Perkins T6354 Turbo replacement

[riccardo193]

Hi to all i hope one of you can help me i have a Haterace 34Dc fitted with twin perkins T6354 145 BHP built 1964 the turbo are shot but are not
original and were air cooled i wish to fit water cooled type but no one can tell me what turbos i need Help please.

 

[janglesea]

The original CAV Turbochargers did not work well and most were replaced by Holset 3LDs which Perkins adopted for manufacture in the early '70s. You can still pick up Holset 3LDs as they were used on many engines, including Ford 180 and others. I believe Hendy Power in Southampton list them.

My engines are 1966 and 1968, respectively (Horizontal, both standard rotation). I had both Holset 3LDs (1973 vintage) professionally rebuilt in 2003 but the rebuilds were not very successful, in that after spending £300 per turbo I still lacked boost and had hight EGTs. I do not often push the throttles to the point where this is an issue but in 2010 I picked up a new, unused non-waste-gated Holset H1c from Cummins at a very good price (£132.00) and used it as a replacement for a 3LD. I was advised that the H1c was a drop-in replacement for the 3LD, which it was emphatically not. I had to make an adapter for the exhaust flange to mate with the original exhaust elbow and modify the oil supply and drain connections. I also had to make a custom V clamp for the exhaust connection. The air inlet was also smaller than the original 3LD; the T4 manifold connection was the same. The Holset H1c has a wider exhaust "snail" than the 3LD and so I could not fit the original heat shield. The original heat shield has a welded reinforcing baffle inside which limited the space for the turbo so instead I had a stainless fabricator make me a simple rolled U plate of 1mm brushed A4 which does the same job and was cheap and easy to fit.


In service I have found the H1c to be a better Turbocharger than the Holset as I get boost at lower rpm and the exhaust runs 100 degrees cooler. But the cost and time to adapt the new turbo to the oil and exhaust connections made me look hard for another Holset 3LD when the other engine needed a replacement turbo. Which I found eventually (a factory rebuilt Perkins unit for £152) and fitted with a successful outcome.

I do not know of any water cooled Turbos used on the T6354 although that is not to say no-one has ever fitted them. My understanding of water-cooled turbochargers is that unless you have to, you shouldn't. Most current installations appear to use heat jackets to keep heat into the turbo and exhaust elbow for improved power, rather than a water jacket to cool them down and lose power. The insulated jackets help keep the engine space temperature down, which I assume is what you wish to do.

 

[riccardo193]

Turbos

Thanks so much for the information regards Rick

The original CAV Turbochargers did not work well and most were replaced by Holset 3LDs which Perkins adopted for manufacture in the early '70s. You can still pick up Holset 3LDs as they were used on many engines, including Ford 180 and others. I believe Hendy Power in Southampton list them.

My engines are 1966 and 1968, respectively (Horizontal, both standard rotation). I had both Holset 3LDs (1973 vintage) professionally rebuilt in 2003 but the rebuilds were not very successful, in that after spending £300 per turbo I still lacked boost and had hight EGTs. I do not often push the throttles to the point where this is an issue but in 2010 I picked up a new, unused non-waste-gated Holset H1c from Cummins at a very good price (£132.00) and used it as a replacement for a 3LD. I was advised that the H1c was a drop-in replacement for the 3LD, which it was emphatically not. I had to make an adapter for the exhaust flange to mate with the original exhaust elbow and modify the oil supply and drain connections. I also had to make a custom V clamp for the exhaust connection. The air inlet was also smaller than the original 3LD; the T4 manifold connection was the same. The Holset H1c has a wider exhaust "snail" than the 3LD and so I could not fit the original heat shield. The original heat shield has a welded reinforcing baffle inside which limited the space for the turbo so instead I had a stainless fabricator make me a simple rolled U plate of 1mm brushed A4 which does the same job and was cheap and easy to fit.


In service I have found the H1c to be a better Turbocharger than the Holset as I get boost at lower rpm and the exhaust runs 100 degrees cooler. But the cost and time to adapt the new turbo to the oil and exhaust connections made me look hard for another Holset 3LD when the other engine needed a replacement turbo. Which I found eventually (a factory rebuilt Perkins unit for £152) and fitted with a successful outcome.

I do not know of any water cooled Turbos used on the T6354 although that is not to say no-one has ever fitted them. My understanding of water-cooled turbochargers is that unless you have to, you shouldn't. Most current installations appear to use heat jackets to keep heat into the turbo and exhaust elbow for improved power, rather than a water jacket to cool them down and lose power. The insulated jackets help keep the engine space temperature down, which I assume is what you wish to do.

 

[riccardo193]

Thanks so much for the information regards Rick

Thanks so much for the information regards Rick

Thanks so much for the information regards Rick

 

[Skylark]

I'd respectfully suggest that the best advice you're likely to be offered would be for someone with the same engine to read the turbo nameplate details and pass them along for you to source the correct product.

The turbo needs to be matched to the engine. The basic model designation will only likely define the compressor and turbine series and their overall diameters. Each of the 2 wheels is machined to a "trim", a ratio of inducer to exducer (in the case of the comp, oppositite for the turbine). The volute of the turbine housing is sized by another ratio called A/R. The ratio of its area to radius at the throat.

Some examples. If the compressor trim is too small, low engine speed airflow requirements will not be hugely impacted but the compressor stage will soon choke and/or overspeed (measured in Mach numbers as it's an aerodynamic device). Conversely, too large and the stage will surge at low speed.

The same is true of the turbine wheel, a radial outflow turbine, but the housing size is likely to be dominant. Think of it as a funnel. If the A/R is too large, the exhaust gas will not be accelerated quickly enough to give up its energy (mass flow x Cp x DTemp) to spinning the turbine. So the compressor will be unable to generate enough boost. Too small an A/R and the gas will accelerate too quickly and overspeed the device, leading to premature failure, probably by high cycle fatigue. Another common turbine overspeed failure mode is harmonic resonace of the exducer.

As to turbine housing cooling. A bit of a nightmare for the designer to be honest. The requirement is to maintain "touch temperature" in the engine bay. The water cooling meets this and the cooling effect of the exhaust gas can be roughly compensated by dropping down 1 A/R size. The biggest challenge is iron casting technology. It's a very complicated shape and it sees quite high temperature profiles. A perfect recipe for cracking in service. Not impossible to get a unit unscathed through a 3,000 engine endurance test but a bit of a challenge, to say the least. Thermal wrap, when done correctly, provides an eloquent solution.

I spent 20 years in the turbocharging business working in close cooperation with major engine builders. My advice would be, in the first instance, to ask Perkins for the correct spec and part number and then do some Googling to find one.

 

[riccardo193]

thanks for clearing that up but the real problem still being that holset do not make the 3ld turbo any more and kno one can replace it ???????

I'd respectfully suggest that the best advice you're likely to be offered would be for someone with the same engine to read the turbo nameplate details and pass them along for you to source the correct product.

The turbo needs to be matched to the engine. The basic model designation will only likely define the compressor and turbine series and their overall diameters. Each of the 2 wheels is machined to a "trim", a ratio of inducer to exducer (in the case of the comp, oppositite for the turbine). The volute of the turbine housing is sized by another ratio called A/R. The ratio of its area to radius at the throat.

Some examples. If the compressor trim is too small, low engine speed airflow requirements will not be hugely impacted but the compressor stage will soon choke and/or overspeed (measured in Mach numbers as it's an aerodynamic device). Conversely, too large and the stage will surge at low speed.

The same is true of the turbine wheel, a radial outflow turbine, but the housing size is likely to be dominant. Think of it as a funnel. If the A/R is too large, the exhaust gas will not be accelerated quickly enough to give up its energy (mass flow x Cp x DTemp) to spinning the turbine. So the compressor will be unable to generate enough boost. Too small an A/R and the gas will accelerate too quickly and overspeed the device, leading to premature failure, probably by high cycle fatigue. Another common turbine overspeed failure mode is harmonic resonace of the exducer.

As to turbine housing cooling. A bit of a nightmare for the designer to be honest. The requirement is to maintain "touch temperature" in the engine bay. The water cooling meets this and the cooling effect of the exhaust gas can be roughly compensated by dropping down 1 A/R size. The biggest challenge is iron casting technology. It's a very complicated shape and it sees quite high temperature profiles. A perfect recipe for cracking in service. Not impossible to get a unit unscathed through a 3,000 engine endurance test but a bit of a challenge, to say the least. Thermal wrap, when done correctly, provides an eloquent solution.

I spent 20 years in the turbocharging business working in close cooperation with major engine builders. My advice would be, in the first instance, to ask Perkins for the correct spec and part number and then do some Googling to find one.

 

[cryan]

What's wrong with the current T/C's? Can they not be refurbished?

 

[riccardo193]

Turbos

Hi Holset do not make spares for these turbos any more and i have been told that rebuilding them is not recommend. What gone wrong is that the oil seals have gone.

Regards Rick

What's wrong with the current T/C's? Can they not be refurbished?