Almost supercharged BIS.

[fly]

Quick one of the charger all plumbed in, can't seem to post directly as can't get the file size small enough!

http://instagram.com/p/o_iMMQMzDZ/

Had the engine running this morning, whiich I didn't expect from the first attempt but the belt keeps throwing off so a bit if tinkering to do but all-in-all pretty positive.

[Mics126]

hows this car/project turned out.

I did not quite understand if you droped your compressition ratio or kept it standard.

Mike

[fly]

I haven't touched it in ages, too much other stuff going on (new baby an all that!).

I just need to brace the engine and charger, when it gets up into 'proper' boost the engine is twisting on the mount causing the belt to throw off.  It'll only be when I can get it running for a sustained period that I'll then be able to tinker with timing / fueling etc.

As for compression, no, all standard, I'm even running the standard carb with an electric pump.  I'm not aiming for anything crazy, just a bit more oomph for hills and the likes.

[poxxxy]

Look forward to seeing more progress with this one! Looks mad with everything mounted over that side .

[Mics126]

Sounds fairly good once you sort out the mouting issue. I was mainly asking because i was wondering about the compression ratio because i'm currently halfway building an air-cooled 650 turbo and was gong to run about 0.5 bar of max boost and most of the time 0.2, i have spoken to small cox but his engine is not exactly standard so the compression ratios will be different anyway. if you you had use it on the road and 0.7-0.8 worked then i would have probbably tryed that pressure because I know the bis has a slightly higher compression ratio so if yours survived and didn't start pinking or anything then as i said before i will try a higher boost pressure when i get it on the road.

I may end up advising you soon as i will robably get mine on the road some time this month.

thank for answering anyway.

Mike

[fly]

Sorry, yeah, misunderstood a little bit.

Max boost (basically calculated) is around 0.7 (possibly 0..  As I've done it as a draw through system, I shouldn't theoretically have the issues that are inherent of blow through, and particularly turbo systems - ie excessive heat.

Any advice you can give would be greatly received.  I really need to put some time aside to fettle mine, it's only a few hours work to get it sorted (I hope).

[Mics126]

sorry its taken a long time to reply but i have been away.

the few of possibly many issues of using forced induction(turbo/supercharger) on a standard engine is one the con rods can't take the power (you can get that if you just tune the engine with natrally aspirated parts but its a bit harder to do that), but the main issue is pinking or pre-detonation of the fuel/air mix before the spark plug fires. there are 2 main issues with that 1) you loose power because of incoret timing and the fuel being burnt incoretly, 2) you can damage the engine in to main ways 1) the con rod will get more stress because its being forced down when it is trying to go up and 2) the pre-detonations are in little pockets of fuel and air and are extreamly hot and you get whats known as "pepper pot holes" in the piston, Cylender head.

the main way of stoping this without changing the cylender head for a low compresion head is always use super unleaded ( the higher octane helps), and don't run high boost, thats why i'm mainly only going to use 0.2 bar most of the time but i will get more experiance as i drive it(sould be on the road in a week or two hopefully).

Hopefuly that helped I could spend a long time talking about this partcular subjrct but it would take a long time.

Mike

[Mics126]

something i forgot to say in my last post is i did not want to scare you about what i said. the best thing to do is if posible control your maximum boost and gradualy increse it as you drive. if you hear what sounds like a bag of pins in your engine(pinking) then back the pressure off. another thing i forgot to say is if you run the engine a bit richer than normal that should help aswell.

as i said before when mine is on the road i will try to help you if you need/want any help.

Mike