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> Porting a type 4 head, Not much of a short side
Shivers
post Sep 8 2024, 06:47 PM
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Because the port is almost straight, with little long side short side concerns, with what there is , do you find it necessary to slow the flow down on the “short side” to get good flow out of the valve. I was reading about something mepstein posted a picture of. Small divots, like a golf ball. So I’m going to do that on the long side, just wondering if there is any reason not to also do it on the short side. Thanks guy’s (IMG:style_emoticons/default/smile.gif)

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brant
post May 10 2025, 10:42 AM
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The GT classes in PCA were designed to run 110hp per a liter

Making the 6 cylinders more competitive at any displacement than a -4

But our redline was 7k and the type 4 can be made to do that easily

There is a really competitive guy out here with a 2.0
Great driver too
And redlines at 7500 rpm
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stownsen914
post May 11 2025, 08:57 PM
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QUOTE(brant @ May 10 2025, 12:42 PM) *

The GT classes in PCA were designed to run 110hp per a liter

Making the 6 cylinders more competitive at any displacement than a -4



I believe PCA CR indexes aircooled 4's at 85 hp/L and 6's at 110. Edit - actually just checked, it's 90, not 85.


There was a fellow here on the east coast who ran a 914/4 in the GT classes a bunch of years ago, and did well against bigger cars. Usually outran them. Mostly his driving, to be fair. It can be done.
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Posts in this topic
Shivers   Porting a type 4 head   Sep 8 2024, 06:47 PM
Brett W   The Intake port isn't the problem. You can ea...   Apr 23 2025, 08:34 AM
Shivers   The Intake port isn't the problem. You can e...   Apr 23 2025, 10:44 AM
technicalninja   Exh port is where the restriction lives IMO. Does...   Apr 23 2025, 10:52 AM
Shivers   Exh port is where the restriction lives IMO. Doe...   Apr 23 2025, 06:36 PM
brant   You really need a flow bench to measure whether yo...   Apr 23 2025, 02:19 PM
914sgofast2   just polish the exhust port and leave the intake p...   Apr 23 2025, 09:26 PM
Shivers   just polish the exhust port and leave the intake ...   Apr 24 2025, 09:13 AM
HAM Inc   Hey all. It's been a while since I jumped into...   Apr 30 2025, 07:58 AM
Shivers   Hey all. It's been a while since I jumped int...   Apr 30 2025, 08:03 PM
Charles Freeborn   The heads on my previous race car built by Allen J...   May 6 2025, 11:21 PM
Shivers   The heads on my previous race car built by Allen ...   May 7 2025, 05:45 AM
brant   I used to run the same AJRS heads in the 1990...   May 7 2025, 10:21 AM
Shivers   I used to run the same AJRS heads in the 1990...   May 7 2025, 05:24 PM
Charles Freeborn   I used to run the same AJRS heads in the 1990...   May 9 2025, 11:14 AM
Shivers   I used to run the same AJRS heads in the 1990...   May 9 2025, 02:58 PM
Charles Freeborn   [quote name='Charles Freeborn' post='3204716' dat...   May 10 2025, 09:40 AM
brant   The GT classes in PCA were designed to run 110hp p...   May 10 2025, 10:42 AM
Charles Freeborn   The GT classes in PCA were designed to run 110hp ...   May 10 2025, 03:47 PM
stownsen914   The GT classes in PCA were designed to run 110hp ...   May 11 2025, 08:57 PM
brant   The GT classes in PCA were designed to run 110hp...   May 12 2025, 10:30 PM
Charles Freeborn   [quote name='stownsen914' post='3205073' date='Ma...   May 13 2025, 09:34 AM
Shivers   Thanks everybody, I am motivated. :)   May 10 2025, 03:05 PM
HAM Inc   It's true that there aren't many 200hp 2.0...   May 14 2025, 07:15 AM
Charles Freeborn   It's true that there aren't many 200hp 2....   May 14 2025, 11:20 PM
HAM Inc   It's true that there aren't many 200hp 2...   May 16 2025, 06:54 AM
Charles Freeborn   [quote name='Charles Freeborn' post='3205549' dat...   May 19 2025, 09:55 AM
brant   Those are numbers I didn’t know about Amazing   May 14 2025, 07:38 PM
ClayPerrine   Is there anything in the rules that says you canno...   May 16 2025, 09:21 AM
HAM Inc   EFI was only legal with the O.E. system back then....   May 16 2025, 02:45 PM
ClayPerrine   EFI was only legal with the O.E. system back then...   May 16 2025, 02:53 PM
Charles Freeborn   EFI was only legal with the O.E. system back the...   May 19 2025, 09:51 AM


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