3/8 to 11/13 valves early Hemi heads

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jcisworthy
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3/8 to 11/13 valves early Hemi heads

Post by jcisworthy » Sun Dec 02, 2018 4:42 pm

Installed bronze guides in a pair of early Hemi heads for a friend. I ended up core drilling, reaming and trimming the factory guides for a .502 OD bronze guide.

1.94/1.66 SBC intake and Pontiac exhaust ended being very close to stock 3/8 factory valves. Also did a valve job and back cut on the valves which in not in any of the pictures

I used a 2.234 long intake guide and 2.600 long exhaust guide for about .300 stick out on the bowl side
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"Discouragement drains our spirits; perseverance accomplishes the job"
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Carnut1
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Re: 3/8 to 11/13 valves early Hemi heads

Post by Carnut1 » Mon Dec 03, 2018 8:32 pm

Very cool project, what mill are they from John? 331?
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Geoff2
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Re: 3/8 to 11/13 valves early Hemi heads

Post by Geoff2 » Tue Dec 04, 2018 5:00 am

CJ,
From Top Aussie Supercars magazine, that tested all the Aussie Muscle car era cars.

Fastest over the 1/4 mile: E49 Charger 14.4 secs. Not bad for six cyl...

GTHO Phase III: 14.7 secs. Pushed hard, it gets 8 mpg. 'Quieter' driving gets a whopping 10.4 mpg. [ Gotta love them Holleys...]


The E49: Cruising 15-17 mpg, overall for the road test 13.8 mpg. This comment: "...you can drive around town at a steady 1500 rpm-30 mph- & never need to change down unless you want hard acceleration."

At the same 1500 rpm for the GTHO: " It will crawl along from 1500 in top...[but ] doesn't entirely hide it's displeasure." Apparently this was ' better' than the older GT because: " This sort of low speed flexibility was non-existent in top in the old car,. It bucked & shook at 40 or below.

The Falcon GT also got dusted off by the 340 Charger, quicker to 100 mph by 0.8 sec. Falcon supposedly had 25 more hp. Hmm..

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Re: 3/8 to 11/13 valves early Hemi heads

Post by jcisworthy » Tue Dec 04, 2018 5:27 am

Carnut1 wrote:
Mon Dec 03, 2018 8:32 pm
Very cool project, what mill are they from John? 331?
I think the engine is for a street rod Charlie, they are for a friend of a friend.

My friend had me do the guides, valve job and back cut on the valves and he is doing the rest. My understanding is he is not looking to break any records its just a cruiser

It looks like the head bolts also hold the shafts on because no holes have threads. Without making a way to position my valve opening devise I had no way to flow them other than by hand.

Intake went 227 and the exhaust went 157 both at 28"
"Discouragement drains our spirits; perseverance accomplishes the job"
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Re: 3/8 to 11/13 valves early Hemi heads

Post by mag2555 » Tue Dec 04, 2018 7:15 am

Nice job on the guide reduction!!
Looks like you could Attain like 165 Exh cfm if you Boat tail down that original as cast Exh guide support !

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Re: 3/8 to 11/13 valves early Hemi heads

Post by jcisworthy » Tue Dec 04, 2018 8:52 am

Thank you. There is a lot of material in the way for sure!
"Discouragement drains our spirits; perseverance accomplishes the job"
David Jeremiah

https://rbjracing1.wixsite.com/website

Phone 518-915-3203

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