 2 cycle Detroits were very popular in boats due to simplicity and good power density. I know many people who have even 1960's Detroits and still get parts for them.

 

[CLady]

Detroit diesel mechanic

Craig Strange in San Diego, (well known DD expert), did a marvelous job on my 1985 turbo DD 300 including turbo rebuild, gorgeous stainless exhaust elbow and heat exchanger. He has a mechanic he has trained who works on them with Craig being available for consultation.
Craig cell (619) 392-1141.

 

[CLady]

Correct DD mechanic name

Craig Strange. Autocorrect changed it to Strange.

 

[CLady]

One more time -Craig Stange

'Sorry for the repeated problem with autocorrect.

 

[Shaunc]

I have a 53 Hatteras motoryacht. They are literally hundreds and hundreds of these motoryacht still in service today. All of these came out with Detroit diesel‘s and many power along with little to no problem if looked after. It’s very seldom for us to arrive at an Anchorage or marina along Florida coast and not see you another Hatteras in the marina or Anchorage.

Parts are freely available and new parts are available in most cases.

With so many being around our local marine junkyard has piles and piles of parts for these motors. O urs per along and all extremely reliable.

They are noisy and oily but they are relatively maintenance free.

I have a great mechanic who is in his late 60s and has been working on these motors since he was a teenager.

He literally can rebuild an engine in his sleep .

These guys are hard to come by but worth their weight in gold

 

[Cleanslate]

I get any parts I need for mine new or rebuilt by MTU who took over DD. I get them from Johnson & Towers, which is now part of Western Branch Diesel.
That being said some of the cast iron stuff is no longer made, but you can find aftermarket stuff or used. Anyway, I always am able to get parts never have any problems. My motors are 471 TIs. I do most of the work myself, but I have a few DD techs that I'm able to call in. I think they are great engines. Not computer junk to deal with! All mechanical .

 

[markrkrebs]

DD forever

Beast is the right word,, they are very heavy.. few mechanics these days around that have any real knowledge..>>>Dan

In the seattle area, there's great DD service From DC Diesel, in Ballard (Seattle) Washington.

 

[garbler]

Not sure why anybody would worry about finding a Detroit Diesel mechanic or parts but let me just say this. The two cycle 71 series ( 271,371,471,671 inlines and 8V71, 12V71 and 16V71 ) are the most common smaller engines in the world. WW II was powered by 71 series engines and hence they are ubiquitous here and the Pacific rim. Almost all of the oil field crew, rig tender vessels and drill equipment ran them until Penske and following owners realized they could not be altered enough to comply with upcoming Tier III emission specs and hence discontinued. But parts and mechanics are everywhere. When Penske bought that division the 71 series held about 40% of all road vehicles and probably close to, or more, construction machinery.

Nevertheless I would never worry about parts and service for these engines. There are warehouses full of these engines including the 53 and 92 series in the South.The only issues with these is, and always has been, weight, noise and oil leakage. The old saying was if a Jimmy doesn’t leak oil it’s out of oil. They are one engine that can literally be rebuilt in most boats with decent clearance.

 

[bumpkin]

The biggest problem is finding mechanics. Find a mechanic before you buy your DD. The second biggest problem is heat from Hp. A 92 set up for over 600 hp is more likely to have problems than your 71 at 250-300.

Talk to fanatic sport fishers who had the high horsepower monsters and they will tell you about the 2 stroke junk pile.

Mike