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Search found 210 matches

by juuhanaa
Sat Oct 01, 2022 3:32 pm
Forum: Engine Tech
Topic: A visual example of the 90 degree crank drawback.
Replies: 14
Views: 433

Re: A visual example of the 90 degree crank drawback.

As with a lot of things automotive, the flat plane vs cross plane issue is another compromise ...... Smaller capacity V8s, predominantly those racing in the tighter regulated formulae where winning is down to the last 'enth', will almost always be 'flat' Larger capacity V8s, where the rules are loo...
by juuhanaa
Sat Oct 01, 2022 5:47 am
Forum: Engine Tech
Topic: Venturi Port by David Vizard
Replies: 28
Views: 1050

Re: Venturi Port by David Vizard

Like I've said before.... how do you define... what the throat is? What part is the throat in this illustration? https://www.thesamba.com/vw/gallery/pix/2054896.jpg Throat is the smallest cross section of the flow path, it defines to a major part how much oxygen can pass per stroke and it is, in mo...
by juuhanaa
Sat Oct 01, 2022 3:13 am
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 262
Views: 7489

Re: Does quench affect power?

Mmmmhhhh...seems to be different combustion regimes, 7° IGT difference :D. Took me like 1.5 Years to figure noise that started at idle, came from my faulty piston pin machining :D Thats a another thing. It is not enough to get clearance right and round, bushing needs to be straight in relation to t...
by juuhanaa
Sat Oct 01, 2022 2:28 am
Forum: Engine Tech
Topic: A visual example of the 90 degree crank drawback.
Replies: 14
Views: 433

Re: A visual example of the 90 degree crank drawback.

So there should be some cheap wrong cranks for hot rodders to buy now. =P~
by juuhanaa
Fri Sep 30, 2022 3:30 pm
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 262
Views: 7489

Re: Does quench affect power?

Here is a prtsc about interference between R19 and experimental stuff.. Its a pain for me, but i can do roughly something using cars own system. I didn't check or optimize ignition advance with respect to crank position, so that table doesnt have much value for this topic.. Now for a comparison oth...
by juuhanaa
Fri Sep 30, 2022 10:13 am
Forum: Engine Tech
Topic: Camshaft lobe design by Billy Godbold
Replies: 48
Views: 1760

Re: Camshaft lobe design by Billy Godbold

I picked some alloy and my collaugue helped measuring the conductivity. Very nice :). You call yourself a hobbyist? That is top level hobbyist which is not achieved by quite a few professional. I've done this for my doctoral thesis, measuring and validating heat fluxes to calculate heat transfer co...
by juuhanaa
Fri Sep 30, 2022 9:49 am
Forum: Engine Tech
Topic: Venturi Port by David Vizard
Replies: 28
Views: 1050

Re: Venturi Port by David Vizard

As my wife says, the inner values count. What was the redline and what were the pipe lengths? Info regarding headers can be found at page 19, and it was little scary how it turned out to be. https://www.speed-talk.com/forum/viewtopic.php?f=15&t=55767&start=270 And here at page 6... https://www.spee...
by juuhanaa
Fri Sep 30, 2022 8:07 am
Forum: Engine Tech
Topic: Venturi Port by David Vizard
Replies: 28
Views: 1050

Re: Venturi Port by David Vizard

Static flow: Area which has lowest static pressure, but dynamically area which has highest pressure. Its not all about changes in walls, it comes to how that area is utilized by the flow, so pulsed flow and NA vs boosted make also a difference? Just thinking. That's an interesting point. Pulsed flo...
by juuhanaa
Fri Sep 30, 2022 6:05 am
Forum: Engine Tech
Topic: Camshaft lobe design by Billy Godbold
Replies: 48
Views: 1760

Re: Camshaft lobe design by Billy Godbold

I dont understand why we have plastic hammers in my daily job. I often take a copper one, and i hold it from end of the stem. My colleagues think im nut. The Copper-Berilium valve seat do not only have a great heat transfer coefficient material-wise but also have better valve bounce calm property t...
by juuhanaa
Fri Sep 30, 2022 3:52 am
Forum: Engine Tech
Topic: Venturi Port by David Vizard
Replies: 28
Views: 1050

Re: Venturi Port by David Vizard

If I remember right the David V illustration was a result of flowbench research, and probably FOR something like a crossflow hemi, something valve size limited, where the valve can flow all the way around. Which isn't a very common situation for what most of us are doing. But I still think it has a...
by juuhanaa
Fri Sep 30, 2022 2:11 am
Forum: Engine Tech
Topic: Camshaft lobe design by Billy Godbold
Replies: 48
Views: 1760

Re: Camshaft lobe design by Billy Godbold

I’ll have to find it, but he has said elsewhere that this came about when they flipped an old cam designer’s lobe around and found it worked better. He also referred to that cam designer as the “John Daly” of designers in terms of his designs. You can take a guess who he is talking about. I have he...
by juuhanaa
Thu Sep 29, 2022 4:25 pm
Forum: Engine Tech
Topic: Venturi Port by David Vizard
Replies: 28
Views: 1050

Re: Venturi Port by David Vizard

The 2-valve heads have an advantage on combustion, especially the low inclined angle wedge heads. Here the porter get to a combustion preparation guy while the 4-valve porter just optimize velocity in one direction. I think open chamber stuff and wrong seat angles are cool. Also open chamber with n...
by juuhanaa
Thu Sep 29, 2022 4:09 pm
Forum: Engine Tech
Topic: Venturi Port by David Vizard
Replies: 28
Views: 1050

Re: Venturi Port by David Vizard

Sometimes adding material helps more on the dyno and track as on the flow bench :D. Yes, well, some ports are just too big. I recall reading on some motorbike site or another that it was noted that an 80s 400cc 4 cylinder bike had similar port sizes to a more modern litre bike. The takeaway was tha...
by juuhanaa
Thu Sep 29, 2022 3:43 pm
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 262
Views: 7489

Re: Does quench affect power?

Here is a prtsc about interference between R19 and experimental stuff.. Its a pain for me, but i can do roughly something using cars own system. I didn't check or optimize ignition advance with respect to crank position, so that table doesnt have much value for this topic.. ignition BWM evo1.png Now...
by juuhanaa
Thu Sep 29, 2022 12:18 pm
Forum: Engine Tech
Topic: Venturi Port by David Vizard
Replies: 28
Views: 1050

Re: Venturi Port by David Vizard

But even less then the 2-Liter 4-valve of Opel (Vauxhall) C20XE with 2 x 35 mm valves used for STW and BTCC. My rally car has 2 x 34.5 intake valves and i was thinking reverse flow when i did this chamber work. I also installed a complex 4-2-1 header design with chokes fitted every Y -junction star...