When Mike would hear someone claim 200+ he would ask if there was a spark plug in the chamber.
I think both of mine that were flowed were 190ish on the intake.
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| Head Flow Infomation Wanted https://www.slantsix.org/forum/viewtopic.php?t=67075 |
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| Author: | hyper_pak [ Tue Feb 07, 2023 8:44 am ] |
| Post subject: | Head Flow Infomation Wanted |
Picking some brains here. Has anyone flowed a stock head with no mods? I did some searching for information and I found the thread with the DIY ford head. Looks like they got in the low 200 cfm on the intake. Seems to me that is close to what I have seen for our race prepped heads. Am I missing some head flows that were higher? Please share anything you would like. Thanks |
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| Author: | Greg Ondayko [ Tue Feb 07, 2023 9:10 am ] |
| Post subject: | Re: Head Flow Infomation Wanted |
I bet John has some data to share on this. Greg |
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| Author: | Rick Covalt [ Tue Feb 07, 2023 10:08 am ] |
| Post subject: | Re: Head Flow Infomation Wanted |
A lot of the numbers depend on the flow bench and inches they are flowed at. None of our 3 race heads flowed 200 at 28”. All 3 were flowed on the same bench |
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| Author: | slantzilla [ Tue Feb 07, 2023 10:41 am ] |
| Post subject: | Re: Head Flow Infomation Wanted |
When Mike would hear someone claim 200+ he would ask if there was a spark plug in the chamber. I think both of mine that were flowed were 190ish on the intake. |
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| Author: | Badvert65 [ Tue Feb 07, 2023 12:43 pm ] |
| Post subject: | Re: Head Flow Infomation Wanted |
This is a flow chart made of the slant six head that one of my racing buddies had done some work on. I believe it is a drool tube style head and he had set it up for street use, not all out performance. These figures were taken at 28" and was done at a machine shop in Newport News Virginia. It's a little difficult to tell in the picture, but from top to bottom you have Ported intake, stock intake, ported exhaust, then stock exhaust at the bottom. Attachment: flow.jpg [ 233.5 KiB | Viewed 3828 times ] |
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| Author: | hyper_pak [ Tue Feb 07, 2023 12:55 pm ] | ||
| Post subject: | Re: Head Flow Infomation Wanted | ||
Here is some of what I found. I think these are Doug's plots.
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| Author: | Rick Covalt [ Tue Feb 07, 2023 4:00 pm ] |
| Post subject: | Re: Head Flow Infomation Wanted |
Here is our 3 tested on the same machine on the same cylinder at 28" Ryan's had been professionally done with 7mm valves. Mine was one of the last ones Mike did. Seymour's was the one on the car when Ryan got it from him. Attachment: IMG_20170930_0001.jpg [ 177.19 KiB | Viewed 3790 times ] |
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| Author: | DadTruck [ Tue Feb 07, 2023 7:01 pm ] |
| Post subject: | Re: Head Flow Infomation Wanted |
Rick, notice that Mikes head had the best intake flow of the three heads at the lower valve lifts. I remember Mike saying that he was willing to give up flow at the largest valve openings to get more flow across the total intake duration. It’s what is called ‘area under the curve’. Remember the valve only sees the max lift once, it sees the other lift openings twice, once on the way open and once on the way closed. The way the numbers look on the MJ head I bet those are 30 degree intake seats. |
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| Author: | Rick Covalt [ Wed Feb 08, 2023 2:58 am ] |
| Post subject: | Re: Head Flow Infomation Wanted |
Yes my head does have the 30 degree intake valve |
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| Author: | DadTruck [ Wed Feb 08, 2023 5:01 am ] |
| Post subject: | Re: Head Flow Infomation Wanted |
Flow benches are like weather vanes, they give direction, but by them selves don’t tell the whole story. Rick when Ryan went from Seymour’s head to the professionally ported head did he at the same time make a lot of other car/engine changes or did he just swap on the new head? If there were no other changes it would be interesting to know how the head swap affected strip times. Maybe use a Hp calculator to see what the Hp change was. If Ryan did make other changes maybe at some point in time you could swap his or even the Seymor head on to your Valiant, minimizing any other changes and see how strip times and calculated Hp are affected. The correlation between flow and Hp would be interesting. |
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| Author: | CNC-Dude [ Wed Feb 08, 2023 8:56 am ] |
| Post subject: | Re: Head Flow Infomation Wanted |
About 12 years ago, there was a huge dyno test project on Inliners conducted to test recipe combos for the Chevy 250 and 292 six cylinders. The biggest debate was with the cylinder heads and a device that is bolted into intake ports that increases the port flow by over 30 CFM. The late, great Kay Sissell had a version that he created where he brazed up the intake port floor and called a "lump". A big battle between two guys in Inliners as to whose bolt in "lumps" produced the most flow and made the most power. Up until these dyno tests, only flowbench data was these guys only source of info to determine what these "lumps" actually did. Numerous cylinder head combos with different valves sizes were tested. I challenged the guy performing the engine dyno tests to do a before and after test back to back, with and without the lumps installed, while all other variables remained the same. Long story short, with an increase of 30 CFM by installing the lumps with no other changes made, the lumps only added 6 HP. Which half of that gain could easily be the inconsistency of one dyno pull to the next....! It definitely hurt those guys feelings to know all the work and hype they had been bragging about for a lot of years was basically futile......and all the people that bought those lumps to put in their heads were greatly disappointed.... Like Dadtruck said, it's not all about the flow bench.... |
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| Author: | Rick Covalt [ Wed Feb 08, 2023 9:05 am ] |
| Post subject: | Re: Head Flow Infomation Wanted |
I am 99% Ryan's new engine used the same cam as was in the car before. Bottom end was .085 over just like my engine. I think the compression ration is 13.4 instead of whatever Seymour was running. But the car went from a best on 11.40's to and 11.00 in the quarter. That is a lot when you are going that fast already. I would like to see flow data on a head that only has Engine builder valves and a home port job. |
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| Author: | hyper_pak [ Wed Feb 08, 2023 9:38 am ] |
| Post subject: | Re: Head Flow Infomation Wanted |
Good information, thanks for sharing. Rick, the head on the Colt right now is close to what you were asking about. It had a mild gasket match when I got it. I had 1.75 intake valves and 1.50 exhaust valves installed with a semi completion valve job. Not exactly sure what the valve job was, but I was told it was tighter than daily driver stuff. These were longer 318 V8 valves. 3/8 Stem. Drool tube head. .050 cut. After the valve installation I did some mild clean up in the bowl area. A little around the guides. I just recently heard about a guy doing heads close to me. I am going to see what he would charge to flow it. |
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| Author: | Dart270 [ Wed Feb 08, 2023 10:42 am ] |
| Post subject: | Re: Head Flow Infomation Wanted |
200 CFM is very good, and should be good for around 300HP with other good components/design. I have several head flows plotted. Will try to find that soon and post. Lou |
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| Author: | CNC-Dude [ Wed Feb 08, 2023 12:10 pm ] |
| Post subject: | Re: Head Flow Infomation Wanted |
Respectable numbers for sure Rick...! |
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