 Porting a type 4 head, Not much of a short side |
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| Shivers |
 Sep 8 2024, 06:47 PM
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#1
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Senior Member  Group: Members Posts: 3,049 Joined: 19-October 20 From: La Quinta, CA Member No.: 24,781 Region Association: Southern California  |
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 |
May 7 2025, 10:21 AM
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914 Wizard Group: Members Posts: 11,987 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains 
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I used to run the same AJRS heads in the 1990's on a type 4
38x48, thin stemmed valves, Dual valve springs, and titanium retainers with holes drilled in them |
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| Charles Freeborn |
May 9 2025, 11:14 AM
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#3
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Member Group: Members Posts: 295 Joined: 21-May 14 From: United States Member No.: 17,377 Region Association: Pacific Northwest |
QUOTE(brant @ May 7 2025, 09:21 AM)  I used to run the same AJRS heads in the 1990's on a type 4 38x48, thin stemmed valves, Dual valve springs, and titanium retainers with holes drilled in them Allen is quite the wizard. The most impressive (to me) aspect is the weld build up to allow porting. He cut o-ring grooves in the mating surface of the intake manifolds... I'm not sure of the valve stems I had, definitely not lightened retainers, but dual spring. Very well thought out and executed. Very nice guy too. I spoke on the phone a couple of times. Got some parts, etc. Old school honest. |
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| Shivers |
May 9 2025, 02:58 PM
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#4
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Senior Member Group: Members Posts: 3,049 Joined: 19-October 20 From: La Quinta, CA Member No.: 24,781 Region Association: Southern California |
QUOTE(Charles Freeborn @ May 9 2025, 10:14 AM) QUOTE(brant @ May 7 2025, 09:21 AM) I used to run the same AJRS heads in the 1990's on a type 4 38x48, thin stemmed valves, Dual valve springs, and titanium retainers with holes drilled in them Allen is quite the wizard. The most impressive (to me) aspect is the weld build up to allow porting. He cut o-ring grooves in the mating surface of the intake manifolds... I'm not sure of the valve stems I had, definitely not lightened retainers, but dual spring. Very well thought out and executed. Very nice guy too. I spoke on the phone a couple of times. Got some parts, etc. Old school honest. Thanks Charles. (IMG:style_emoticons/default/smile.gif) The RPM's must have been impressive. How did he get it to breath out as well as he got it to breath in? That exhaust port, especially the 2.0 heads have little that can be removed. Did he weld those up too or is it big valve, massaging the port right after the valve and polish...Kind of hope for the best? Some of the work these Guy's do is real magic |
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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 Shivers
I used to run the same AJRS heads in the 1990... May 7 2025, 05:24 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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