MCSA for Pro Topline 220 cast Iron S C

[65dragster]

I am trying to learn from the Speed Talk community. Does anyone know, or can you tell me where to find, the MCSA for a set of Pro Topline cast iron 220 heads. No port work has been done. I am interested in buying the Meaux software, but it might be too smart for me. If someone can get me in the ballpark for these heads, I feel like I can learn some more. Thanks!

[steve cowan]

I am trying to learn from the Speed Talk community. Does anyone know, or can you tell me where to find, the MCSA for a set of Pro Topline cast iron 220 heads. No port work has been done. I am interested in buying the Meaux software, but it might be too smart for me. If someone can get me in the ballpark for these heads, I feel like I can learn some more. Thanks!

On most 23 deg heads the pushrod pinch is the minimum cross section, you need to calculate the area of the valve throat which is 1/2 the diameter x 3.1416 minus the valve stem area (0.09") for a 11/32 stem.
Calculate area at the pinch minus corner radius. Length of port for 23 deg usually 5.45" long,setting the average CSA OF A PORT and induction dictates where engine will peak hp, more to it than that but that is just basic take on the subject.

[steve cowan]

Can you give more details on valve size etc and are they original pro action heads or RHS?? I was trying to find information on these.
Want to clarify with my first equation-
Area of valve and or valve throat area.
1/2 diameter squared x pi (3.1416)
Eg- 2.02" valve
2.02 ÷ 2 = 1.01 x 1.01 = 1.0201 x 3.1416 = 3.204 - 0.09" (valve stem) =3.11" area.
Valve throat @89%
2.02"-11%=1.79"/2 = 0.8989 x 0.8989 = 0.808 x 3.1416 = 2.53 " - 0.09"(valve stem)= 2.44" area.
A 220 cc head with a avg csa of 2.45" will make a 383 ci engine peak around 7000 rpm aprox
2.02" @ 89% = 2.44" including stem
2.05" @89% = 2.51" including stem
2.08" @ 89% = 2.60" including stem
2.10" @ 89% = 2.65" including stem
Plenty more equations available but it's not set in stone

[mag2555]

Can you post up how many cid this motor is that these heads might bolt onto?

[65dragster]

The heads are original Pro Topline, not RHS. They have 2.02 intake and 1.60 exhaust valves. No porting. They were on a 383 2-barrel restrictor motor. It used an Isky solid roller #201654 with .645/.645 lift 260/264 duration on a 104 LSA with 1.5 rocker arms. Victor Jr intake, 11.3:1 compression. Dry sump oiling system. It made 520 HP @ 6200 and 480 lb/ft @ 5000 (both are corrected #’s). I am trying to understand if I can use the heads and cam on a 10.5:1 355 bracket drag motor (no street use) 300-25 Strip Dominator with 950HP using a T-350 using 5,000 stall (can change later) and 5.13 gears with a 28” tall slick. Car is 3150 with driver. I am fine with 7200 shift point and 7800 through the lights. I just want to get a baseline setup before I make expensive changes. More importantly, I want to learn how to develop a right combination, so understanding the calculations and variables will really help me. Thanks!

[65dragster]

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[mag2555]

If the drag car is around 3000 lbs, then my 2 cents worth would be that with 355 cid those 220 CC ports with there average minimum port area will eat into the average torque numbers too hard!

A 200 CC head would serve you better in that below 7800 rpm power band.

[6.50camaro]

If it was my equipment I would have no problem running those parts . I would get the heads angle milled to get the compression as high as I could with that cam ,keep the piston to heads clearance between .035 to .040 . again to keep the compression as hi as possible. And plan on adding more stall in the future if the 60' times were poor. If the 950 is one of those with the 750 body with an 850 baseplate I would use it . Dan

[65dragster]

Thanks for the feedback. I know the easiest thing is to have Mike Jones design a cam, which I will ultimately do. With Steve’s calculations for MCSA, I can work on understanding the process and ligicfor selecting components. And thank you to 6.50camaro for the encouragement to run what I’ve got, but to raise compression and plan for more converter. Mag2555, you are no doubt correct that a 200 cc runner would be a better choice. My hope is to grow this 350 into a 383 after I get some time on this setup.so much to learn!

[racear2865]

I have 2 sets of these heads --one is from ProTopline and other is RHS new in the box. On the first set, we installed on a 350 that was suppose to be 9:1 engine. Rules stated flat top piston cast iron head. Most people were running platinum 49 cc. We chose to angle mill. Memory here .200 angle mill then flat milled until we hit edge of intake valve. Ended up around 50CC. Had cam made to match. Car consistently out ran every car around, but we didnt mind throwing gear to car. Carried 3 sizes of carb depending on track and pulled timing back in straight aways. Other set still in the box. Guess I need to sale as this class went away but\\\\\\/
reed

[steve316]

Forget about port volume; csa is what to concentrate on. A constant port velocity or as close to it is more important than the volume.

[SpeierRacingHeads]

IMO, it's all about average velocity (port volume) and localized velocity at the apex of the short side on a 23 degree head. The apex speed trumps the MIN CSA at the pinch.

[steve316]

Smaller csa faster speeds; larger csa slower speeds.

[SpeierRacingHeads]

Smaller csa faster speeds; larger csa slower speeds.

That is why average velocity is important and I'm talking localized at the apex.

[65dragster]

Chad, from your perspective, are those heads okay “as is” or do they need substantial massaging? In particular, using them on a 355?