Open chamber Edelbrock head this time

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pittsburghracer

pittsburghracer

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Waiting on payment and all I have to do to a finished set of Speedmaster heads is set up the springs, leave the inners out, and ship them out. So I stripped down one head so I could get it in my tank. I’m not a big fan of porting stuff that was already worked on but these have minimal work done. Someone was of all things brave enough to work over the short turn lightly then they lightly buffed the bottom of the intake runner and half the bowl. They got more aggressive on the gasket match. This is we’re I tell you guys if you are going to do it go further into the port. Here’s a few quick shots. The valve job may or may not of been touched but it looks stockish. These will get ported and upgraded to a 2.055 Ferrea valve. Exhaust port looks stock. I will update with flow numbers as delivered later this week.

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Well I finally threw this head on my flowbench and it wasn’t good but not terrible either. Then I threw it on my porting bench and had a very productive day getting it 90-95% roughed in. I’ll strip down the other one tomorrow hopefully and get it soaking in the parts tank. This one’s about ready to get opened up for a 2.055 intake valve. If I would accomplish this much 3-4 days a week I could make some money around here.

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What does one of these have bone stock untouched on your bench?
 
I’ve brought this up before and did not get a response. I’m far from knowledgeable on the subject but I’m a big follower of your work.
So… it is my understanding that opening the pushrod pinch has little gains compared to the sum of all of your other port modifications. Ha, spell check just corrected “port” to ”poetry”. Not far off.
ANYWAY, I would like to see the results from maxing the ”pinch“ but, instead of matching the intake to the as cast port, I have to wonder what would happen if the area from the pinch to the port entrance was straightened with a matching intake manifold port, effectively straightening that part of the air intake instead of the hour glass shape that area creates.
 
pittsburghracer said:
It’s been a long time since I flowed a totally stock head but the flow numbers are posted on the head flow chart post.
Click to expand...

Understood. Wondering what kind of improvement the bowl blend and port match got them.

A plus to see comparisons on same bench and operator.
 
If you go to the several Speedmaster posts that are stickied in the Speedmaster group I broke those mods down and did lots of flow testing. The Edelbrock and speedmaster head ports are exactly the same to the way I go about porting them is the same too.
 
Bodyperson said:
I’ve brought this up before and did not get a response. I’m far from knowledgeable on the subject but I’m a big follower of your work.
So… it is my understanding that opening the pushrod pinch has little gains compared to the sum of all of your other port modifications. Ha, spell check just corrected “port” to ”poetry”. Not far off.
ANYWAY, I would like to see the results from maxing the ”pinch“ but, instead of matching the intake to the as cast port, I have to wonder what would happen if the area from the pinch to the port entrance was straightened with a matching intake manifold port, effectively straightening that part of the air intake instead of the hour glass shape that area creates.
Click to expand...

It’s kind of hard to explain but I’ve done so many of these it’s kind of a back and forth for first time porters especially guys that have to calculate strain every area of the port by measuring. Just for the heck of it I checked airspeed at the bulge of the pushrod pinch and it was maxed out on my flowbench at 402FPS. But the short turn wasn’t maxed out because with the bulge the air struggled to even get to half of the short turn because of the bulge. Now that I tube the pushrod holes and two common wall head bolts I hit those areas first to open up the port to easier access to everything else
 
Now that I am doing more porting I have to start using these head stands more often. Takes about 2-3 minutes max to bolt one down and it sure makes it nice to hold a head in any position. Wait till you guys see what I’m building next week. Looks like I’ll have about 150-160.00 in it. Parts start arriving tomorrow.

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pittsburghracer said:
Well I finally threw this head on my flowbench and it wasn’t good but not terrible either. Then I threw it on my porting bench and had a very productive day getting it 90-95% roughed in. I’ll strip down the other one tomorrow hopefully and get it soaking in the parts tank. This one’s about ready to get opened up for a 2.055 intake valve. If I would accomplish this much 3-4 days a week I could make some money around here.

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Looks like the exhaust is crossing over the intake seat. All of the research that I've done on this and machine shops that I've talked to said that there has to be a minimum of.030" better the valve's. Is this true?
 
Dan the man said:
Looks like the exhaust is crossing over the intake seat. All of the research that I've done on this and machine shops that I've talked to said that there has to be a minimum of.030" better the valve's. Is this true?
Click to expand...

It’s funny you ask this. We were flowing a set of heads my buddy ported on Wednesday and we were talking about valves and a 2.100 valve entered the discussion. He’s an engineer and 10 times smarter than me so we kick things back and forth between us all the time. He commented about Indy heads having a bigger valve but I told him Edelbrock heads valves are pretty close with a 2.08 valve. We took a fast look at his Speedmaster and guessed .040 between them. Well when I saw your post I checked the set of Edelbrock heads I’m doing for myself and it more like .030 clearance. Just for kicks I may order a 2.100 valve, cut down an exhaust valve slightly for more clearance and give it a whirl. I’m pushing [email protected] and [email protected] lift. The 6 cfm isn’t that jumpy at least compared to the 15-20 I’ve seen on an Airwolf head but it’s more than I like to see. If a 2.100 valve calmed it just a touch and added 10cfm it would force me to jump up from my .650 lift cam. I go more by airspeed on the exhaust anyway so I could give up a little valve size on the exhaust valve. My flowbench head fixture is 4.015 and my block is 4.030
 
Dan the man said:
Looks like the exhaust is crossing over the intake seat. All of the research that I've done on this and machine shops that I've talked to said that there has to be a minimum of.030" better the valve's. Is this true?
Click to expand...

I‘ve run .020 but that was with 5/16 stems and about as tight of guide clearance as I was uncomfortable with. I was at .0009 and .0011 and that made me wet myself every time I started it the first four or five times.

Then I shat myself the first few dyno pulls. After that I pulled it down, all was good and I put it back together and sent it.
 
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