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Re: Exhaust and intake resonances

Posted: Wed Apr 03, 2013 5:36 pm
by timinator
Thank you GC. Glad I pre-ordered a copy of your soon to be released black and white version of your 2010 limited edition. I might have trouble remembering all of this extract from chapter 9 of your 2010 book. Your new book is definitely a good bargain.

Re: Exhaust and intake resonances

Posted: Wed Apr 03, 2013 6:02 pm
by Guy Croft
Indeed you did order the 2013 revised & updated B&W version Tim - and I thank you most warmly for doing so!

You may like to know that the enhancement of the cylinder pressure state around BDC on the ex cycle was one researched personally and confirmed by the late Prof Blair.

It was however first researched many years previously (and pre-electronics) by Smith and Morrison for their good (but now - quite naturally - outdated book, 'Design of Exhaust and Intake Systems' - the 3rd edn of which I read at university in 1977!!

Along with 'Design and Tuning of Competition Engines'

which is still a good read - a very nice blend of tech and practical - and there is a Fiat TC on the cover and some info on my old F1 boss Brian Hart in there too!

That book more than anything got me into what I do now!

http://www.google.co.uk/search?hl=en&as ... as_rights=

Still stuck on its 6th edition of that year!

I contacted publisher Josh Davidson at Bentley some years ago, he said he knew of me from my 1995 book which was nice. I offered to revise and update it and wrote some stuff (heavily researched) about Formula Ford. I was told that whilst they would appreciate my help (here and there) they had a guy (who had scratch-built his own racing engine) who was doing the 'Seventh Edition' but it is still not in the market place...

Anyhow for your kind interest - attached is what I wrote. Completely unrelated to the topic so just an attachment. Shortly after, Josh, a good friend of the Bentley family, took a 'golden handshake' and left... !

I wonder why I bother sometimes, I truly do...


Very sincerely,

G

Re: Exhaust and intake resonances

Posted: Wed Apr 03, 2013 6:24 pm
by Guy Croft
Here's Harty

a rarity this one!


http://www.youtube.com/watch?v=9CldeiOpIRY

G

Re: Exhaust and intake resonances

Posted: Fri Apr 05, 2013 6:48 am
by timinator
reflected wave lowers the pressure state across the exhaust valve and reduces the pumping loss. That alone can be worth 20bhp on a 180bhp engine because it not only reduces piston work, it gives way better charge density.
This is interesting. I thought the inertial scavenging of the exhaust gas was responsible for reducing pumping loss. Even more interesting was that you, GC, researched this for Prof. Blair.
I wonder why I bother sometimes, I truly do...

Probably because you are hard wired that way. I started doing Yoga, a long time ago, to get out of that type of downward spiraling thought.

The plenum on the formula Ford engine is a work of art. Having more crudely constructed manifolds, on engines I have built, makes me wish that my last name was Ford. Enjoyed the Formula Ford article.

Very much enjoyed the interview with Brian Hart. It was easy to see that he thought the interviewer was a dolt. He remained very pleasant though, much to his credit.

Thank you for adding these things to your post. It adds certain flavor to the forum.

Re: Exhaust and intake resonances

Posted: Fri Apr 05, 2013 11:38 am
by Guy Croft
Hi Tim

thanks for your kind remarks.

I must make it clear I never had any connection with Prof Blair nor do I seek to take any credit from anything he did.

I wrote 'researched personally and confirmed by Prof Blair' meaning he personally researched and confirmed it.

G