Turbo lag / valvetrain design

[burell]

Hi all,

Your automotive forums make wonderful reading for an amateur, so much to learn! Apologies for posting while not being in the same engineering field but I will appreciate any info you will/can give me.

I have two unrelated questions:

1) I know turbos have lag as a disadvantage compared to a compressor. Although the problem is much less now due to optimal design, two smaller turbos instead of one big one etc it hasn't gone away. Would it be an idea to have some sort of canister continuously pressurized by the exhaust flow and when turbo power is needed have this pressure (partially) dumped into the turbo, much like starting a turbine?

2) I wonder if the limit to the # of revs the valve train can take is a (the?) main inhibitor of generating more power from an internal combustion engine? I have been thinking about a system whereby a classic valve train is left largely intact but could potentially rev much higher without valve float. BTW it isn't anything like Ducati's desmodromic system.

Again any input is appreciated ...

Kind regards,

Jochen, The Netherlands

 

[patprimmer]

burrel

It might have been better if you started separate threads for each question, then the professionals who wish to participate can do so with lower investment of their time, as the resultant threads will be more organised and focused.

Re your first question:-
There has been considerable discussion on this subject before. Please do a search using words like turbo lag and accumulator.

Re your second question:-
There has also been some discussion on this in the past, although I cannot remember any particular threads like above, so also do a search with words like factors effecting maximum engine speed.

I can say that valve train is a common limitation, but so can factors like airflow restriction, oil control, piston speed, rod and rod bolt strength, flame speed, ring flutter etc.

If you have an idea you want to share, just start a thread and share it.

If you think your idea can be patented and developed, you SHOULD NOT PUBLISH IT IN ANY PUBLIC FORUM, nor with any individual, unless that individual has signed a confidentiality agreement, as a patent can be challenged due to "prior knowledge".


Regards
pat pprimmer@acay.com.au
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