Perkins HT6 354

gunnarsilins

gunnarsilins

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I´m asking of behalf of a friend who owns two of these big, slow-revving diesels delivering only 145 Hp despite almost 6 litre volume and a turbo charger.
Is it known that the ouput can be increased to let's say 200 Hp? Are there any specialists or tuning kits around?
 
The Perkins T6.354 engines (horizontal and upright versions) can't generally be upgraded higher than about 165HP - depending on the turbo-charger fitted.

The earlier Simms turbos can't produce more than 145HP due the lack of boost pressure, but the later Holset turbo-chargers produced enough boost to extract 165HP if the fuel pumps uprated.

Burgundyben may be able to expand on this as I know he's tried it - I think he has one engine at 165 and the other at about 157HP :-)
 
Don't wish to be picky but I seem to remember 175bhp being the maximum power output available from the 6354 - from new at least. Certainly fitted to some early Moonrakers instead of the standard 145's and possibly Ocean/ Broom 37. Byron will know for sure.
 
There was a 175hp version of the T 6 354M, using a Holset 3LD Turbo and bigger fuel pump etc etc.
However some spares these days are getting difficult to come by, and I would guess that to uprate would involve changing turbo, intercooler, water cooled exhaust manifold, fuel pump etc...probably not worth it.

However...dont knock the engines they are noted for their longevity, and will probably outlast any other marine engine on the market and if it's a particularly good one, probably you and the boat.

The basic engine was produced originally for agricultural use, and there are still millions about all over the world in tractors, combine harvesters, generators etc as well as dodge trucks.
Most spares are still available from www.diperk.co.uk although specific marinisation parts are getting more difficult to get, particularly for the lowline and horizontal engines.
www.tadiesels.com in the US have certain parts and also www.lancingmarine.com in the UK do a few marinisation parts.
www.ejbowman.co.uk still carry most of the cooling equipment ie intercoolers, heat exchangers, gear and engine oil coolers etc.

Hope this Helps.

Steve.
 
Thank you!

I think it´s settled then.
It seems like the best thing is to leave the engines alone. Taking the spares situation and high costs involved into consideration it´s probably not worth the effort to try to get just 25-30 more horses out of them.

My friend has to either re-power his boat, or stick to the 14 knot cruising speed his boat (Fjord 34 flybridge) manages. Beeing a sailor myself I always try to convince him that 7 knots is more than enough and 14 is almost frightening...
 
Re: Thank you!

175 hp was GT version and had same turbo but much bigger intercooler, all turbo versions have thicker head studs and nitrided cranks and stronger con rods.

Dot 1 and 2 and 3 are all max 145 standard, GTs are 175 and dot 4 which is quite different is 200.

early versions are 135hp.

Mine are overfulled at the pump by 15% to 165hp, a good fuel pump shop should be able to do this although most are not keen due to concerns over going pop, generally I think its considered that beyond 165 will effect longevity significantly, Perkins did provide a small number of engines up at about 200 hp for race boats in the 60's (Alan Burnards Sea Fox for example).

They are as rugged as you like, cheap to run and well supported, my advice would be to make sure they are absolutely on the button and if you want a bit more poke over fuel 15% but you will notice a bit more sootiness.

A very worthwhile mod which perkins nerver did is to change the cooling water in the exhaust manifold to fresh water, the manifold is £1k so worht protecting, plus, 6354s tend to run cool and are a bit more efficient when running at 85-90 degs whihc ishelped by this mod. Its very straighforward on upright engines so I guess cannot be that hard on horizontal ones.
 
Re: Thank you!

I need two chest covers for me T 6354's. Theyve got pinholes in where corroded over the years.
Got the gaskets...but diperk nor anybody else I know have any.
Got any ideas before I get the sheet metal tools out??

You forgot to mention that turbo's also have a concentric piston crown.

Have you done the mod to the exhaust manifold..wheres it fed from...other side of the header tank??..any details?

I had to change both of mine last year, but got em off two fire damaged engines.
I think Lancing were charging £549 for a non-genuine manifold.

Most expensive item Ive bought so far were two stainless two part exhaust oulets with fireproof bonnets...from Tad. Cost me best part of £1500 once customs had slapped on import duty and VAT.

Steve.
 
Re: Thank you!

have you tried local commercial or agricultural places? I got new injector pipes from local agricultural engineers just about the time diperk was coming up and they did not have a clue.

the mod is easy, I'm away from home when I get back I can mail you the insrructions.
 
burgundyben said:
175 hp was GT version and had same turbo but much bigger intercooler, all turbo versions have thicker head studs and nitrided cranks and stronger con rods.

Dot 1 and 2 and 3 are all max 145 standard, GTs are 175 and dot 4 which is quite different is 200.

early versions are 135hp.

Mine are overfulled at the pump by 15% to 165hp, a good fuel pump shop should be able to do this although most are not keen due to concerns over going pop, generally I think its considered that beyond 165 will effect longevity significantly, Perkins did provide a small number of engines up at about 200 hp for race boats in the 60's (Alan Burnards Sea Fox for example).

They are as rugged as you like, cheap to run and well supported, my advice would be to make sure they are absolutely on the button and if you want a bit more poke over fuel 15% but you will notice a bit more sootiness.

A very worthwhile mod which perkins nerver did is to change the cooling water in the exhaust manifold to fresh water, the manifold is £1k so worht protecting, plus, 6354s tend to run cool and are a bit more efficient when running at 85-90 degs whihc ishelped by this mod. Its very straighforward on upright engines so I guess cannot be that hard on horizontal ones.
Click to expand...

Hi Ben
Sorry to bother you but can you mail me the mod for the freshwater cooling of the exhaust manifolds? Many Thanks Mike
 
Also remember that it is the propeller that moves his Fjord (boat that is) ... so pointless just getting more HP capability out of the engine.

If he uprate the engines, he'll also need new propellers...Engine will run at same RPM, but having the fuelling/air capacity to produce more HP at that given RPM... but without a more heavily loaded propeller, he cannot translate that extra capacity to thrust...
 
gunnarsilins said:
I´m asking of behalf of a friend who owns two of these big, slow-revving diesels delivering only 145 Hp despite almost 6 litre volume and a turbo charger.
Is it known that the ouput can be increased to let's say 200 Hp? Are there any specialists or tuning kits around?
Click to expand...

Do not even consider it.

Despite howls from the diehards any increase in cylinder pressure by up-fueling at your existing 2,400 rpm rated speed will compromise the already limited cylinder pressure capability of the Dot 2 engine. Getting the old style multi layer steel gasket is now very difficult. I addition likely you have hydraulically governed CAV DPA fuel pump, for which rotor heads are heads are no longer available.

These once popular old engines are responsible for more spoiled boating than any other. Use them until they fail, but never spend money on them they will bite you in the wallet.
 
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The last pair I rebuilt were the dot4 220 range 4 motors, I understand manifold are no longer avialable for these models, very smokey on cold start up.
 
FWIW: I had both P175s from my Moonraker overhauled by Golden Arrow Marine some years ago and on dynamometer testing they achieved 196bhp. With new 4 blade props the boat could just top 20kts at 2550rpm and cruise at 16. It's now used mainly on the river, so speed is not reqd.
 
volvopaul said:
The last pair I rebuilt were the dot4 220 range 4 motors, I understand manifold are no longer avialable for these models, very smokey on cold start up.
Click to expand...

Perkins combined Manicooler was manufactured by Serck. When Perkins dumped marinisation on to Sabre Serc wanted a fee to retain Manicooler patterns, no fee was forthcoming so Seck scrapped off patterns. Many Dot4's were sold in the U.S. and there was a huge fuss regarding Manicooler availability so fresh patterns were made up. However pattern making is big $$ and investment had to be recouped therefore new Manicoolers are circa 4K, but are available.

Dot 4 is a far nicer and more capable motor in the head gasket area than Dot 2 also has decent water cooled turbo.

I you want to regularly pull near 200hp out of a Dot 2 T6.354 it will have the durability of a disposable cigarette lighter. Original T6.354 175Gt was never a true 175 as rating was to optimistic BS AU141A. Well suited to running at river speeds. Also note rise in rated speed from 2,400 rpm of the 145's to reduce PCP's, downside is that the skinny jack-shaft DPA fuel pump dive (beefed up on Dot4) will be having a merry dance at 2,500 rpm!

Love to see the final invoice from Golden Arrow
 
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