[GONZO]

A properly built RAV aluminum street head, would sell by the truck load!!
However since I now have glucoma and several other unexplained mental issues from reading, please refresh:

What Intake would be used?
What Exhaust manifolds?
It would HAVE to be engineered to fit a standard block, to sell in quanitity I think, otherwise tooling costs will never be made up.

[theoldone]

Originally Posted by NHRASuperStock455SD

Thanks Jim,


The stock RA-V port has 4.74 square inches. That tells a story in itself, doesnt it?

Lynn

If you factor in the port area lost to the original airfoils, it is actually much smaller than that.

[NHRASuperStock455SD]

Stock with a few improvements I think is good enough, dont you think GONZO? However, we wont stop until we can imcorporate as much technology without changing the head completely. Our biggest improvement for the street is to make the ports smaller to increase the velocity, while also improving the flow. Even race heads, velocity is where it is as long as you arent splitting out the fuel to achieve it.

We also think we can do that so that the intake can feed the stock heads, or the heads will fit the stock intakes.

GONZO, I love your name, because when my brother gets tired of his wife's attitude, he goes to his shop, works on the Super Stocker and sleeps in his motorhome! We call him GONZO!

For those of you too young, GONZO if my brain is remembering correctly, was the young intern in the Medical Center with Chad Everett that lived in a Winnebego in the hospital parking lot.

Old One,

You are 100% correct, but what about velocity before and after the tube? So, my opinion that is where we start. We have some good ideas, but we are still on paper. If you have any ideas, let hear it.

We are doing an intake single plane with choice of tops. It will be designed so that we can machine the top for hood clearance issues, and bolt the top to it after machining to proper height for the application.

Headers are being manufactured for several applications out in california, and doesnt NUNZI still make them for a 67-69 Firebird?

Lynn

[7T2]

finally devoted the time to at least scan the whole thread, and i must say i am impressed by the depth of technical knowledge and pontiac engine experience contained on this site's contributors. it makes my 22 years of poncho racing pale in comparison.
that being said, im sure somebody can answer this question:
it seems to be accepted that the 4" stroke is the best for max power, due to the piston speed. it has been said that the 4.21" stroke actually hinders power because the piston speed is too high. but i thought one of the main reasons for resurrecting the v head was for the increase port area, which should alleviate the piston speed "choke" of the standard head. if thats true, then can the v head accomodate an even longer 4.5" stroke? this will be necessary for 500 cubes from a standard production block. so what are the possibilities that we can convince the Chicoms to "update" the 4.25/3 cast steel to 4.5/3? the block can easily clear the recip with BBC steel rods.
from a street and limited race aspect, this would be the icing on the v cake.
oh by the way(unrelated) what will the pushrod tube dia be? can a guy buy the v heads with small guide reference holes, then bore for tubes desired. so you can press in which ever tube desired so that port obtrusion can be minimized for a 5/16" chrome moly/street app?
thanks, jim

[pro-tour79]

the original RAV heads used a guide tube that was press fitted after the air foil was placed so you could instal any size tube within the limits of the air foil now on the new heads I don't know what Lynn's plan is for the air foil but the late ford racing heads used a solid aluminium air foil with a hole in it for the push rod

[NHRASuperStock455SD]

Havent gotten that far yet. We are suppose to have that discussion. All I know is that it is costing about $100 extra to do the tube operation. Making a foil is a whole different matter. I suspect we will leave that up to the purchaser. We have also discussed oval tubes instead of round tubes to fit the different ratio rockers. You also will be able to purchase them without tubes drilled so you can do it yourself.

I am going through a nightmare right now trying to get a set of special stands made up with the new springs in my SS engine. I am probably the only guy in the country running a 2.20 installed height with a 5.33 length valve and a 1.8 rocker. My $2500 worth of Jesel in the garage doesnt fit no matter what I do.

Lynn

[pro-tour79]

Lynn e-mail me at admin@pro-touringf-body.com if you want I'll give you some ideas based on the Ford design, and again the ford tunnel ports I'm talking about are not the 30+ year old ones but the early to mid 90's that not to many people have seen

[theoldone]

Originally Posted by pro-tour79

Lynn e-mail me at admin@pro-touringf-body.com if you want I'll give you some ideas based on the Ford design, and again the ford tunnel ports I'm talking about are not the 30+ year old ones but the early to mid 90's that not to many people have seen

For anyone interested here is the Dove Mfg. links where the Ford tunnel ports are discussed- the TP was Ford's answer to the 426 Hemi in NASCAR racing.

Hit link a small page will come up- move cursor to lower right hand corner of page and a symbol will appear in about a second- click that symbol to expand the page image and read it, upper left corner has printing/save options that also appear if cursor is moved there.

Dove is getting 400 cfm intake/300 cfm exhaust from their FE heads. This is good news and information for Pontiac fans, as the FE Ford engine is very similiar to a Pontiac in that the bore spacing is only .020" difference. Basically both engines share the same bore/head shrouding relationship, and many times what works on a Ford FE will work on a Pontiac as well. And a Pontiac actually has a better oiling system than a Ford FE top oiler from the factory.

http://www.doveengineparts.com/images/InsightFE-A03.jpg

http://www.doveengineparts.com/image...umHeads-06.gif

http://www.doveengineparts.com/image...onHeads-07.gif

[GTOGEORGE]

You guys may want to consider openings for 9/16" head bolts/studs. Anything to help seal the heads to the block! That way all someone has to do is to drill and tap their IA, IA2 or MR-1 block for the bigger bolts/studs.

[tom s]

George,any worry about the strength of the material being TQed with 9/16?How much TQ will be needed to get the correct "stretch" for proper clamping force?Tom

[Steve Barcak]

I have used 9/16" studs in my Pontiac for years. it works fine.
Steve Barcak www.pontiacheaven.org

[pro-tour79]

Theoldone, I'm talking about NEW tunnel port heads that ford made in the early to mid 90's for stock car racing they have square intake ports, I need to find my pic and scan it !

[NHRASuperStock455SD]

Thanks George, we hear you on the head gasket issues. I am sure we can leave enough material for the bigger bolts. I will make a mental note.

My preference would be to add head bolts, some small ones in strategic areas in the top and the bottom. Of course that would take a RA-V block, or someone to add it.



Lynn

[NHRASuperStock455SD]

Originally Posted by 7T2

it seems to be accepted that the 4" stroke is the best for max power, due to the piston speed. it has been said that the 4.21" stroke actually hinders power because the piston speed is too high. but i thought one of the main reasons for resurrecting the v head was for the increase port area, which should alleviate the piston speed "choke" of the standard head. if thats true, then can the v head accomodate an even longer 4.5" stroke?

You are correct with limits. We can overcome choke, but then the limiting factor becomes bore size in a hurry. Our plan is to make the The RA-V we have calcuated to go up to 500 cubic inches, and that is where we start losing power due to bore size restrictions and flow per valve sizes. So we are going to get innovative with bore sizes as much as possible. If you look at the equation for Choke, it is by square of the bore and linearly with the stroke. So we can do some stroke stuff, but the limit remains to be seen. However, if you run the calcuation, it look very interesting doesnt it?

Calculations:

CA = ( Bore * Bore * Stroke * RPM * .00353 ) / 614 fps
= 4.4 * 4.4 * 4.5 * 9000 * .00353 / 614 fps
= 4.508 square inches.

Remember that the BBC ProStock engines get 2.7 to 2.8 HP per cubic inches out of a 500 cubic inch engine.

Originally Posted by 7T2

this will be necessary for 500 cubes from a standard production block. so what are the possibilities that we can convince the Chicoms to "update" the 4.25/3 cast steel to 4.5/3? the block can easily clear the recip with BBC steel rods.

My 502 is going to be probably a 4.36 X 4.21 A 4.25 has too much valve shrouding. However we can minimize that effect with valve seat angles.

Originally Posted by 7T2

from a street and limited race aspect, this would be the icing on the v cake.
oh by the way(unrelated) what will the pushrod tube dia be? can a guy buy the v heads with small guide reference holes, then bore for tubes desired. so you can press in which ever tube desired so that port obtrusion can be minimized for a 5/16" chrome moly/street app?

You can buy with or without tubes installed.

Originally Posted by 7T2

thanks, jim

[7T2]

capiche'
after running the choke formula on my street 4.46 stroke app, the required area of 3.2 sq" is barely obtainable with a std head with pounds of metal removed. however it is also one third smaller than the 4.74" of the std v head.
therefore i see the viability of a street head. lynn if you could convince tom s. to let your mold guy make a pattern of his heads, there would be your street piece. at a hi velocity 370cfm w/minor clean up: like someone else said... you'd sell a truckload of 'em.
i paroused the dove engineering stuff, but was disappointed with the 400 cfm figure. from a previous post on this thread, the stock v is already there. im not sure what if any improvements dove made to their head before reintroducing. what is nice is that we can probably pilfer the air foil hardware, since it is current tooling again.
hopefully a high port v would give the 450-500cfm needed to create the market for the lunatic fringe(positive sense) market. move and twist the oversize valves to achieve sounds doable.
lynn, i feel this has the possibility of being the next big thing, so naturally i would entertain the possibility of what i could contribute to attain that street dealer status. e-mail me if youre interested... rolandradio@earthlink.net
jim

[tom s]

FYI,a "stock"V intake port is in the 315-320 CFM range at 600 lift.Would need to go back to my original 400 head chart to be sure.Also so as far as flo goes my tubes did not flo any diff from my foils,I think they would show improvement with very high lift.Tom

[NHRASuperStock455SD]

Flow is only 1/2 the battle.

Engines take a pulse and not continuous flow. If flow was the only answer, then bolting that 320-400 cfm port onto a 303 cubic inch engine would be all you need to worry about right? We all know that the RA-V heads were a miserable failure with the 303, so there must be something else.

When velocities are too slow it reduces the engine's ability to gain volumetric efficiency. To do this we draft the intake charge into the cylinder by utilizing the exhaust flow to "aspirate" intake charge. This is more efficient than using the piston because it occurs when the piston speed is very slow.

Additionally, you gain volumetric efficiency by building pressure on the face of the intake valve when it closes, and snap the intake valve open before it bounce back creating a RAM EFFECT. As velocity goes down, the ability to gain volumetric efficiency over 100% falls off drastically.

Too much volumetric efficiency and you pull intake charge right into the header pipe, but that is a different post.

Too much velocity in certain areas cause fuel to separate. Fuel is much more dense that air, so when it tries to turn the corner while going to fast, it separates. This is flow that actually reduces horsepower and combustion efficiency.

Choke calculation is not a maximum number, it is a minimum number. How far you can go over is a much more complicated and varies with the application. I would also be very careful in applying the choke calculation to a street motor. Other factors are at play in street motors, that dont show up in a race engine. Dont get me wrong, it still applies as a starting point, but then there are different considerations and limiting factors that show up.

Lynn

[7T2]

uh huh,
but still i believe the salient point of the velocity remains. to optimize part throttle driving conditions, yet not compromise top end ve charge, choke calculations must be applied on the small side. i understand and agree that dry flow isnt everything. wet flow dynamics is very tricky stuff, and requires not only velocity, but port shape as well. suspension of wet flow is a delicate balancing act.
a reduced volume v head like tom s' has been engineered to meet those criteria within the 400ci street envelope. correct me if i am wrong tom, but with the cam of about 250deg@.050", your engine probably makes great streetable(3-7k rpm) power. this would not be the case with a stock port volume v head, as juan wisely accomodated for.
i think you stated in a previous post, lynn, about casting a street head that was filled in the bottom... or was it so late that night that i dreamed that?
anyway, with a high port v, the fuel would not be as apt to separate on the turn due to the reduction of flow transition angle. this, in addition to the increase inpotential flow #'s from the high port design, would make this head viable for much larger ci/rpm apps. but a baseline thereof would be required, or one would run into a mismatch like the 303/v debacle.
jim

[tom s]

I have found V engines like a lot of lift.I run 660ish lift on all my motors.My short deck 390in motor not only has the reduced port vol but also a short 5.98in rod.The cam is 113 LC and stock RA V type duration.It drives like a stocker untill the 4000 RPM range when bad(or good) things happen.I have built a couple other std deck V motors and the best IMO was a 4.125 stroke and 4.150 bore.The SAME setup,cam, carb, heads,with a 4.21 stroke made no more HP although 9 more CI.In fact it made less.I REALLY like the 4.125 stroke with a 4.30 bore for a V race motor.Tom

[theoldone]

Originally Posted by 7T2

uh huh,
but still i believe the salient point of the velocity remains. to optimize part throttle driving conditions, yet not compromise top end ve charge, choke calculations must be applied on the small side. i understand and agree that dry flow isnt everything. wet flow dynamics is very tricky stuff, and requires not only velocity, but port shape as well. suspension of wet flow is a delicate balancing act.
a reduced volume v head like tom s' has been engineered to meet those criteria within the 400ci street envelope. correct me if i am wrong tom, but with the cam of about 250deg@.050", your engine probably makes great streetable(3-7k rpm) power. this would not be the case with a stock port volume v head, as juan wisely accomodated for.
jim

good post- the stock V heads are too big for a 400 CID engine IMO- I drove in one and it was a dog below 4000 rpm

but the stock V heads work quite well in a 455+ size engine, as the extra cubes create the additional needed torque and idle vacuum to make the heads tractable at street rpms

the engines still need to be geared somewhat low if a stick car, or a loose converter if an automatic car

my advice to anyone running a stock RA V head on the street is, use the 455 engine for sure.