Search found 360 matches
- Thu Apr 27, 2023 8:52 am
- Forum: Engine Tech
- Topic: Dykem and a Flow Bench
- Replies: 83
- Views: 4667
Re: Dykem and a Flow Bench
I have posted images of this in the past. I doubt that I still have them but could make new ones. Could you? Sure, here you go. As you can see, the air circulates around in a toroidal path. It changes at various piston levels quite differently. CFD flow follows piston.png Makes one wonder if other ...
- Thu Apr 27, 2023 8:06 am
- Forum: Engine Tech
- Topic: Dykem and a Flow Bench
- Replies: 83
- Views: 4667
Re: Dykem and a Flow Bench
Darin was previously showing burn marks and carbon deposits of a ran head, which matched almost identically to his Dykem testin on flowbench. Some think fuel washes the surfaces, when an alternative view could be that the fuel on wetted surfaces burns poorly (rich) during combustion leaving carbon ...
- Thu Apr 27, 2023 7:50 am
- Forum: Engine Tech
- Topic: Pipemax question
- Replies: 2
- Views: 446
Pipemax question
Learning to use the Pipemax (latest version pro 4.7) and getting these lines in airflow calcs. Wondering if I have something wrong in my data input that could cause it. Mach Z-Factor Valve Lift = Level=10 Cam calculated Speed of Sound velocity thru Valve Curtain Areas Pumping Choke Valve Lift = Leve...
- Mon May 10, 2021 5:05 am
- Forum: Engine Tech
- Topic: Helping air around a curve?
- Replies: 8
- Views: 1187
Re: Helping air around a curve?
Widen where it's red. It will slow down the high speed areas and even out the pressure in the tube, using the area better. It will also reduce secondary flow which is a result of having unequal pressures across the port.
- Wed Dec 30, 2020 6:33 am
- Forum: Engine Tech
- Topic: Reducing the header exhaust port area?
- Replies: 29
- Views: 3442
Re: Reducing the header exhaust port area?
If you look at the typical low loss venturi shapes, the contraction can be much more abrupt than the expansion without flow loss. Nicely rounded entry to right size pipe would not lose much and it would flow poorly backwards.
- Thu Jun 25, 2020 2:26 pm
- Forum: Engine Tech
- Topic: Port work on a Fiat 124 2L head
- Replies: 9
- Views: 1072
Re: Port work on a Fiat 124 2L head
- Thu Jun 25, 2020 1:47 am
- Forum: Engine Tech
- Topic: Ignition curve discussion
- Replies: 24
- Views: 2665
Re: Ignition curve discussion
That is certainly part of the equation. I know each different pipe had a different optimal curve. The fun part came when we found that a two stroke at constant throttle and rpm, would increase EGT with time. Now it was time for the really sharp tuners to go have a beer. :lol: Well, EGT sensors are ...
- Wed Jun 24, 2020 1:36 pm
- Forum: Engine Tech
- Topic: Port work on a Fiat 124 2L head
- Replies: 9
- Views: 1072
- Wed Jun 24, 2020 1:00 pm
- Forum: Engine Tech
- Topic: Ignition curve discussion
- Replies: 24
- Views: 2665
Re: Ignition curve discussion
In our two stroke shifterkart engines, the curve for best wide open power was very advanced down low and got progressively more retarded through the rev range. Probably due to some form of the same phenomenon. 2-strokes retard at high rpm to put more heat into pipe, which changes the speed of sound...
- Wed Jun 03, 2020 6:04 am
- Forum: Engine Tech
- Topic: Blasting media to restore as cast finish to alloy?
- Replies: 17
- Views: 2693
Re: Blasting media to restore as cast finish to alloy?
Vapour blasting seems to give nice results. Several youtube videos about that and nice pictures from google search. A local guy built his own setup picking features from different videos and gets nice results. He uses glass "crush" as media mixed with water. Although not sure if it's a sol...
- Sun May 31, 2020 5:01 pm
- Forum: Engine Tech
- Topic: Weird colored reversion.
- Replies: 12
- Views: 1711
Re: Weird colored reversion.
PCV into the rear of the carb?
- Tue May 12, 2020 12:38 am
- Forum: Engine Tech
- Topic: What SBF head is this? 289hipo/302/hi-port iron hybrid
- Replies: 21
- Views: 50069
Re: What SBF head is this? 289hipo/302/hi-port iron hybrid
Those look like the same casting, but without the plugged thermactor holes.
- Mon May 11, 2020 11:50 pm
- Forum: Engine Tech
- Topic: Piston oil squirters in NASCAR engines
- Replies: 71
- Views: 12196
Re: Piston oil squirters in NASCAR engines
IIRC, 351C stock rods also have a piston oil squirter channel in the big end cap parting line and a small notch in the rod bearing. By my understanding, those are for wrist pin and bore wall oiling, not for piston cooling. Piston cooling requires a different nozzle and flow volume. Not sure what th...
- Mon May 11, 2020 12:36 pm
- Forum: Engine Tech
- Topic: What SBF head is this? 289hipo/302/hi-port iron hybrid
- Replies: 21
- Views: 50069
Re: What SBF head is this? 289hipo/302/hi-port iron hybrid
Makes sense, but it did seem different enough to be cast differently. Can't claim expertise however.
- Mon May 11, 2020 12:03 pm
- Forum: Engine Tech
- Topic: What SBF head is this? 289hipo/302/hi-port iron hybrid
- Replies: 21
- Views: 50069
Re: What SBF head is this? 289hipo/302/hi-port iron hybrid
It's C8ZE
Google search on the crane Fireball head shows a same head. Didn't notice Crane stamping on these though. May have just missed it, or it wasn't there...
Google search on the crane Fireball head shows a same head. Didn't notice Crane stamping on these though. May have just missed it, or it wasn't there...