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 997 matches

by Erland Cox
Sat Dec 03, 2022 6:14 pm
Forum: Engine Tech
Topic: Burn patterns on piston and chamber
Replies: 7
Views: 134

Re: Burn patterns on piston and chamber

https://scontent.fmmx4-1.fna.fbcdn.net/v/t39.30808-6/313331380_5128605613912632_8354222126848402811_n.jpg?_nc_cat=101&ccb=1-7&_nc_sid=dbeb18&_nc_ohc=v4F40NrioXcAX_2tKOD&_nc_ht=scontent.fmmx4-1.fna&oh=00_AfAef5_6NtRZGqnC9UVC-bWiaQk64bgkfaNbZ9XMyRAykw&oe=639147E8 With burr finish in ports and chamber...
by Erland Cox
Fri Dec 02, 2022 12:18 pm
Forum: Engine Tech
Topic: Intake Manifold Porting Show ‘n Tell
Replies: 183
Views: 4416

Re: Intake Manifold Porting Show ‘n Tell

There we go ,the more we do the math the less we know! Experience,r&d is everything.I have read so much expert knowledge that is no where near what goes on.People think they find something,and that's cool.Most things do not duplicate enough for us to understand.Thats why I only do what intrigued me...
by Erland Cox
Fri Dec 02, 2022 12:02 pm
Forum: Engine Tech
Topic: Intake Manifold Porting Show ‘n Tell
Replies: 183
Views: 4416

Re: Intake Manifold Porting Show ‘n Tell

what did the 7.28 combination make on your dyno? At that time I did not have a dyno and it was me and 2 Danish guys that had the car so we dynoed it in Denmark. If I remember right the old engine from Bob Ingles had 1075 hp and the one with my heads 1090 with more average. I do not remember the tor...
by Erland Cox
Fri Dec 02, 2022 6:48 am
Forum: Engine Tech
Topic: Intake Manifold Porting Show ‘n Tell
Replies: 183
Views: 4416

Re: Intake Manifold Porting Show ‘n Tell

Vanniks software would show the curves and what happens with different tapers and lengths. The dyno would show what the result was. Erland There we go ,the more we do the math the less we know! Experience,r&d is everything.I have read so much expert knowledge that is no where near what goes on.Peop...
by Erland Cox
Thu Dec 01, 2022 6:26 pm
Forum: Engine Tech
Topic: Intake Manifold Porting Show ‘n Tell
Replies: 183
Views: 4416

Re: Intake Manifold Porting Show ‘n Tell

Vanniks software would show the curves and what happens with different tapers and lengths.
The dyno would show what the result was.

Erland
by Erland Cox
Thu Dec 01, 2022 4:12 pm
Forum: Engine Tech
Topic: Intake Manifold Porting Show ‘n Tell
Replies: 183
Views: 4416

Re: Intake Manifold Porting Show ‘n Tell

No. There is no frequency for it during valve open. Outgoing wave velocity is the local speed of sound minus the flow velocity. Ingoing wave velocity is the local speed of sound plus the flow velocity. Forget the earlier waves, everything starts with the energy from the exhaust and the piston, IVO t...
by Erland Cox
Thu Dec 01, 2022 1:44 pm
Forum: Engine Tech
Topic: Intake Manifold Porting Show ‘n Tell
Replies: 183
Views: 4416

Re: Intake Manifold Porting Show ‘n Tell

Dry flow?

Erland
by Erland Cox
Wed Nov 30, 2022 4:36 pm
Forum: Engine Tech
Topic: Intake Manifold Porting Show ‘n Tell
Replies: 183
Views: 4416

Re: Intake Manifold Porting Show ‘n Tell

The secondary ramming wave cancels out the higher cylinder pressure before TDC and both prevents reversion, lets the intake cycle start a little earlier and cleans the combustion chamber of residuals which means that som loss out the exhaust is necessary. . It is a positive wave, next we need a nega...
by Erland Cox
Wed Nov 30, 2022 10:56 am
Forum: Engine Tech
Topic: Intake Manifold Porting Show ‘n Tell
Replies: 183
Views: 4416

Re: Intake Manifold Porting Show ‘n Tell

Look at the negative pressure drawn at 400 degrees. This sets up the pressure the engine has to work with the next 650 something degrees. Every time it changes sign means it har reflected at the other side of the runner. A taper adds duration to the wave but takes amplitude from it. The cylinder has...
by Erland Cox
Wed Nov 30, 2022 4:35 am
Forum: Engine Tech
Topic: Intake Manifold Porting Show ‘n Tell
Replies: 183
Views: 4416

Re: Intake Manifold Porting Show ‘n Tell

Good morning, I dont get it. When the the calculated frequency match the given rpm, over scavenging doesnt have to be a problem and when taper is used to increase CSA, it changes the reflections on lower rpm to happen higher rpm. -juhana As soon as there is a discontinuity in area in the port the o...
by Erland Cox
Tue Nov 29, 2022 6:56 am
Forum: Engine Tech
Topic: Intake Manifold Porting Show ‘n Tell
Replies: 183
Views: 4416

Re: Intake Manifold Porting Show ‘n Tell

There is a good thing with constant taper and that is that it keeps the boundary layer thinner. But there is a bad thing too. The reflections för stuffing air into the engine are used before they are needed. And you will never be able to pull a really deep depression before maximum piston velocity....
by Erland Cox
Sun Nov 27, 2022 11:09 am
Forum: Engine Tech
Topic: Intake Manifold Porting Show ‘n Tell
Replies: 183
Views: 4416

Re: Intake Manifold Porting Show ‘n Tell

There is a good thing with constant taper and that is that it keeps the boundary layer thinner. But there is a bad thing too. The reflections för stuffing air into the engine are used before they are needed. And you will never be able to pull a really deep depression before maximum piston velocity. ...
by Erland Cox
Wed Nov 23, 2022 8:16 pm
Forum: Engine Tech
Topic: What ll this make? Rammed 496 bbc
Replies: 12
Views: 387

Re: What ll this make? Rammed 496 bbc

That sounds about right, I believe around 800 too.

Erland
by Erland Cox
Tue Nov 22, 2022 5:29 pm
Forum: Engine Tech
Topic: 350ci 470HP Peak at 6000RPM
Replies: 86
Views: 2575

Re: 350ci 470HP Peak at 6000RPM

If it was made to peak earlier it would probably give even more power earlier. I built a 445 hp 350 that peaked around 6000 but it was around 12:1 cr. L98 1.94-1.50 heads ported, ported and matched Victor JR, Crane hydraulic .480" lift 228 at .050. 106 0r 107 lobe separation. Heads flowed 240 in do...
by Erland Cox
Tue Nov 22, 2022 4:24 pm
Forum: Engine Tech
Topic: 350ci 470HP Peak at 6000RPM
Replies: 86
Views: 2575

Re: 350ci 470HP Peak at 6000RPM

If it was made to peak earlier it would probably give even more power earlier. I built a 445 hp 350 that peaked around 6000 but it was around 12:1 cr. L98 1.94-1.50 heads ported, ported and matched Victor JR, Crane hydraulic .480" lift 228 at .050. 106 0r 107 lobe separation. Heads flowed 240 in don...