[PAUL K]

Originally Posted by Skip Fix

So I'll throw a slightly related but tangential question -why did most of the jet boats in the 70s early 80s use Olds 455s vs Chevy 454, Pontiac , Buick 455s?

Tons of torque from the long and relatively small intake tract.... IMO

[PontiacJim1959]

Reading this post we have different conversations going all over the place, from 428 to Olds power boats.

Let's start with emissions. Thank you, California. Yep, that's where it began. 1961 an administrative organization called the Motor Vehicle Pollution Control Board (MVPCB) was created. Later changed to the State of California Air Resources Board in 1967.

In 1961 the board required all new motor vehicles sold in California to have crankcase emission control devices (namely to control engine blow-by gases) as factory installed equipment aimed at reducing hydrocarbons down from 1.25 pounds per car per day to 1.0 pounds. This changed in 1966 when unburned hydrocarbons had to be limited to 275 part per million (ppm) and the carbon monoxide to a 1.5% concentration by volume dropping the pollution levels to .046 pounds per day per car. The projected number that California was looking to see by 1970 was 0.20 pounds per vehicle per day.

Thus began the introduction of the PCV valve, the closed crankcase system, A.I.R. systems, open chamber heads, thermostats changed from 180 to 200 degrees, reduction of idle port holes/limited idle screw adjustments, retarded timing controls and the double acting vacuum advance can, the catalytic "after burner" (yes, 1968), and the gasoline vapor recovery systems. All thanks to California and mandatory on all cars/engine sold in California and this was all by 1968, and of course more was to come after 1968. In other states, some of these requirements were not required and thus a CA car will have the AIR system while one in New York would not, but still had the AIR heads. The better burning open chamber heads did away with the AIR system......but it did return at a later date along with those charcoal canisters if anyone recalls those.

The use of the Oldsmobile 403CI came about because it was the only comparable engine to the Pontiac 400CI that met California emissions standards. So California cars were fitted with the Olds engine in lieu of a Pontiac 400. The 403 was also an optional engine on the Catalina.

The Olds may have had smaller valves (2.07/1.62) and even flowed less than a Pontiac head, but the use of a longer duration and higher lift did wonders for the W30 option. The 1970 W30 455 was rated at 370HP @ 5200 RPM and 500TQ @ 3600. The cam had a 328 duration on Int/Ex, Lift was .475, and had an overlap of 108 degrees! So do you want to compare it to the 370HP RA IV or the 360HP 455? Oldsmobile had some hot set-ups to include the W31 350 with its 308 duration cam and .474" lift and 82 degree overlap cam. Same HP as the Pontiac 350HO, but my guess is it'll outrun the 350HO.

You can also look to an earlier time when the engine option in 1966 on the 442 could be had with the 400CI, tri power, ram air induction, close ratio 4-speed, and 4.33 gears and would have been the match to Pontiac's 389 XS tri power, ram air option.

I have never owned an Olds 442, but I would say they had a few engine options that may have put a hurting on a Pontiac GTO, or a Tempest/Lemans with the 350HO.

[Schurkey]

Originally Posted by PontiacJim1959

the catalytic "after burner" (yes, 1968)

No catalyst before model-year 1975. I think you mean "Thermal Reactors".

Essentially after-burning exhaust manifolds fed with fresh air from the AIR pump or the Pulse Air system. The added oxygen allowed the overly-rich mixture to continue to oxidize.

[PontiacJim1959]

Originally Posted by Schurkey

No catalyst before model-year 1975. I think you mean "Thermal Reactors".

Essentially after-burning exhaust manifolds fed with fresh air from the AIR pump or the Pulse Air system. The added oxygen allowed the overly-rich mixture to continue to oxidize.

Ah, you are an automotive engineer - I say that with no disrespect. So here is the complete info I got this from as the word "catalytic" caught my attention. The topic is headed AFTERBURNERS. My book source is published 1968 and specific to automotive emissions systems of all the US manufacturers and the diagnosing, troubleshooting, calibrating, and repair of the systems.

"The two types of afterburners that have received extensive development work to date are the catalytic and the flame type. The catalytic afterburner is designed to consume the discharged hydrocarbons by means of heat developed through a chemical reaction. The units may be positioned at the muffler or in the exhaust manifold. Chemically coated pellets are arranged so that the flow of hot gases activates them; the pellets then promote oxidization of the unburned hydrocarbons. The flow of gases also must agitate the pellets in order to reduce carbon build up in the catalytic bed. Temperatures required to maintain this chemical reaction range from 400 degrees to 1,300 degrees."

So, as you can read, it is exhaust heat activating chemically treated pellets - not air injection.

However, the same section also describes another system - a flame-type afterburner:

"The flame-type afterburner consumes unburned hydrocarbons by means of an open flame. This system requires the adjustment of the carburetor and distributor to produce, as fuel for the flame, a controlled concentration of the unburned material in the exhaust stream. The exhaust must be kept rich enough or the afterburner will "flame out." If the exhaust is too rich, the unit will burn out from excess heat. Also, the extra gasoline needed to keep the burner going exacts a 3-7 percent fuel consumption penalty."

So both devices/concepts use heat and I fail to see in the description of either anything about injecting air?

The type system you describe has nothing to do with a catalytic system as described above, but the Air Injection Reaction System (A.I.R) is what you reference. For your recollection, and the others who may have never even seen one of these nifty units, I will clarify and describe some basic operations of the system.

"The AIR system consists of an air pump (belt driven) that constantly forces air into each exhaust port immediately after the exhaust valve. Since the exhaust gases at this point are above kindling temperature and have an excess of hydrocarbons, the infusion of oxygen starts the mixture burning and so consumes the hydrocarbons that normally would be expelled into the atmosphere.
The AIR system pump draws air from the air cleaner/air filter canister and forces it through two outlet hoses (one for each side on a V8 engine) through a check valve and into an air manifold, where it is delivered to each cylinder through stainless steel nozzles that project into the exhaust port."

I won't get into the fine points as the system has many features in the event of backfires, pressure changes, high speed pumping, and the like.

[Formulajones]

Originally Posted by Skip Fix

So I'll throw a slightly related but tangential question -why did most of the jet boats in the 70s early 80s use Olds 455s vs Chevy 454, Pontiac , Buick 455s?

Hmmm, all the jet boats and mini off shore racers I ever saw or rode in were mainly BBC's with a few exceptions. My buddies jet boat ran a 460 ford with a tunnel ram. I don't ever recall seeing one with an Olds.

[geeteeohguy]

Originally Posted by Skip Fix

So I'll throw a slightly related but tangential question -why did most of the jet boats in the 70s early 80s use Olds 455s vs Chevy 454, Pontiac , Buick 455s?

There were a lot of Olds powered jet boats in the early 80's were I was in CA as well. As a mechanic at a general shop (worked on every make) from the late 70's through the mid '90's, I saw a lot of the old large-bore V8's. Of them all, the Oldsmobile 455 was the most durable, and would put up with the most abuse/neglect. So running an Olds in a boat at high load most of the time would make sense, as there would be less down time. BBC's had valve issues, Cadillacs liked to toss rods, and Pontiacs liked to spin bearings. The old FE Fords were durable, but by then, the 427's were a lot of money. Used Olds 455's were cheap and all over the place...and they held up.

[MarkS57]

Originally Posted by geeteeohguy

There were a lot of Olds powered jet boats in the early 80's

I really wanted to get into jet boats in the mid 70's and likewise, those blue 455 Olds jets seemed to be everywhere.

My friend was really into the W30 455's in those days and had some trouble keeping the rod bearings from spinning.

[455Grandville]

Originally Posted by MarkS57

I really wanted to get into jet boats in the mid 70's and likewise, those blue 455 Olds jets seemed to be everywhere.

My friend was really into the W30 455's in those days and had some trouble keeping the rod bearings from spinning.

Olds V8s are pretty durable but had a flimsy weak bottom end if you plan on pushing them unless you use the diesel block or girdled it.

[John Milner]

I'm kind of partial to 428's. They just build tons of torque and love to rev. I wish Pontiac could have made a Ram Air IV 428 in '69. That really would have been a great engine for a GTO or Firebird.

[Douglas Willinger]

Thread on my 434 Ram Air Iv build:

http://psp.aquacomp.net/topic.asp?TO...TOPIC_ID=13682

[72LuxuryLeMansLa.]

Originally Posted by Douglas Willinger

Thread on my 434 Ram Air Iv build:

http://psp.aquacomp.net/topic.asp?TO...TOPIC_ID=13682

Doug,
The link brings me to the log on page.... Guidance to find the thread?

[goatwgn]

How about the 455 block, fitted with a 428/421 crank, and correct pin height pistons?

[slowbird]

Originally Posted by Skip Fix

So I'll throw a slightly related but tangential question -why did most of the jet boats in the 70s early 80s use Olds 455s vs Chevy 454, Pontiac , Buick 455s?

Because no one would care if the boats sank

[Stan Weiss]

Unless I am thinking of something else jet boats were not high RPM.

Stan

[Stan Weiss]

If under square was the way to go why did Pontiac use the Olds 403 - 4.351" x 3.385"?

Stan

[Mr Anonymous]

Originally Posted by Stan Weiss

If under square was the way to go why did Pontiac use the Olds 403 - 4.351" x 3.385"?

Stan

Simple. 403 came out in 77, replaced applications that used the 455. They needed 400ci +/-, and all small block olds cranks were all 3.385. Only way to get it big enough as a small block was to take the bore out huge. A friend in FL just stuffed an aftermarket 4.00 crank in his 403, its 484" if memory serves. My 350 diesel with 4.00 425 crank and 0.197" overbore ended up 454ci. Still small block.

The olds motor from 1968 to 1976 only had two different combustion chamber sizes, and two different piston dish sizes. They were durable, inexpensive, and did the job. That meant 442s, land barges, jet boats, irrigation pumps, etc. Eight years of production with few changes (besides w-30 specific parts) means that they're quite plentiful, unlike the 455 Pontiac.

I'd love to see two cars of similar weight and gear, one with 428 Poncho and one with 425 Olds, and let them go at it. I'd bet theyd be close.

[67GP428]

I miss driving my 428 GP. It ran very strong. The 428 was a unheard motor outside the Pontiac world.

[hurryinhoosier62]

Originally Posted by Stan Weiss

If under square was the way to go why did Pontiac use the Olds 403 - 4.351" x 3.385"?

Stan

Stan, you are making this too easy. It was already EPA and CARB certified for CA and high altitude areas. The Pontiac 350 and 400 were NOT. Look at the cam specs, carb jetting and ignition timing of the 403s. Then, consider the 403 had an air pump, catalytic convertor and was designed to burn unleaded fuel.

[Schurkey]

Originally Posted by hurryinhoosier62

emissions. Under square engines produce few emissions than over square or square engines. The first emissions control protocols were already in effect in CA.

From the perspective of the times, this is true.

Given the decades of additional research, not so much. But also consider, Chevy was cutting bore size and increasing stroke by 1965 compared to the engines designed in the '50s. The 409 "W" Chevy had a much shorter stroke than the 396/402 "Mk IV" Chevy; the 348 W" had a much shorter stroke than the 350 sbc. Even the '66 Buick 401 had a shorter stroke than the '67 Buick 400.

Originally Posted by PAUL K

I thought they added stroke to make up for the loss of compression. I also think they did a lot of bad guessing when diving into the emissions part.

They were scrambling like mad. They made many bad choices, but I think Management had a hand in that also--by insisting everything be as absolutely cut-rate cheap as possible. It took a couple of decades and on-board computers to even begin to bring power numbers up. If they'd made better choices then about compression ratio, quench distance, in-cylinder turbulence, restrictive pellet-type catalysts instead of monolithic/honeycomb, and a host of other factors, we'd be remembering much nicer cars to drive.

Buick, Olds, Cadillac each built larger engines in the '67--68 time frame, just as the switch-pitch feature was getting deleted from the TH400 and TH425. It was cheaper to enlarge the displacement than to fancy-up the torque converter.

Originally Posted by steve25

First and foremost it was the switch to the open chamber heads that got most manufacturers in compliance with the Fed's limits on emissions!

Followed by Bigger motors stroke wise made for increase Torque which allowed less rear gear.
Lower rpm and less emissions go hand in hand!

But open-chamber heads tend to have poor turbulence, slow burn, and need lots of spark advance. They mitigated one problem, but caused two more: Low power and crappy mileage.

"Stroke" doesn't increase torque. Increased displacement increases torque. The Buick 455 was a torque-monster; and it had the shortest stroke of all the GM 454-455s.

Originally Posted by napster

Think about it. Bunky Knunsen (SP) was at Ford and they had the BOSS 429 and chevy had Delorean and they came out with the 454 LS-6. All Pontiac guys that were gear heads.

Bunkie Knudsen left GM to go to Ford. Later, he was fired from Ford.

Henry Ford: "History is bunk!" 1916
Henry Ford II: "Bunkie is history!" 1969

Originally Posted by Formulajones

I tend to believe it was more along the lines of cost. Due to limited bore spacing, the only way Pontiac could increase the CI comparable to other brands was to simply shove a long crank in it, otherwise they would have to spend more money to completely redesign and cast a new block.

The Pontiac block and the Olds block have similar bore-center measurements, along with the FE Ford. I've heard that the same raw forging can be machined into Pontiac, Olds, or FE crankshafts just by altering the way it's machined.

Pontiac "could" have siamesed the cylinders like Olds did with the 403, and had a significantly larger bore (or just gone paper-thin like Ford did with the 427). I wonder if Pontiac management/engineering ever considered that.

Originally Posted by Skip Fix

So I'll throw a slightly related but tangential question -why did most of the jet boats in the 70s early 80s use Olds 455s vs Chevy 454, Pontiac , Buick 455s?

Originally Posted by PAUL K

Tons of torque from the long and relatively small intake tract.... IMO

Originally Posted by Stan Weiss

Unless I am thinking of something else jet boats were not high RPM.

Far as I can tell, the Olds management made engines available to the Berkeley Jet company cheap. Olds also sold engines to companies producing agricultural irrigation pump systems. Maybe the Olds engine plant(s) had excess capacity and needed a way to dispose of a heap of engines. Every time I saw a jet-powered ski boat with a white painted (Berkeley) jet drive, there was an Olds engine powering it. Every time I saw an Olds engine in a jet-powered ski boat, it had a white Berkeley jet drive. There were other brands of jet drives, but Berkeley was "the" main player in the market I was exposed to.

Ever driven a jet boat? The L-A-S-T thing you need is big bottom-end torque. Low-RPM torque is TOTALLY WASTED. A jet pump is a centrifugal pump. At 2K rpm, they barely move any water. I think a Techumsah lawn-mower engine could spin one at 2000 rpm. It takes ~600 horsepower to spin them 6000 rpm, and probably 400+ horsepower to spin one 5000 rpm. The power absorption of the pump is VERY non-linear. (i.e., it takes much more than double the power to double the RPM.)

So lots of Olds/Berkeley power packs ran 4500--4800 for hours on end, 'cause that was WFO and all the engine could do. The torque curve of the engine intersects with the torque absorption of the jet pump; and that's it for RPM unless the boat hits a wave and the pump sucks air.

Originally Posted by steve25

Other then the Olds motor bring lighter then a BBC for use in a Boat I can't see why Edelbrock made the needed water cooled Exh Manifolds for them.

I think Mondello was twisting Vic's Arm a lot to do that!

Edelbrock made marine parts for heaps and piles of different engines. Marine engine mounts, timing covers that could mount a cam-driven marine water pump, and water-cooled aluminum exhausts for Ford small-block, Ford FE, Ford 460, SBC, BBC, Olds, Pontiac, Mopar B-RB-Hemi...Edelbrock made lots of marine stuff. Far as I know, every bit of it was discontinued decades ago.

Originally Posted by chiphead

Yeah, now we understand the concept of crevice volume and how much unburned hydrocarbons hide there. This is one reason there are precious few modern engines over 4" bore. The unburned HC emisions go up along with bore size. Top ring placement has an impact on crevice volume, so even that affects emissions. They didn't undertand any of that yet in the late 60s.

There was also the idea that large-scale production machine tooling couldn't control tolerances very well. The quench distance was huge. Part of that was the machining engineers telling GM they couldn't hold tight tolerances, and they had to go big because going small could result in things hitting each other. The other part of it was LIES told to the upper management. Example: There was a problem with certain Chevy engines not making advertised horsepower. Engineers grabbed several engines from a warehouse, and measured them. The cylinder blocks were too tall, leading to the piston being way "down in the hole" which lowered compression. Why? It cost less to leave the blocks too tall rather than spend the machining time and tool wear to cut them lower. The plant manager probably got bonuses for increasing production and lowering the wear on the tooling, while at the same time he was sabotaging the power, efficiency, and emissions output of the engines he was making.

Originally Posted by chiphead

There were no overdrive automatics in 1970s american cars, so the only way to move a heavy car around with freeway gears is to put a larger engine in... ...The emission laws of the early 80s caused a slaughter of engine families, Pontiac, IHC, Caddy, most Olds and Buick, among others ,were discontinued by '82

Yeah, the outright failure of GM and the competition to produce a REAL automatic transmission with additional gear ratios was a stunning mistake. The TH400 and variants was a great trans, but it needed another gear. This happened in '91 or '92, but only in trucks, and only with computer control. They needed it in '73 or earlier, with no electronic controls beyond the kickdown. Same with the TH350. It was sort-of replaced with the 700 a decade or more too late; but the 700 was a piece of crap for the first three or four years, and wasn't really right until...1988? And even then, it was at best a "light-to-medium duty" trans, and at worst it was a hand grenade.

'Course, we could see what was happening in '67, when GM killed the switch-pitch TH400 for the '68 model year. They were carving money and utility out of the transmissions even then. The Powerglide was even worse. Had GM spent a little more, a little earlier, they'd have eliminated untold problems in the '73--'90 timeframe; and they'd have pissed-off fewer customers in the process.

[steve25]

The old 403 has terrible flowing heads which was ashame since it had a great big Bore size.

Buick wise other then the nail head motors they have quite poor oiling systems even for just a steady 4500 rpm, so they out of all of these motors would never survive!

Other then the Olds motor bring lighter then a BBC for use in a Boat I can't see why Edelbrock made the needed water cooled Exh Manifolds for them.

I think Mondello was twisting Vic's Arm a lot to do that!