bertram31.com

Thanks,

ANDY

Another pic!

453 natural if I had to guess. Buzz

I think it's a 453 turbo.

Looks like a turbo blanket in the back

Looks like a 453, some of the early 60's 31 had them installed from the Bertram factory, boats were slugs 16-18 knots top end. Timmy knows his oil slinging dump truck motors from years of oil absorbing pads in the bilge and slick out the bilge pumps. Timmy it's 76 degrees down here, have you got your plow on for next week.

453 turbo.

The 453 naturals (135hp) were the engines that produced the 16-18kt top end....not that engine. I'm not familiar with that engine in a 31? Not sure what speeds 420 hp (total) would produce in a 31 Bert?

Isn't that strange, everything nice and clean, what-da-you know. The turbo's make a less noise than the naturals. Not sure how that boat would run...but those are nice little engines. Based on the hot manifold it may be a truck, or industrial transplant. Most of the marine turbo 453's were "pancake" (lay on their sides) engines and Hatterass installed a bunch of them.

Someone may have added the turbo....but, unlike most Detroits, you can't just add a turbo to a 453. Besides the difference in compression ratios, the natural and turbo use different blocks. The turbo block is stronger, larger crank & rod journals, etc. I would run the S/N's, if the engine came as a natural??? Althought, a 453N may very well survive with a turbo added, most internals on a DD are heavier than other diesels to start with. and the blocks are super heavy castings.

It could be a "home made" set up. The air intake box, piped to the turbo is a air intake silencer, from a natural. Typically that housing bolts directly to the blower. The hp on that engine is dependant on which injectors are in it. Could be anything from 150-220hp?? No aftercooler...which means that they should NOT have that engine turned up much past 150-170 esh hp...if it is expected to live.

The mind-mixer is the thermostat/coolant out let hose terminating into thin air, and there's no place for the standard forward coolant/exchanger tank???? Maybe it has an outboard mounted heat exchanger that's currently off the engine?

The color is odd as well. Most were Alpine green or white.

pete , just hooked the snowblower to the tractor today....... couple of iches tonight , they claim

what's up thudddster....

I wish we had snow down here, so we could play with diesel powered toys to move it around.

We're still moving MOUNTAINS of sea weed around with excavators and dozers.

How's the ark coming along?

Does not sound good?

The engines that is!

Does not sound good?

It depends on the guy that designed the reconfiguration. Detroits are extremely modular engines. Parts from an 8V53 would fit on that engine, and vice-versa, sorta like Lincon Logs....stuff will fit in all types of configurations. So, "if" they knew what they were doing it could be a nice set up, make good hp and last 10,000 BMOH's.

There should be a specific book for the reconfiguration, detailing everything about the engine from liner P/N, injector size, turbo ASR & P/N, etc....is there a book, or build sheet??

It is difficult to find the right people for such experiments. Most certified DD mechanics know what can be done, but they won't share the info...they stick to the book for CYA reasons, can't blame them.

Typically Detroit HP levels and longevity are measured "by the hole". A 71 series can make 85-90hp per/hole...but won't live long. For a 71 series the Sport Boat balance comes in around 70 HP per/hole....for a 2,000-3,000 hour engine. The 53 series will be less, maybe 50 HP per/hole (assuming aftercooler, etc)...the 92 series will be more, say maybe 85 per/hole @ 2,500 hours.

Now reduce those numbers to 30-40 per/hole and you have a 10,000-20,000 hour engine. Take your pick (the numbers may shift around a bit but that holds true for all diesels)

Thanks, that really helps me understand. I am not a diesel mechanic. This guy just sent me the photos and acts like he does not know a lot of info. I am going to get some specifics this week.

-ANDY

hello folks...new here.
Scot has it down.
the 2cycle Detroits are very versitile. blocks and heads are all reversible.
changing rotation is also very easy, although it is done during eng. build.
on in-line engines, the blower can be on either side. same with heads. the exhaust can be set to either side and rotation makes no difference.
I'm not very familiar with the 53 series, but with the 71's, different style pistons were used for turbo applications(trunk vs cross-head'two-piece').
adding a turbo to a naturally aspirated(roots blown) will increase power, but to get full benefit, turbo pistons and bigger unit injectors are needed to get factory turbo rating. unless the injectors were changed to a bigger output, adding a turbo(properly sized) shouldn't hurt engine life. also the unit injectors have more configurations than leaves on a tree. so properly sized and tagged injectors are critical.

Kurt,

The trunk vs cross head is more of an age thing. Both Turbo & Natural engines came with both...depending on the age of the engine. The cross head ( 2 piece) replaced the trunk. The last design (cross head) tends to "slobber" a bit more when the engine is idled extensively...but the cross head is a better set up for an engine that spends most of it's life at higher RPMS.

The primary difference is the compression ratio. In the 71 series a turbo engine runs at 17:1, and a natural uses the 19:1 ratio. With that said, it is ok to run a turbo with 19:1 pistons. The 17:1 turbo pistons make the engines harder to start in smaller displacement engines (like the 453). It's an old DD mechanic trick to run 19:1 pistons with a turbo (I'm building one like that now) Makes for an easy starting small displacement engine + a little more HP gained by the additional compression.

Your correct on the injectors, the turbo alone will only typically add between 10-25 hp...BUT, it does put enough air in the engine to greatly increase the HP ratings with larger injectors. It's very easy to double the HP rating on a Detroit by "bolting on" a turbo + big injectors.

A turbo sends hot pre-heated air toward the engine and heat build up in the cylinder from a BIG ignition (caused by big injectors) is the serious issue, and that's were the aftercooler comes in. That engine is missing an aftercooler?....so if the injector size was greatly increased the engine could have cooling problems.

Maybe that's why the exchanger is off the engine, the engine runs hot and someone figured it was caused by a plugged up, or under sized heat exchanger????

I'm like you, I don't know much about the 53 series.

I'm no DD mechanic, but I play one on the internet. lol.

not a Detroit wrench here either, tho we played with them in college in the mid-seventies(Diesel mech tech) I actually worked for Cummins in San Antonio for a few years after college(found out I didnt like being cooped up in a shed all day, so I started driving. ended up with an 83 Pete with, yep, a Cat 3406. :-D ). just looking at the pics, it could be a 4-71. not sure. I seem to remember the 53 series as having 3,4, or v6 design. the 71's went from 2 to 16 cyl. long periods of slow iding are one of the worst things to do to any mechanical injected diesel. poor fuel metering at low speeds causes mech injectors to slobber resulting in poorly atomized spray which didnt combust completly leading to raw fuel washing the cyl walls and premature ring and liner wear. bumping up the idle to about a grand stopped most of this. back to the pics, with little references, I cant tell if the engine is a 53 or 71 series.

Am I missing something?

I see a valve cover of what looks like a straight 4 detroit. See the turbo shroud and what appears to be an unfiltered air intake.

Don't see a coolant tank or heat X-changer (maybe one or both are missing) WHY?????

If the sender of the pictures is the owner/seller? And doesn't know what he's looking at/owns; automatically this situation your in whatever it is becomes an all stop, ,,,,,,,

What is the intent of the thread, you looking to buy the B31 Sportsman in the pictures with these mystery engines? I would advise not until it runs...

JP-

I concur.

Thanks