[motorcitymusclecar]

The 69 and 70 Ram Air 4 rated at 370 HP and the ram air 3 366 HP - How can they only be 4 HP differet - The standard GTO engine 350 HP.

Has anybody dyno'ed an original Ram Air 4 or a rebuild to STOCK Spec's Ram Air 4.

What is the true HP rating

Thanks john

[GTO JOHN]

My 69 RAIV completely stock rebuilt two years ago engine dyno was 399hp. All factory stock.

[Uncle Judge]

Originally Posted by motorcitymusclecar

The 69 and 70 Ram Air 4 rated at 370 HP and the ram air 3 366 HP - How can they only be 4 HP differet - The standard GTO engine 350 HP.

Has anybody dyno'ed an original Ram Air 4 or a rebuild to STOCK Spec's Ram Air 4.

What is the true HP rating

Thanks john

That was strictly a decoy for the money hungry insurance companies. Those "in the know" were only too happy to cough up the additional $389.68 for "Only 4HP"!

[Ram Air IV Jack]

Originally Posted by Uncle Judge

That was strictly a decoy for the money hungry insurance companies. Those "in the know" were only too happy to cough up the additional $389.68 for "Only 4HP"!

Right on Uncle!! That was the whole reason for the deception. Jim Wangers has spoken about this in the past. HPP a few years back in an article claimed a good running RAIV will turn 335-350 to the rear wheels. Even today that is considered very good. But sadly, so many original RAIV engines were tested on street and strip in those days, over revved and hatched.

A TRUE numbers matching RAIV car is so rare to find today. The ones that have survivied should be placed in a museum and honored as one of finest street engines made and a true testament to Pontiac engineering.

[SWEETJUDGE]

that was all a marketing & insurance issue...... same as any hiperf car at that time they are much closer to 400HP

[johnta1]

The HP was also at a higher RPM than the RA III.

[2manyponchos]

There is an interesting couple pages in the latest Pontiac Enthusiast from John Sawruk discussing the 'published' or advertised hp ratings for the '62-'63 SD cars. Basically says that for insurance or competitive reasons, the engines were underrated. Got a sneaky feeling that the same thing still goes on today...to an extent.

[snakepod]

-After mine was rebuilt, it dynoed at 411HP. That was with lowering the compression to 9.84-1 compression(dished pistons) and with 4-tube headers on an engine dyno. I spoke with Arnie Beswick years ago. He told me that a blue-printed RA 4 was good for between 425-450 HP, Ken

[mmarx]

For comparison, has anybody dyno'd a RA III?

[TR]

Originally Posted by mmarx

For comparison, has anybody dyno'd a RA III?

Well FWIW: Yeah, some magazine ( the original 'Musclecar Classics ) a few years back. They also did a RAIV. But I'll take 'GTO JOHN's word and others here the most creedance

I recall the RAIV made 394 with the A-body RA exhaust manifolds, and an even 400 with the longer F-body ones. It was stock but they did fiddle with timing and mixture for experimenting.

The RA III they dynoed came out pertty much to stock specs, but the actual number was slightly lower but they mentioned that their engine wasn't totally "bare" as in the case when the SAE gross ratings taken by the manufacturers. I wanna say their readings were like 357 @ 4900 RPM. They did say they were running the 068 cam ( and not the 744 )

Even if we never actually knew a dynoed reading, the MPH at the end of the quarter they ran ( in bone stock condition ) should be proof enough. 2 to 3 more than the RA III in tests I've read.

[north]

Funny thing though is that in period roadtests 350hp, 366hp and 370hp engines (with the same trans and gears: 4spd 3.90's) were all about 99 MPH cars.

I suspect that to get the extra oats out of a IV it needs to be set up "just right."

[gloryrestoparts]

go to the 70-73 Firebird/TA forum. Look at the 455 HO forum thread. In there, yes all 19 pages, but more towards pages 18 and 19 IIRC, Mark Weymouth talks about his 70 RAIV Pure Stock Drags Judge. He's dynoed that motor. He (and Dan Jensen I would assume too) are about to dyno a RAIII motor. OUTSTANDING information in that thread from Mark.

[Lloyd-TX]

Originally Posted by gloryrestoparts

go to the 70-73 Firebird/TA forum. Look at the 455 HO forum thread. In there, yes all 19 pages, but more towards pages 18 and 19 IIRC, Mark Weymouth talks about his 70 RAIV Pure Stock Drags Judge. He's dynoed that motor. He (and Dan Jensen I would assume too) are about to dyno a RAIII motor. OUTSTANDING information in that thread from Mark.

Linky to that thread, and a great thread it is!

http://forums.maxperformanceinc.com/...d.php?t=538654

We are fortunate indeed to have Mark baring his soul on here, and in the HPP PSD articles as well.

[gloryrestoparts]

thanks Lloyd. I was too lazy to do that. lol