Forced induction 100cc

**husaberg** · 5th May 2014, 23:16

Originally Posted by Brian d marge

The cooling comes from the change of phase from a liquid to a gas and the mire you can get that to happen in the squish flame front area the more stable the combustion and the higher pressures you can run
Apart from beefing up crankcases and studs waste heat transfer one method of reducing head walk was to have a raised lip around the bore lapped into a groove around the head combustion chamber ,. Cant think of the name applied to this method .dry no gasket and as smooth and as flat as u can get it
Possible on a 4cyl easy on me single enfield hahahaha

Stephen

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the word ya looking for Stephen is "Spigot"

**Brian d marge** · 5th May 2014, 23:25

Thats the one . .im tapping this out on a phone in the middle of a storm in north canterbury
So not near my books and a very dodgy memory.

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**husaberg** · 5th May 2014, 23:28

How long are you here Stephen..........

**speedpro** · 6th May 2014, 06:35

Originally Posted by Brian d marge

The cooling comes from the change of phase from a liquid to a gas and the mire you can get that to happen in the squish flame front area the more stable the combustion and the higher pressures you can run

Oddly we went the other way with my turbo and reduced the squish area as much as possible. The only remaining squish area was next to the inlet valve. A mate had experimented with this sort of thing and determined that this was the go. The added advantage was that doing it reduced the compression. Whatever, when it was all going good it made more power than you could use even at Puke' except at the end of the back straight.

**Grumph** · 6th May 2014, 07:26

Originally Posted by speedpro

Oddly we went the other way with my turbo and reduced the squish area as much as possible. The only remaining squish area was next to the inlet valve. A mate had experimented with this sort of thing and determined that this was the go. The added advantage was that doing it reduced the compression. Whatever, when it was all going good it made more power than you could use even at Puke' except at the end of the back straight.

yeah, there are some oddities with blown motors. Fuel mixing - as in well homogenised fuel and air - is very good, as is usually distribution. Very simple manifolding works pretty well. Personally I doubt if squish is as important in blown motors - but chamber shape definitely is. The more compact the chamber shape the better. It's hard enough to light the fire with high pressures - and a poor chamber shape just leads to even more advance...and more problems.
O ringing the bores in the usual style with 20G stainless wire helps too.

**Sketchy_Racer** · 6th May 2014, 22:45

Loving all the input guys, I am reading it all. Next week I will be pulling the motor out of the frame as this week is busy now with other projects and im away this weekend. I've got access to some beryllium copper here so I am tempted to machine some valve guides and valve seats in a hope of controlling valve temps and I'll also degree the stock cam to get an idea of where that is. I like the idea of running a lot of overlap for valve cooling, esp in this case of such small valves and only 2 of them.

Out of curiosity, it makes me wonder how much power is lost through poor engine mounting. Obviously when an engine is vibrating in chassis that energy is coming from somewhere.

I will also o-ring the head and look into what is involved in dry decking the head. I dont think it will be hard as the oil gallery at the moment just travels up one of the studs.

I have already up graded the stock head studs from M8 to M10 wasted stud. I hope that will help with the things stretching.

**speedpro** · 7th May 2014, 06:57

Originally Posted by Sketchy_Racer

I've got access to some beryllium copper here so I am tempted to machine some valve guides and valve seats in a hope of controlling valve temps

That is nasty shit if my training in the Air Force is correct. OK as a complete tool or object but dangerous to work. Highly carcinogenic or something. Take care working it. I had a special toolkit for working around particularly strong magnets. If a tool was to break we were told very forcefully to vacate the area.

**Grumph** · 7th May 2014, 07:27

Originally Posted by speedpro

That is nasty shit if my training in the Air Force is correct. OK as a complete tool or object but dangerous to work. Highly carcinogenic or something. Take care working it. I had a special toolkit for working around particularly strong magnets. If a tool was to break we were told very forcefully to vacate the area.

i agree .....Admiralty bronze is much safer and thermally very good. Personally, I'd only do guides as disturbing the OE seats could potentially cause more probs than it would solve....

The big overlaps I like are very unfashionable now. Historically, the best example was the Alfa Romeo 159 - post war GP car. Two stage blown 1.5 litre straight eight. 350 plus HP on Meth. So much overlap they referred to it as the extra stroke - or cooling stroke....
But it kept it reliable for 3 hour plus GP's with the materials available.
As an aside I remember reading a Don Garlits interview. Towards the end of his career and he'd just moved to the Donovan Hemi setup. He was hogging out ports and asking for more and more cam - including overlap - and was going faster and faster. He'd gone in the opposite direction to the popular Donovan setup - small ports, short cam - and was making way more power than the other Donovan users.

**Sketchy_Racer** · 7th May 2014, 19:28

Originally Posted by speedpro

That is nasty shit if my training in the Air Force is correct. OK as a complete tool or object but dangerous to work. Highly carcinogenic or something. Take care working it. I had a special toolkit for working around particularly strong magnets. If a tool was to break we were told very forcefully to vacate the area.

I've had the fun of working with it for many years now, I make optic inserts out of the material for a living. It's not the danger beast that is perceived, you do need to be careful around the dust particles so it is important to always machine it wet, never dry.

I'll see if I can find some photos of the stuff I make. It's an amazing material so many awesome properties!

**speedpro** · 19th December 2014, 19:02

and now it is . . . . . . .

**Pumba** · 19th December 2014, 21:21

There was a video on FB a couple of days ago with it running.

**Sketchy_Racer** · 20th December 2014, 17:30

Yeah been back in the shed tinkering with the supercharger bucket again. Slightly different configuration to what I was running earlier but seems promising.

Now running a AMR300 roots blower with a draw through system rather than EFI. Got a really basic cdi on there at the moment for ignition but plan on going ignitech in the future.

https://www.facebook.com/video.php?v...57&pnref=story for video

**Grumph** · 20th December 2014, 22:34

So as i said about 30 pages back, one step sideways, one step back, half a step forward....normal progress on a blower installation.

Bigger blower running slower and a basic draw through layout...At least it may see a track in that configuration. Make that work with usable boost levels then refine it...

So far, you and a lot of others have learned a lot from this. Your machining and fabrication skills have been developed. It doesn't seem to have cost you a lot of dosh either...Carry on.