70 Judge RAIV and V continuation

[tjs44]

Steve,one reason it was pulled is the engine would not perform as good as a RAIV!EVERYTHING with the combo was no good for making HP.The dual plane intake quits around 6100,the ports are way to big and have good flo but NO velocity,the rods were way too heavy,the exhaust ports were reg pontiac design with turn down ports that have the WORST intake exhaust ratio of ANY pontiac head made.The list goes on as to the complete failure of the project.The heads need big CI,huge lift cams and hi CR to take advantage of the ports.I use a 660 lift cam in my motors.They are a great piece of pontiac history and I have tried to preserve some of it but it was and is a poor combo for racing.Tom

[Steve_Hoog]

Tom

Reality bites!!! But the motor still gets me excited. I can't help it, Pontiac is in my veins.

[Jeff H]

A similar situation to the Chevy small block hemi heads for the 302. They did not better than a slightly worked set of stock heads so the program was scrapped. Those RAV heads have HUGE intake ports. I can see why they didn't perform in real world situations.

[Steve_Hoog]

Some interesting things in the The Big Little GTO by Albert Drake, page 142 and 143. Credits Joh MacDonald with killing the program. Several insights from George DeLorean, and substantialy more engines are around according to George than is typically talked about... It says John D left for Chevy in late 68, which it has been my understanding it was 69. Typos and errors can always be present.

[MotownMadman]

Guys,
It is hard to believe how much these Pontiac heads look like the Ford 302 Tunnel Port heads. It seems Pontiac "Borrowed" the idea from Ford, which doesnt make a lot of sense since Ford had problems with this head configuration in 1968. SCCA rules required any race application engine to be a street unit, although Ford had everyone convinced the Tunnel Port was being released to the public, even a magazine cover showed a street version testing against a Z28, Ford never actually released a street version due to ongoing problems with the head configuration for street use. The SCCA let Ford finish the season with the engine and that was it. They then went to the Boss engine. So why would Pontiac copy a design that proved to be troublesome for both street and racing applications? If anyone is interested I can post some photos of the Ford heads, with the exception of a small difference in exhaust port design they are almost identical.
Thanks,
Motown [img]/ubbthreads/images/graemlins/dunno.gif[/img]

[Steve_Hoog]

Matt

Here's a quote from Ablert Drake's book, page 142:

"One of the Ford factory sponsored cars had a 427 built by Homan and Moody. Delorean (G), fascinated by this powerful, high revving and durable engine, persuaded the driver, Benny Parsons, to lend him the heads, valve train and camshaft. He took these to Pontiac engineers in charge of experimental engine development and they studied the parts closely. The result was Ram Air V."

[MotownMadman]

Steve,
The 427 Tunnel Port performed well as a race engine, but Fords first attempt at using the Tunnel Port design on a production street engine was the 302 in 1968. That is when all the problems had developed for street use. I would have thought that Pontiac would have taken notice to that, but possibly they already had the Pontiac V engine developed to the point of no return, based on the performance of the Ford 427 engine. For that design to work correctly it required huge cubic inches and high RPM which both the Ford 302 and Pontiac 400 were lacking for constant street use.
Motown [img]/ubbthreads/images/graemlins/beers.gif[/img]

[John Glasgo]

I can say from experience that the RA 5 was not the dog that everybody acts like,the 69 GTO that i did with the 5 motor,stock GTO exhaust manifolds,2.5 kinked full exhaust system,4.88 gears ran a 12.4 at 111.00,this was in a concours show car.It pulled hard to 7000 rpm,i drove it once when i first finished it with no exhaust,and 2 foot dumps,that car flat out flew,the exhaust really hurt it.I have had every Pontiac motor made,the RA5 car was definetely the neatest.the biggest flaw with the motor was that the rods were junk,and most of them let go before the true potential of the motor was realized.

[tjs44]

John,I never meant to say the V is a dog.My motor is 446CI,9.5CR and makes 555HP at 6100 with a single 950 holley.I have had a few V motors on the dyno and they all gave up around 6100 with the factory single 4.The 2-4 tunnel ram pulled all the way to 6900.What I was saying is if you put the same setup with a RAIV head with the same flo numbers as the V head,the IV would make more HP.I have not done the compare my self,just from a eduacated guess.Tom