PONTIAC V8 ENGINE HISTORY

A RUN DOWN OF PONTIAC ENGINE HISTORY
CORRECTION !! 421 CID IS 4.094 BORE STD IT IS LISTED INCORRECTLY IN THE VIDEO

[@edwardvaldiviez1137]

My first car was a 70 GTO 400 with a TH 400 I was never the same after I sold that car

[@garyvisser8987]

1973 GTO was my second car first was a four-door 69 Ventura which donated its engine when I spun a rod bearing in the goat. All 69 Pontiacs were 10.5 compression. Even the two barrels which the Ventura was. You are pretty cool in high school when you can do a rolling burnout at 20 miles an hour for a block in drive!!! I sure miss those old cars...

[@Pablo-cp9nc]

I was never the same after my 400 Firebird formula. What a beast.

[@joshuagibson2520]

This series has been one of the best gifts that I've ever recieved from anyone. Thank you so much for publishing these engine history videos.

[@buzzwaldron6195]

The Pontiac 326 was actually 336" in its first year... as used in earlier 1950s GMC pickups... to fake its way under the GM 330" max limit for '63 mid size cars... the Pontiac 350 was actually 354"...

[@trentdawg2832]

Yeah he killed it with this awesome lineup!!! Nailed it from start to finish!!!

[@Myvintageiron7512]

@@buzzwaldron6195 Yes you are correct it was 336, but they didn't really fake it Pontiac actually reduced the bore size of the 336 to make the engine an actual 326 CID

[@buzzwaldron6195]

@@Myvintageiron7512 - Well they did fake it by calling it a 326 while it was actually still a 336... for a year? 6 months? To use up the remaining 336s...

[@Myvintageiron7512]

@@buzzwaldron6195 yea I think that's fair to say

[@robertheymann5906]

My dad loved Pontiacs, a 59 Catalina I remember when I was young and then a 65' Bonneville that was a beast, big 2 door with dual exhaust, 8 lug wheels and a 421 . Dad said it felt like it could climb up a telephone pole if it had traction. I was about 13 or 14 and I read the Chiltons motor manual like a Bible and learned all about compression that I applied to my Briggs and Stratton powdered mini bike removing the cylinder head and sanding it with wet/dry 220 grit placed on the sidewalk. Made dad smile

[@slaquero1]

Hey Robert, I did the same thing to my B&S , added a 5 hp carb…and a lighter flywheel from a rotary mower! When my dad’s lawnmower engine broke, I put that thing on it and he said it dragged him around the front yard. Good times

[@robertheymann5906]

@@slaquero1 Love it!!

[@robertheymann5906]

And of course the governor was the first thing to go!

[@Diesel257]

God bless Butler Performance for helping to keep the Poncho alive.

[@Myvintageiron7512]

Agreed I have used many of Butlers Kits over the years their stuff is top notch they are my go-to guys for all things Performance

[@brittmrmanly4982]

Great job as always! My father bought a fuel injected Pontiac back in 1957. The fuel injection worked well but he couldn't find anyone (even the Pontiac dealership) that knew how to work on it. When the injection system started have problems, Dad swapped it for 3 deuce setup. I wish you would have discussed the rare SD-455 as well. A friend of mine had a 1974 SD-455 Trans Am back during the late 1970's. It was extremely fast for a Malaise era car. Too bad I didn't buy it when I had the chance.

[@BrandonLeeBrown]

My uncle bought a lightly used 1958 fuel injected Pontiac, when it wasn't very old. The seller started having problem with the fuel injection. My uncle said that back then unleaded gas wasn't common, but there was low lead gas and full lead gas would clog the Rochester fuel injection. They should use low lead or unleaded gas. The trick was you had to be someplace where you could buy low lead gas. That was the problem with the fuel injection, but with low lead gas, it worked fine.

[@michaelbenardo5695]

That was the fate of many of those, for exactly that reason.

[@jamessharp9790]

While I became familiar with the different engine families for some reason in my teens ( 55 now) , I greatly appreciate correct information getting out to counter legends and tall tales .

[@buzzwaldron6195]

In 1950s, Pontiac got a bigger engine than a Chevy... Olds bigger than a Pontiac... Buick bigger than an Olds... but Cadillac fell behind for a while... until getting the 500" engine...

[@jamessharp9790]

@@buzzwaldron6195 yeah and none of them had the bore size or cylinder heads of the BB Chevy. Only some Fords matched it ( 351C 4V and 385 series Ford)

[@TheMrmmkkpro]

Great stuff , I have a collection of Pontiac engines. I'm running a 1972 455HO bored with trw L2394 pistons , comp cam , 7f6 heads , torker 1 intake with a 850 holley hp series carb. The thing about the 455 is it makes gobbs of torque down low in the rpm range. Low rear gears are a substitute for hp and tq. The trick is keep a 3.08 or so. Love my Pontiacs. Great work👍👍🏁🏁

[@1crazypj]

I only have 2 Pontiac motors, a 389 out of a 1965 Catalina and a 1976 400 out of a Formula 400 Firebird. If the 389 didn't have super deep rust pits in bores it would have gone in the '76 Firebird 😧 Much smaller combustion chambers on 389 so should be good to modify with bigger valves and some porting to replace the ultra low compression 76 heads

[@79tazman]

I have a 455 in my 1973 T/A and it's rated at 250hp the next one up from that was the 310HP 455 SD that is the most wanted engine of the 73/74 years

[@JDStaffylover]

My first car was a 65 GTO 389 4speed. I wish everyday that I still had that car.

[@davidhimeback9087]

Glad you add the OHC 6cyl Was a good running engine..

[@crazexskater]

My first car was a 67' Firebird with the sprint 6 ohc.

[@elliottbutts153]

Back in the late 80’s my dad had a 72 Catalina with a 400 2bl. You would have never guessed it was only a 2bl. Plenty of torque to get that car moving

[@cam3002]

Thanks for including the Trophy 4 and Sprint 6.

[@quadsman11]

I'm a fan of, and addicted to the Three GM dedicated engine brands, Pontiac, Buick, and Oldsmobile ! Excited to see your AMC video next ! Keep 'em comin' !

[@Myvintageiron7512]

More to come!

[@w41duvernay]

Myron, Thanks for this. Didn't know Yunick split over development of Pontiac V8 due to journal size of the cranks. Today's stroker cranks for Pontiac's are based on the 400's main journal size of 3", which proves what Yunick was saying. I know you were speaking on limited time, so I also wished you had covered the stillborn OHC 3 valved Pontiac v8 that were on the cover of Hot Rod magazine March 1968. These didn't happen because Pontiac replaced John Delorian ( after he left for Chevy) with a bean counter style GM, which caused Pontiac development problems internally for newer Powertrain development, like the SD 455, because engineers had to fight and kick and scream at top level management to get newer powertrains to get done according to Pontiac High Performance magazine. Also to back up on the Pontiac Sprint 6 OHC engines they were known to jump Chevy 327 v8 with 3.90 rear end gearing. Oddly enough, Chrysler had stolen the valvetrain for their later 2.2 and 2.5 4 cylinders in the 70's and 80's. Bobcat wasn't the only manufacter of early 60's Pontiac large cube performance cars. The other primary producer was Myrtle Motors, of New York which cost around about today's equivalent $ of 50k. These clocked in the 12 second range in the Quarter Mile. Also, note this wasn't the first time a 428/421 was slipped into a Pontiac, if fact, Pontiac had given the press to test a press car 1965 GTO that they had slipped in a 421, and didn't tell anyone they did they before test driving.

[@87mini]

I remember that issue! We were a Pontiac family, and when I got my Hot Rod in the mail that month, I was on cloud 9!

[@kenp211]

They also used the 1955 low compression 287 with a hydromatic transmission in a 1955 2nd Generation GMC 100 truck. I know because I have one. I never heard about a reverse flow cooling system but i know mine has something like a 6 gallon cooling system with its huge radiator. I've never seen another truck exactly like mine but I love it but finding parts is fun but a lot easier now than 20 years ago!

[@jimdavis6833]

I had a 1959 Bonneville with the 389CID engine W/4bl Rochester. Later, I bought a 1969 GTO with the same junk carb which I swapped out for a Holley 800CFM double pumper, put some Cyclone headers on it, and a Manley cam. Did a 10.7 quarter in it and crushed 3 valve springs plus 2 bent valves because the cam had too much lift. I had to swap the cam back to stock. That was one mean machine.

[@paul44235]

I love this series of videos.

[@dadalebreton184]

The 421 had a standard bore of 4.093". Not 4.93". I know cause I was trying to find wich engine pistons were interchangeable with my 389ci and the 0.030" overbored 389 4.062 where the same as 421ci combinaison. I understand it's just a little decimal mistake cause I love all your teaching videos and very accurate on everything usualy. I learned a lot from it. Im rebuilting a 71" 350ci block with 74" 4c(46)2H small valves with factory screw-in studs studs heads as a DIY project. I even started little KZbin videos to teach old school performance tricks that I learn trought drag racing familly and from the best teachers like you. It's also to leave my girls memories of daddy's mecanic videos. DIY PONTIAC 350CI in case you want to laugh a bit. Once you go Pontiac, you never go back! Hehe

[@kevin122759]

I had the 350 in a 70 Lemans. It would be awesome if you could find a set of 350 HO heads from the late 60s. Probably impossible to find.

[@Myvintageiron7512]

yea your right checked it that was a miss I added a correction in the comments above

[@waylinbuerger2753]

I have a complete original 1969 350 Pontiac HO engine here from carburetor to oil pan with #48 ram air heads on it, so they are out there. @@kevin122759

[@kellynestegard5208]

389 and 421 pistons are not interchangeable; the compression height is different.

[@blackbuttecruizr]

Love thia video series.

[@tonysendrick6347]

The 350 Pontiac is suppose to be 354 cid. But they called it a 350

[@Myvintageiron7512]

true that was a marketing thing the 350 cid was well known in most GM lines

[@michaelyounger4497]

I had a 68 bonneville with a 428 4bbl and 4 speed. That car could accelerate so hard it would lift its front wheels off the ground..and that was a factory stock engine..fond memories of frightening my high school sweetheart with that beast

[@JC-gw3yo]

I know a lot about American engines, but this mans knowledge blows me away... impressive knowledge

[@kregchapman6981]

Another great video! thank you 🙂

[@billd.8336]

After learning to drive at age 14 with my dad always with me until age 16, I was later amazed with the blinding acceleration of my dad's next car, a 1958 Pontiac with the 370 CI engine. It had a two barrel carburetor. Us car crazy kids paid attention to these things.

[@greggc8088]

As you said near the end, I'm a big Ford fan too. The Ford 3 valve is my favorite as repairing those POS's paid for my last house and the current Ecoboost engines are setting me up well for retirement.

[@Fred_NaughT]

😂 Ford is making everybody money except their customers !

[@youngblood2]

All I know is you have done an unbelievable amount of research to get us this information. I think I'm on my 5th video of yours, through all the different engines and the variants! Thank you so much for your dedication!

[@Myvintageiron7512]

Wow, thank you!

[@tylerbounds8918]

Great video! Love this series! Keep it up!

[@johnnymartinez7576]

I feel that you should have touched on the 455 Super Duty engine. It was a great engine that Pontiac produced during the smog era.

[@Slugg-O]

I miss the Pontiacs. We had several when I was a kid, and one was a mid size car with the 326. I don't remember the name but I remember it ran smooth as butter. Actually, all of the Pontiacs we owned were great. The 455 is still a brute. There are several dyno vids showing the 455 turning out some insane numbers, especially torque. My first car was a Tempest with the OHC six and three on the tree. Strange little motor. I didn't like it because I didn't know how to work on it but it did run quite well. I think I paid $200 for the car.

[@socalfun64]

I had a 67 Lemans with a 326 and a power glide. Loved it!

[@robertkeime4907]

Great video

[@MVPisME383]

Great video, been watching you since 2018 when I built my first engine and found your video on adjusting sbc valves w/ hydraulic lifter

[@Myvintageiron7512]

Glad to help

[@cma8165]

Thanks for admiting your error and posting the correct bore of the 421 cubic inch Pontiac engine.

[@danhambrick6331]

Back in the early 80's my brother had a 1975 Pontiac T/A with a 455 in it and man was that thing fast.....😁💪👍👍

[@hallwest9650]

This is a great series! Thank you sir! Helps me explain some things to my son and son-in-law

[@Myvintageiron7512]

Glad to hear it!

[@tomnekuda3818]

John DeLorean, the Father of the GTO was a genius......too bad he got the shaft at GM and he turned to the dark side. I did an engine rebuilding class with Smokey Yunick as guest speaker/engine tester. Whadda genius..! And you never doubted where he stood on things because he let you know quick. I remember us blowing up a SBC on the Superflow dyno. All Smokey said was, "Looks like that was a fragile engine." I split a gut! LOL! It was the instructors engine! Haha! On another topic....I remember seeing an OHC6 Poncho engine and had the same reaction that you did

[@jamescutler8055]

I was raised Ford and still own and drive a 66 Fairlane, and 63 1/2 Galaxy but I always had a soft spot for Pontiacs I own three Tran Am 72, 79,79. Only GM Brand I like.

[@trentdawg2832]

Did you do a caddilac v-8 history yet…id like to see that one…..love the knowledge your dropping on all of us….it is a real treat to watch and learn alot of stuff I.E. bore x stroke combos and compression ratios etc etc….you are a wealth of internal combustion american knowledge!!!

[@Myvintageiron7512]

No AMC is coming next and then Cadillac

[@bparksiii6171]

Ironic Pontiac and International had the same idea for a 4 cylinder derived from the V8.

[@Myvintageiron7512]

Yea for sure I am doing International soon I think I am going to look into that and see if there are any connections between the folks that engineered those two engines.

[@odb_roc_hound4186]

@@Myvintageiron7512Porsche did the same thing in the 80’s. The 924 used an old Audi engine as the car was originally designed for VW to replace the Karmann Ghia. When VW declined the design Porsche inherited the car and soon needed a better performance engine, so they cut the V8 from the 928 in half and renamed the car 944.

[@paul44235]

Awesome!

[@robertgoulet1961]

I actually rebuild 1 of those 4 cylinder Pontiacs when I got the call from one of my shops to rebuild it I thought they were screwing with me till I researched it and found out that it really did exist, my buddy had a car when we we're in High School that had that OHC six cylinder, it was definitely a unique engine for a 60s Era car.

[@TheGrover1968]

I'm enjoying this.

[@jesseduke694]

I've really enjoyed these series u have dun. I learned quite a bit about some of these manufacturers that I didn't know. Looking forward to the AMC next. Oh ya, when I was in high school I a 74 Lamans that had a 400 in it. I bought from a guy that had rebuilt it & put better cam & headers n stuff. I loved that car. It was only so fast but I felt like it was fast back then. My buddies did too. We didn't really know what real fast was at that time so I guess u could say ignorance was bliss!

[@shootermcgavin2819]

thank you for the good content 👍🏻

[@DarthEcoli]

You're so spot on about earlier 400s. They were such monsters and loved them especially in Grand prixs

[@pietscholtanus]

Great college again,hats of for your knowledge and explanation,a joy to watch

[@Myvintageiron7512]

Glad you enjoyed it

[@hoytwhitmore8872]

Love The Video Keep Them Coming SIR

[@alhodge4051]

very informative, thanks

[@rickyteague447]

I'm still learning.thank you

[@danhoyland142]

I love your channel so don’t take this as a knock, but the 301 turbo has 210 horsepower and the regular 301 4 barrel had 150 hp in the trans am. You actually got a 400 some odd dollar rebate in 1979 if you opted for a 301 over a 403 or 400. The 301 sucked

[@NebukedNezzer]

I bought a 55 pontiac in Long Beach california 1965 for 200bucks. it had the 287v8 2 barrel carb and hydromatic trans. except for not having power brakes and it was not easy to get the car to stop. a year later the car was totaled in San Francisco. sold the car to another navy man and he put the engine in his big pontiac he said less power but better mileage. good engine.

[@mountainmansrevenge9295]

I raced street / strip Pontiacs for years, the big journal bearing issue is a myth if the engine is built properly with adequate oil pressure, .80 psi and high volume. Stroke dictates the torque band so at the 4.00 stroke you didn't need to rev as high as the 3.75 stroke and the 4.21 stroke not as high as the 4.0 stroke. A 455 cid could easily make over 500HP at under 5800 RPM with all OEM parts except cam and pistons. So with the increased stroke RPM was not needed, the issue becomes he longer the stroke the higher piston sped at a given RPM but the low end torque is incredible. Unfortunately all that torque can't be put to use on the street you just spin the tires. (

[@tonysendrick6347]

Ace Wilson was responsible for the Pontiac the Royal bobcat Pontiacs.. from Royal oak Michigan.to day they are rare and worth big $$$

[@ssboot5663]

Thanks for the videos! Very interesting to see HP and cubic inches compared! I never realized that bearing diameter limited RPM capability.

[@doomman700]

The trade off from large diameter strength is high bearing surface speed. Pontiac over done it. I build 389-400 blocks to get the 3” main , but use the 4.250 stroker cranks in them, .040 more than that stock 455. They live a long life

[@SweatyFatGuy]

@@doomman700 I've never had a problem with main bearings in a 455 or a 400. The 400 blocks are a lot easier to find because they were produced longer, which is why we were putting 428-455 cranks in 400s and 389s in the 70s to 90s before the aftermarket cranks came out in the early 00s. Even the round port iron cylinder heads don't flow enough to feed 428s and 455s over 6000rpm, because they have long high velocity ports that make incredible torque from 2000 to 5000rpm. That is why you don't need to spin them tighter than 6000, you're just wasting torque with deep gears and big stalls. If you're shifting a 455 or larger higher than 6000 without some heavily worked aftermarket heads (320cfm and up) you're doing it wrong. Its extremely difficult to break a Pontiac crank regardless of the size. The journal size is a non issue unless you're doing some kind of sustained 6000rpm+ thing like LSR, nascar, etc. Even the 505 in my 68 LeMans won't see more than 6500, no need to spin it that tight even with 340cfm heads. I suppose I could go to 7000 or so with 380cfm high ports. That reminds me, I need to back off the rocker arms for the winter. Been building and racing Pontiacs since the 1980s, my 455s and 400s last decades. I have one 400 I built in 1995 that has been in my 70 GTO, 65 GTO, 76 C10, 71 Firebird, 79 Formula, 79 TransAm, and is currently waiting to go in a 72 Ventura with SD ported 48 heads that were milled to 64cc. I have two 455s from the 90s as well. Funny story how I ended up putting that 400 in so many vehicles. I run all my Pontiacs on E85 now, except the 455 HO in the 72 Formula because it has 8:1 compression.... its waiting its turn in my shop to get rebuilt and the rust cut out of it so I am not driving it. Besides, do I want to daily drive a 1 of 276 that was special ordered so its a 1 of 1? Not really... I have lots of others to drive and race.

[@doomman700]

@@SweatyFatGuywhen you come Super Stock racing and beat me, talk to me about what I am doing wrong.

[@SweatyFatGuy]

@@doomman700 didn't say you were doing anything wrong, unless you have a 4.10, 4.33, 4.56, 4.88, 5.13 gear behind an iron head 455, because then you'd be going faster if you dropped to a 3.08 to 3.42. However, it is easier to hook up with the deep gears, so you're more consistent for bracket racing. With aluminum heads, like KRE or Edelbrock, you can get more RPM out of them if you want to. Do SS rules allow aluminum heads and roller cams? 12.60s with 2.93 gears in a 4100lb 70 GTO with 8.8:1 compression from stock 5C heads, running a 224/228/110 cam and cheap Summit headers isn't too bad. Only my round ports get something better than the 1 5/8" Summit headers. Usually Super Comps or Dougs. 11.40s with a 3.42 gear, 670 heads on a 455, 228/232/110 cam, Th400, 1900 stall in a 3750lb Firebird is decent for a $2700 stock rod TRW piston build. With the 4.10 in this one turning 28" tires it slowed to 12.1-11.9 and was done before 900ft. The rest of the quarter was at 6000rpm. Those 670s are on the 455 in my 65 GTO, its quite a bit lighter than the Bird was when it had those heads. Its my summer daily driver on E85. It has a small juice roller cam in it because lifters were having big problems when I built it in 2010. Its quicker than the Bird was with 3.08s, but haven't taken it to the track yet. It keeps breaking transmissions. I have a TKO for it now, didn't have a driveshaft that would fit with a Th400. Those are my iron head combos that I have ETs for, I don't take all of them to the track. They also have stock suspension, except the 65 GTO it has BMI tubular rear arms. What's your combo and ET? I don't do Super Stock or any index racing. All the tracks that ran SS classes were too far away for my limited budget over the years. Closest track to me now is a 5 hour one way drive. Been thinking of doing the Pure Stock (PSMCD) with the 71 Firebird cloned into a 72 455 HO Formula, if I can scrounge up some 7F6 heads for one of my 455s. Milan is a 12 hour drive, but at least I stay in Michigan for the entire trip.

[@doomman700]

@@SweatyFatGuywe run stock port sizes in stock heads. Fill the floor raise the roof. I also spin the motor 8500-9000. That’s why I know you will never beat me in Super Stock. Guys like you are 5-6 cars back wondering how do I catch them, I was there once.

[@lsrx101]

Thanks so much for this series! It's a really good overview of the V8 engines thst all car guys love, without diving into mind numbing variations and minutae. I'm primarily a Ford guy, but I love me some B.O.P goodness. I feel like they were purposely overshadowed, and maybe even hindered, by GM in favor of Chevrolet. They had to try harder and, as a result, came up with some of the coolest cars and powerplants of the 60-70s. My 1966 Galaxie 7-Litre really wants a 1969 or 70-73 Firebird and an Olds Vista Cruiser to keep it company in the garage. It wants a bunch of others too, but I made it pick 2, lol.

[@louislepage5111]

265 ci ? , did not know that Pontiac made that engine, thank you , learned something new today 😊

[@stuckinmygarage6220]

I think there's Pontiac blood in my Mopar body. My dad's first car when he got out of OTC was a brand new "fast Buick", Mom said. 😉 Nice presentation!

[@bartoncourcier414]

My first car was a "69 Pontiac Ventura. It had the 400, but it had the high compression heads and a 2BBL Rochester carb from the factory. This was a CA car. I bought it for $700 in 1986. This car also had factory air and the front brakes were disk. Bench seats front and rear, no B pillar so when you rolled down both sets of windows you had this big open side. It was awesome. Wish I still had it.

[@kellynestegard5208]

In '67, the valve angle was changed from 22 degrees (not 17) to 14 degrees

[@1crazypj]

Even though you had limited time I think you should have mentioned the cylinder heads were completely different The Ram Air HO heads were round exhaust port and not the semi Siamese center exhaust ('D') port which were the 'standard production design'. Otherwise, some interesting stuff I never heard before. There is a pretty good history in Jim Hand's 'How to Build Max Performance Pontiac V-8s' but, it only covers the V-8

[@Headbanger427]

My Grandpa had a 1978 Pontiac Grand Prix with a 301 & traveled for work. My Grandma always called it "Old Faithful." It was always a very reliable car.

[@lelandrogers1078]

Back in the '50s I used to watch Fireball Roberts race his Pontiac at Atlanta Speedway.

[@Myvintageiron7512]

CORRECTION !! 421 CID IS 4.094 BORE STD IT IS LISTED INCORRECTLY IN THE VIDEO

[@alexanderspenser4960]

Thanks for some new info, and to end the confusion that there are no big nor small Pontiac blocks. That's how the GTO was snuck out. I was perked up when I saw Oldsmobile models and heard misinformation. Pontiac blocks were made by Pontiac, at the Pontiac Michigan Engine plant. As Buicks were in Flint, and Chevrolet in Tonawanda, NY & GM Canada, St. Catharines, Ont. Engine Plant. The Turbo Trans Am 301, LU8 200 hp turbo, was developed to replace the 6.6 Litre Pontiac W72, which had two horse power ratings depending on which vehicle and options, which is 200 & 220 hp, never to be confused with the Olds hi-altitude , California 403 6.6 @ 185 hp. There was a second 301, L27, 135 hp, which has very little in common with the 1979-81 Turbo Trans Am LU8. I own all 3, unfortunately the W72 blew.

[@brucejones7389]

Great video on the Pontiacs! I had a friend in high school that had a 77 T/A who street raced a lot and won almost every time using a 400 pontiac that was modified quite a bit. He switched to a 455 after blowing up his 400 and he ended up selling it because the 400 was much faster he said.

[@SweatyFatGuy]

If he blew it up, he was spinning too much RPM, its not a chevy. Also the only way a 455 is slower than a 400 is if you have too much gear behind it. A 4.10 and deeper will go slower than a 3.55 and taller unless you increase airflow through the heads by 100cfm. If you try to set up a 455 like you would a 350 chevy, you will go slower. My 70 GTO weighs 4100lbs with me in it, I had a 2.93 (yes two nine three) rear gear, a Th400, 1900 stall, and a very mild 455 (224/228/110 cam, RPM intake) that I shifted at 5800rpm. It ran 12.60s around 110mph. No power adder, and it only had 8.8:1 compression. On 275 65 15 BFG street radials it would do 1/8th mile burnouts by simply whacking the throttle from idle, no need to hold the brakes at all. It made lots of sbc guys cry who told me Pontiacs don't run and a 350 will go faster for less money. I found that amusing since I had less than $2000 in rebuilding that 455 with .030 over pistons and a balanced bottom end. I built it in 1996 and its still running, currently sitting in my 65 LeMans that is going to be a straight axle gasser.

[@deadeye4543]

My Dad bought a 1968 Ram Air lll GTO in 1972 for me to drive back and forth to college. It had a 400 tranny and 4:30 gears in the rear end. Pontiac put a milder cam in the auto version of the RAIII than the standard, but still rated it at 360 HP. Playing around one afternoon at 5800 RPM, the aluminum camshaft gear shorn itself of its nylon teeth. It did not end well. Damage was limited to 16 bent valves, and upon a complete tear down 1,500 miles later, one piston was found that did NOT swing freely on its wrist pin. I don't remember you mentioning the RA IV heads, you know the ones where the exhaust ports of the two inboard cylinders are NOT siamesed but round. That's what I installed on the rebuilt 400 along with TRW forged high compression pistons, a Crane Zip 510 solid lifter cam, Cloyes roller timing gear set, 1 7/8" Hooker headers, and a Muncie 4 speed. I'm sorry to say I parted the car out in 1976.

[@pamwalker8394]

I had a 74 Grand Prix with a 455, and I ordered it with a towing package. It would pull my. 18ft. Don I at 100 MPH . But with all the pollution crap on it wasn’t a very big HP motor, but a lot of torque.

[@davidfusco6600]

I loved the video. You said that the 421 had a bore of 4.937 and a stroke of 4.000. Then you said the 428 was bored out larger to a bore size of 4.120 and the same 4.0 stroke. Did you mean to say 5.120? That would .183 larger than the 421 IF that were the case. I’m a big fan of Pontiac, to me they were the best GM division. Thanks again for the excellent video!

[@Myvintageiron7512]

421 Bore 4.0975

[@kensteigerwald3484]

Interesting he did not mention the SD455 from 1973 and 1974. At the time it was probably the fastest car in those two years compared to what was left of any muscle car.

[@macintiermyers2601]

I would be interested in hearing more about the few HEMI engines that pontiac has had in the past Like the 427 sohc hemi chrysler helped them develop with specs but never seen production, and there seems to be 2 other hemis like a 421 and something else (not the 421 sd) that i think used for drag racing (not street) like some of the Ford hemis that were for racing. I never hear to much about them and seem to never get talked about. Like the videos, been subscribed for a few years.

[@w41duvernay]

Same with 3 valve still born SOHC v8 engines that were on cover of late 60's Hot Rod magazine.

[@hydroy1]

One thing you missed, GMC ! from 1955 to 59 many GMC heavy trucks had Pontiac 287 or 315 motors in them and many are still in use today in 2 ton or bigger GMCs & Dump trucks. Also the 67 to 69 Pontiac 428 came in 2 horse powers 90% of the GPs & big cars that came with 428s had the 376hp. as the 390hp were only special order. I am with you---- best bang for the buck is a 400 block with aftermarket forged steek crank & rods as many of the400were drilled & tapped for 4 bolt mains that any CNC shop can cut you a set of 4 bolt 4140 billet caps and you can power shit that 400 well over 8,000rpm put a set of them aftermarket aluminum round tunnel port V heads on and big twin turbos and you got a beast. P/S I like the 330 & 425 Olds to.

[@michaelbenardo5695]

People, it is HYDRA MATIC. Hydra for hydraulic, Matic for automatic. Not hydromatic.

[@joejones4296]

I love your content-but-I wish you could tame down that loud intro music. I have to turn the volume down then back up to hear you.

[@tommcqueen2840]

I have a complete aftermarket Pontiac V8 being built for a 70 GTO project. All aluminum 482 ci.

[@russellalbertson1670]

This comment respectfully points out that the one year only 1955 Pontiac 287 V8 used the same bore as a Chev small block 265 V8 and the same stroke as a Chev 327 V8. Shortly after getting out of high school I landed a job parking cars at a Chev dealer. When one of my fellow employees had a 63 Chevy II Nova Super Sport up on the lube rack, he pointed to the transmission and explained how that at that time, Ford had the patent rights to the fully synchronized (first gear) 4 on the floor stick shift. The only way Chev could put it into their cars was to obtain this transmission from Ford, he pointed to the FoMoCo part number + Chev part # on the trans. How funny, a Ford trans in a Chev from the factory no less!

[@KM3W]

My first car was a 63 Grand Prix 389 tri power...I then bought a 67 GTO 400 HO.

[@AZ-JKUR-HR]

The actual HP of the sprint 250 was 230hp with manual transmission in 69 only. The auto was still 215hp. I drive a 67 Firebird 230 ohc 1bbl auto!

[@greenhunter52]

With regard to your comments about the 6.6 l shaker hood those were the 403 cubic inch Oldsmobile engine as the Pontiac 6.5 l was a 400 and since I had one in my 66 GTO I can be considered an authority on this one tiny detail. I love your shows I love your videos and I hope that you don't take this as a criticism in any way shape or form.

[@grand73am]

From 1977 to 1979, if the TA came with a Pontiac W72 400 engine, the shaker would have a "T/A 6.6" decal. In 77, they used the "6.6 Litre" decal for both the standard L78 Pontiac 400 and the Olds 403. 78 was a strange year for shaker decals. Only the W72 400 got a decal, the "T/A 6.6". The L78 400 and the Olds 403 didn't get a decal that year. In 79, the only Pontiac 400 available was the W72, so it still got the "T/A 6.6" decal, and the 403 Olds got the "6.6 Litre" decal again. The vast majority of 79 TA's had the Olds 403. So they did start calling the Pontiac 400 a 6.6 in the late 70's. Similar thing happened with the 455, initially called a 7.4 and later called a 7.5.

[@robertgoulet1961]

Actually I've raced Pontiacs and Mopars for decades now also own an auto Machine shop for 35 years build many of these motors, it's true all the motors I've worked on all had the same external block dimensions, I never researched this fact but I was told by a Pontiac enthusiast that all the motors the 421, 428, 455 had a 3.250" diameter crankshaft main journal size were considered big blocks and all the other motors had 3.00" main journal diameter on motors like the 326, 350,389, 400 crankshafts not sure how true that is but this is what I was told decades ago.

[@Myvintageiron7512]

That's what he wants them to be, but Pontiac never gave their engines the bb / sb distinction all I can do is go with the folks that actually designed and manufactured them

[@KM3W]

The 4 cylinder was also called the Iron Duke

[@jnljnl8485]

The cranks on the trophy are not like a v8 crank. They are set up like any 4 banger crank where the center cylinders go up and down together and the outer cylinders go up and down together.

[@chrisconsidine4322]

Thus the " rattle"😊

[@abruptlyblunt]

i don't know if you've thought of this but i believe from an engineering point of view would make an interesting video to do a design and history comparison of all the GM V6's together. The 229, 231 2.8, 3.1, 3.8 series 1&2, 4.3 and the mid 60's GMC V6 were all derived from in different ways and are each unique in their own way. i know some of it but i think you're unique ability to categorize details and specs would put it all together.......

[@craigbenz4835]

I loved the overview, but @29:11 4.937" bore x 4" stroke = 613 CID. 421 CID with 4" stroke = 4.093" bore.

[@itseithergonnaworkoritaint7852]

That would of been cool if they did make the bore that big!😎

[@Myvintageiron7512]

yea there is a correction listed above for that THX

[@eaglelubricants]

Thank you for the videos. I've always been curious about the different engines. AMC should be very interesting, and are you going to do a Cadillac engine video?

[@Myvintageiron7512]

That's the plan! AMC , Cad, and international in that order

[@chevyrc3623]

That's pretty cool video about the Pontiac V8. So our of all these engines from all these different manufacturers. Which engine would you make if all of them were available and have unlimited aftermarket and so forth. Which engine would you pick on small block side and big block side.

[@Myvintageiron7512]

that's a tough question I have had 2 Pontiac's in my life and they were both very fast and I had very little trouble with them, I owned an Oldsmobile with a 455, had several big block Ford's many small block and big block Chevy's had a jeep with a 360 AMC engine and too many big and small block Mopar's to list I can honestly say I loved them all, I have never had a car that I hated except for one and it was a 1984 Oldsmobile FWD with a 2.5 iron duke 4 cylinder that thing was a POS

[@chevyrc3623]

@@Myvintageiron7512 oh nice wow you seen to had all of them and you loved them well that's good. It's sad that all the big blocks are gone and all we have left is Ford coyotes and Godzilla I guess is considered a big block I guess. Chevy LT engine and Dodge hemis.

[@grand73am]

4:33 The Chevy 283 wasn't produced the same year. The Pontiac 287 was 1955. First year for the Chevy 283 was 1957.

[@Texasmule]

So essentially, every Pontiac block is a big block by default? Just with small block bore and stroke?

[@Myvintageiron7512]

no its not a big block or a small block it's just a Pontiac, look at it this way if you take a Honda 4 cylinder just as a random example they made lots of different engines with many cid sizes but no one says I have a big block Honda because its a 2.4 Liter you have a small block Honda because you have a 1.5 liter no it's just a Honda engine same with Pontiac it's just a Pontiac engine

[@Texasmule]

@@Myvintageiron7512 exactly, the base block is just a big block if they can use big block internals and they just use small block internals instead like bore size and stroke

[@Texasmule]

@@Myvintageiron7512 Honda wouldnt be a big block anyway because it's not bigger then 452 c.i

[@Texasmule]

@@Myvintageiron7512 I see what you mean tho

[@guyconnell2250]

Had a '71 Lemans Sport with the 400 in the late 70s. I thought I was all that until I got educated on Main by a Hemi Charger.

[@reggeckmann3993]

I'm an Oldsmobile fan. But I enjoy everything but more Chevy stuff. Lol

[@t.l.robinson2162]

I hope that you will do a history of Cadillac engines.

[@Myvintageiron7512]

yep its coming up

[@TheMKEWERBY]

You touched on AMC at the end. I don't think they had a big-or a small-block either, did they?

[@jaydurych]

From 1983 to the early 1990s I had a Pontiac Lemans with a rebuilt 389 with a Carter AFB carb, headers, and dual exhausts. The transmission was a rebuilt TH-400. For a heavy car it was pretty fast. I should never have sold it.

[@davidreed6070]

I missed the 421 tri power.

[@jasonhooey5677]

You grew up in the glory days, so jealous. The cars were great, the music was great, the economy was great, the times were so much better.

[@tl5108]

Did he cover the Pontiac OHC 421 from 62-63. Was a prototype engine, so they only built like 5/6 of them and one is still around today

[@brutusbreechcake]

On the 421 I think there is a zero missing after the decimal for the bore. (4.09375)

[@michaelknorr6825]

I had a 1968 Pontiac GTO, ho 400, 375 horse power and 455 ftlbs torque.

[@babaoreally8220]

The only late 60s engine I can recall,over 370 hp was the 428HO,and I believe it was rated at 378 hp.Even the later 455HO was only 360/370.The most potent engine since the early 60s’ 421SD was the iconic 69/70 RA/IV,at an extremely under rated 370 hp.Years later,some showroom stock GTO’s were chassis dyno’d at in the 380/390 range.This means the actual crank rating should have been 450hp.This was one of the engines that NHRA refactored because of its dominance in stock class.Its precursor was the round port RA/II in ‘68 with 340hp,which was surely underrated also.

[@srmsrm3676]

Great rundown of the Pontiac engine history! I'd say the 303 engine though was really a short deck version of the 400 4-Bolt block. The 301 was a totally different block design and like the 265, did not share the same external dimensions of the other engines because their bore spacing was smaller and crankshafts shorter. It's the bore spacing and deck height consistency that provides the cylinder head and intake manifold interchangeability we Pontiac guys love so much. In my 1970 Firebird, I'm running 6X4 heads from a W72 optioned 400 engine on a 350 block with a 4.25" stroker crank. The cylinder walls of the 350 block were chamfered from the factory allowing the use of the big valve heads. It produces 442 LbFt at 4300rpm and 453 HP at 5600rpm. My automotive engineering professor at General Motors Institute was Jim Lyons who became head of the Turbo 301 development team, then main chassis engineer on the 3rd generation Firebird. The 301's power output was limited by its crankshaft strength. 220 was considered the durability limit for production use. At 280 horsepower, it would become a pretzel. Always wondered what the dyno numbers were from the Pontiac 350 that you rebuilt?

[@duane4972]

All the manufacturers have made some very good engines, I like the Chevrolet engines best for their better swapping abilities.

[@buzzwaldron6195]

Pontiac invented the stamped steel rocker arms used for Chevys...

[@davidbeutler7665]

Questions, is this hydraulic flat tappet only not to include roller block or retro roller. You said you no longer build flat tappet due to the lifter manufacturing issues. Have these issues been fixed?