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Search found 1374 matches

by digger
Mon Aug 10, 2020 5:17 am
Forum: Engine Tech
Topic: Low and medium lift Flow
Replies: 38
Views: 1654

Re: Low and medium lift Flow

can you post the full graph and the data for both the heads (flow, areas or volume)?

ive seen many tests where 706 comes out on top on the smaller size LS's mostly becasue the cross sectional areas are sufficient to meet the engines needs.
by digger
Sun Aug 09, 2020 8:28 am
Forum: Engine Tech
Topic: Low and medium lift Flow
Replies: 38
Views: 1654

Re: Low and medium lift Flow

There are lots of permutations e.g - a baseline flow curve - reduced low lift flow but the same high lift flow - reduces low lift flow but more high lift flow - more low lift flow but same high lift flow - more low lift flow but less high lift flow If you have a valve that lifts 0.800” if the head i...
by digger
Sun Aug 09, 2020 4:12 am
Forum: Engine Tech
Topic: Low and medium lift Flow
Replies: 38
Views: 1654

Re: Low and medium lift Flow

Isn’t the right experiment for simulations to increase and reduce the low lift flow map of the head and then see what happens to mass flow and power? The increase could be done either by increasing the area keeping the coefficient constant or increasing the coefficient keeping the area constant. ye...
by digger
Sun Aug 09, 2020 4:11 am
Forum: Engine Tech
Topic: Low and medium lift Flow
Replies: 38
Views: 1654

Re: Low and medium lift Flow

Yes you input flow numbers and sizes of port throat, port entry and valve/seat sizes Cool, It seems a bigger valve would be more prone to reversion on opening and a smaller port would be less prone to velocity lag but that is just an assumption on my part. here is a comparison by taking the same en...
by digger
Sat Aug 08, 2020 11:28 pm
Forum: Engine Tech
Topic: Low and medium lift Flow
Replies: 38
Views: 1654

Re: Low and medium lift Flow

Does this program allow you to account for valve size vs port size, for example a 2.08 valve on a 230cc port vs 2.08 on 180cc port? Yes you input flow numbers and sizes of port throat, port entry and valve/seat sizes Cool, It seems a bigger valve would be more prone to reversion on opening and a sm...
by digger
Sat Aug 08, 2020 6:13 pm
Forum: Engine Tech
Topic: Low and medium lift Flow
Replies: 38
Views: 1654

Re: Low and medium lift Flow

further to that here is the mass flow and cumulative mass flow(%) and valvelift(%) it shows that from 50% lift to peak to 50% the cumulative mass flow went from 6% to 96% so bulk of mass flow happens when the valve lift is medium to high and you simply are not going to make much gains with low lift...
by digger
Fri Aug 07, 2020 8:31 pm
Forum: Engine Tech
Topic: Low and medium lift Flow
Replies: 38
Views: 1654

Re: Low and medium lift Flow

further to that here is the mass flow and cumulative mass flow(%) and valvelift(%) it shows that from 50% lift to peak to 50% the cumulative mass flow went from 6% to 96% so bulk of mass flow happens when the valve lift is medium to high and you simply are not going to make much gains with low lift ...
by digger
Fri Aug 07, 2020 7:01 pm
Forum: Engine Tech
Topic: Low and medium lift Flow
Replies: 38
Views: 1654

Re: Low and medium lift Flow

Flow numbers at maximum lift have very little meaning since peak air demand occurs at maximum piston velocity. If peak piston speed is at 74 deg ATC, then whatever valve lift is present at that crank angle will determine air flow. On the exhaust side things are a little different. Maximum exhaust g...
by digger
Thu Aug 06, 2020 6:42 am
Forum: Engine Tech
Topic: Low and medium lift Flow
Replies: 38
Views: 1654

Re: Low and medium lift Flow

We all see heads advertised and we usually focus their high lift valve flow but, should we be focusing just as much, on the low and mid lift numbers? What does the low and mid lift flow do to the HP curve? What will happen if your head flow peaks at .500 lift and levels off or, even decreases a lit...
by digger
Wed Aug 05, 2020 8:12 am
Forum: Engine Tech
Topic: Low and medium lift Flow
Replies: 38
Views: 1654

Re: Low and medium lift Flow

I’d worry about the top 1/3 of the valve lift curve that’s where all the heavy hitting is done.
by digger
Fri Jun 19, 2020 3:15 am
Forum: Engine Tech
Topic: Too much oil in sump
Replies: 26
Views: 882

Re: Too much oil in sump

There’s an engine masters video Ep32 I think about this. You need to sign up for free subscription
by digger
Thu Jun 18, 2020 4:20 am
Forum: Engine Tech
Topic: Applying the DV 128 formula on a Supercharged engine
Replies: 211
Views: 4275

Re: Applying the DV 128 formula on a Supercharged engine

If you do not like the DV 128 method thats ok. But you must prove it to convince me its wrong. If you don't like the DV 128 method for what It is intended for,, You may not like this method either... Ghats ok. But your car, your street supercharged engine and your budget does not care what you like...
by digger
Thu Jun 18, 2020 4:16 am
Forum: Engine Tech
Topic: Applying the DV 128 formula on a Supercharged engine
Replies: 211
Views: 4275

Re: Applying the DV 128 formula on a Supercharged engine

F-BIRD'88 wrote: Wed Jun 17, 2020 7:33 pm
Dude : If you don't like the DV 128 formula method used as it was intended for.. ( This was discribed and stressed by DV over and over and over again) DON'T USE IT.!
umm read what you wrote and apply it to the first post
by digger
Mon Jun 15, 2020 7:10 am
Forum: Engine Tech
Topic: Applying the DV 128 formula on a Supercharged engine
Replies: 211
Views: 4275

Re: Applying the DV 128 formula on a Supercharged engine

The fanboys forget the DV oversold it from the start
by digger
Sun Jun 14, 2020 5:38 am
Forum: Engine Tech
Topic: Applying the DV 128 formula on a Supercharged engine
Replies: 211
Views: 4275

Re: Applying the DV 128 formula on a Supercharged engine

All simulations need to be validated in some way to be truly valid it doesn’t matter what the underlying equations are based on.