Bettering High port head flow
 

Broke down and ordered a set of High ports from Jeff. Goal is to get as close to 700hp on pump gas with stock block 455 .060 over. Jeff told me the as cast High ports will be good enough to reach my goal. The as cast ports are 1.20 x 2.30, my victor intake has 1.20 x 2.40 ports. Talking with Jeff there is no problem opening the heads up to my intake as long as I make a long transition. Just out of curiosity I asked the port dimensions on the 365 cfm head, 1.20 x 2.40.
While I am using the burr to open up the port .100 is there anything I should do to the stock head to increase the flow a little?
The 365 cfm head is a little to much for what I need. Would like about 340cfm.
This is going to be a high effort pump gas combo. Will have 11-1 compression and jeff agrees that that will work with 93 octane with the cam I have.

Want to run 10.00 in the summer at 3200 lbs.
Old combo had 692hp (calculated from et) with 11.75 compression and Old E-heads that flow 330.

What lift did the e-heads flow 330?

So what do the High ports flow out of the box?

With your compression you should only need to achieve 330 cfm @28” to make 700 hp.

If it where me I would use epoxy to gradually neck down the runners in your manifold that.100” sonner then open up the intake runner at the head flange.

It’s much easier to sand out the epoxy if you ever need/ want to reuse that intake then weld up the heads.

Expansions in runner area need to be gradual so as to not narrow down the upper part of the motors power band.

The opposite side of the coin in terms of having a wide power band holds true also, that being that within the whole intake tract there should be only one point of minimum port area.

What Density Altitude do you normally run in during the summer?

Stan

Nov 2005 when I bought a set of High Port bare castings the reported as cast flow numbers for the intake with a 2.320 x 1.18 port opening:
.100 85
.200 170
.300 234
.400 284
.500 316
.600 322
.700 331
2.200" intake valve
277cc as cast port volume


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The old eheads flowed 328 at 700 and 321 at .600. I only am running .620 lift. The high ports will let run 1.65 rockers to get .693 lift.
Usually the da is between 1000 to 300. On occasion it will go above 2000.

These are my 80cc High Ports. Dave just used a cutter and opened up the bowl area a little and blended. Runner openings just had casting flash removed.
They are 73cc now so might flow a tad more.
Think you might want to have a cam with over .700 lift. Dave told me he would run a .750ish lift cam.
The cam I had was .759 lift but was too aggressive for a PMD block IMO. Had it re ground and have .731 lift now.

Flow numbers look really good! How is Dave’s business recovery going?

Thanks so much, That's was what I was looking for.

I am going to check piston to valve clearance for .700+ lift. I will probably start with the 1.5 rockers and .620 lift and if I need more hp put the 1.65 rockers on.
I want a nice reliable bracket engine that can go years.
Funny story, I pitted with the same guys for years. Last year took my hood off and they came over and said this is the first time we ever seen your engine. They always commented on that I never do anything to the car.

Dave was doing well the last time we E mailed. He is doing a lot of Harley stuff these days.

I think you might want to epoxy the intake before grinding on the heads. Back when I was building it I did the math on the air speed using CSA. I want to say it was in the sweet spot just as the heads were.
I see no reason why you can't get to 10.00, your car is 250 lbs lighter than mine. I only had 2 passes after I jacked the timing up from 32 deg to 36. Car jumped 8 tenths. ran a 10.33 then a 10.27 and did it with tires on their last runs. Used a a 4150 carb too, never put the 4500 on.
I think I can get my car to ten teens at least. Maybe crack a high 9. 60 foots like crazy.
I bet you are going to luv your new heads.

Pay attention to your distance from coil bind with valve springs set up at or near the cylinder heads 2-inch installed height.

https://www.hotrod.com/how-to/how-mu...arance-is-safe

"Anything more than 0.150 inch may cause spring surge, which can greatly reduce the available spring load needed to close the valve"

And with a spring load in mind. A valve at 6.200" long x 2.20" diameter could be a bit heaver than the springs in the Edelbrock cylinder heads.



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Jeff just made 722hp on race gas with a 461, solid roller, port matched heads.

And how much info will the Secret squirrels divulge ?


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Negative ghost rider.

I'll take that as generally being considered a "good" character :)

Around the time the High Port heads were first introduced 20+ years ago they touted 775 hp with unported HP heads on a 505 CID combo..... when asked for further info from a few intrested, this was their reply....

https://www.youtube.com/watch?v=CpGtBnVZLSk

If you hear of one of their combinations and ask about the camshaft in use.......

https://cdn.hanna-barberawiki.com/3/...t_Squirrel.png

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Got the heads today. Hopefully they are as good as they look. They feel heavier than the e-heads, going to weigh them tomorrow out of curiosity. Checked piston to valve and have plenty for .700 lift.
Jeff recommended 10.30" pushrods, I checked with an adjustable pushrod and need 10.10" to get the roller center thru it's travel. Don't know why but check 4 times. Comp solid roller cam, comp solid roller lifters and harlen sharp rockers.

High Ports have a lot more meat on them than E heads. Seem to be very thick everywhere.
They do miss on of the three 3/8" treaded holes on the ends for accessory brackets ect.
Are you going to run them as cast ? I would be temped do do some moderate port work. Does not take a lot of work to get them to really flow.
Mine flow almost like a early Wide Port head with just a little bowl work.

Hi ports are thin in the short turn area. Always take extreme caution when modifying this area

Going to clean up the ports a little. Exhaust bowl has a big ridge I'm going to smooth out. Intake bowl has a little ridge. I'm guessing from cutting the seats.

Sweet

GT