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LDS VS LDT and the real differences

rustystud

Well-known member
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You can always think positive thoughts like, It will be busted when he gets it. That should help to calm you down.
Actually I hope it turns out Ok for him. It's just that I've been looking for a few years now and have recently given up when this happens ! I guess it just wasn't meant to be. Probably blow-up my engine hot-rodding it around town !
 

ShawnIfert

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Location
chatham PA
LDS 465 1A Intake Rocker Arms

I checked the LDS rocker arms to the LDT rocker arm. I set the Rocker Arm Shaft up on my mill and I did not find a difference. I pushed the valve side of the Rocker Arm down .100 in and the push rod side came up .077 in. But my test was flawed. I had the adjustment screw all the way in. I found when I had installed the LDS Rocker Arms part number 11641735 in my LDT 465 1D the adjustment screw came out at an angle that change the ratio when the lash was set. The LDS Rocker arm was .030 in shorter.


I ran my truck in the stock engine configuration and my Turbo boost was 14 psi and my EGT's were 1150 up a big hill. I do have the LDS piston/liners installed. My intake and Exhaust system is from a M35 A3. I installed the LDS Rocker Arms and I ran the truck up the big hill again the boost was 12 psi and the EGT's were 900. This test proves that the LDS Rocker arms let 50 or more CFM in the engine. I just need to install the Injection Pump and the Injector and then I will have a LDS 1A. 2015-10-21_10-38-07.jpg2015-10-21_10-38-32.jpg2015-10-21_11-07-24.jpg2015-10-21_11-40-49.png2015-10-22_13-14-54.jpg2015-10-21_10-36-40.jpg2015-10-21_10-37-09.jpg
 

brianp454

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Portland, OR
Thanks ShawnIfert! I haven't followed this thread in a while and was not aware that the LDS and LDT used different rocker arms. When you say the LDS is shorter, can you elaborate? Can you do a pic of each for a side by side comparison?

Nice AR-15 mat!
 
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ShawnIfert

Member
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Location
chatham PA
The over all length is .030 in shorter, but the adjustment screw hole in the rocker are is on a angle that brings the ball end of the rocker closer to the Rocker shaft changing the ratio. I did not see it until I installed the Rocker Arm and adjusted the screw out. To set the lash you have to put the adjustment screw almost all the way in. The engine has a very different sound as well, more of a loop. You can hear more air entering the air intake as well.
 

rustystud

Well-known member
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Woodinville, Washington
Good job Shawn. We knew there was a difference, but no one had actually tested it to see how much of a difference it was. 50 CFM's is a big difference, couple that with the different cam used and I'm sure that will explain all the extra Horsepower of the LDS engine.
By the way, where did you get the LDS rocker arms from ?
Thanks.
 
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ShawnIfert

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Location
chatham PA
I went through all the manuals from 1965 to the last one in the 90's and all the cams were the same. The ldt 465 1d, I know has to same cam as the lds 1a. The LDS 2 has may differences. Some of them are a bit crazy. The engine seems to have been a replacement for the old gas engines. It has not been made for very long time. Parts would very hard to find to make one. The LDS 2 is really pushing the edge of what you can get out of a 465 block. I believe from looking all the info on a LDS 2 that it would have a short life spam. I was able to get NOS Arms From WB Parts in FL.
 

rustystud

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The reason you can not find different part numbers is that they consolidated them into one design after they no longer bought new LDS engines. Why confuse things when one cam will do it all.
 

brianp454

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Rusty

I looked back through the threads as I remembered you posting more on the cams.
See post 355 on page 36, 367 on page 37, 386 on page 39, and 389 on page 39.

Please give me a holler with what you find on the rockers

-Brian
 

ShawnIfert

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Location
chatham PA
I am heading back to the bush to work in the mines in Mali. I will be back for xmas. I will install the lds injectors and pump and I will post the results. I did some research on the LDS injectors and found that they went to one hole in the later years instead of two hole. I have an nos set of lds one hole injectors from the late 80's that were 55 buck each so I going to use them. But all of my research show one hole injectors were use torward the end of production.
 

rustystud

Well-known member
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Location
Woodinville, Washington
I am heading back to the bush to work in the mines in Mali. I will be back for xmas. I will install the lds injectors and pump and I will post the results. I did some research on the LDS injectors and found that they went to one hole in the later years instead of two hole. I have an nos set of lds one hole injectors from the late 80's that were 55 buck each so I going to use them. But all of my research show one hole injectors were use torward the end of production.
Actually you have that backwards. They went from the one hole injector to the two hole injector. One hole is bigger then the other allowing a misting instead of a spray in one and a spray in the other. This allowed better atomizing of the fuel. The way multifuel engines work the spray fills the bowl in the piston with fuel and it allows the fuel to slowly burn off, but adding a misting action allowed for better initial combustion like modern diesel engines.
 

ShawnIfert

Member
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Location
chatham PA
injector

View attachment LDS465Tdroubleshooting.pdfI am a diesel mechanic and I do understand hypercycle combustion very well. The two hole injector would work better. The injector has two small holes that are about equal to the size of the one hole injector. The difference between the two injectors is the one hole puddles fuel in the combustion bowl where the two hole injector puddles/sprays fuel into the combustion bowl and the top of the piston. The two hole has two dispersion angles. Here is a manual I found. I cant remember where I had found it but it is a manual from continental date 1965. It has a lot of good information in it.
 

ShawnIfert

Member
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Location
chatham PA
You must keep in mind that the Continental 465 series engine is not a true diesel engine. The 465 is a Hypercycle combustion multifuel engine. Due to the 465’s design their many limitations of what can be done to improve the engines performance.
1. The ports in the head swirls the air entering the engine.
2. The compression ratio is 22:1. This limits how much boost and fuel can be added to increase performance.
3. The Fuel injectors are what they call a pooling injector. The injector does not atomize the fuel like a regular diesel engine injector. The reason for this is to prevent pre ignition when using fuels other than diesel. You would have a bad knock when using gasoline if the fuel was atomized.
4. The design of the combustion bowel in the piston is a lot different. The bowl control evaporation rate of the fuel and prevents it from cracking until the correct fuel to air ratio is reached to prevent knock.
 

cattlerepairman

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I have just finished my LDS rebuild and I was very attentive to spot the details and differences mentioned here, compared to the LDT. Let's be precise here: I am an amateur and have torn through the innards of exactly 1 LDS (Continental factory rebuilt before) and 1 LDT engine for a rebuild, and not side by side. As far as what was visible with the naked eye, I can confirm (as stated earlier) that the rocker arms are different. The IP is different. The heads appeared exactly the same. The valve springs appeared different between the LDS and the LDT (but then, there are earlier and later valve spring setups). Both the LDS and the LDT had block mounted oil squirters for each piston that appeared to be the same. The pistons looked "sleeker" on the LDS (is the skirt longer?), but the rings appeared the same, (which surprised me). The LDS crankshaft appeared better machined (the LDT had perfect journals but the non-contact surfaces were quite a bit rougher). Not sure if that matters any. Exhaust manifold was the same, intake manifold is slightly different on the LDS (the angled part where it connects to the turbo). I could not determine whether the intake manifold itself has a wider space inside for better/more air flow on the LDS. It looked and mounted the same. Main and rod bearings were the same.


IMG_20151101_110816.jpgIMG_20151022_095811.jpgIMG_20151022_163209.jpgIMG_20151012_134402.jpg
LDS Rocker arms and valve springs, piston tops, better view of LDS valve train and LDS pistons from below


LDS and LDT certainly have slight differences and if your engine is factory-new, then you probably have a "pure" LDS or LDT.

I do wonder, however, if you are still getting the same "pure" distinction on either one after the first rebuild (or even after some unit-level maintenance). It seems to me that, during a rebuild, innards that fit would have been matched and used (e.g. LDS piston set inside an LDT; complete heads taken off the shelf and used in either LDS or LDT etc.). Add to that the variety of block castings that is out there, on top of TD vs. non-TD and the variations become huge (well...they all look the same, but you know what I mean).
My impression (and it is nothing more) was that the LDS appeared to be assembled with "better" parts (tighter specs, less tolerance?), in addition to the different fuel IP.

I am very proud of my LDS rebuild, but I was hoping to see the secrets of LDS power first hand - and it was certainly underwhelming in that department.
 
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ShawnIfert

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chatham PA
The manual I just posted 575 has a lot of info on how this engine works.
They were many companies over the years that had made this engine and there has been a few design changes over the years. Continental, Hercules, White and MAN have produced this engine. The block and heads on my engine have the MAN symbol on the castings. Some of the differences are due to the manufacturer as far as machine work and other things.
 

gimpyrobb

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Any fhance of you posting a pic of the "man" symbol? I've never seen one and would like to know what it looks like. For all the conjecture this thread has, its nice to be getting good info.
 
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