Speed-Talk is running on www.Speed-Talk.com

IMPORTANT: Update your bookmarks to https://www.speed-talk.com/forum/
(Right-click the URL and select "Bookmark this link")

Search found 192 matches

by juuhanaa
Wed Sep 28, 2022 11:39 am
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6944

Re: Does quench affect power?

If your compression ratio requirements are such that you can run an approximately flat top piston in a four-valve pentroof engine, you're just going to win win win whether you have squish or not. Just run a high tumble port. The trouble begins with large included valve angle heads run normally aspi...
by juuhanaa
Wed Sep 28, 2022 11:07 am
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6944

Re: Does quench affect power?

Then we have Germans, Italians and French..

Aand a lot comes from USA.


https://www.youtube.com/watch?v=i3Xk-hcqVt4

https://www.youtube.com/watch?v=aR4DlG8jDdI

enjoy,
by juuhanaa
Wed Sep 28, 2022 10:32 am
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6944

Re: Does quench affect power?

The way i see it, its one thing that has to work with the others. In Finland guys run engines like this. it would be nice to have little bit more below 8k. Then i would be bussy in settin the diff and chassy.



-juhana
by juuhanaa
Wed Sep 28, 2022 9:58 am
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6944

Re: Does quench affect power?

Here is a picture of matching chamber and piston with some dimensions...Cold squish clearance was approx 1.3mm Squish area, only from piston side, don't know if they match the squish area of the head too, is 16.5 % according your data: bore = 84 mm and segment height is 11.5 mm. Thanks! Ah of cours...
by juuhanaa
Wed Sep 28, 2022 3:16 am
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6944

Re: Does quench affect power?

I have told earlier that my static cr been on 11 range, but in reality that is approximate and it includes errors in measuring. Anyway its an value where i have been willing to reduce. I started to remember VW did also something in the 90s. Pictures above was added by request :D Attached one page of...
by juuhanaa
Tue Sep 27, 2022 1:56 pm
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6944

Re: Does quench affect power?

Here is a picture of matching chamber and piston with some dimensions. This one survived, but eventually threw a light weight connecting rod (my own mistake at least in machining). Dished version surprised me, felt more stronger and bent a crank, but thats a good thing. Please forgive me paint art a...
by juuhanaa
Tue Sep 27, 2022 10:28 am
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6944

Re: Does quench affect power?

I have lift to valve diameter ratio of .309 and 1.3mm cold squish clearance. Max lift and and piston TDC no contact. Interesting to see how this response on a dyno to "slight" intake advance. I mean the rally car i have mentioned in other topic.. Its a coctail engine, but round and round we go :D Sc...
by juuhanaa
Tue Sep 27, 2022 6:55 am
Forum: Engine Tech
Topic: Camshaft lobe design by Billy Godbold
Replies: 31
Views: 1134

Re: Camshaft lobe design by Billy Godbold

[quote=gruntguru post_id=926029 time=1664252387 user_id=25870] Here you go. [url]https://www.physicscurriculum.com/interactivephysics#:~:text=Sampling%20of%20simulations.-,Interactive%20Physics%20is%20a%20versatile%20program%20that%20allows%20users%20to,or%20elaborate%20systems%20on%20screen.[/url] ...
by juuhanaa
Tue Sep 27, 2022 6:01 am
Forum: Engine Tech
Topic: Camshaft lobe design by Billy Godbold
Replies: 31
Views: 1134

Re: Camshaft lobe design by Billy Godbold

People think 4 valves are hard to improve and yet the same group of people are more than willing to change their cams. Comparing camshafts can be a bit more complicated than often assumed. Let's compare two camshaft angle area; that is to say the areas under their lift curves. Assume both are 3-4-5...
by juuhanaa
Mon Sep 26, 2022 4:51 pm
Forum: Engine Tech
Topic: Camshaft lobe design by Billy Godbold
Replies: 31
Views: 1134

Re: Camshaft lobe design by Billy Godbold

how much value should be given to area rule? Last winter i had a exiting moments in calculus. 122cid 4 banger 240@seat and 7500rpm? :shock:

IMG_20220926_211759.jpg
by juuhanaa
Mon Sep 26, 2022 2:01 pm
Forum: Engine Tech
Topic: Camshaft lobe design by Billy Godbold
Replies: 31
Views: 1134

Re: Camshaft lobe design by Billy Godbold

People think 4 valves are hard to improve and yet the same group of people are more than willing to change their cams.
by juuhanaa
Mon Sep 26, 2022 1:08 pm
Forum: Engine Tech
Topic: Larry's Soft Head
Replies: 75
Views: 40953

Re: Larry's Soft Head

Volvo Touring Cars 242T's were pretty dependant on Toluene mixed with LL Avgas in the mid 80's. Seems to be it was modern that time using that quite toxic octane adder. The 240T I don't know very well, the ETCC wasn't well known here. More popular were here the STW, DTM and BTCC were also Volvo par...
by juuhanaa
Mon Sep 26, 2022 11:01 am
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6944

Re: Does quench affect power?

What CID, VE and RPM? I think it's a reasonable solution for any normally-aspirated four-valve engine that has a large bore relative to stroke and needs a high compression ratio. Those tend to be relatively high rpm engines. Whether it's a 150cc Suzuki cylinder, 500cc BMW cylinder, or 667cc Porsche...
by juuhanaa
Mon Sep 26, 2022 10:58 am
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6944

Re: Does quench affect power?

That sounds like a really nice playground for different approaches. Do you have a cylinder pressure indication system to find out more about the heat release over crank angle curve? _MG_9390.jpg Yep, like Fiat Tipo has close the same base plate than Alfa 156 :wink: No, i only have heard about TFX a...
by juuhanaa
Mon Sep 26, 2022 9:39 am
Forum: Engine Tech
Topic: Does quench affect power?
Replies: 253
Views: 6944

Re: Does quench affect power?

I concentrate only on the maximum squish velocity to see how big the impulse can be. My 0D-model uses the approach of G.P. Blair, which gives a rough idea what is happening in the chamber and when it happens. Of course a 3D-approach would clarify all the interaction, but this is out of my budget an...