F1technical.net

riff_raff wrote:Seems strange that they use an aluminum piston and a steel bore sleeve. I can see the reason for using an aluminum piston, both in terms of reduced mass and heat transfer required from the gas compression heating occurring within the cylinder volume. Would be interesting to know why they use a steel sleeve in the aluminum cylinder housing. There are very durable coatings like Nikasil that can be applied to aluminum, which would seem to be a better option than using a separate steel liner in the aluminum housing. But I'm sure the guys designing the system knew what they were doing, and had a reason for making it like that.

Was the liner always there?

http://www.racecar-engineering.com/wp-c ... orth-2.jpg

My eyes are not great but I cannot see it here, nor the top flange, gap & retainer ring.

Brian Coat wrote:

riff_raff wrote:Seems strange that they use an aluminum piston and a steel bore sleeve. I can see the reason for using an aluminum piston, both in terms of reduced mass and heat transfer required from the gas compression heating occurring within the cylinder volume. Would be interesting to know why they use a steel sleeve in the aluminum cylinder housing. There are very durable coatings like Nikasil that can be applied to aluminum, which would seem to be a better option than using a separate steel liner in the aluminum housing. But I'm sure the guys designing the system knew what they were doing, and had a reason for making it like that.

Was the liner always there?

http://www.racecar-engineering.com/wp-c ... orth-2.jpg

My eyes are not great but I cannot see it here, nor the top flange, gap & retainer ring.

I'm told that the liner was always there, and had been removed from the assemblies in some photos - it was certainly removed from the well publicized magazine article which featured a photo of the barrel assembly. There is an o-ring present in that shot down the bore which made no sense - and one of many reasons I set out obtaining one. Turns out that o-ring was for sealing the steel liner. Many pictures circulating up until this cannot be trusted with some parts omitted to keep designs under wraps.

@riff_raff, I guess aluminum pistons and steel liners in an aluminum housing is well understood - particularly given the fact that many F1 engines themselves used the same combination; sleeved blocks.

The steel liner/sleeves for the "AVS" Pneumatic Valve Spring assemblies are also listed as being made by an outside vendor.

Brian,

Brian.G wrote:

Brian Coat wrote:

riff_raff wrote:Seems strange that they use an aluminum piston and a steel bore sleeve. I can see the reason for using an aluminum piston, both in terms of reduced mass and heat transfer required from the gas compression heating occurring within the cylinder volume. Would be interesting to know why they use a steel sleeve in the aluminum cylinder housing. There are very durable coatings like Nikasil that can be applied to aluminum, which would seem to be a better option than using a separate steel liner in the aluminum housing. But I'm sure the guys designing the system knew what they were doing, and had a reason for making it like that.

Was the liner always there?

http://www.racecar-engineering.com/wp-c ... orth-2.jpg

My eyes are not great but I cannot see it here, nor the top flange, gap & retainer ring.

I'm told that the liner was always there, and had been removed from the assemblies in some photos - it was certainly removed from the well publicized magazine article which featured a photo of the barrel assembly. There is an o-ring present in that shot down the bore which made no sense - and one of many reasons I set out obtaining one. Turns out that o-ring was for sealing the steel liner. Many pictures circulating up until this cannot be trusted with some parts omitted to keep designs under wraps.

@riff_raff, I guess aluminum pistons and steel liners in an aluminum housing is well understood - particularly given the fact that many F1 engines themselves used the same combination; sleeved blocks.

The steel liner/sleeves for the "AVS" Pneumatic Valve Spring assemblies are also listed as being made by an outside vendor.

Brian,

Thanks, Brian. Very interesting.

Got a chance this evening to press out the sleeve - heated body to approx 180 degrees first then light pressure with delrin anvils pushed it out - there was possibly no need for heat, but this assembly was pretty expensive so I want to try keep hammer marks to a minimum....





I really need to get lint free micro fiber cloths...





Decent chamfer at the top of alloy assembly,



Sealing o-ring as mentioned in previous post,



Inserted a few mm once again,



A view from the bottom, with liner and o-ring in view,



Tomorrow evening I hope to have a good look at the intake pressurized air way and return drilling,

Brian,

Wow, excellent thread. Though I think you may have "blown your cover" (with a wink wink) with that serial number on the sleeve.....

hpras wrote:Wow, excellent thread. Though I think you may have "blown your cover" (with a wink wink) with that serial number on the sleeve.....

I didn't say anything

Thanks for comment on thread!


Brian,

Holy --- this is amazing! I write for Jalopnik -- could I use one of these pictures on a post about this on Jalopnik? I'd link back to here and credit you, it's just so cool to be able to see one of these things in full. -- Raphael (feel free to email me at [email protected])

raphaelorlove wrote:Holy --- this is amazing! I write for Jalopnik -- could I use one of these pictures on a post about this on Jalopnik? I'd link back to here and credit you, it's just so cool to be able to see one of these things in full. -- Raphael (feel free to email me at [email protected])

Raphael, yes, sure - no problem at all.

Brian,

Brian.G wrote:

hpras wrote:Wow, excellent thread. Though I think you may have "blown your cover" (with a wink wink) with that serial number on the sleeve.....

I didn't say anything

Thanks for comment on thread!


Brian,

Its a good giveway. Really enjoying seeing this stuff out in public view for once.

Are you a collector of F1 parts/memorablia?

Facts Only wrote:

Brian.G wrote:

hpras wrote:Wow, excellent thread. Though I think you may have "blown your cover" (with a wink wink) with that serial number on the sleeve.....

I didn't say anything

Thanks for comment on thread!


Brian,

Its a good giveway. Really enjoying seeing this stuff out in public view for once.

Are you a collector of F1 parts/memorablia?

Not a collector no - Just like to get a close look at some of the more interesting parts! I don't believe in filling cabinets with pretty parts and would chop up anything in a heartbeat if I thought ya'd learn from it.

Brian,

Thanks for the post. Brian number 1.

The mechanism itself is very simple... just a piston some guides a few seals.. a spring.. a ball.. etc.. but when you talk about engineering design and optimization it is some aerospace level stuff..

I can only imagine how light it is.. probably only a few grams...

I was impressed with the steel sleeve and that it was actually honed.

I wonder how long the piston seal lasts though.

And it looks like it came from a cosworth engine?

Excellent as always Brian.

Top Notch
Thank You Brian.G

Excellent writeup and top notch photographs thanks for sharing!

Thanks folks!

Hoping to get time soon to have a look at the air pressure drillings as mentioned and maybe get it pressurized to do some tests.

Brian,