700+hp sbc 23 degree heads

[user-9274568]

Thanks, I just stapled it to the wall, above my desk.

cool.. It has a really nice velocity profile as well.

PS.. It comes in iron also!

[Stan Weiss]

Here is a pdf of a set I just did last week. Just a valve job and a little blending.

http://www.speierracingheads.com/v2.72_flow.pdf

Chad,
I have to ask because I see many people do it this way. Why when you calculate the throat velocity do you not remove the valve stem csa?

Stan

[user-9274568]

Here is a pdf of a set I just did last week. Just a valve job and a little blending.

http://www.speierracingheads.com/v2.72_flow.pdf

Chad,
I have to ask because I see many people do it this way. Why when you calculate the throat velocity do you not remove the valve stem csa?

Stan

it's probably wrong.. But in my defense, I "know" how it effects the numbers.. Different sized stems and such...

I should probably rework my spreadsheet. I'm just not smart enough to do it. Do you wanna? I'd pay you..

[Stan Weiss]

Here is a pdf of a set I just did last week. Just a valve job and a little blending.

http://www.speierracingheads.com/v2.72_flow.pdf

Chad,
I have to ask because I see many people do it this way. Why when you calculate the throat velocity do you not remove the valve stem csa?

Stan

it's probably wrong.. But in my defense, I "know" how it effects the numbers.. Different sized stems and such...

I should probably rework my spreadsheet. I'm just not smart enough to do it. Do you wanna? I'd pay you..

Chad,
I do not work with Excel that much. But if you email me the spreadsheet in xls format (not the newer xlsx) I will see what I can do. No charge.

Stan

srweiss@erols.com

[mdross1]

Been away from it too long I guess.Always was led to believe that a port will only flow what is let through the seat,and was taught the 85% rule.Make the seat opening at least 85% of the valve diameter,always figured that the pinch area was not a big deal.Obviously I do not play with a flow bench,sure would like to! Honestly the flow numbers are interesting and I will always enjoy talking about technical side,bottom line is I need a topend that will give me the big number or very close to it and on street gas.Because this motor will be in a motorcycle torque is not a big deal.Will insist on instant throttle response don't we all.

Yea, you've been away too long! The port will only flow what is let through the minimum CSA, wherever that might be. I agree, it should be the seat ring. A 85% seat is really small. Even my street heads are 90%+..

Of course it all makes sense,great getting up to speed and feeling better all the time about getting what I'm looking for.Once all the parts are here polished,clearanced,balanced and assembled it will be a joy dailing it in.Finding this forum hearing what you guys are saying sure takes the pressure off.Guess it's time to arcive my old books since thay are just a little outdated.

[levisnteeshirt]

The alu block is NOT a good idea, I have had several really BAD results. Just get a Dart iron block, 434 crank assembly, some AFR 245 heads, and you can make 750 HP on pump gas. On serious race builds, I am seeing very close to 900 HP with the same AFR 245 heads and a lot of trick parts to go along with them. Do not waste your money on the alu block.


JOE SHERMAN RACING ENGINES

i saw one mag article of a 434 , 18 degree heads , small roller , 252/260 on a 110 ,, it got over 700 hp on pump gas

[mdross1]

The alu block is NOT a good idea, I have had several really BAD results. Just get a Dart iron block, 434 crank assembly, some AFR 245 heads, and you can make 750 HP on pump gas. On serious race builds, I am seeing very close to 900 HP with the same AFR 245 heads and a lot of trick parts to go along with them. Do not waste your money on the alu block.


JOE SHERMAN RACING ENGINES

i saw one mag article of a 434 , 18 degree heads , small roller , 252/260 on a 110 ,, it got over 700 hp on pump gas

Sure would like to know more about this one,just to get some ideas.

[user-9274568]

Want to thank Stan for hooking me up with an updated spreadsheet! Very cool of him!

THANKS

[BlitzA64]

^^^^^^^^^^^^^^^^^^^^

[Stan Weiss]

Want to thank Stan for hooking me up with an updated spreadsheet! Very cool of him!

THANKS

Chad, you are welcome.

I would like to believe that why most of us are here is to share knowledge and help others out when we can.

Stan

[mdross1]

Want to thank Stan for hooking me up with an updated spreadsheet! Very cool of him!

THANKS

Chad, you are welcome.

I would like to believe that why most of us are here is to share knowledge and help others out when we can.

Stan

Exactly why I for one am using a site like this.Been building engines most all my adult life, since the 60's.An aweful lot of old school still lurking around the grey matter which by the way has served me very well.Getting these motors into the 1.8 to 2.0 or more hp per ci be streetable and reliable,makes the need to know more a requirement.Mike Ross

[Tony B]

The alu block is NOT a good idea, I have had several really BAD results. Just get a Dart iron block, 434 crank assembly, some AFR 245 heads, and you can make 750 HP on pump gas. On serious race builds, I am seeing very close to 900 HP with the same AFR 245 heads and a lot of trick parts to go along with them. Do not waste your money on the alu block.


JOE SHERMAN RACING ENGINES

What issues have you had with aluminum blocks????TB

[bigjoe1]

The biggest problem is always about stripped out threads every where. I have seen heads studs. bell housing bolt holes. motor mounts holes and so forth have the threads pull out. When one was used with NOS, the leak downs were terrible after just a few runs. They also seem to loose 4o or more Hp compared to a Dart cast iron block. The cost to save 100 pounds does not seem to be a good deal at all


JOE SHERMAN RACING

[Avadoo]

....Out of interest Joe, how much shorter did you build the alu block over your normal iron version ?


Im still on the fence as to alu Dart or lightened Iron Dart for a 582/598 road racer winter build.

[Tony B]

You lose 2% going aluminum, but circle track guys don't care, they need the weight off to get their percentages right. We do quite a few of them, love them. Call Brodix, they offer many options, most at no extra cost. Yes, they don't hold the same vacuum as an identical engine built with steel, but we have no issues with ring seal, if they are properly prepaired.TB



P.S. DO NOT BUY A DART ALUMINUM BLOCK. The steel ones are great, but the aluminum ones leak like a stuck hog, and they crack. Don't believe me if you want, but you better ask an engine builder b4 you make a purchase. TB