ESE's works engine tuner

[Flettner]

According to Irving, it was sandblast the liner, preheat and slip it into the mould sharpish....pour making sure there was a good flow up past the liner and it was shaped so as to eliminate undercuts or areas which would trap air....Very unsophisticated.

You may be thinking of the "Al - fin" process which had several steps before casting in - and once in even though it was a parallel wall could never be removed. generally 4 stroke only, that one.

What is this " Al - fin " process? I will never need to remove the sleeve.

[Frits Overmars]

What is this " Al - fin " process? I will never need to remove the sleeve.

If I remember correctly (it is about a century ago) Al-Fin meant dipping the sleeve in molten aluminium and then inserting it in the mold after which the fins were cast.

[Flettner]

If I remember correctly (it is about a century ago) Al-Fin meant dipping the sleeve in molten aluminium and then inserting it in the mold after which the fins were cast.

We won't go there.

Frits, do you have any idea on pre treating ( brass in this case ) liners to make the aluminium " stick ".
I would rather not use a liner but if I want these small cylinders I will need to use brass so I can hard chrome onto the bore.

[Ocean1]

I think a Hydrofluric acid bath is needed for the hard chrome straight to alloy process. Not the sort of bath you would want to have.

No personally, no.

Is solid cast high silicon aluminium not an option?

[husaberg]

No personally, no.

Is solid cast high silicon aluminium not an option?

Yam are doing something similar now Chevy Vega flashbacks

[Ocean1]

Yam are doing something similar now Chevy Vega flashbacks

Corvair. If high silicon alloy casts as well as it welds it'd be a starter I reckon.

[husaberg]

Corvair. If high silicon alloy casts as well as it welds it'd be a starter I reckon.

Vega had em too high silicon copper bit iron bit mag etched after casting to expose silicon
Add link if I can be arsed
http://bbs.homeshopmachinist.net/arc...p/t-60286.html
Hard case they had to iron coat the pistons (actually oh that makes sense)

We won't go there.

Frits, do you have any idea on pre treating ( brass in this case ) liners to make the aluminium " stick ".
I would rather not use a liner but if I want these small cylinders I will need to use brass so I can hard chrome onto the bore.

Worth a read half way down page can add text on silly tablet ......

. GM Research Labs had been working on a sleeveless aluminum block since the late '50s. The incentive was cost. Engineering out the four-cylinder's block liners would save $8 — a substantial amount of money at the time. Reynolds Metal Co. developed an alloy called A-390, composed of 77 percent aluminum, 17 percent silicon, 4 percent copper, 1 percent iron, and traces of phosphorus, zinc, manganese, and titanium. The A-390 alloy was suitable for faster production diecasting which made the Vega block less expensive to manufacture than other aluminum engines. Sealed Power Corp. developed special chrome-plated piston rings for the engine that were blunted to prevent scuffing. Basic work had been done under Eudell Jackobson of GM engineering, not at Chevrolet. Subsequently, Chevrolet was given job of putting the ohc sleeveless, aluminum block into production.

The Vega engine block was cast in Massena, New York - at the same factory that had produced the Corvair engine. Molten aluminum was transported from Reynolds and Alcoa reduction plants to the foundry, inside thermos tank trucks. The block was cast using the Accurad process. The casting process provided a uniform distribution of fine primary silicon particles approximately 0.001 inches in size. Pure silicon provides a hard scuff and wear resistant surface, having a rating of 7 on the mohs scale of hardness, the same as quartz, as compared to diamond which is 10. The blocks were aged 8 hours at 450 °F to achieve dimensional stability. Before being shipped to Tonawanda, the blocks were inpregnated with sodium silicate, where they were machined through the outer skin. From Massena, the cast engine blocks were shipped as raw castings to Chevy's engine plant in Tonawanda, New York. Here they underwent the messy etch and machining operations. The cylinder bores were rough and finish-honed conventionally to a 7-microinch finish then etched by a new (then) electro-chemical process. The etching removed approximately 0.00015-inch of aluminum leaving the pure silicon particles prominent to form the bore surface.

The technical breakthroughs of the block lay in the die-casting method used to produce it, and in the silicon alloying which provided a compatible bore surface without liners. With a machined weight of 36 pounds, the block weighed 51 pounds less than the cast-iron block in the Chevy II 153 CID inline-4. Plating the piston skirts was necessary to put a hard iron skirt surface opposite the silicon of the block to prevent scuffing. The plating was a four layer electo-plating process. The first plate was a flash of zinc followed by a very thin flash of copper. The third and primary coating was hard iron, 0.0007-inch thick. The final layer was a flash of tin. The zinc and copper were necessary to adhere the iron while the tin prevented corrosion before assembly of the piston into the engine. Piston plating was done on a 46 operation automatic line. From Tonawanda, the engineswent to the Chevrolet assembly plant in Lordstown, Ohio.

Eudell Jackobson of GM engineering pointed out one of the early problems with unexplained scuffing and discovered excessive pressure on the bore hones was causing the silicon to crack. He said:"...We were trying to put a product into production and learning the technology simultaneously. And the pressure becomes very, very great when that happens. The hone-pressure problem was solved before engines actually went out the door, affecting only pre-production engines.

Makes you think only one side needs to be hard ?Neil isn't that how it works ???????

[Frits Overmars]

Frits, do you have any idea on pre treating ( brass in this case ) liners to make the aluminium " stick ".

Nope.

I would rather not use a liner but if I want these small cylinders I will need to use brass so I can hard chrome onto the bore.

If you must use a liner, think about Jan Thiel's idea of a conical fit. He used a morse cone angle for both sleeve and cylinder; then you can stick them together and take them apart as often as you wish; only the last mm of depth required a light axial press fit.
Why use brass at all? Hard chroming an aluminium bore should be a piece of cake. You could even consider doing it at home. We used to do it for the prototype cylinders of our 6.5 cc aero engines (the production engines are made by Profi in Charkov, Ukrain)
('we' being chemist professor Bert Metkemeijer who passed away recently, so I can no longer ask him for details).

[Yow Ling]

I watched a youtube on car engine manyfacturing where just before thy poured the block they inserted induction heating coils to preheat the sleeves, they were only in there for maybe 5 seconds , so maybe just getting it real hot is all thats necessary

in this video at 3.16

[wobbly]

The term port "effective area " is defined as the port chordal width * height * cosine of down angle,and I have found that getting the duct exit down to 90% of this actual area
gives the best power for a single port in the bore.

The other scenario of say a tripple port, the duct exit area that is the best, is around 75% of the total effective - and this works out in most cases to be exactly the effective area of the main port only
( ie deduct the area of the Aux ports ).

[Flettner]

Nope.If you must use a liner, think about Jan Thiel's idea of a conical fit. He used a morse cone angle for both sleeve and cylinder; then you can stick them together and take them apart as often as you wish; only the last mm of depth required a light axial press fit.
Why use brass at all? Hard chroming an aluminium bore should be a piece of cake. You could even consider doing it at home. We used to do it for the prototype cylinders of our 6.5 cc aero engines (the production engines are made by Profi in Charkov, Ukrain)
('we' being chemist professor Bert Metkemeijer who passed away recently, so I can no longer ask him for details).

Talking to the hard chrome platers here at Hamilton airport ( they chrome steel aviation cylinders ) and they say the only way to plate to aluminium direct is to pre etch with Hydrofluric, which they are not interested in using. It's not a very nice acid to have kicking around the workshop. Perhaps they are wrong, perhaps there is another way? Did you used a 4 volt DC power supply?
You are right, often the best way is to just do it yourself, the only way to get what you want.

[TZ350]

Some of the sophisticated tooling to be found in the ESE workshop.

A grunty skill saw with a fine blade does a good job of cutting alloy plate and heat sinks.



Lower heat sinks in place with copper fins on the side, these will get bent up at 45 deg later and the sharp edges rounded off.

Just got to figure out how to get the fuel injection in there too ....

[monkeyfumi]

Hello Guys,
Although I don't really contribute to this thread, I do read all of it, and greatly appreciate the shared knowledge it provides.
Given that Tee Zee is now playing around with RGV cylinders, I thought now might be a good time to show some of the stuff I've been attempting as a result of the thread.

First, some background. Bike is an Aprilia RS250 (road bike), which as we all know, uses the VJ22 RGV engine.

It is currently copping a crank up rebuild due to a wayward big end.
For the moment I'm concentrating on the cylinders. Port heights are standard (though I will be using cougar power valves, which give a slightly different timing), but the transfers have got some work, inspired by this thread.
The A transfers roof has been filled to angle it at 25 degrees, and the B port wall has been filled to make it perpendicular to the bore, as well as some small filling of the B-port rear hook. I've also radiused the bore edge at the start of the transfers.
IMG_3459 by monkeyfumi13, on FlickrI'm now looking to make an exhaust duct nozzle, with an oval to round transition, like Wobbly has advised often.
I have sourced some high temperature putty, and had a fitment model of my flange 3D printed in ABS to help when it comes to grinding the duct to size.
IMG_3456 by monkeyfumi13, on FlickrIMG_3457 by monkeyfumi13, on Flickr

I just wanted to ask Wobbly if he runs a crush gasket with his nozzle flanges, and what grade of alloy he makes them from?
Hope this triggers some productive discussion for your RGV cylinder conversion Tee Zee

[TZ350]

Your project looks good, keep posting and thanks.

[Neal]

I had some ally oval to round stubs made , we used a viton o ring instead of the crush washer and it worked very well . One of my stubs eventually sheared off , there was a straight edge instead of a radius where the spigot joined the flange causing a weak spot .