[charlie66]

Yeah 4 valves ain't happening for a pontiac . Would be nice though.

I think 8000 would be enough to make huge power with a pontiac under boost. Im only shiffting a 6500 and doing ok for power.. Ive noticed for every 5 psi added the power peak goes up 500 rpm. So that tells me that its moving smaller more dense air through the port. More boost more power as long as the charge stays cool.. I know that technically its not flowing more cfm but it is still making more power by compressing the air charge into smaller form (if you will) being under more pressure. So its almost like having more air flow. lol

[charlie66]

Originally Posted by Tom Vaught

A "Modern head" would be a Overhead Camshaft 4 valve head like Mack McKeller came up with many years ago, (in the 60s). But because it wasn't a production head, "Can't do that". Course even the RA-V heads were not Production Heads, or the Aftermarket heads that look like a Hemi Head.

Run what you have Charlie, have fun, look for that good block, and ignore the comments from the cheering section that brags about a engine that does not resemble your 4 cylinder efforts.

Tom V.

I will . Thanks Tom...

[charlie66]

I just went from a 325 cfm head to a 280cfm head. The car is just as fast.. No power loss .

Just sayin....

[Tom Vaught]

Charlie, what you have posted is very possible.
It has to do with the port design of the head and combustion chamber.

Charlie, your original e-head was an older design E-head and was ported in a given manner to give a higher flow number vs your current head.
Lets call that head a "High Angle/ high cfm flow" head design.

So now you buy a modern design e-Head that has for example a "Direct line of sight" port", the design allows for a line of sight from the inlet directly to the front opening of the intake valve.

Sometimes this design gives A LOWER FLOW VALUE but because it is straight, THE PORT ATTAINS A HIGHER VELOCITY OF FUEL/AIR entering chamber. It also creates a turbulent spin or swirling in the combustion chamber, yielding a MORE EFFICIENT and MORE COMPLETE BURN and MAKES MORE POWER for the same boost number.

So what you have posted IS possible, despite the comments from some "experts".

My previous company used to spend millions to find these better ports for both emissions purposes and horsepower purposes.

https://media.ford.com/content/fordm...e-year-fo.html

Ford 1.0-liter EcoBoost petrol engine named 2017 International Engine of the Year “Best Engine Under 1.0-liter” for the sixth year in a row
Fuel-efficient, compact and powerful engine has won 10 International Engine of Year awards since launch in 2012; powers one in five Ford vehicles sold in Europe
Ford to offer 1.0-liter EcoBoost with innovative cylinder deactivation technology for further reduced CO2 emissions and improved fuel-efficiency from early 2018

You are doing something when your engine is the best small engine for 6 years in a row.

So your 4 cylinder 199 cid engine with the new head vs the older design head with more cfm flow could be a better design engine under boost.

Tom V.

[charlie66]

Originally Posted by Tom Vaught

Charlie, what you have posted is very possible.
It has to do with the port design of the head and combustion chamber.

Charlie, your original e-head was an older design E-head and was ported in a given manner to give a higher flow number vs your current head.
Lets call that head a "High Angle/ high cfm flow" head design.

So now you buy a modern design e-Head that has for example a "Direct line of sight" port", the design allows for a line of sight from the inlet directly to the front opening of the intake valve.

Sometimes this design gives A LOWER FLOW VALUE but because it is straight, THE PORT ATTAINS A HIGHER VELOCITY OF FUEL/AIR entering chamber. It also creates a turbulent spin or swirling in the combustion chamber, yielding a MORE EFFICIENT and MORE COMPLETE BURN and MAKES MORE POWER for the same boost number.

So what you have posted IS possible, despite the comments from some "experts".

My previous company used to spend millions to find these better ports for both emissions purposes and horsepower purposes.

https://media.ford.com/content/fordm...e-year-fo.html

Ford 1.0-liter EcoBoost petrol engine named 2017 International Engine of the Year “Best Engine Under 1.0-liter” for the sixth year in a row
Fuel-efficient, compact and powerful engine has won 10 International Engine of Year awards since launch in 2012; powers one in five Ford vehicles sold in Europe
Ford to offer 1.0-liter EcoBoost with innovative cylinder deactivation technology for further reduced CO2 emissions and improved fuel-efficiency from early 2018

You are doing something when your engine is the best small engine for 6 years in a row.

So your 4 cylinder 199 cid engine with the new head vs the older design head with more cfm flow could be a better design engine under boost.

Tom V.

Its 198ci Tom just the be exact ! lol

Thats very impressive with that 1.0-liter engine. Great accomplishment to be on top for 6 years!

Thanks

[Tom Vaught]

In simple Physics terms, Air in the atmosphere (which is what some people drag race in has a given amount of oxygen molecules per each cubic foot of air at sea level.

So if the Roots Guy was racing at 12 psi of boost pressure at Seal Level conditions he will be filling the engine with 1.8 atmospheres of oxygen and other gases vs being naturally aspirated. And lets assume a 300 cfm head in this example.

So the cfm flow in the head port would stay the same in both the naturally aspirated engine and the boosted engine with engine at 12 psi of boost pressure.
The change would be the number of oxygen molecules in the second case. 80% more oxygen molecules for each combustion cycle. So you add the right amount of fuel for the fuel/air ratio and you make a given power minus parasitic losses. In the Roots case
the 10/71 supercharger would consume about 120 hp to drive the supercharger.

In the third case with the guy with the turbocharger, lets say he is putting 3 atmospheres of air mass thru the engine. The cfm was the same as his atmospheric cfm in this case 280 cfm but the oxygen molecules going into the engine is 3 times higher.
So in his case if he adds the correct amount of fuel for those oxygen molecules he will make a LOT more HP vs the naturally aspired engine, in simple math 3 times the HP with the same cfm number. So Charlies little 200 cid engine has made 4 times the hp you would expect from a naturally aspirated engine making 1 hp per cubic inch of the engine.

In all three cases the CFM did not make any real difference, the combustion forces and the force pushing down on the pistons changed a great deal based on the amount of air mass and the time the air.fuel mass was burning and forcing the piston down in the bore.

So cfm of the head is important if you are running naturally aspirated or you are running a boosting device that has a limited Pressure Ratio (boost) capability.

Course some will never understand this stuff. They will continue to brag about cfm.
Air Charge Density is the key to the discussion.

Just saying.

Tom V.

[charlie66]

Originally Posted by Tom Vaught

In simple Physics terms, Air in the atmosphere (which is what some people drag race in has a given amount of oxygen molecules per each cubic foot of air at sea level.

So if the Roots Guy was racing at 12 psi of boost pressure at Seal Level conditions he will be filling the engine with 1.8 atmospheres of oxygen and other gases vs being naturally aspirated. And lets assume a 300 cfm head in this example.

So the cfm flow in the head port would stay the same in both the naturally aspirated engine and the boosted engine with engine at 12 psi of boost pressure.
The change would be the number of oxygen molecules in the second case. 80% more oxygen molecules for each combustion cycle. So you add the right amount of fuel for the fuel/air ratio and you make a given power minus parasitic losses. In the Roots case
the 10/71 supercharger would consume about 120 hp to drive the supercharger.

In the third case with the guy with the turbocharger, lets say he is putting 3 atmospheres of air mass thru the engine. The cfm was the same as his atmospheric cfm in this case 280 cfm but the oxygen molecules going into the engine is 3 times higher.
So in his case if he adds the correct amount of fuel for those oxygen molecules he will make a LOT more HP vs the naturally aspired engine, in simple math 3 times the HP with the same cfm number. So Charlies little 200 cid engine has made 4 times the hp you would expect from a naturally aspirated engine making 1 hp per cubic inch of the engine.

In all three cases the CFM did not make any real difference, the combustion forces and the force pushing down on the pistons changed a great deal based on the amount of air mass and the time the air.fuel mass was burning and forcing the piston down in the bore.

So cfm of the head is important if you are running naturally aspirated or you are running a boosting device that has a limited Pressure Ratio (boost) capability.

Course some will never understand this stuff. They will continue to brag about cfm.
Air Charge Density is the key to the discussion.

Just saying.

Tom V.

AMEN TO THAT Tom!!

[Tom Vaught]

Stan, Can you use your prediction capabilities and match up a 3.66 1/8 mile et with what hp that would be with your software?

I saw an article in Hot Rod recently where they posted that a Belt Driven Boosted 521 cid Engine that makes 3000 hp and runs that 3.66 et in the 1/8th. Not 3100 hp or 3200 hp or 3300 hp.
Isn't that 2 or 3 tents quicker vs our fastest guy that you have been making predictions on?

How close is the article to your predictions. Decent aero for the late 60s body.

Tom V.

[Stuart]

This discussion got seriously off track, so by request I deleted a bunch of posts that had nothing to do with the original topic.