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 Post subject: Diesel stuff
PostPosted: April 6, 2024, 3:15 pm 
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Joined: August 12, 2011, 1:46 pm
Posts: 90
OK, So I've been building a inline 5 cyl diesel for a while and I'll share it here as well .
The superturbodiesel forum is a bit out of shape now so I'll put my posts from there in this topic .

An OM605 turbo was bought on the cheap and is now proudly weighing on a cart in my garage . Came up with a super simple exhaust manifold which I'll show a bit later .Also a simple design of an intake is on the way .







Edit :
Some pictures of the intake and exhaust
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It's a two piece construction . The bottom pieces are 20 mm thick and use a gasket from a 606 . the seal to the top piece uses O rings . And the top piece is attached with three studs to the bottom pieces .

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The exhaust is just flat stock laser cut to fit and the space in between is made from 33.7 90 degree beds just cut up and welded together.

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Next is the injection pump which got 7.7mm elements while the stock ones were 5.5mm . Fuel quantity is raised from about 50cc to 140cc .
The classical solution to limit smoke is to have a pressure actuator from a turbocharger pulling on the stop lever, which limits rack travel and cc.
that has one issue in my mind as it takes about 1 bar of boost for it to move at all . They are preloaded . So I made my own from a small format pneumatic cylinder acting on a valve spring with no preload . That moves almost immediately.

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The bottom end got a strengthening plate from 10mm mild steel, and spacers from 42CrMo4 . The bolts used will be head bolts from a Dacia 1.5dci as they are 12.9 grade and the proper thread just slightly longer .

Attachment:
IMG_0627.v01.jpg


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 Post subject: Re: Diesel stuff
PostPosted: April 6, 2024, 3:32 pm 
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Joined: August 12, 2011, 1:46 pm
Posts: 90
Continued :
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The spacers aren't in the pictures .

The valves got lightened on my mill .

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It's a very wonky setup and the stems of the valves are very flexible for those light cuts so I had to support them with a piece of teflon bar .

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Only the intake valves got that treatment . Exhaust are filled with sodium, so I didn't modify them .
Then they got ceracoated .

I machined a flywheel from 1045 plate to accept a pressure plate from an e34 M5 . The reason being the short input shaft of the NSG37- transmissions .

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To slow the oil pump down the original sprocket is cut of and one from a petrol version is welded on. The reduction is from 19 to 18 teeth, which is enough to eliminate cavitation in the oil pump .
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The next massive project, which took me ages it the balancing of the crank, which was a good idea since this is a five banger i.e inherently out of balance . It's a job, I'll tell you that . The bobweights :
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IMG_0748.v01.jpg


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 Post subject: Re: Diesel stuff
PostPosted: April 6, 2024, 3:35 pm 
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Joined: August 12, 2011, 1:46 pm
Posts: 90
Continued :
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IMG_0757.v01.jpg


I'll add some pictures of the second iteration of my balancing machine which worked (unlike the first one).

This much for now .
Cheers


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 Post subject: Re: Diesel stuff
PostPosted: April 6, 2024, 4:01 pm 
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Mid-Engined Maniac

Joined: April 23, 2006, 8:26 pm
Posts: 6425
Location: SoCal
Fantastic fabrication. Were exhaust pressure pulsations factored into the design of the exhaust manifold? Most manifolds use tubing or at least curved surfaces to prevent flexing of the assembly. Not only do flat surfaces create a sounding board (making for a loud engine), but the physical flexing of the surface can lead to cracking.

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 Post subject: Re: Diesel stuff
PostPosted: April 7, 2024, 9:06 am 
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Joined: August 12, 2011, 1:46 pm
Posts: 90
Ease of manufacturing was my whole motivation for this design, and while you raise a valid point, I'm not at the stage where I can confirm that . three slugs were added to prevent deformation of the flat plates .
An unexpected bonus here is the volume . From what I understand there's three places where expansion can occur in the port itself, the collector and the turbine housing . The combination I have here is the smallest housing 0.46AR on a s257sxe with a lot of volume in the header . That supposedly will result in early spool, and the header volume will make the rpm range after choke less of a restriction(or should I say reduce torque less rapidly), moving the max power rpm to the right .
In theory .


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 Post subject: Re: Diesel stuff
PostPosted: April 19, 2024, 6:25 am 
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Joined: August 12, 2011, 1:46 pm
Posts: 90
So this is what I managed with cerakote's stuff .
It's their reflective piston coat solution in the air drying version .
Intake valves got coated on the combustion chamber side while the exhaust got a coating on the thinned out part of the stem, as well .
The piston faces didn't turn out perfect but that'll do .
Also another tip on the pistons, since some guys run 100+ bhp on these motors without coating or anything they trim the diameter above the top ring -0.2mm . That has been done here along with the coating .
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Here's a few photos of my pump building experiment .
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The distances between these was set using gauge blocks set to the precise center to center distance between the barrels, which gave a surprisingly consistent fuel amount .
This is probably not the right way to phase a pump, but the testbench confirmed the angles are good between cylinders . Turns out this is the easiest way to snap a crank on a diesel .
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If anybody is interested in my approach to designing the flywheel and clutch assembly, just ask .
I'll take the time to describe in detail .


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