LDS VS LDT and the real differences

[gringeltaube]

I'm meeting with a guy today that can test these two ip's. It might take a few days but I hope to have an answer. It would be nice to find out that you swap out a spring in all our ldt's and then the injector pumps are the same.
....................

Very good! Although I think it could be more than a spring...

According to the book the IPs for the 5ton engines (B & F codes) take the HD90EH101A hydraulic head (which is also interchangeable with the HD90EH111A, for the "A" code LDS465-2 engine). From the book again, the pumps for all C, D and E code engines (LD & LDT) are equipped with the HD90EH100A head.

I have found 5ton IPs installed in 2.5ton engines and working well, but they always had the corresponding "correct" HH installed.
Question now is: what could be the difference between both model heads and what happens if we cross-matched them? What I mean is that just swapping out a mechanical part of the IP doesn't convert the -100A head into a 101A, if there really was a difference in performance and not just the relative position of the fuel inlet hole, or such.

It sure would be interesting to know if and how the only replacement heads currently availabe (HD90100A, FSN 2910-828-7176) would work in a typical LDS 465-1A IP (#PSB6A 90EH 5828A1), in a LDS465-1A equipped Deuce!?

G.

 

[gimpyrobb]

I have fuel leaking out of the 12 point plug on the side of my HH. It is an LDS motor. I am getting ready to swap in a 100a head. I will let you know of any noticeable differences.

Anyone know what causes the head to leak at that plug?

 

[Recht71]

Lds

Clinto We had that happen to us on the WILDTHING gun Truck coming back from Fort Eustis V.A. In Everet P.A . Called thought it was the head we were told that they crack . It was the 12 point plug after a very expensive tow bill Might want to try put another plug in. Till Later Randy

 

[bottleworks]

I seem to recall that the LDS troubleshooting manual stated that the one-hole injectors are to be replaced with two-hole.

Exactly what I have been thinking when reading this thread. That is stated in the LDS manual. It's not the injectors which give the additional power. LDS have been using both.

 

[jasonn]

So my little brother stops by today with his bobbed duece that I built for him. He tells me it's leaking something and wants mr to check it out so I lift the hood and I'm trying to see this oil leak behind the air pump and I look down and long behold there is a LDS injector pump on his truck his truck has an LDT motor in it so I check a little further it also has the same injectors as my LDS. But it has the little whistler turbo on it. I have drove his truck 20 times or more there I'd no noticeable hp increase over my bobbed duece with an LDT with the non-whistler turbo. Some one mentioned
the hydraulic head might be a difference I'm gonna check those numbers on his truck to see if it's also the same.

 

[SCSG-G4]

So right now we have the wastgate turbo, the lower compression pistons, the hydraulic head and the injector pump as the differences between the LDT and the LDS. If the IP is not making a difference as jasonn has said and the HH is the same, that only leaves two items to investigate, but at least we are narrowing things down!

 

[rebel_raider]

I perused the engine manual and I came up with two other differences.

1. LDS has different intake rocker arms. Exhaust is the same as both on the LDT. They could have a higher ratio and allowing more air into the motor.

2. The rearmost part of the exhaust manifold is different on the LDS. I assume that is for better flow also.

 

[Squirt-Truck]

I believe that the wast-gate turbo was dropped when they went to the 1A engine. I have a 1990 LDS-1A it does not have a waste gate turbo and has single hole injectors. It has not been altered since it left Continental in that they were able to provide me with the correct replacement parts. It even still has the silicone injector body seals in place. Hercules still provides these engines.

Wonder if they will share what is different???

 

[Recht71]

More food for thought These pic's are from TM9-2815-210-34p .So much for Turbo 's looks like they used these on either engines

 

[Brian H.]

Maybe I can help a little bit with my knowledge of diesels and souping them up.

Wastegated turbo+ lower compression pistons = greater boost normally, but it's not so simple as that. There are some reasons there is a wastegate on that turbo, and not the other turbos. The wastegate serves as a limiting device which allows some exhaust gasses to by-pass the turbine wheel, therby accomplishing two things, reducing drive pressure, and also limiting boost pressure. Most likely, all three turbos will all produce similar boost, as you guys have stated that you've seen C and Ds on LDS motors. The reason this third turbo has the wastegate is the "AR Ratio" is smaller, making the turbine spin faster than the other two turbos at low rpm, making it make more boost at a low rpm, letting the engine burn more fuel without smoke and also giving you greatly increased bottom end power.

I saw pictures of the C and D turbos next to each other on the truck, and the C turbo has a much smaller AR ratio (what it is I do not know) than the D turbo, which is why the C looks like a snail and the D looks more squared off. The reason the C turbo whistles so much out the exhaust is three fold, the Turbine speed is higher than the D at idle, the turbine may have less or more fins than the D and also being the turbine speed is higher at idle, you're hearing more of the turbine action than you are the exhaust note. The D turbo whistles too out of the exhaust, but you just can't hear it until the engine exhaust noise drowns it out almost totally. I'm young and my hearing is still excellent and I can hear the D turbo whistle some, but not anywhere close to the same as the C.

 

[Brian H.]

Maybe I can help a little bit with my knowledge of diesels and souping them up.

Wastegated turbo+ lower compression pistons = greater boost normally, but it's not so simple as that. There are some reasons there is a wastegate on that turbo, and not the other turbos. The wastegate serves as a limiting device which allows some exhaust gasses to by-pass the turbine wheel, therby accomplishing two things, reducing drive pressure, and also limiting boost pressure. Most likely, all three turbos will all produce similar boost, as you guys have stated that you've seen C and Ds on LDS motors. The reason this third turbo has the wastegate is the "AR Ratio" is smaller, making the turbine spin faster than the other two turbos at low rpm, making it make more boost at a low rpm, letting the engine burn more fuel without smoke and also giving you greatly increased bottom end power. It also has the wastegate because having such a small AR ratio, the turbo will make maximum boost at a low engine rpm, and to prevent the drive pressure (backpressure between engine and turbo) from going up astronomically. When the boost reaches a set PSI, the pressure coming from the turbo pushes the wastegate ]actuator open which causes the wastegate to open, letting the extra un needed exhaust gasses bypass the turbo.

Most waste gates are adjustable, and you can increase boost somewhat without increasing fuel, but you may lose some top end power as the engine will be working against itself trying to push the exhaust through the turbo.

I saw pictures of the C and D turbos next to each other on the truck, and the C turbo has a much smaller AR ratio (what it is I do not know) than the D turbo, which is why the C looks like a snail and the D looks more squared off. The reason the C turbo whistles so much out the exhaust is three fold, the Turbine speed is higher than the D at idle, the turbine may have less or more fins than the D and also being the turbine speed is higher at idle, you're hearing more of the turbine action than you are the exhaust note. The D turbo whistles too out of the exhaust, but you just can't hear it until the engine exhaust noise drowns it out almost totally. I'm young and my hearing is still excellent and I can hear the D turbo whistle some, but not anywhere close to the same as the C.

 

[jimk]

Here are some good pictures MikeON posted (photos labeled c-d ) and his associated text.

I recently swapped turboes and took pictures while they were both out. Installed a pyrometer probe at the same time.

The C turbo gave 7 psi max boost, the D gave 8 psi max, and gives some boost at much lower engine RPM. I since turned up the fuel and get 12 psi. Turned the truck from a real dog into a decent runner.

Mike

http://www.steelsoldiers.com/deuce/16562-turbo-classification-2.html


The last four pictures- D compressor wheel head on (a different view of the one posted earlier this thread), D turbine (rusty housing), a different D turbine with slightly curved blades (painted housing), cross section dia.

Two of these last four pictures (d compressor wheel and d turbine w/ rusty housing made 16+psi when added to a smokey LD. I turned it down but it is safe to say it probably would have made more if turned up.

(looks like the order got scrambled. Should be easy to sort with info provided)

 

[doghead]

any updates? Has this thread been dropped?

 

[midcounty]

I will put my 2 cents in. I have a LDS and just recently acquired a LDT. Both trucks have the C turbo. The LDS runs circles around the LDT. I don't believe the turbo is any real difference in power. Both trucks are still as bought from GL as far as fuel settings, and seem to smoke the same amount. I am planning to put boost and EGT gauges on both trucks in the near future and start tuning. Then I will know for sure if the LDS is making more power when both engines are cranked up to the same EGT limits. If the LDS still makes more power then, it will be certain the turbo is not the difference.

 

[Mikey90744]

sorry chiming in late, but has anyone checked their EGTs with the 5 ton turbo? I know you can bring down EGTs if you bring down intake temps, and you can bring down intake temps with different turbos, and different turbos will bring down the EGTs just from less restriction on the exhaust side. how much I don't know though, and the other thing is have you really compared the heads? specifically the intake runners. Im just curious and didnt see anything as I read through the thread right now but I didnt read everything in detail, I apologize if those things have been answered already

 

[Mikey90744]

just had one more thought, rocker arms the same? another trick to get more lift out of a cam. just a thought

 

[gringeltaube]

......... I don't believe the turbo is any real difference in power.........

I'm with you on this. Please let us know your results after "tuning".

G.

 

[Squirt-Truck]

I keep seeing reference to the "waste gate" turbo for the 5-ton.
My manual gives the wastegate turbo on the LDS-465-1 engine and a non-wastegate turbo on the LDS-465-1A. Just like the two hole injectors on the -1 and single hole injectors on the -1A. Thoughts??

 

[wb1895]

Pardon my ignorance, but I would like to know what some of the specs are on the LD motor, besides it doesn't have a turbo.

 

[Fredo Corleone]

I have two 1971 deuces one with a LDS with a D turbo and a LDT with a C turbo. The LDS is the way to go I have been spoiled. When I got the LDT I was surprised at the differance.