Re: Ram Air IV versus 455 HO
 

I have 100% orig. '65 GTO 389-6 at Glasgo's getting the Phase III blueprint that will put the car in the 12's with the skinnies and full exhaust. And,they swear by the Comp cam XE274H.

Re: Ram Air IV versus 455 HO
 

If you can not run your best time with full exhaust these days, you best put it back on the trailer. These younger kids racing today have corrected my way of thinking. Don't get me wrong, I still love the sound of open headers but when they run down the track in a full exhausted 9 second car.... I have to rethink things.

Dude, I love that repo Magnum the Glasco's built. Very very nice. I would think any work they do for you will be top notch.

Re: Ram Air IV versus 455 HO
 

Yes I like that cam as well. 230/236 degrees duration and .488/.491 lift with stock 1.5 rockers. A good street cam. Especially for a 389/400.
The 455 SD can take a slight step up in camshaft without affecting idle quality noticeably.(particularily lift) But that one is ok.

Re: Ram Air IV versus 455 HO
 

So I can use the comp XE274H and some Ross 10-1 Pistons, have no valve to piston clearance worries ? Yes this is a 73 SD that is bone stock.

Re: Ram Air IV versus 455 HO
 

You will have no problems with clearance, Ross will take very good care of you. I would suggest using 1.6 full rollers. Jim Butler is great to do business with, if you need a reference.

Re: Ram Air IV versus 455 HO
 

Ross, JE, or CP pistons...can't go wrong with any of them. I went with CP's in our last L-72, and they were BEATIFUL. I *believe* they're a tad lighter as well. I'd use them again in a heartbeat...

Re: Ram Air IV versus 455 HO
 

Charley speaking of references: I can vouch for the Butlers,I personally speak to Rodney/Jim/David almost daily about Pontiac set up tricks and applications. I also like Paul Spotts, He's a good guy and I can help you with him as well. Email me if you are thinking of using any Pontiac guys to do any of your work.

Re: Ram Air IV versus 455 HO
 

My engine parts are at my machinists right now. They are also recommending a hyd roller cam so I guess before I commit to a roller I need to know that I don't have to modify the lifter valley at all. And what Comp Cams hyd roller. This SD block has all that extra webbing around the lifter bores so I don't want any suprises.

Re: Ram Air IV versus 455 HO
 

"I would recommend a Hyd roller possibly a Comp XR276HR or a XR288HR "
The 276 would idle just fine. The 288 will be a little lumpy, with about 14 inches of idle vacuum. But will give you more upstairs. If you are looking to just drive the car without ANY headaches the XR276HR would be fine. You do not need to modify the lifter gallery. But you MUST buy the whole Comp Cams kit including pushrods for you to not run into any geometry problems. 1.65 roller rockers would be great with this setup.
I had this exact Camshaft in a 400 RAIV car, and it idles fine, and runs 12.50's (with headers & stock quiet mufflers) all day long.
-------------------------------
On a previous note: The RAII heads were not exactly the same as RAIV heads with a different camshaft rocker arm ratio. The RAII heads had the same intake openings as d-port heads, much smaller then RAIV intake openings. However because of this extra casting they can be ported today very well.

Re: Ram Air IV versus 455 HO
 

Can I just run the stock rockers ?

Re: Ram Air IV versus 455 HO
 

Yes you can run stock lifters, Pontiacs are much better at top oiling than a Big Block.

Re: Ram Air IV versus 455 HO
 

You can run stock rockers 1.50 ratio if you want but why??
If you are getting an expensive HR cam why would you put stock rockers on it. You could get roller tip 1.65 ratio rockers, but if you gonna do it, do it right.Get Roller Rockers. They will fit under the stock valve covers, if you use 2 valve cover gaskets. Look Stock....Go Fast

Steved...I think you meant stock rockers, not lifters with the HR cam

Re: Ram Air IV versus 455 HO
 

I don't want to double the valve cover gaskets, now what ? https://www.yenko.net/ubbthreads/imag...ns/burnout.gif

Re: Ram Air IV versus 455 HO
 

So use roller tip rockers, they look like stock rockers with roller tips. Comp Cams has those as well.

Re: Ram Air IV versus 455 HO
 

Yes I meant stock rockers, see Charley gets me all twisted up when he starts talking Pontiacs. But I say throw stock rockers in the trash, we finally have a multitude of goodies to choose from now. Lets use em!!!!

https://www.yenko.net/ubbthreads/imag...arleySucks.gif

Re: Ram Air IV versus 455 HO
 

So I get the comp 1.5 ratio roller tips because the 1.65 ratio require double gaskets ? And the XR276HR ? and 10-1 compression and I will be happy...... https://www.yenko.net/ubbthreads/imag...lins/smile.gif

Re: Ram Air IV versus 455 HO
 

You can choose either .15 ratio or 1.65 stamped steel roller tips rocker arms. NEITHER will hit the valve covers. I would choose 1.65's.
----------
The full Aluminm roller rockers are the one that need 2 gaskets. because the aluminum rocker itself is much bulkier.

Re: Ram Air IV versus 455 HO
 

Charley...I would really suggest you take these guy's advice and use someone who KNOWS PONTIAC...they are different animals.

Re: Ram Air IV versus 455 HO
 

I can't believe I'm saying this, but I agree with Belair. From talking to SuperStock guys, those Ponchos seem to do things kind of bassackwards of a Chevy.

Re: Ram Air IV versus 455 HO
 

You know the distributor spins the opposite direction, right?

https://www.yenko.net/ubbthreads/imag...ns/naughty.gif

Re: Ram Air IV versus 455 HO
 

I will be fine.. @##$%%crash bang boom@#$%^&...Now does anybody know where I might find NOS SD intake gaskets ?

Re: Ram Air IV versus 455 HO
 

They just have their own set of tricks and don't respond to the things a big block responds to....am I close here Poncho dudes...

Re: Ram Air IV versus 455 HO
 

You can find Intake gaskets no problem.. fel pro makes them.I find the exact number Charlie if you want.
As far as ass backwards from chevy?? Yes the distributor turns the other way, and you can take it out of the car without pulling the intake manifold and draining all of your antifreeze out of the radiator. Pontiacs are much easier than most engines to work on, and any competent engine builder should be able to work on any brands.

As far as what makes them go or special tricks?? Most engines regardless of brand respond to mostly the same things...which is the right combination of parts. And careful building techniques, I am not sure what you guys think makes an engine tick. They all are just blocks, heads, intakes & exhaust and camshaft. Air pumps if you will, the more efficient you can make any brand the better.

Putting that discussion aside, everybody has a few tricks up their sleeve(that probably work on all brands), but that comes later, if you have a good engine builder your 455SD will make you very happy.

Re: Ram Air IV versus 455 HO
 

I kind of worded the above incorrectly, but hey it was midnight my time. Here's some things you will find different about a Pontiac versus a Chevy:

1.All Pontiac performance heads used screw-in rocker studs from 67+
2. Pontiac performance heads have some of the largest valve sizes in the auto world 2.11/1.77 ,only the BBC performance heads 2.19/1.88 are bigger in a wedge head, except Ford cleveland intakes were 2.19
3. Pontiac engines all use a valley pan, which seperates the hot oil from hitting the bottom of the intake manifold. A definite BIG performance boost. You could also cut off the water neck and change the intake manfold and distributor within 15 minutes at the track and never drain any antifreeze!
4. No dirt, antifreeze or gasket parts can get inside the motor when changing the intake manifold.
5. You do not have to pull the distributor to change the intake manifold.
6. The (balancer) comes off without a pulley.
7. All engines are internally balanced already, no mis matched externally balanced nonsense.
6. The timing cover can be removed without loosening up the oil pan.
7. Changing a timing chain in a pontiac takes 1/3 of the time as a chevy.
8. Pontiac bottom ends are very strong and beefy, all main caps are centered and go in one place only. No snapping them into the block and hope they stay in one place.
9. Todays Rod technology puts the strength of all rods on an equal basis, Some older non-performance Pontiacs had somewhat weaker rods. It has been claimed, although they were probably over revved.
10. All Pontiacs use 4/5 to full lenght very good windage trays. Only the Highest performance chevys had them and they were of inferior design.
11. All Pontiac combustion chambers are machined not cast
12. No Pontiac head bolts go into water jackets like most Chevy's. Cylinder head distortion because of uneven heating is not a problem in a Pontiac.
13. Pontiac stock rods are already among the longest in the industry, a recently recognized slight performance advantage. (basically more leverage)
14.Pontiac holds in the camshaft with a separate retainer plate, not relying upon the timing cover & chain to do the job.

Thats all I can think of for now, I am sure I am missing quite a few things. Anyway Charlie, you will find your Pontiac 455 SD will give you very good performance, last forever without needing a valve job or any other annoying big problem and be very easy to work on.
--------------
For you Chevy guys about to cry Foul!! I own 2 BBC Chevy's and do not have anything against them, I am just pointing out different building techniques which make the Pontiac engine much easier to work on and very well designed.
-------------------------

A an example: When I run my RAIV 69' Judge at the track, I use the stock aluminum intake with the heat crossover removed, just as the factory had already designed it. I constantly get Chevy guys coming over to look at the motor and asking if that is the "new" Holley Air Gap intake manifold. I have to explain to them that Pontiac designed this 35 years ago. And it is not a aftermarket intake. Lots of shaking heads and grumbles as people walk away, seemingly insisting that I MUST have a non-stock part.

I like all muscle cars, they all are cool to me www.kingofmusclecars.com

Re: Ram Air IV versus 455 HO
 

"6. The (balancer) comes off without a pulley." ..Ha.. When tearing down the engine I spent about 15 minutes scrounging around for the right length bolts to bolt my puller onto the balancer. Ended up going to the hardware store. I bolt it on and then the balancer just slid right off into my hands..... Where were these tidbits a couple weeks ago........ https://www.yenko.net/ubbthreads/imag...mlins/grin.gif

Re: Ram Air IV versus 455 HO
 

Sorry Charlie I wasn't here https://www.yenko.net/ubbthreads/imag...lins/crazy.gif !

All Pontiacs are internally balanced (like any good motor really should be). In fact in the later years Pontiac discarded the dampner as it is called in the Pontiac world altogether. And used hubs. Their only purpose is to to show where the timing marks are. As a side benefit you can find any dampner and stick it on any engine that fits without throwing the engine out of balance.

Re: Ram Air IV versus 455 HO
 

I think the 68/9 birds would of been quicker than GTOs. I have a 69 raiv TA, it seems like it is faster than my 70 raiv judge. https://www.yenko.net/ubbthreads/imag...ins/3gears.gif https://www.yenko.net/ubbthreads/imag...mlins/flag.gif

Re: Ram Air IV versus 455 HO
 

Should be its about 200-250lbs lighter. probably 2 tenths quicker

Re: Ram Air IV versus 455 HO
 

Use the Ram Air IV valve cover gaskets they are thicker because the IV's use 1:6 rockers stock. Ames or Performance Years have them in their catalogues. https://www.yenko.net/ubbthreads/imag...mlins/flag.gif

Re: Ram Air IV versus 455 HO
 

RAIV valve cover gaskets are the same as any other valve cover gaskets. The rockers are 1.65 ratio stock, but they were stamped steel and not any bigger than 1.50 ratio rockers. Only Aftermarket Roller Rockers need 2 valve cover gaskets to fit.

To add one more thing to Mike Noun's point about the 455SD motor in 1973-1974. Most performance cars with lowered compression and added emissions at this time were solid mid-high 15 second cars. The 455SD was burdened with the same problem, but was running at least 2 seconds faster than the competition in a 4000lb car!! That is really almost unbelieveble. Too bad it wasn't made in 1970 with high compression & less emission garbage, with an open hood scoop.....it probably would have been considered the ultimate muscle car mass produced engine.

Re: Ram Air IV versus 455 HO
 

bill, your right that the 1.65's are the same size, BUT, because of the pitch of the rocker they will hit the valve covers! https://www.yenko.net/ubbthreads/imag...ns/worship.gif RAM AIR IV'S ABSOLUTLY TAKE THE THICKER GASKET! HAS ITS OWN PART NUMBER. look it up,its in the service manual.. https://www.yenko.net/ubbthreads/imag...lins/beers.gif https://www.yenko.net/ubbthreads/imag...lins/beers.gif

Re: Ram Air IV versus 455 HO
 

maybe this will clear it up. I have 2 RAIV's always used the RAIV gaskets and never noticed they were any different.

Re: Ram Air IV versus 455 HO
 

Supergonzo, I guess I will throw out the two NOS sets I have since you say they don't exist, they are infact almost a 1/4 inch thick and carry a different part number. A lot of Poncho people don't know that the IV's valve cover gaskets are thicker, go figure. They also used longer valve cover bolts. The valve cover gasket part number is 9797580 and the bolt part number is 9784378. https://www.yenko.net/ubbthreads/imag...mlins/flag.gif https://www.yenko.net/ubbthreads/imag...lins/beers.gif

Re: Ram Air IV versus 455 HO
 

heres another one
The rocker on far left is full roller rocker, then a roller tip rocker , then a 1.65 rocker , then a 1.5 rocker.
Can you see any size difference between the 1.5 and the 1.65??

You could be right, but I never measured the difference in gaskets, but The rockers never hit the valve covers either way. As you can see the 1.5 and the 1.65's are identical in size.

Re: Ram Air IV versus 455 HO
 

The rockers look the same but the ratio / geometry is different, the IV's also used longer pushrod and a special anti-pump up lifter. Having owned both a 455HO and a RA IV car not many engines have a better sound at idle, except for maybe a solid lift 427 Chevy https://www.yenko.net/ubbthreads/imag...mlins/flag.gif https://www.yenko.net/ubbthreads/imag...ins/3gears.gif https://www.yenko.net/ubbthreads/imag...ins/3gears.gif https://www.yenko.net/ubbthreads/imag...ns/naughty.gif

Re: Ram Air IV versus 455 HO
 

[ QUOTE ]
From talking to SuperStock guys, those Ponchos seem to do things kind of bassackwards of a Chevy.

As far as what makes them go or special tricks?? Most engines regardless of brand respond to mostly the same things...which is the right combination of parts. And careful building techniques, I am not sure what you guys think makes an engine tick. They all are just blocks, heads, intakes & exhaust and camshaft. Air pumps if you will, the more efficient you can make any brand the better.

[/ QUOTE ]

I'm a page late, but better than never I guess. What I meant by "bassackwards" was that from what I've read and what the Poncho racers have told me is that in the Stock/SuperStock ranks have to take a different approach than you would with a Chevy. With a Chevy you can let the engine accellerate the car, which gives you the "mechanical advantage" of running your typical loose race converter with some steep gears out back...quite the opposite with the Pontiacs. The Pontiac engines don't like to accellerate as well, so they've got to get the revs up and "hang them up", as they say, using a tight converter and geared down out back. Therein lies the problem, as with most cars you run 5.13s or whatever with a loose converter, and you gain a mechanical advantage with that...you lose some of that on the Pontiacs because of the converter/gear setup.

Re: Ram Air IV versus 455 HO
 

If you have ever raced dirt bikes, maybe this will work for comparison. Small block = 125, Pontiac = 250, Big Block = 500. A Pontiac is more like a Big Block, but there are still differences.

Pontiacs definitely love a lot of fuel.

Re: Ram Air IV versus 455 HO
 

Yup, you right Rob, Chevy's you can gear to the track better. Because the power is at High Rpm's where the heads flow air like nobody's business. Pontiacs have much more of a street friendly hi-torque type of power band, So tighter converters and more street friendly gears work better.
Rob that car of yours is awesome, BTW...Hope to see you in July

All of this is related to ORIGINAL stroke and crank journal size, of which most Pontiac racers now use a smaller 400 3" main bearing size and aluminum rods which bring the disparity of Rev-ability much closer.

Re: Ram Air IV versus 455 HO
 

[ QUOTE ]
I think the 68/9 birds would of been quicker than GTOs. I have a 69 raiv TA, it seems like it is faster than my 70 raiv judge. https://www.yenko.net/ubbthreads/imag...ins/3gears.gif https://www.yenko.net/ubbthreads/imag...mlins/flag.gif

[/ QUOTE ]

This was the reason that Pontiac placed a throttle stop on all 1967-1969 Firebird 400's. They didn't want the Firebird outrunning the GTO.

Re: Ram Air IV versus 455 HO
 

A factory bracket car?? Wow, Pontiac really WAS ahead of the game! https://www.yenko.net/ubbthreads/imag...mlins/grin.gif